Update basic diagnostic capitalization/punctuation (#4328)

This is a primarily automated change: - Search & replace for capitalization - `(CARBON_DIAGNOSTIC\((?:\n\s+)?\w+,(?:\n\s+)?\s\w+,(?:\n\s+)?\s")([A-Z])` - `$1\L$2` - Search & replace for period - `(CARBON_DIAGNOSTIC\((?:\n\s+)?\w+,(?:\n\s+)?\s\w+,(?:\n\s+)?\s"(?:[^)]|\n)+)\.("[,)])` - `$1$2` - Limited search & replace for `ERROR: ` -> `error: ` in streamed things - Leaving a TODO for command_line because there's more cleanup that can be done there - Modify diagnostic_consumer.cpp - ERROR -> error - WARNING -> warning --------- Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2026-10-05 15:51:07 +01:00 · 2024-09-19 21:32:53 +00:00
parent 7f6d684b29
commit e7aebbe581
578 changed files with 2166 additions and 2173 deletions
@@ -9,30 +9,30 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/builtin/fail_redefined.carbon

 fn A(n: i32, m: i32) -> i32 = "int.sadd";
-// CHECK:STDERR: fail_redefined.carbon:[[@LINE+7]]:1: ERROR: Redefinition of `fn A`.
+// CHECK:STDERR: fail_redefined.carbon:[[@LINE+7]]:1: error: redefinition of `fn A`
 // CHECK:STDERR: fn A(n: i32, m: i32) -> i32 { return n; }
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_redefined.carbon:[[@LINE-4]]:1: Previously defined here.
+// CHECK:STDERR: fail_redefined.carbon:[[@LINE-4]]:1: previously defined here
 // CHECK:STDERR: fn A(n: i32, m: i32) -> i32 = "int.sadd";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
 fn A(n: i32, m: i32) -> i32 { return n; }

 fn B(n: i32, m: i32) -> i32 { return n; }
-// CHECK:STDERR: fail_redefined.carbon:[[@LINE+7]]:1: ERROR: Redefinition of `fn B`.
+// CHECK:STDERR: fail_redefined.carbon:[[@LINE+7]]:1: error: redefinition of `fn B`
 // CHECK:STDERR: fn B(n: i32, m: i32) -> i32 = "int.sadd";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_redefined.carbon:[[@LINE-4]]:1: Previously defined here.
+// CHECK:STDERR: fail_redefined.carbon:[[@LINE-4]]:1: previously defined here
 // CHECK:STDERR: fn B(n: i32, m: i32) -> i32 { return n; }
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
 fn B(n: i32, m: i32) -> i32 = "int.sadd";

 fn C(n: i32, m: i32) -> i32 = "int.sadd";
-// CHECK:STDERR: fail_redefined.carbon:[[@LINE+6]]:1: ERROR: Redefinition of `fn C`.
+// CHECK:STDERR: fail_redefined.carbon:[[@LINE+6]]:1: error: redefinition of `fn C`
 // CHECK:STDERR: fn C(n: i32, m: i32) -> i32 = "int.sadd";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_redefined.carbon:[[@LINE-4]]:1: Previously defined here.
+// CHECK:STDERR: fail_redefined.carbon:[[@LINE-4]]:1: previously defined here
 // CHECK:STDERR: fn C(n: i32, m: i32) -> i32 = "int.sadd";
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 fn C(n: i32, m: i32) -> i32 = "int.sadd";
@@ -8,7 +8,7 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/builtin/fail_unknown.carbon

-// CHECK:STDERR: fail_unknown.carbon:[[@LINE+3]]:23: ERROR: Unknown builtin function name "unknown.builtin.name".
+// CHECK:STDERR: fail_unknown.carbon:[[@LINE+3]]:23: error: unknown builtin function name "unknown.builtin.name"
 // CHECK:STDERR: fn UnknownBuiltin() = "unknown.builtin.name";
 // CHECK:STDERR:                       ^~~~~~~~~~~~~~~~~~~~~~
 fn UnknownBuiltin() = "unknown.builtin.name";
@@ -9,7 +9,7 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/call/fail_not_callable.carbon

 fn Run() {
-  // CHECK:STDERR: fail_not_callable.carbon:[[@LINE+3]]:16: ERROR: Value of type `String` is not callable.
+  // CHECK:STDERR: fail_not_callable.carbon:[[@LINE+3]]:16: error: value of type `String` is not callable
  // CHECK:STDERR:   var x: i32 = "hello"();
  // CHECK:STDERR:                ^~~~~~~~
  var x: i32 = "hello"();
@@ -13,52 +13,52 @@ fn Run1(a: i32) {}
 fn Run2(a: i32, b: i32) {}

 fn Main() {
-  // CHECK:STDERR: fail_param_count.carbon:[[@LINE+7]]:3: ERROR: 1 argument(s) passed to function expecting 0 argument(s).
+  // CHECK:STDERR: fail_param_count.carbon:[[@LINE+7]]:3: error: 1 argument(s) passed to function expecting 0 argument(s).
  // CHECK:STDERR:   Run0(1);
  // CHECK:STDERR:   ^~~~~
-  // CHECK:STDERR: fail_param_count.carbon:[[@LINE-8]]:1: Calling function declared here.
+  // CHECK:STDERR: fail_param_count.carbon:[[@LINE-8]]:1: calling function declared here
  // CHECK:STDERR: fn Run0() {}
  // CHECK:STDERR: ^~~~~~~~~~~
  // CHECK:STDERR:
  Run0(1);
-  // CHECK:STDERR: fail_param_count.carbon:[[@LINE+7]]:3: ERROR: 2 argument(s) passed to function expecting 0 argument(s).
+  // CHECK:STDERR: fail_param_count.carbon:[[@LINE+7]]:3: error: 2 argument(s) passed to function expecting 0 argument(s).
  // CHECK:STDERR:   Run0(0, 1);
  // CHECK:STDERR:   ^~~~~
-  // CHECK:STDERR: fail_param_count.carbon:[[@LINE-16]]:1: Calling function declared here.
+  // CHECK:STDERR: fail_param_count.carbon:[[@LINE-16]]:1: calling function declared here
  // CHECK:STDERR: fn Run0() {}
  // CHECK:STDERR: ^~~~~~~~~~~
  // CHECK:STDERR:
  Run0(0, 1);

-  // CHECK:STDERR: fail_param_count.carbon:[[@LINE+7]]:3: ERROR: 0 argument(s) passed to function expecting 1 argument(s).
+  // CHECK:STDERR: fail_param_count.carbon:[[@LINE+7]]:3: error: 0 argument(s) passed to function expecting 1 argument(s).
  // CHECK:STDERR:   Run1();
  // CHECK:STDERR:   ^~~~~
-  // CHECK:STDERR: fail_param_count.carbon:[[@LINE-24]]:1: Calling function declared here.
+  // CHECK:STDERR: fail_param_count.carbon:[[@LINE-24]]:1: calling function declared here
  // CHECK:STDERR: fn Run1(a: i32) {}
  // CHECK:STDERR: ^~~~~~~~~~~~~~~~~
  // CHECK:STDERR:
  Run1();
-  // CHECK:STDERR: fail_param_count.carbon:[[@LINE+7]]:3: ERROR: 2 argument(s) passed to function expecting 1 argument(s).
+  // CHECK:STDERR: fail_param_count.carbon:[[@LINE+7]]:3: error: 2 argument(s) passed to function expecting 1 argument(s).
  // CHECK:STDERR:   Run1(0, 1);
  // CHECK:STDERR:   ^~~~~
-  // CHECK:STDERR: fail_param_count.carbon:[[@LINE-32]]:1: Calling function declared here.
+  // CHECK:STDERR: fail_param_count.carbon:[[@LINE-32]]:1: calling function declared here
  // CHECK:STDERR: fn Run1(a: i32) {}
  // CHECK:STDERR: ^~~~~~~~~~~~~~~~~
  // CHECK:STDERR:
  Run1(0, 1);

-  // CHECK:STDERR: fail_param_count.carbon:[[@LINE+7]]:3: ERROR: 0 argument(s) passed to function expecting 2 argument(s).
+  // CHECK:STDERR: fail_param_count.carbon:[[@LINE+7]]:3: error: 0 argument(s) passed to function expecting 2 argument(s).
  // CHECK:STDERR:   Run2();
  // CHECK:STDERR:   ^~~~~
-  // CHECK:STDERR: fail_param_count.carbon:[[@LINE-40]]:1: Calling function declared here.
+  // CHECK:STDERR: fail_param_count.carbon:[[@LINE-40]]:1: calling function declared here
  // CHECK:STDERR: fn Run2(a: i32, b: i32) {}
  // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~
  // CHECK:STDERR:
  Run2();
-  // CHECK:STDERR: fail_param_count.carbon:[[@LINE+6]]:3: ERROR: 1 argument(s) passed to function expecting 2 argument(s).
+  // CHECK:STDERR: fail_param_count.carbon:[[@LINE+6]]:3: error: 1 argument(s) passed to function expecting 2 argument(s).
  // CHECK:STDERR:   Run2(0);
  // CHECK:STDERR:   ^~~~~
-  // CHECK:STDERR: fail_param_count.carbon:[[@LINE-48]]:1: Calling function declared here.
+  // CHECK:STDERR: fail_param_count.carbon:[[@LINE-48]]:1: calling function declared here
  // CHECK:STDERR: fn Run2(a: i32, b: i32) {}
  // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~
  Run2(0);
@@ -11,13 +11,13 @@
 fn G(a: i32) {}

 fn F() {
-  // CHECK:STDERR: fail_param_type.carbon:[[@LINE+9]]:3: ERROR: Cannot implicitly convert from `f64` to `i32`.
+  // CHECK:STDERR: fail_param_type.carbon:[[@LINE+9]]:3: error: cannot implicitly convert from `f64` to `i32`
  // CHECK:STDERR:   G(1.0);
  // CHECK:STDERR:   ^~
-  // CHECK:STDERR: fail_param_type.carbon:[[@LINE+6]]:3: Type `f64` does not implement interface `ImplicitAs`.
+  // CHECK:STDERR: fail_param_type.carbon:[[@LINE+6]]:3: type `f64` does not implement interface `ImplicitAs`
  // CHECK:STDERR:   G(1.0);
  // CHECK:STDERR:   ^~
-  // CHECK:STDERR: fail_param_type.carbon:[[@LINE-9]]:1: Initializing parameter 1 of function declared here.
+  // CHECK:STDERR: fail_param_type.carbon:[[@LINE-9]]:1: initializing parameter 1 of function declared here
  // CHECK:STDERR: fn G(a: i32) {}
  // CHECK:STDERR: ^~~~~~~~~~~~~~
  G(1.0);
@@ -11,10 +11,10 @@
 fn Foo() -> f64 { return 1.0; }

 fn Run() {
-  // CHECK:STDERR: fail_return_type_mismatch.carbon:[[@LINE+6]]:3: ERROR: Cannot implicitly convert from `f64` to `i32`.
+  // CHECK:STDERR: fail_return_type_mismatch.carbon:[[@LINE+6]]:3: error: cannot implicitly convert from `f64` to `i32`
  // CHECK:STDERR:   var x: i32 = Foo();
  // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~
-  // CHECK:STDERR: fail_return_type_mismatch.carbon:[[@LINE+3]]:3: Type `f64` does not implement interface `ImplicitAs`.
+  // CHECK:STDERR: fail_return_type_mismatch.carbon:[[@LINE+3]]:3: type `f64` does not implement interface `ImplicitAs`
  // CHECK:STDERR:   var x: i32 = Foo();
  // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~
  var x: i32 = Foo();
@@ -8,7 +8,7 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/fail_param_in_type.carbon

-// CHECK:STDERR: fail_param_in_type.carbon:[[@LINE+3]]:23: ERROR: Array bound is not a constant.
+// CHECK:STDERR: fail_param_in_type.carbon:[[@LINE+3]]:23: error: array bound is not a constant
 // CHECK:STDERR: fn F(n: i32, a: [i32; n]*);
 // CHECK:STDERR:                       ^
 fn F(n: i32, a: [i32; n]*);
@@ -8,10 +8,10 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/fail_param_redecl.carbon

-// CHECK:STDERR: fail_param_redecl.carbon:[[@LINE+6]]:14: ERROR: Duplicate name being declared in the same scope.
+// CHECK:STDERR: fail_param_redecl.carbon:[[@LINE+6]]:14: error: duplicate name being declared in the same scope
 // CHECK:STDERR: fn F(n: i32, n: i32);
 // CHECK:STDERR:              ^
-// CHECK:STDERR: fail_param_redecl.carbon:[[@LINE+3]]:6: Name is previously declared here.
+// CHECK:STDERR: fail_param_redecl.carbon:[[@LINE+3]]:6: name is previously declared here
 // CHECK:STDERR: fn F(n: i32, n: i32);
 // CHECK:STDERR:      ^
 fn F(n: i32, n: i32);
@@ -58,57 +58,57 @@ library "[[@TEST_NAME]]";

 import library "api";

-// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE+10]]:1: ERROR: Redeclarations of `fn A` must match use of `extern`.
+// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE+10]]:1: error: redeclarations of `fn A` must match use of `extern`
 // CHECK:STDERR: extern fn A();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
-// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE-5]]:1: In import.
+// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE-5]]:1: in import
 // CHECK:STDERR: import library "api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: api.carbon:4:1: Previously declared here.
+// CHECK:STDERR: api.carbon:4:1: previously declared here
 // CHECK:STDERR: fn A();
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR:
 extern fn A();
-// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE+10]]:1: ERROR: Redeclarations of `fn B` must match use of `extern`.
+// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE+10]]:1: error: redeclarations of `fn B` must match use of `extern`
 // CHECK:STDERR: extern fn B(b: i32) -> i32;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE-16]]:1: In import.
+// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE-16]]:1: in import
 // CHECK:STDERR: import library "api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: api.carbon:5:1: Previously declared here.
+// CHECK:STDERR: api.carbon:5:1: previously declared here
 // CHECK:STDERR: fn B(b: i32) -> i32;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
 extern fn B(b: i32) -> i32;
-// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE+10]]:1: ERROR: Redeclarations of `fn C` must match use of `extern`.
+// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE+10]]:1: error: redeclarations of `fn C` must match use of `extern`
 // CHECK:STDERR: extern fn C(c: (i32,)) -> {.c: i32};
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE-27]]:1: In import.
+// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE-27]]:1: in import
 // CHECK:STDERR: import library "api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: api.carbon:6:1: Previously declared here.
+// CHECK:STDERR: api.carbon:6:1: previously declared here
 // CHECK:STDERR: fn C(c: (i32,)) -> {.c: i32};
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
 extern fn C(c: (i32,)) -> {.c: i32};
-// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE+10]]:1: ERROR: Redeclaration of `fn D` is redundant.
+// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE+10]]:1: error: redeclaration of `fn D` is redundant
 // CHECK:STDERR: extern fn D();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
-// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE-38]]:1: In import.
+// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE-38]]:1: in import
 // CHECK:STDERR: import library "api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: api.carbon:7:1: Previously declared here.
+// CHECK:STDERR: api.carbon:7:1: previously declared here
 // CHECK:STDERR: extern fn D();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR:
 extern fn D();
-// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE+10]]:1: ERROR: Redeclarations of `fn E` must match use of `extern`.
+// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE+10]]:1: error: redeclarations of `fn E` must match use of `extern`
 // CHECK:STDERR: extern fn NS.E();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE-49]]:1: In import.
+// CHECK:STDERR: fail_redecl_api.carbon:[[@LINE-49]]:1: in import
 // CHECK:STDERR: import library "api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: api.carbon:10:1: Previously declared here.
+// CHECK:STDERR: api.carbon:10:1: previously declared here
 // CHECK:STDERR: fn NS.E();
 // CHECK:STDERR: ^~~~~~~~~~
 // CHECK:STDERR:
@@ -142,68 +142,68 @@ var e: () = NS.E();

 library "[[@TEST_NAME]]";

-// CHECK:STDERR: fail_merge.carbon:[[@LINE+65]]:1: In import.
+// CHECK:STDERR: fail_merge.carbon:[[@LINE+65]]:1: in import
 // CHECK:STDERR: import library "api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern_api.carbon:4:1: ERROR: Duplicate name being declared in the same scope.
+// CHECK:STDERR: extern_api.carbon:4:1: error: duplicate name being declared in the same scope
 // CHECK:STDERR: extern library "redecl_extern_api" fn A();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_merge.carbon:[[@LINE+59]]:1: In import.
+// CHECK:STDERR: fail_merge.carbon:[[@LINE+59]]:1: in import
 // CHECK:STDERR: import library "api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: api.carbon:4:1: Name is previously declared here.
+// CHECK:STDERR: api.carbon:4:1: name is previously declared here
 // CHECK:STDERR: fn A();
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_merge.carbon:[[@LINE+52]]:1: In import.
+// CHECK:STDERR: fail_merge.carbon:[[@LINE+52]]:1: in import
 // CHECK:STDERR: import library "api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern_api.carbon:5:1: ERROR: Duplicate name being declared in the same scope.
+// CHECK:STDERR: extern_api.carbon:5:1: error: duplicate name being declared in the same scope
 // CHECK:STDERR: extern library "redecl_extern_api" fn B(b: i32) -> i32;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_merge.carbon:[[@LINE+46]]:1: In import.
+// CHECK:STDERR: fail_merge.carbon:[[@LINE+46]]:1: in import
 // CHECK:STDERR: import library "api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: api.carbon:5:1: Name is previously declared here.
+// CHECK:STDERR: api.carbon:5:1: name is previously declared here
 // CHECK:STDERR: fn B(b: i32) -> i32;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_merge.carbon:[[@LINE+39]]:1: In import.
+// CHECK:STDERR: fail_merge.carbon:[[@LINE+39]]:1: in import
 // CHECK:STDERR: import library "api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern_api.carbon:6:1: ERROR: Duplicate name being declared in the same scope.
+// CHECK:STDERR: extern_api.carbon:6:1: error: duplicate name being declared in the same scope
 // CHECK:STDERR: extern library "redecl_extern_api" fn C(c: (i32,)) -> {.c: i32};
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_merge.carbon:[[@LINE+33]]:1: In import.
+// CHECK:STDERR: fail_merge.carbon:[[@LINE+33]]:1: in import
 // CHECK:STDERR: import library "api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: api.carbon:6:1: Name is previously declared here.
+// CHECK:STDERR: api.carbon:6:1: name is previously declared here
 // CHECK:STDERR: fn C(c: (i32,)) -> {.c: i32};
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_merge.carbon:[[@LINE+26]]:1: In import.
+// CHECK:STDERR: fail_merge.carbon:[[@LINE+26]]:1: in import
 // CHECK:STDERR: import library "api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern_api.carbon:7:1: ERROR: Duplicate name being declared in the same scope.
+// CHECK:STDERR: extern_api.carbon:7:1: error: duplicate name being declared in the same scope
 // CHECK:STDERR: extern library "redecl_extern_api" fn D();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_merge.carbon:[[@LINE+20]]:1: In import.
+// CHECK:STDERR: fail_merge.carbon:[[@LINE+20]]:1: in import
 // CHECK:STDERR: import library "api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: api.carbon:7:1: Name is previously declared here.
+// CHECK:STDERR: api.carbon:7:1: name is previously declared here
 // CHECK:STDERR: extern fn D();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_merge.carbon:[[@LINE+13]]:1: In import.
+// CHECK:STDERR: fail_merge.carbon:[[@LINE+13]]:1: in import
 // CHECK:STDERR: import library "api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern_api.carbon:10:1: ERROR: Duplicate name being declared in the same scope.
+// CHECK:STDERR: extern_api.carbon:10:1: error: duplicate name being declared in the same scope
 // CHECK:STDERR: extern library "redecl_extern_api" fn NS.E();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_merge.carbon:[[@LINE+7]]:1: In import.
+// CHECK:STDERR: fail_merge.carbon:[[@LINE+7]]:1: in import
 // CHECK:STDERR: import library "api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: api.carbon:10:1: Name is previously declared here.
+// CHECK:STDERR: api.carbon:10:1: name is previously declared here
 // CHECK:STDERR: fn NS.E();
 // CHECK:STDERR: ^~~~~~~~~~
 // CHECK:STDERR:
@@ -220,68 +220,68 @@ var e: () = NS.E();

 library "[[@TEST_NAME]]";

-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+64]]:1: In import.
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+64]]:1: in import
 // CHECK:STDERR: import library "extern_api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: api.carbon:4:1: ERROR: Duplicate name being declared in the same scope.
+// CHECK:STDERR: api.carbon:4:1: error: duplicate name being declared in the same scope
 // CHECK:STDERR: fn A();
 // CHECK:STDERR: ^~~~~~~
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+58]]:1: In import.
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+58]]:1: in import
 // CHECK:STDERR: import library "extern_api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern_api.carbon:4:1: Name is previously declared here.
+// CHECK:STDERR: extern_api.carbon:4:1: name is previously declared here
 // CHECK:STDERR: extern library "redecl_extern_api" fn A();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+51]]:1: In import.
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+51]]:1: in import
 // CHECK:STDERR: import library "extern_api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: api.carbon:5:1: ERROR: Duplicate name being declared in the same scope.
+// CHECK:STDERR: api.carbon:5:1: error: duplicate name being declared in the same scope
 // CHECK:STDERR: fn B(b: i32) -> i32;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+45]]:1: In import.
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+45]]:1: in import
 // CHECK:STDERR: import library "extern_api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern_api.carbon:5:1: Name is previously declared here.
+// CHECK:STDERR: extern_api.carbon:5:1: name is previously declared here
 // CHECK:STDERR: extern library "redecl_extern_api" fn B(b: i32) -> i32;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+38]]:1: In import.
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+38]]:1: in import
 // CHECK:STDERR: import library "extern_api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: api.carbon:6:1: ERROR: Duplicate name being declared in the same scope.
+// CHECK:STDERR: api.carbon:6:1: error: duplicate name being declared in the same scope
 // CHECK:STDERR: fn C(c: (i32,)) -> {.c: i32};
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+32]]:1: In import.
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+32]]:1: in import
 // CHECK:STDERR: import library "extern_api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern_api.carbon:6:1: Name is previously declared here.
+// CHECK:STDERR: extern_api.carbon:6:1: name is previously declared here
 // CHECK:STDERR: extern library "redecl_extern_api" fn C(c: (i32,)) -> {.c: i32};
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+25]]:1: In import.
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+25]]:1: in import
 // CHECK:STDERR: import library "extern_api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: api.carbon:7:1: ERROR: Duplicate name being declared in the same scope.
+// CHECK:STDERR: api.carbon:7:1: error: duplicate name being declared in the same scope
 // CHECK:STDERR: extern fn D();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+19]]:1: In import.
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+19]]:1: in import
 // CHECK:STDERR: import library "extern_api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern_api.carbon:7:1: Name is previously declared here.
+// CHECK:STDERR: extern_api.carbon:7:1: name is previously declared here
 // CHECK:STDERR: extern library "redecl_extern_api" fn D();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+12]]:1: In import.
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+12]]:1: in import
 // CHECK:STDERR: import library "extern_api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: api.carbon:10:1: ERROR: Duplicate name being declared in the same scope.
+// CHECK:STDERR: api.carbon:10:1: error: duplicate name being declared in the same scope
 // CHECK:STDERR: fn NS.E();
 // CHECK:STDERR: ^~~~~~~~~~
-// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+6]]:1: In import.
+// CHECK:STDERR: fail_merge_reverse.carbon:[[@LINE+6]]:1: in import
 // CHECK:STDERR: import library "extern_api";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern_api.carbon:10:1: Name is previously declared here.
+// CHECK:STDERR: extern_api.carbon:10:1: name is previously declared here
 // CHECK:STDERR: extern library "redecl_extern_api" fn NS.E();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 import library "extern_api";
@@ -25,10 +25,10 @@ var x: () = F();
 library "[[@TEST_NAME]]";

 extern fn F();
-// CHECK:STDERR: fail_redecl.carbon:[[@LINE+7]]:1: ERROR: Redeclaration of `fn F` is redundant.
+// CHECK:STDERR: fail_redecl.carbon:[[@LINE+7]]:1: error: redeclaration of `fn F` is redundant
 // CHECK:STDERR: extern fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
-// CHECK:STDERR: fail_redecl.carbon:[[@LINE-4]]:1: Previously declared here.
+// CHECK:STDERR: fail_redecl.carbon:[[@LINE-4]]:1: previously declared here
 // CHECK:STDERR: extern fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR:
@@ -39,10 +39,10 @@ extern fn F();
 library "[[@TEST_NAME]]";

 extern fn F();
-// CHECK:STDERR: fail_redecl_extern.carbon:[[@LINE+7]]:1: ERROR: Redeclaration of `fn F` is redundant.
+// CHECK:STDERR: fail_redecl_extern.carbon:[[@LINE+7]]:1: error: redeclaration of `fn F` is redundant
 // CHECK:STDERR: fn F();
 // CHECK:STDERR: ^~~~~~~
-// CHECK:STDERR: fail_redecl_extern.carbon:[[@LINE-4]]:1: Previously declared here.
+// CHECK:STDERR: fail_redecl_extern.carbon:[[@LINE-4]]:1: previously declared here
 // CHECK:STDERR: extern fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR:
@@ -53,12 +53,12 @@ fn F();
 library "[[@TEST_NAME]]";

 class C {
-  // CHECK:STDERR: fail_member_extern.carbon:[[@LINE+4]]:3: ERROR: `extern` not allowed on `fn` declaration that is a member.
+  // CHECK:STDERR: fail_member_extern.carbon:[[@LINE+4]]:3: error: `extern` not allowed on `fn` declaration that is a member
  // CHECK:STDERR:   extern fn F();
  // CHECK:STDERR:   ^~~~~~
  // CHECK:STDERR:
  extern fn F();
-  // CHECK:STDERR: fail_member_extern.carbon:[[@LINE+3]]:3: ERROR: `extern` not allowed on `fn` declaration that is a member.
+  // CHECK:STDERR: fail_member_extern.carbon:[[@LINE+3]]:3: error: `extern` not allowed on `fn` declaration that is a member
  // CHECK:STDERR:   extern fn G[self: Self]();
  // CHECK:STDERR:   ^~~~~~
  extern fn G[self: Self]();
@@ -28,13 +28,13 @@ library "[[@TEST_NAME]]";

 import library "extern_library";

-// CHECK:STDERR: fail_extern_library_nonowner.carbon:[[@LINE+10]]:1: ERROR: Declaration in library "extern_library_nonowner" doesn't match `extern library` declaration.
+// CHECK:STDERR: fail_extern_library_nonowner.carbon:[[@LINE+10]]:1: error: declaration in library "extern_library_nonowner" doesn't match `extern library` declaration
 // CHECK:STDERR: extern fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
-// CHECK:STDERR: fail_extern_library_nonowner.carbon:[[@LINE-5]]:1: In import.
+// CHECK:STDERR: fail_extern_library_nonowner.carbon:[[@LINE-5]]:1: in import
 // CHECK:STDERR: import library "extern_library";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern_library.carbon:4:1: Previously declared with `extern library` here.
+// CHECK:STDERR: extern_library.carbon:4:1: previously declared with `extern library` here
 // CHECK:STDERR: extern library "extern_library_owner" fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
@@ -46,13 +46,13 @@ library "[[@TEST_NAME]]";

 import library "extern_library";

-// CHECK:STDERR: fail_extern_library_nonextern.carbon:[[@LINE+10]]:1: ERROR: Redeclarations of `fn F` must match use of `extern`.
+// CHECK:STDERR: fail_extern_library_nonextern.carbon:[[@LINE+10]]:1: error: redeclarations of `fn F` must match use of `extern`
 // CHECK:STDERR: fn F();
 // CHECK:STDERR: ^~~~~~~
-// CHECK:STDERR: fail_extern_library_nonextern.carbon:[[@LINE-5]]:1: In import.
+// CHECK:STDERR: fail_extern_library_nonextern.carbon:[[@LINE-5]]:1: in import
 // CHECK:STDERR: import library "extern_library";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern_library.carbon:4:1: Previously declared here.
+// CHECK:STDERR: extern_library.carbon:4:1: previously declared here
 // CHECK:STDERR: extern library "extern_library_owner" fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
@@ -64,13 +64,13 @@ library "[[@TEST_NAME]]";

 import library "extern_library";

-// CHECK:STDERR: fail_extern_library_redecl.carbon:[[@LINE+10]]:1: ERROR: Declaration in library "extern_library_redecl" doesn't match `extern library` declaration.
+// CHECK:STDERR: fail_extern_library_redecl.carbon:[[@LINE+10]]:1: error: declaration in library "extern_library_redecl" doesn't match `extern library` declaration
 // CHECK:STDERR: extern library "extern_library_owner" fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_extern_library_redecl.carbon:[[@LINE-5]]:1: In import.
+// CHECK:STDERR: fail_extern_library_redecl.carbon:[[@LINE-5]]:1: in import
 // CHECK:STDERR: import library "extern_library";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern_library.carbon:4:1: Previously declared with `extern library` here.
+// CHECK:STDERR: extern_library.carbon:4:1: previously declared with `extern library` here
 // CHECK:STDERR: extern library "extern_library_owner" fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
@@ -86,16 +86,16 @@ extern library "extern_library_owner" fn F();

 library "[[@TEST_NAME]]";

-// CHECK:STDERR: fail_extern_library_collision.carbon:[[@LINE+13]]:1: In import.
+// CHECK:STDERR: fail_extern_library_collision.carbon:[[@LINE+13]]:1: in import
 // CHECK:STDERR: import library "extern_library";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern_library_copy.carbon:4:1: ERROR: Duplicate name being declared in the same scope.
+// CHECK:STDERR: extern_library_copy.carbon:4:1: error: duplicate name being declared in the same scope
 // CHECK:STDERR: extern library "extern_library_owner" fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_extern_library_collision.carbon:[[@LINE+7]]:1: In import.
+// CHECK:STDERR: fail_extern_library_collision.carbon:[[@LINE+7]]:1: in import
 // CHECK:STDERR: import library "extern_library";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern_library.carbon:4:1: Name is previously declared here.
+// CHECK:STDERR: extern_library.carbon:4:1: name is previously declared here
 // CHECK:STDERR: extern library "extern_library_owner" fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
@@ -114,7 +114,7 @@ library "[[@TEST_NAME]]";

 import library "extern_library_mismatch"

-// CHECK:STDERR: fail_extern_library_mismatch_owner.carbon:[[@LINE+4]]:1: ERROR: `import` declarations must end with a `;`.
+// CHECK:STDERR: fail_extern_library_mismatch_owner.carbon:[[@LINE+4]]:1: error: `import` declarations must end with a `;`
 // CHECK:STDERR: extern fn F();
 // CHECK:STDERR: ^~~~~~
 // CHECK:STDERR:
@@ -124,7 +124,7 @@ extern fn F();

 library "[[@TEST_NAME]]";

-// CHECK:STDERR: fail_extern_self_library.carbon:[[@LINE+4]]:1: ERROR: `extern library` cannot specify the current library.
+// CHECK:STDERR: fail_extern_self_library.carbon:[[@LINE+4]]:1: error: `extern library` cannot specify the current library
 // CHECK:STDERR: extern library "extern_self_library" fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
@@ -142,13 +142,13 @@ library "[[@TEST_NAME]]";

 import library "extern_of_import";

-// CHECK:STDERR: fail_extern_of_import_redecl.carbon:[[@LINE+9]]:1: ERROR: Redeclarations of `fn F` must match use of `extern`.
+// CHECK:STDERR: fail_extern_of_import_redecl.carbon:[[@LINE+9]]:1: error: redeclarations of `fn F` must match use of `extern`
 // CHECK:STDERR: extern library "extern_of_import" fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_extern_of_import_redecl.carbon:[[@LINE-5]]:1: In import.
+// CHECK:STDERR: fail_extern_of_import_redecl.carbon:[[@LINE-5]]:1: in import
 // CHECK:STDERR: import library "extern_of_import";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern_of_import.carbon:4:1: Previously declared here.
+// CHECK:STDERR: extern_of_import.carbon:4:1: previously declared here
 // CHECK:STDERR: fn F();
 // CHECK:STDERR: ^~~~~~~
 extern library "extern_of_import" fn F();
@@ -28,13 +28,13 @@ package Foo library "[[@TEST_NAME]]";

 import library default;

-// CHECK:STDERR: fail_wrong_library.carbon:[[@LINE+9]]:1: ERROR: Declaration in library "wrong_library" doesn't match `extern library` declaration.
+// CHECK:STDERR: fail_wrong_library.carbon:[[@LINE+9]]:1: error: declaration in library "wrong_library" doesn't match `extern library` declaration
 // CHECK:STDERR: extern fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
-// CHECK:STDERR: fail_wrong_library.carbon:[[@LINE-5]]:1: In import.
+// CHECK:STDERR: fail_wrong_library.carbon:[[@LINE-5]]:1: in import
 // CHECK:STDERR: import library default;
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: default.carbon:4:1: Previously declared with `extern library` here.
+// CHECK:STDERR: default.carbon:4:1: previously declared with `extern library` here
 // CHECK:STDERR: extern library "expected" fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 extern fn F();
@@ -26,13 +26,13 @@ library "[[@TEST_NAME]]";

 import library "extern_library";

-// CHECK:STDERR: fail_wrong_library.carbon:[[@LINE+9]]:1: ERROR: Declaration in library "wrong_library" doesn't match `extern library` declaration.
+// CHECK:STDERR: fail_wrong_library.carbon:[[@LINE+9]]:1: error: declaration in library "wrong_library" doesn't match `extern library` declaration
 // CHECK:STDERR: extern fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
-// CHECK:STDERR: fail_wrong_library.carbon:[[@LINE-5]]:1: In import.
+// CHECK:STDERR: fail_wrong_library.carbon:[[@LINE-5]]:1: in import
 // CHECK:STDERR: import library "extern_library";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern_library.carbon:4:1: Previously declared with `extern library` here.
+// CHECK:STDERR: extern_library.carbon:4:1: previously declared with `extern library` here
 // CHECK:STDERR: extern library default fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 extern fn F();
@@ -21,24 +21,24 @@ fn ReturnDUnused() -> D;
 fn ReturnDUsed() -> D;

 fn Call() {
-  // CHECK:STDERR: fail_incomplete_return.carbon:[[@LINE+10]]:3: ERROR: Function returns incomplete type `C`.
+  // CHECK:STDERR: fail_incomplete_return.carbon:[[@LINE+10]]:3: error: function returns incomplete type `C`
  // CHECK:STDERR:   ReturnCUsed();
  // CHECK:STDERR:   ^~~~~~~~~~~
-  // CHECK:STDERR: fail_incomplete_return.carbon:[[@LINE-12]]:1: Class was forward declared here.
+  // CHECK:STDERR: fail_incomplete_return.carbon:[[@LINE-12]]:1: class was forward declared here
  // CHECK:STDERR: class C;
  // CHECK:STDERR: ^~~~~~~~
-  // CHECK:STDERR: fail_incomplete_return.carbon:[[@LINE-11]]:18: Return type declared here.
+  // CHECK:STDERR: fail_incomplete_return.carbon:[[@LINE-11]]:18: return type declared here
  // CHECK:STDERR: fn ReturnCUsed() -> C;
  // CHECK:STDERR:                  ^~~~
  // CHECK:STDERR:
  ReturnCUsed();
-  // CHECK:STDERR: fail_incomplete_return.carbon:[[@LINE+10]]:3: ERROR: Function returns incomplete type `D`.
+  // CHECK:STDERR: fail_incomplete_return.carbon:[[@LINE+10]]:3: error: function returns incomplete type `D`
  // CHECK:STDERR:   ReturnDUsed();
  // CHECK:STDERR:   ^~~~~~~~~~~
-  // CHECK:STDERR: fail_incomplete_return.carbon:[[@LINE-22]]:1: Class was forward declared here.
+  // CHECK:STDERR: fail_incomplete_return.carbon:[[@LINE-22]]:1: class was forward declared here
  // CHECK:STDERR: class D;
  // CHECK:STDERR: ^~~~~~~~
-  // CHECK:STDERR: fail_incomplete_return.carbon:[[@LINE-20]]:18: Return type declared here.
+  // CHECK:STDERR: fail_incomplete_return.carbon:[[@LINE-20]]:18: return type declared here
  // CHECK:STDERR: fn ReturnDUsed() -> D;
  // CHECK:STDERR:                  ^~~~
  // CHECK:STDERR:
@@ -54,36 +54,36 @@ library "[[@TEST_NAME]]";
 import library "incomplete_return";

 fn CallFAndGIncomplete() {
-  // CHECK:STDERR: fail_use_imported.carbon:[[@LINE+16]]:3: ERROR: Function returns incomplete type `C`.
+  // CHECK:STDERR: fail_use_imported.carbon:[[@LINE+16]]:3: error: function returns incomplete type `C`
  // CHECK:STDERR:   ReturnCUnused();
  // CHECK:STDERR:   ^~~~~~~~~~~~~
-  // CHECK:STDERR: fail_use_imported.carbon:[[@LINE-6]]:1: In import.
+  // CHECK:STDERR: fail_use_imported.carbon:[[@LINE-6]]:1: in import
  // CHECK:STDERR: import library "incomplete_return";
  // CHECK:STDERR: ^~~~~~
-  // CHECK:STDERR: fail_incomplete_return.carbon:4:1: Class was forward declared here.
+  // CHECK:STDERR: fail_incomplete_return.carbon:4:1: class was forward declared here
  // CHECK:STDERR: class C;
  // CHECK:STDERR: ^~~~~~~~
-  // CHECK:STDERR: fail_use_imported.carbon:[[@LINE-12]]:1: In import.
+  // CHECK:STDERR: fail_use_imported.carbon:[[@LINE-12]]:1: in import
  // CHECK:STDERR: import library "incomplete_return";
  // CHECK:STDERR: ^~~~~~
-  // CHECK:STDERR: fail_incomplete_return.carbon:7:20: Return type declared here.
+  // CHECK:STDERR: fail_incomplete_return.carbon:7:20: return type declared here
  // CHECK:STDERR: fn ReturnCUnused() -> C;
  // CHECK:STDERR:                    ^~~~
  // CHECK:STDERR:
  ReturnCUnused();
-  // CHECK:STDERR: fail_use_imported.carbon:[[@LINE+15]]:3: ERROR: Function returns incomplete type `C`.
+  // CHECK:STDERR: fail_use_imported.carbon:[[@LINE+15]]:3: error: function returns incomplete type `C`
  // CHECK:STDERR:   ReturnCUsed();
  // CHECK:STDERR:   ^~~~~~~~~~~
-  // CHECK:STDERR: fail_use_imported.carbon:[[@LINE-23]]:1: In import.
+  // CHECK:STDERR: fail_use_imported.carbon:[[@LINE-23]]:1: in import
  // CHECK:STDERR: import library "incomplete_return";
  // CHECK:STDERR: ^~~~~~
-  // CHECK:STDERR: fail_incomplete_return.carbon:4:1: Class was forward declared here.
+  // CHECK:STDERR: fail_incomplete_return.carbon:4:1: class was forward declared here
  // CHECK:STDERR: class C;
  // CHECK:STDERR: ^~~~~~~~
-  // CHECK:STDERR: fail_use_imported.carbon:[[@LINE-29]]:1: In import.
+  // CHECK:STDERR: fail_use_imported.carbon:[[@LINE-29]]:1: in import
  // CHECK:STDERR: import library "incomplete_return";
  // CHECK:STDERR: ^~~~~~
-  // CHECK:STDERR: fail_incomplete_return.carbon:8:18: Return type declared here.
+  // CHECK:STDERR: fail_incomplete_return.carbon:8:18: return type declared here
  // CHECK:STDERR: fn ReturnCUsed() -> C;
  // CHECK:STDERR:                  ^~~~
  ReturnCUsed();
@@ -8,84 +8,84 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/no_prelude/fail_modifiers.carbon

-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+11]]:1: ERROR: `default` not allowed on `fn` declaration outside of an interface.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+11]]:1: error: `default` not allowed on `fn` declaration outside of an interface
 // CHECK:STDERR: default protected fn WrongOrder();
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+7]]:9: ERROR: `protected` must appear before `default`.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+7]]:9: error: `protected` must appear before `default`
 // CHECK:STDERR: default protected fn WrongOrder();
 // CHECK:STDERR:         ^~~~~~~~~
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: `default` previously appeared here.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: `default` previously appeared here
 // CHECK:STDERR: default protected fn WrongOrder();
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR:
 default protected fn WrongOrder();

-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+11]]:1: ERROR: `virtual` not allowed on `fn` declaration outside of a class.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+11]]:1: error: `virtual` not allowed on `fn` declaration outside of a class
 // CHECK:STDERR: virtual virtual fn DuplicateVirtual() {}
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+7]]:9: ERROR: `virtual` repeated on declaration.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+7]]:9: error: `virtual` repeated on declaration
 // CHECK:STDERR: virtual virtual fn DuplicateVirtual() {}
 // CHECK:STDERR:         ^~~~~~~
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: `virtual` previously appeared here.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: `virtual` previously appeared here
 // CHECK:STDERR: virtual virtual fn DuplicateVirtual() {}
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR:
 virtual virtual fn DuplicateVirtual() {}

-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+7]]:9: ERROR: `protected` not allowed on declaration with `private`.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+7]]:9: error: `protected` not allowed on declaration with `private`
 // CHECK:STDERR: private protected fn TwoAccess();
 // CHECK:STDERR:         ^~~~~~~~~
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: `private` previously appeared here.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: `private` previously appeared here
 // CHECK:STDERR: private protected fn TwoAccess();
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR:
 private protected fn TwoAccess();

-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+11]]:1: ERROR: `abstract` not allowed on `fn` declaration outside of a class.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+11]]:1: error: `abstract` not allowed on `fn` declaration outside of a class
 // CHECK:STDERR: abstract virtual fn ModifiersConflict() {}
 // CHECK:STDERR: ^~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+7]]:10: ERROR: `virtual` not allowed on declaration with `abstract`.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+7]]:10: error: `virtual` not allowed on declaration with `abstract`
 // CHECK:STDERR: abstract virtual fn ModifiersConflict() {}
 // CHECK:STDERR:          ^~~~~~~
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: `abstract` previously appeared here.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: `abstract` previously appeared here
 // CHECK:STDERR: abstract virtual fn ModifiersConflict() {}
 // CHECK:STDERR: ^~~~~~~~
 // CHECK:STDERR:
 abstract virtual fn ModifiersConflict() {}

-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: ERROR: `base` not allowed on `fn` declaration.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: error: `base` not allowed on `fn` declaration
 // CHECK:STDERR: base fn InvalidModifier();
 // CHECK:STDERR: ^~~~
 // CHECK:STDERR:
 base fn InvalidModifier();

-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+18]]:1: ERROR: `default` not allowed on `fn` declaration outside of an interface.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+18]]:1: error: `default` not allowed on `fn` declaration outside of an interface
 // CHECK:STDERR: default final virtual fn ModifiersConflict2() {}
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+14]]:9: ERROR: `final` not allowed on declaration with `default`.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+14]]:9: error: `final` not allowed on declaration with `default`
 // CHECK:STDERR: default final virtual fn ModifiersConflict2() {}
 // CHECK:STDERR:         ^~~~~
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+11]]:1: `default` previously appeared here.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+11]]:1: `default` previously appeared here
 // CHECK:STDERR: default final virtual fn ModifiersConflict2() {}
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+7]]:15: ERROR: `virtual` not allowed on declaration with `default`.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+7]]:15: error: `virtual` not allowed on declaration with `default`
 // CHECK:STDERR: default final virtual fn ModifiersConflict2() {}
 // CHECK:STDERR:               ^~~~~~~
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: `default` previously appeared here.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+4]]:1: `default` previously appeared here
 // CHECK:STDERR: default final virtual fn ModifiersConflict2() {}
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR:
 default final virtual fn ModifiersConflict2() {}

-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+6]]:8: ERROR: `private` must appear before `extern`.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+6]]:8: error: `private` must appear before `extern`
 // CHECK:STDERR: extern private fn ExternOrderAndConflict() {}
 // CHECK:STDERR:        ^~~~~~~
-// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+3]]:1: `extern` previously appeared here.
+// CHECK:STDERR: fail_modifiers.carbon:[[@LINE+3]]:1: `extern` previously appeared here
 // CHECK:STDERR: extern private fn ExternOrderAndConflict() {}
 // CHECK:STDERR: ^~~~~~
 extern private fn ExternOrderAndConflict() {}
@@ -8,11 +8,11 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/no_prelude/fail_pattern_in_signature.carbon

-// CHECK:STDERR: fail_pattern_in_signature.carbon:[[@LINE+7]]:6: ERROR: Expected name in binding pattern.
+// CHECK:STDERR: fail_pattern_in_signature.carbon:[[@LINE+7]]:6: error: expected name in binding pattern
 // CHECK:STDERR: fn F((a: {}, b: {}), c: {});
 // CHECK:STDERR:      ^
 // CHECK:STDERR:
-// CHECK:STDERR: fail_pattern_in_signature.carbon:[[@LINE+3]]:6: ERROR: Semantics TODO: `Error recovery from keyword name.`.
+// CHECK:STDERR: fail_pattern_in_signature.carbon:[[@LINE+3]]:6: error: semantics TODO: `Error recovery from keyword name.`
 // CHECK:STDERR: fn F((a: {}, b: {}), c: {});
 // CHECK:STDERR:      ^
 fn F((a: {}, b: {}), c: {});
@@ -9,50 +9,50 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/declaration/no_prelude/fail_redecl.carbon

 fn A();
-// CHECK:STDERR: fail_redecl.carbon:[[@LINE+7]]:1: ERROR: Redeclaration of `fn A` is redundant.
+// CHECK:STDERR: fail_redecl.carbon:[[@LINE+7]]:1: error: redeclaration of `fn A` is redundant
 // CHECK:STDERR: fn A();
 // CHECK:STDERR: ^~~~~~~
-// CHECK:STDERR: fail_redecl.carbon:[[@LINE-4]]:1: Previously declared here.
+// CHECK:STDERR: fail_redecl.carbon:[[@LINE-4]]:1: previously declared here
 // CHECK:STDERR: fn A();
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR:
 fn A();

 fn B(x: ());
-// CHECK:STDERR: fail_redecl.carbon:[[@LINE+7]]:1: ERROR: Redeclaration of `fn B` is redundant.
+// CHECK:STDERR: fail_redecl.carbon:[[@LINE+7]]:1: error: redeclaration of `fn B` is redundant
 // CHECK:STDERR: fn B(x: ());
 // CHECK:STDERR: ^~~~~~~~~~~~
-// CHECK:STDERR: fail_redecl.carbon:[[@LINE-4]]:1: Previously declared here.
+// CHECK:STDERR: fail_redecl.carbon:[[@LINE-4]]:1: previously declared here
 // CHECK:STDERR: fn B(x: ());
 // CHECK:STDERR: ^~~~~~~~~~~~
 // CHECK:STDERR:
 fn B(x: ());

 fn C();
-// CHECK:STDERR: fail_redecl.carbon:[[@LINE+7]]:1: ERROR: Redeclaration differs because of parameter count of 1.
+// CHECK:STDERR: fail_redecl.carbon:[[@LINE+7]]:1: error: redeclaration differs because of parameter count of 1
 // CHECK:STDERR: fn C(x: ());
 // CHECK:STDERR: ^~~~~~~~~~~~
-// CHECK:STDERR: fail_redecl.carbon:[[@LINE-4]]:1: Previously declared with parameter count of 0.
+// CHECK:STDERR: fail_redecl.carbon:[[@LINE-4]]:1: previously declared with parameter count of 0
 // CHECK:STDERR: fn C();
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR:
 fn C(x: ());

 fn D() {}
-// CHECK:STDERR: fail_redecl.carbon:[[@LINE+7]]:1: ERROR: Redeclaration of `fn D` is redundant.
+// CHECK:STDERR: fail_redecl.carbon:[[@LINE+7]]:1: error: redeclaration of `fn D` is redundant
 // CHECK:STDERR: fn D();
 // CHECK:STDERR: ^~~~~~~
-// CHECK:STDERR: fail_redecl.carbon:[[@LINE-4]]:1: Previously declared here.
+// CHECK:STDERR: fail_redecl.carbon:[[@LINE-4]]:1: previously declared here
 // CHECK:STDERR: fn D() {}
 // CHECK:STDERR: ^~~~~~~~
 // CHECK:STDERR:
 fn D();

 fn E() {}
-// CHECK:STDERR: fail_redecl.carbon:[[@LINE+6]]:1: ERROR: Redefinition of `fn E`.
+// CHECK:STDERR: fail_redecl.carbon:[[@LINE+6]]:1: error: redefinition of `fn E`
 // CHECK:STDERR: fn E() {}
 // CHECK:STDERR: ^~~~~~~~
-// CHECK:STDERR: fail_redecl.carbon:[[@LINE-4]]:1: Previously defined here.
+// CHECK:STDERR: fail_redecl.carbon:[[@LINE-4]]:1: previously defined here
 // CHECK:STDERR: fn E() {}
 // CHECK:STDERR: ^~~~~~~~
 fn E() {}
@@ -11,7 +11,7 @@
 // --- fail_no_body.carbon

 library "[[@TEST_NAME]]";
-// CHECK:STDERR: fail_no_body.carbon:[[@LINE+4]]:1: ERROR: Semantics TODO: `function with positional parameters`.
+// CHECK:STDERR: fail_no_body.carbon:[[@LINE+4]]:1: error: semantics TODO: `function with positional parameters`
 // CHECK:STDERR: fn A;
 // CHECK:STDERR: ^~~~~
 // CHECK:STDERR:
@@ -20,7 +20,7 @@ fn A;
 // --- fail_todo_brace_body.carbon

 library "[[@TEST_NAME]]";
-// CHECK:STDERR: fail_todo_brace_body.carbon:[[@LINE+4]]:1: ERROR: Semantics TODO: `function with positional parameters`.
+// CHECK:STDERR: fail_todo_brace_body.carbon:[[@LINE+4]]:1: error: semantics TODO: `function with positional parameters`
 // CHECK:STDERR: fn A {
 // CHECK:STDERR: ^~~~~~
 // CHECK:STDERR:
@@ -31,11 +31,11 @@ fn A {

 // TODO: We don't have parsing support for this yet.
 library "[[@TEST_NAME]]";
-// CHECK:STDERR: fail_todo_arrow_body.carbon:[[@LINE+7]]:1: ERROR: Semantics TODO: `function with positional parameters`.
+// CHECK:STDERR: fail_todo_arrow_body.carbon:[[@LINE+7]]:1: error: semantics TODO: `function with positional parameters`
 // CHECK:STDERR: fn A => 0;
 // CHECK:STDERR: ^~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_todo_arrow_body.carbon:[[@LINE+3]]:6: ERROR: `fn` declarations must either end with a `;` or have a `{ ... }` block for a definition.
+// CHECK:STDERR: fail_todo_arrow_body.carbon:[[@LINE+3]]:6: error: `fn` declarations must either end with a `;` or have a `{ ... }` block for a definition
 // CHECK:STDERR: fn A => 0;
 // CHECK:STDERR:      ^~
 fn A => 0;
@@ -30,17 +30,17 @@ extern fn A();

 impl library "[[@TEST_NAME]]";

-// CHECK:STDERR: fail_extern_api.impl.carbon:[[@LINE+14]]:1: ERROR: Redeclarations of `fn A` must match use of `extern`.
+// CHECK:STDERR: fail_extern_api.impl.carbon:[[@LINE+14]]:1: error: redeclarations of `fn A` must match use of `extern`
 // CHECK:STDERR: fn A();
 // CHECK:STDERR: ^~~~~~~
-// CHECK:STDERR: fail_extern_api.impl.carbon:[[@LINE-5]]:6: In import.
+// CHECK:STDERR: fail_extern_api.impl.carbon:[[@LINE-5]]:6: in import
 // CHECK:STDERR: impl library "extern_api";
 // CHECK:STDERR:      ^~~~~~~
-// CHECK:STDERR: extern_api.carbon:4:1: Previously declared here.
+// CHECK:STDERR: extern_api.carbon:4:1: previously declared here
 // CHECK:STDERR: extern fn A();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_extern_api.impl.carbon:[[@LINE+4]]:1: ERROR: No definition found for declaration in impl file
+// CHECK:STDERR: fail_extern_api.impl.carbon:[[@LINE+4]]:1: error: no definition found for declaration in impl file
 // CHECK:STDERR: fn A();
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR:
@@ -56,13 +56,13 @@ fn A();

 impl library "[[@TEST_NAME]]";

-// CHECK:STDERR: fail_extern_impl.impl.carbon:[[@LINE+9]]:1: ERROR: Redeclarations of `fn A` must match use of `extern`.
+// CHECK:STDERR: fail_extern_impl.impl.carbon:[[@LINE+9]]:1: error: redeclarations of `fn A` must match use of `extern`
 // CHECK:STDERR: extern fn A();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
-// CHECK:STDERR: fail_extern_impl.impl.carbon:[[@LINE-5]]:6: In import.
+// CHECK:STDERR: fail_extern_impl.impl.carbon:[[@LINE-5]]:6: in import
 // CHECK:STDERR: impl library "extern_impl";
 // CHECK:STDERR:      ^~~~~~~
-// CHECK:STDERR: extern_impl.carbon:4:1: Previously declared here.
+// CHECK:STDERR: extern_impl.carbon:4:1: previously declared here
 // CHECK:STDERR: fn A();
 // CHECK:STDERR: ^~~~~~~
 extern fn A();
@@ -52,7 +52,7 @@ fn C();

 impl library "[[@TEST_NAME]]";

-// CHECK:STDERR: fail_decl_in_api_decl_in_impl.impl.carbon:[[@LINE+4]]:1: ERROR: No definition found for declaration in impl file
+// CHECK:STDERR: fail_decl_in_api_decl_in_impl.impl.carbon:[[@LINE+4]]:1: error: no definition found for declaration in impl file
 // CHECK:STDERR: fn C();
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR:
@@ -66,7 +66,7 @@ library "[[@TEST_NAME]]";

 impl library "[[@TEST_NAME]]";

-// CHECK:STDERR: fail_decl_only_in_impl.impl.carbon:[[@LINE+3]]:1: ERROR: No definition found for declaration in impl file
+// CHECK:STDERR: fail_decl_only_in_impl.impl.carbon:[[@LINE+3]]:1: error: no definition found for declaration in impl file
 // CHECK:STDERR: fn D();
 // CHECK:STDERR: ^~~~~~~
 fn D();
@@ -47,24 +47,24 @@ library "[[@TEST_NAME]]";

 import library "fns";

-// CHECK:STDERR: fail_def_ownership.carbon:[[@LINE+10]]:1: ERROR: Redeclaration of `fn A` is redundant.
+// CHECK:STDERR: fail_def_ownership.carbon:[[@LINE+10]]:1: error: redeclaration of `fn A` is redundant
 // CHECK:STDERR: fn A() {};
 // CHECK:STDERR: ^~~~~~~~
-// CHECK:STDERR: fail_def_ownership.carbon:[[@LINE-5]]:1: In import.
+// CHECK:STDERR: fail_def_ownership.carbon:[[@LINE-5]]:1: in import
 // CHECK:STDERR: import library "fns";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: fns.carbon:4:1: Previously declared here.
+// CHECK:STDERR: fns.carbon:4:1: previously declared here
 // CHECK:STDERR: fn A() {}
 // CHECK:STDERR: ^~~~~~~~
 // CHECK:STDERR:
 fn A() {};
-// CHECK:STDERR: fail_def_ownership.carbon:[[@LINE+10]]:1: ERROR: Redeclaration of `fn B` is redundant.
+// CHECK:STDERR: fail_def_ownership.carbon:[[@LINE+10]]:1: error: redeclaration of `fn B` is redundant
 // CHECK:STDERR: fn B(b: i32) -> i32;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_def_ownership.carbon:[[@LINE-16]]:1: In import.
+// CHECK:STDERR: fail_def_ownership.carbon:[[@LINE-16]]:1: in import
 // CHECK:STDERR: import library "fns";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: fns.carbon:5:1: Previously declared here.
+// CHECK:STDERR: fns.carbon:5:1: previously declared here
 // CHECK:STDERR: fn B(b: i32) -> i32 { return b; }
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
@@ -76,25 +76,25 @@ library "[[@TEST_NAME]]";

 import library "extern";

-// CHECK:STDERR: fail_redecl_then_def.carbon:[[@LINE+10]]:1: ERROR: Redeclarations of `fn A` must match use of `extern`.
+// CHECK:STDERR: fail_redecl_then_def.carbon:[[@LINE+10]]:1: error: redeclarations of `fn A` must match use of `extern`
 // CHECK:STDERR: fn A();
 // CHECK:STDERR: ^~~~~~~
-// CHECK:STDERR: fail_redecl_then_def.carbon:[[@LINE-5]]:1: In import.
+// CHECK:STDERR: fail_redecl_then_def.carbon:[[@LINE-5]]:1: in import
 // CHECK:STDERR: import library "extern";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern.carbon:4:1: Previously declared here.
+// CHECK:STDERR: extern.carbon:4:1: previously declared here
 // CHECK:STDERR: extern fn A();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR:
 fn A();

-// CHECK:STDERR: fail_redecl_then_def.carbon:[[@LINE+10]]:1: ERROR: Redeclarations of `fn A` must match use of `extern`.
+// CHECK:STDERR: fail_redecl_then_def.carbon:[[@LINE+10]]:1: error: redeclarations of `fn A` must match use of `extern`
 // CHECK:STDERR: fn A() {}
 // CHECK:STDERR: ^~~~~~~~
-// CHECK:STDERR: fail_redecl_then_def.carbon:[[@LINE-17]]:1: In import.
+// CHECK:STDERR: fail_redecl_then_def.carbon:[[@LINE-17]]:1: in import
 // CHECK:STDERR: import library "extern";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: extern.carbon:4:1: Previously declared here.
+// CHECK:STDERR: extern.carbon:4:1: previously declared here
 // CHECK:STDERR: extern fn A();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR:
@@ -106,13 +106,13 @@ library "[[@TEST_NAME]]";

 import library "fns";

-// CHECK:STDERR: fail_mix_extern_decl.carbon:[[@LINE+9]]:1: ERROR: Redeclarations of `fn D` must match use of `extern`.
+// CHECK:STDERR: fail_mix_extern_decl.carbon:[[@LINE+9]]:1: error: redeclarations of `fn D` must match use of `extern`
 // CHECK:STDERR: extern fn D();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
-// CHECK:STDERR: fail_mix_extern_decl.carbon:[[@LINE-5]]:1: In import.
+// CHECK:STDERR: fail_mix_extern_decl.carbon:[[@LINE-5]]:1: in import
 // CHECK:STDERR: import library "fns";
 // CHECK:STDERR: ^~~~~~
-// CHECK:STDERR: fns.carbon:7:1: Previously declared here.
+// CHECK:STDERR: fns.carbon:7:1: previously declared here
 // CHECK:STDERR: fn D();
 // CHECK:STDERR: ^~~~~~~
 extern fn D();
@@ -48,7 +48,7 @@ package Test library "[[@TEST_NAME]]";

 import library "def";

-// CHECK:STDERR: fail_local_def.carbon:[[@LINE+4]]:13: ERROR: Name `Def` not found.
+// CHECK:STDERR: fail_local_def.carbon:[[@LINE+4]]:13: error: name `Def` not found
 // CHECK:STDERR: var f: () = Def();
 // CHECK:STDERR:             ^~~
 // CHECK:STDERR:
@@ -60,7 +60,7 @@ package Other library "[[@TEST_NAME]]";

 import Test library "def";

-// CHECK:STDERR: fail_other_def.carbon:[[@LINE+4]]:13: ERROR: Name `Def` not found.
+// CHECK:STDERR: fail_other_def.carbon:[[@LINE+4]]:13: error: name `Def` not found
 // CHECK:STDERR: var f: () = Test.Def();
 // CHECK:STDERR:             ^~~~~~~~
 // CHECK:STDERR:
@@ -78,7 +78,7 @@ package Test library "[[@TEST_NAME]]";

 import library "forward_with_def";

-// CHECK:STDERR: fail_local_forward_with_def.carbon:[[@LINE+4]]:13: ERROR: Name `ForwardWithDef` not found.
+// CHECK:STDERR: fail_local_forward_with_def.carbon:[[@LINE+4]]:13: error: name `ForwardWithDef` not found
 // CHECK:STDERR: var f: () = ForwardWithDef();
 // CHECK:STDERR:             ^~~~~~~~~~~~~~
 // CHECK:STDERR:
@@ -90,7 +90,7 @@ package Other library "[[@TEST_NAME]]";

 import Test library "forward_with_def";

-// CHECK:STDERR: fail_other_forward_with_def.carbon:[[@LINE+4]]:13: ERROR: Name `ForwardWithDef` not found.
+// CHECK:STDERR: fail_other_forward_with_def.carbon:[[@LINE+4]]:13: error: name `ForwardWithDef` not found
 // CHECK:STDERR: var f: () = Test.ForwardWithDef();
 // CHECK:STDERR:             ^~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
@@ -110,7 +110,7 @@ package Test library "[[@TEST_NAME]]";

 import library "forward";

-// CHECK:STDERR: fail_local_forward.carbon:[[@LINE+4]]:13: ERROR: Name `Forward` not found.
+// CHECK:STDERR: fail_local_forward.carbon:[[@LINE+4]]:13: error: name `Forward` not found
 // CHECK:STDERR: var f: () = Forward();
 // CHECK:STDERR:             ^~~~~~~
 // CHECK:STDERR:
@@ -122,7 +122,7 @@ package Other library "[[@TEST_NAME]]";

 import Test library "forward";

-// CHECK:STDERR: fail_other_forward.carbon:[[@LINE+3]]:13: ERROR: Name `Forward` not found.
+// CHECK:STDERR: fail_other_forward.carbon:[[@LINE+3]]:13: error: name `Forward` not found
 // CHECK:STDERR: var f: () = Test.Forward();
 // CHECK:STDERR:             ^~~~~~~~~~~~
 var f: () = Test.Forward();
@@ -38,10 +38,10 @@ extern fn F() {}
 library "[[@TEST_NAME]]";

 extern fn F();
-// CHECK:STDERR: fail_def_extern_mismatch.carbon:[[@LINE+7]]:1: ERROR: Redeclarations of `fn F` must match use of `extern`.
+// CHECK:STDERR: fail_def_extern_mismatch.carbon:[[@LINE+7]]:1: error: redeclarations of `fn F` must match use of `extern`
 // CHECK:STDERR: fn F() {}
 // CHECK:STDERR: ^~~~~~~~
-// CHECK:STDERR: fail_def_extern_mismatch.carbon:[[@LINE-4]]:1: Previously declared here.
+// CHECK:STDERR: fail_def_extern_mismatch.carbon:[[@LINE-4]]:1: previously declared here
 // CHECK:STDERR: extern fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR:
@@ -52,10 +52,10 @@ fn F() {}
 library "[[@TEST_NAME]]";

 fn F();
-// CHECK:STDERR: fail_def_extern_mismatch_reverse.carbon:[[@LINE+7]]:1: ERROR: Redeclarations of `fn F` must match use of `extern`.
+// CHECK:STDERR: fail_def_extern_mismatch_reverse.carbon:[[@LINE+7]]:1: error: redeclarations of `fn F` must match use of `extern`
 // CHECK:STDERR: extern fn F() {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_def_extern_mismatch_reverse.carbon:[[@LINE-4]]:1: Previously declared here.
+// CHECK:STDERR: fail_def_extern_mismatch_reverse.carbon:[[@LINE-4]]:1: previously declared here
 // CHECK:STDERR: fn F();
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR:
@@ -66,18 +66,18 @@ extern fn F() {}
 library "[[@TEST_NAME]]";

 extern fn F();
-// CHECK:STDERR: fail_extern_diag_suppressed.carbon:[[@LINE+7]]:1: ERROR: Redeclaration of `fn F` is redundant.
+// CHECK:STDERR: fail_extern_diag_suppressed.carbon:[[@LINE+7]]:1: error: redeclaration of `fn F` is redundant
 // CHECK:STDERR: fn F();
 // CHECK:STDERR: ^~~~~~~
-// CHECK:STDERR: fail_extern_diag_suppressed.carbon:[[@LINE-4]]:1: Previously declared here.
+// CHECK:STDERR: fail_extern_diag_suppressed.carbon:[[@LINE-4]]:1: previously declared here
 // CHECK:STDERR: extern fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR:
 fn F();
-// CHECK:STDERR: fail_extern_diag_suppressed.carbon:[[@LINE+7]]:1: ERROR: Redeclarations of `fn F` must match use of `extern`.
+// CHECK:STDERR: fail_extern_diag_suppressed.carbon:[[@LINE+7]]:1: error: redeclarations of `fn F` must match use of `extern`
 // CHECK:STDERR: fn F() {}
 // CHECK:STDERR: ^~~~~~~~
-// CHECK:STDERR: fail_extern_diag_suppressed.carbon:[[@LINE-12]]:1: Previously declared here.
+// CHECK:STDERR: fail_extern_diag_suppressed.carbon:[[@LINE-12]]:1: previously declared here
 // CHECK:STDERR: extern fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR:
@@ -88,10 +88,10 @@ fn F() {}
 library "[[@TEST_NAME]]";

 fn F() {}
-// CHECK:STDERR: fail_extern_decl_after_def.carbon:[[@LINE+7]]:1: ERROR: Redeclaration of `fn F` is redundant.
+// CHECK:STDERR: fail_extern_decl_after_def.carbon:[[@LINE+7]]:1: error: redeclaration of `fn F` is redundant
 // CHECK:STDERR: extern fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
-// CHECK:STDERR: fail_extern_decl_after_def.carbon:[[@LINE-4]]:1: Previously declared here.
+// CHECK:STDERR: fail_extern_decl_after_def.carbon:[[@LINE-4]]:1: previously declared here
 // CHECK:STDERR: fn F() {}
 // CHECK:STDERR: ^~~~~~~~
 // CHECK:STDERR:
@@ -105,7 +105,7 @@ library "[[@TEST_NAME]]";

 impl library "[[@TEST_NAME]]";

-// CHECK:STDERR: fail_in_impl.impl.carbon:[[@LINE+3]]:1: ERROR: `extern` entities must have a declaration in the API file.
+// CHECK:STDERR: fail_in_impl.impl.carbon:[[@LINE+3]]:1: error: `extern` entities must have a declaration in the API file
 // CHECK:STDERR: extern fn F() {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~~
 extern fn F() {}
@@ -54,13 +54,13 @@ extern fn F();

 impl library "[[@TEST_NAME]]";

-// CHECK:STDERR: fail_two_file_impl_mismatch.impl.carbon:[[@LINE+10]]:1: ERROR: Redeclarations of `fn F` must match use of `extern`.
+// CHECK:STDERR: fail_two_file_impl_mismatch.impl.carbon:[[@LINE+10]]:1: error: redeclarations of `fn F` must match use of `extern`
 // CHECK:STDERR: fn F() {}
 // CHECK:STDERR: ^~~~~~~~
-// CHECK:STDERR: fail_two_file_impl_mismatch.impl.carbon:[[@LINE-5]]:6: In import.
+// CHECK:STDERR: fail_two_file_impl_mismatch.impl.carbon:[[@LINE-5]]:6: in import
 // CHECK:STDERR: impl library "two_file_impl_mismatch";
 // CHECK:STDERR:      ^~~~~~~
-// CHECK:STDERR: two_file_impl_mismatch.carbon:4:1: Previously declared here.
+// CHECK:STDERR: two_file_impl_mismatch.carbon:4:1: previously declared here
 // CHECK:STDERR: extern fn F();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR:
@@ -82,7 +82,7 @@ import library "indirect_two_file_extern";

 impl library "[[@TEST_NAME]]";

-// CHECK:STDERR: fail_indirect_two_file.impl.carbon:[[@LINE+4]]:1: ERROR: `extern` entities must have a declaration in the API file.
+// CHECK:STDERR: fail_indirect_two_file.impl.carbon:[[@LINE+4]]:1: error: `extern` entities must have a declaration in the API file
 // CHECK:STDERR: extern fn F() {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~~
 // CHECK:STDERR:
@@ -104,7 +104,7 @@ impl library "[[@TEST_NAME]]";

 import library "in_impl_extern";

-// CHECK:STDERR: fail_in_impl.impl.carbon:[[@LINE+3]]:1: ERROR: `extern` entities must have a declaration in the API file.
+// CHECK:STDERR: fail_in_impl.impl.carbon:[[@LINE+3]]:1: error: `extern` entities must have a declaration in the API file
 // CHECK:STDERR: extern fn F() {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~~
 extern fn F() {}
@@ -9,57 +9,57 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/no_prelude/fail_decl_param_mismatch.carbon

 fn F();
-// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE+7]]:1: ERROR: Redeclaration differs because of parameter count of 1.
+// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE+7]]:1: error: redeclaration differs because of parameter count of 1
 // CHECK:STDERR: fn F(x: ()) {}
 // CHECK:STDERR: ^~~~~~~~~~~~~
-// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE-4]]:1: Previously declared with parameter count of 0.
+// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE-4]]:1: previously declared with parameter count of 0
 // CHECK:STDERR: fn F();
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR:
 fn F(x: ()) {}

 fn G(x: ());
-// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE+7]]:1: ERROR: Redeclaration differs because of parameter count of 0.
+// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE+7]]:1: error: redeclaration differs because of parameter count of 0
 // CHECK:STDERR: fn G() {}
 // CHECK:STDERR: ^~~~~~~~
-// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE-4]]:1: Previously declared with parameter count of 1.
+// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE-4]]:1: previously declared with parameter count of 1
 // CHECK:STDERR: fn G(x: ());
 // CHECK:STDERR: ^~~~~~~~~~~~
 // CHECK:STDERR:
 fn G() {}

 fn H(x: ());
-// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE+4]]:9: ERROR: Package `Core` implicitly referenced here, but not found.
+// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE+4]]:9: error: package `Core` implicitly referenced here, but not found
 // CHECK:STDERR: fn H(x: bool) {}
 // CHECK:STDERR:         ^~~~
 // CHECK:STDERR:
 fn H(x: bool) {}

 fn I();
-// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE+7]]:1: ERROR: Function redeclaration differs because return type is `()`.
+// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE+7]]:1: error: function redeclaration differs because return type is `()`
 // CHECK:STDERR: fn I() -> () { return (); }
 // CHECK:STDERR: ^~~~~~~~~~~~~~
-// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE-4]]:1: Previously declared with no return type.
+// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE-4]]:1: previously declared with no return type
 // CHECK:STDERR: fn I();
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR:
 fn I() -> () { return (); }

 fn J() -> ();
-// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE+7]]:1: ERROR: Function redeclaration differs because no return type is provided.
+// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE+7]]:1: error: function redeclaration differs because no return type is provided
 // CHECK:STDERR: fn J() {}
 // CHECK:STDERR: ^~~~~~~~
-// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE-4]]:1: Previously declared with return type `()`.
+// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE-4]]:1: previously declared with return type `()`
 // CHECK:STDERR: fn J() -> ();
 // CHECK:STDERR: ^~~~~~~~~~~~~
 // CHECK:STDERR:
 fn J() {}

 fn K() -> ();
-// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE+6]]:1: ERROR: Function redeclaration differs because return type is `{}`.
+// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE+6]]:1: error: function redeclaration differs because return type is `{}`
 // CHECK:STDERR: fn K() -> {} { return {}; }
 // CHECK:STDERR: ^~~~~~~~~~~~~~
-// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE-4]]:1: Previously declared with return type `()`.
+// CHECK:STDERR: fail_decl_param_mismatch.carbon:[[@LINE-4]]:1: previously declared with return type `()`
 // CHECK:STDERR: fn K() -> ();
 // CHECK:STDERR: ^~~~~~~~~~~~~
 fn K() -> {} { return {}; }
@@ -9,10 +9,10 @@
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/definition/no_prelude/fail_redef.carbon

 fn F() {}
-// CHECK:STDERR: fail_redef.carbon:[[@LINE+6]]:1: ERROR: Redefinition of `fn F`.
+// CHECK:STDERR: fail_redef.carbon:[[@LINE+6]]:1: error: redefinition of `fn F`
 // CHECK:STDERR: fn F() {}
 // CHECK:STDERR: ^~~~~~~~
-// CHECK:STDERR: fail_redef.carbon:[[@LINE-4]]:1: Previously defined here.
+// CHECK:STDERR: fail_redef.carbon:[[@LINE-4]]:1: previously defined here
 // CHECK:STDERR: fn F() {}
 // CHECK:STDERR: ^~~~~~~~
 fn F() {}
@@ -30,13 +30,13 @@ extern fn A();

 impl library "[[@TEST_NAME]]";

-// CHECK:STDERR: fail_extern_api.impl.carbon:[[@LINE+10]]:1: ERROR: Redeclarations of `fn A` must match use of `extern`.
+// CHECK:STDERR: fail_extern_api.impl.carbon:[[@LINE+10]]:1: error: redeclarations of `fn A` must match use of `extern`
 // CHECK:STDERR: fn A() {}
 // CHECK:STDERR: ^~~~~~~~
-// CHECK:STDERR: fail_extern_api.impl.carbon:[[@LINE-5]]:6: In import.
+// CHECK:STDERR: fail_extern_api.impl.carbon:[[@LINE-5]]:6: in import
 // CHECK:STDERR: impl library "extern_api";
 // CHECK:STDERR:      ^~~~~~~
-// CHECK:STDERR: extern_api.carbon:4:1: Previously declared here.
+// CHECK:STDERR: extern_api.carbon:4:1: previously declared here
 // CHECK:STDERR: extern fn A();
 // CHECK:STDERR: ^~~~~~~~~~~~~~
 // CHECK:STDERR:
@@ -52,13 +52,13 @@ fn A();

 impl library "[[@TEST_NAME]]";

-// CHECK:STDERR: fail_extern_impl.impl.carbon:[[@LINE+10]]:1: ERROR: Redeclarations of `fn A` must match use of `extern`.
+// CHECK:STDERR: fail_extern_impl.impl.carbon:[[@LINE+10]]:1: error: redeclarations of `fn A` must match use of `extern`
 // CHECK:STDERR: extern fn A() {}
 // CHECK:STDERR: ^~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_extern_impl.impl.carbon:[[@LINE-5]]:6: In import.
+// CHECK:STDERR: fail_extern_impl.impl.carbon:[[@LINE-5]]:6: in import
 // CHECK:STDERR: impl library "extern_impl";
 // CHECK:STDERR:      ^~~~~~~
-// CHECK:STDERR: extern_impl.carbon:4:1: Previously declared here.
+// CHECK:STDERR: extern_impl.carbon:4:1: previously declared here
 // CHECK:STDERR: fn A();
 // CHECK:STDERR: ^~~~~~~
 // CHECK:STDERR:
@@ -74,13 +74,13 @@ fn A() {}

 impl library "[[@TEST_NAME]]";

-// CHECK:STDERR: fail_redecl_after_def.impl.carbon:[[@LINE+10]]:1: ERROR: Redeclaration of `fn A` is redundant.
+// CHECK:STDERR: fail_redecl_after_def.impl.carbon:[[@LINE+10]]:1: error: redeclaration of `fn A` is redundant
 // CHECK:STDERR: fn A();
 // CHECK:STDERR: ^~~~~~~
-// CHECK:STDERR: fail_redecl_after_def.impl.carbon:[[@LINE-5]]:6: In import.
+// CHECK:STDERR: fail_redecl_after_def.impl.carbon:[[@LINE-5]]:6: in import
 // CHECK:STDERR: impl library "redecl_after_def";
 // CHECK:STDERR:      ^~~~~~~
-// CHECK:STDERR: redecl_after_def.carbon:4:1: Previously declared here.
+// CHECK:STDERR: redecl_after_def.carbon:4:1: previously declared here
 // CHECK:STDERR: fn A() {}
 // CHECK:STDERR: ^~~~~~~~
 // CHECK:STDERR:
@@ -96,13 +96,13 @@ fn A() {}

 impl library "[[@TEST_NAME]]";

-// CHECK:STDERR: fail_redef_after_def.impl.carbon:[[@LINE+10]]:1: ERROR: Redefinition of `fn A`.
+// CHECK:STDERR: fail_redef_after_def.impl.carbon:[[@LINE+10]]:1: error: redefinition of `fn A`
 // CHECK:STDERR: fn A() {}
 // CHECK:STDERR: ^~~~~~~~
-// CHECK:STDERR: fail_redef_after_def.impl.carbon:[[@LINE-5]]:6: In import.
+// CHECK:STDERR: fail_redef_after_def.impl.carbon:[[@LINE-5]]:6: in import
 // CHECK:STDERR: impl library "redef_after_def";
 // CHECK:STDERR:      ^~~~~~~
-// CHECK:STDERR: redef_after_def.carbon:4:1: Previously defined here.
+// CHECK:STDERR: redef_after_def.carbon:4:1: previously defined here
 // CHECK:STDERR: fn A() {}
 // CHECK:STDERR: ^~~~~~~~
 // CHECK:STDERR:
@@ -119,13 +119,13 @@ alias B = A;

 impl library "[[@TEST_NAME]]";

-// CHECK:STDERR: fail_def_alias.impl.carbon:[[@LINE+9]]:1: ERROR: Duplicate name being declared in the same scope.
+// CHECK:STDERR: fail_def_alias.impl.carbon:[[@LINE+9]]:1: error: duplicate name being declared in the same scope
 // CHECK:STDERR: fn B() {}
 // CHECK:STDERR: ^~~~~~~~
-// CHECK:STDERR: fail_def_alias.impl.carbon:[[@LINE-5]]:6: In import.
+// CHECK:STDERR: fail_def_alias.impl.carbon:[[@LINE-5]]:6: in import
 // CHECK:STDERR: impl library "def_alias";
 // CHECK:STDERR:      ^~~~~~~
-// CHECK:STDERR: def_alias.carbon:5:7: Name is previously declared here.
+// CHECK:STDERR: def_alias.carbon:5:7: name is previously declared here
 // CHECK:STDERR: alias B = A;
 // CHECK:STDERR:       ^
 fn B() {}
@@ -37,10 +37,10 @@ library "[[@TEST_NAME]]";
 class C {}

 fn Foo(a: C);
-// CHECK:STDERR: fail_parens.carbon:[[@LINE+7]]:11: ERROR: Redeclaration syntax differs here.
+// CHECK:STDERR: fail_parens.carbon:[[@LINE+7]]:11: error: redeclaration syntax differs here
 // CHECK:STDERR: fn Foo(a: (C)) {}
 // CHECK:STDERR:           ^
-// CHECK:STDERR: fail_parens.carbon:[[@LINE-4]]:11: Comparing with previous declaration here.
+// CHECK:STDERR: fail_parens.carbon:[[@LINE-4]]:11: comparing with previous declaration here
 // CHECK:STDERR: fn Foo(a: C);
 // CHECK:STDERR:           ^
 // CHECK:STDERR:
@@ -80,10 +80,10 @@ class C {}
 alias D = C;

 fn Foo(a: C);
-// CHECK:STDERR: fail_name_mismatch.carbon:[[@LINE+7]]:8: ERROR: Redeclaration differs at parameter 1.
+// CHECK:STDERR: fail_name_mismatch.carbon:[[@LINE+7]]:8: error: redeclaration differs at parameter 1
 // CHECK:STDERR: fn Foo(b: D) {}
 // CHECK:STDERR:        ^
-// CHECK:STDERR: fail_name_mismatch.carbon:[[@LINE-4]]:8: Previous declaration's corresponding parameter here.
+// CHECK:STDERR: fail_name_mismatch.carbon:[[@LINE-4]]:8: previous declaration's corresponding parameter here
 // CHECK:STDERR: fn Foo(a: C);
 // CHECK:STDERR:        ^
 // CHECK:STDERR:
@@ -97,10 +97,10 @@ class C {}
 alias D = C;

 fn Foo(a: C);
-// CHECK:STDERR: fail_alias.carbon:[[@LINE+7]]:11: ERROR: Redeclaration syntax differs here.
+// CHECK:STDERR: fail_alias.carbon:[[@LINE+7]]:11: error: redeclaration syntax differs here
 // CHECK:STDERR: fn Foo(a: D) {}
 // CHECK:STDERR:           ^
-// CHECK:STDERR: fail_alias.carbon:[[@LINE-4]]:11: Comparing with previous declaration here.
+// CHECK:STDERR: fail_alias.carbon:[[@LINE-4]]:11: comparing with previous declaration here
 // CHECK:STDERR: fn Foo(a: C);
 // CHECK:STDERR:           ^
 // CHECK:STDERR:
@@ -114,10 +114,10 @@ class C {}
 alias D = C;

 fn Foo[a: C]();
-// CHECK:STDERR: fail_deduced_alias.carbon:[[@LINE+7]]:11: ERROR: Redeclaration syntax differs here.
+// CHECK:STDERR: fail_deduced_alias.carbon:[[@LINE+7]]:11: error: redeclaration syntax differs here
 // CHECK:STDERR: fn Foo[a: D]() {}
 // CHECK:STDERR:           ^
-// CHECK:STDERR: fail_deduced_alias.carbon:[[@LINE-4]]:11: Comparing with previous declaration here.
+// CHECK:STDERR: fail_deduced_alias.carbon:[[@LINE-4]]:11: comparing with previous declaration here
 // CHECK:STDERR: fn Foo[a: C]();
 // CHECK:STDERR:           ^
 // CHECK:STDERR:
@@ -156,14 +156,14 @@ library "[[@TEST_NAME]]";
 class C {}

 fn Foo(a: const C);
-// CHECK:STDERR: fail_repeat_const.carbon:[[@LINE+10]]:11: WARNING: `const` applied repeatedly to the same type has no additional effect.
+// CHECK:STDERR: fail_repeat_const.carbon:[[@LINE+10]]:11: warning: `const` applied repeatedly to the same type has no additional effect
 // CHECK:STDERR: fn Foo(a: const (const C)) {}
 // CHECK:STDERR:           ^~~~~~~~~~~~~~~
 // CHECK:STDERR:
-// CHECK:STDERR: fail_repeat_const.carbon:[[@LINE+6]]:17: ERROR: Redeclaration syntax differs here.
+// CHECK:STDERR: fail_repeat_const.carbon:[[@LINE+6]]:17: error: redeclaration syntax differs here
 // CHECK:STDERR: fn Foo(a: const (const C)) {}
 // CHECK:STDERR:                 ^
-// CHECK:STDERR: fail_repeat_const.carbon:[[@LINE-8]]:17: Comparing with previous declaration here.
+// CHECK:STDERR: fail_repeat_const.carbon:[[@LINE-8]]:17: comparing with previous declaration here
 // CHECK:STDERR: fn Foo(a: const C);
 // CHECK:STDERR:                 ^
 fn Foo(a: const (const C)) {}
@@ -32,10 +32,10 @@ fn ExplicitAndAlsoDeduced(T:! type, x: T) -> T*;

 // TODO: This should presumably be accepted. We shouldn't deduce values for parameters with explicitly-specified values.
 fn CallExplicitAndAlsoDeduced(n: i32) -> i32* {
-  // CHECK:STDERR: fail_todo_explicit_vs_deduced.carbon:[[@LINE+7]]:10: ERROR: Inconsistent deductions for value of generic parameter `T`.
+  // CHECK:STDERR: fail_todo_explicit_vs_deduced.carbon:[[@LINE+7]]:10: error: inconsistent deductions for value of generic parameter `T`
  // CHECK:STDERR:   return ExplicitAndAlsoDeduced(A, {});
  // CHECK:STDERR:          ^~~~~~~~~~~~~~~~~~~~~~~
-  // CHECK:STDERR: fail_todo_explicit_vs_deduced.carbon:[[@LINE-7]]:1: While deducing parameters of generic declared here.
+  // CHECK:STDERR: fail_todo_explicit_vs_deduced.carbon:[[@LINE-7]]:1: while deducing parameters of generic declared here
  // CHECK:STDERR: fn ExplicitAndAlsoDeduced(T:! type, x: T) -> T*;
  // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // CHECK:STDERR:
@@ -59,10 +59,10 @@ library "[[@TEST_NAME]]";
 fn TupleParam[T:! type](x: (T, i32));

 fn CallTupleParam() {
-  // CHECK:STDERR: fail_todo_deduce_nested.carbon:[[@LINE+7]]:3: ERROR: Cannot deduce value for generic parameter `T`.
+  // CHECK:STDERR: fail_todo_deduce_nested.carbon:[[@LINE+7]]:3: error: cannot deduce value for generic parameter `T`
  // CHECK:STDERR:   TupleParam((1, 2));
  // CHECK:STDERR:   ^~~~~~~~~~~
-  // CHECK:STDERR: fail_todo_deduce_nested.carbon:[[@LINE-6]]:1: While deducing parameters of generic declared here.
+  // CHECK:STDERR: fail_todo_deduce_nested.carbon:[[@LINE-6]]:1: while deducing parameters of generic declared here
  // CHECK:STDERR: fn TupleParam[T:! type](x: (T, i32));
  // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // CHECK:STDERR:
@@ -72,10 +72,10 @@ fn CallTupleParam() {
 fn StructParam[T:! type](x: {.a: T, .b: i32});

 fn CallStructParam() {
-  // CHECK:STDERR: fail_todo_deduce_nested.carbon:[[@LINE+7]]:3: ERROR: Cannot deduce value for generic parameter `T`.
+  // CHECK:STDERR: fail_todo_deduce_nested.carbon:[[@LINE+7]]:3: error: cannot deduce value for generic parameter `T`
  // CHECK:STDERR:   StructParam({.a = 1, .b = 2});
  // CHECK:STDERR:   ^~~~~~~~~~~~
-  // CHECK:STDERR: fail_todo_deduce_nested.carbon:[[@LINE-6]]:1: While deducing parameters of generic declared here.
+  // CHECK:STDERR: fail_todo_deduce_nested.carbon:[[@LINE-6]]:1: while deducing parameters of generic declared here
  // CHECK:STDERR: fn StructParam[T:! type](x: {.a: T, .b: i32});
  // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // CHECK:STDERR:
@@ -91,10 +91,10 @@ library "[[@TEST_NAME]]";
 fn ImplicitNotDeducible[T:! type, U:! type](x: T) -> U;

 fn CallImplicitNotDeducible() {
-  // CHECK:STDERR: fail_deduce_incomplete.carbon:[[@LINE+7]]:3: ERROR: Cannot deduce value for generic parameter `U`.
+  // CHECK:STDERR: fail_deduce_incomplete.carbon:[[@LINE+7]]:3: error: cannot deduce value for generic parameter `U`
  // CHECK:STDERR:   ImplicitNotDeducible(42);
  // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~
-  // CHECK:STDERR: fail_deduce_incomplete.carbon:[[@LINE-6]]:1: While deducing parameters of generic declared here.
+  // CHECK:STDERR: fail_deduce_incomplete.carbon:[[@LINE-6]]:1: while deducing parameters of generic declared here
  // CHECK:STDERR: fn ImplicitNotDeducible[T:! type, U:! type](x: T) -> U;
  // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // CHECK:STDERR:
@@ -108,10 +108,10 @@ library "[[@TEST_NAME]]";
 fn ImplicitNotDeducible[T:! type](x: T, y: T) -> T;

 fn CallImplicitNotDeducible() {
-  // CHECK:STDERR: fail_deduce_inconsistent.carbon:[[@LINE+6]]:3: ERROR: Inconsistent deductions for value of generic parameter `T`.
+  // CHECK:STDERR: fail_deduce_inconsistent.carbon:[[@LINE+6]]:3: error: inconsistent deductions for value of generic parameter `T`
  // CHECK:STDERR:   ImplicitNotDeducible(42, {.x = 12});
  // CHECK:STDERR:   ^~~~~~~~~~~~~~~~~~~~~
-  // CHECK:STDERR: fail_deduce_inconsistent.carbon:[[@LINE-6]]:1: While deducing parameters of generic declared here.
+  // CHECK:STDERR: fail_deduce_inconsistent.carbon:[[@LINE-6]]:1: while deducing parameters of generic declared here
  // CHECK:STDERR: fn ImplicitNotDeducible[T:! type](x: T, y: T) -> T;
  // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  ImplicitNotDeducible(42, {.x = 12});
@@ -8,7 +8,7 @@
 // TIP: To dump output, run:
 // TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/function/generic/fail_todo_param_in_type.carbon

-// CHECK:STDERR: fail_todo_param_in_type.carbon:[[@LINE+3]]:24: ERROR: Semantics TODO: `symbolic array bound`.
+// CHECK:STDERR: fail_todo_param_in_type.carbon:[[@LINE+3]]:24: error: semantics TODO: `symbolic array bound`
 // CHECK:STDERR: fn F(N:! i32, a: [i32; N]*);
 // CHECK:STDERR:                        ^
 fn F(N:! i32, a: [i32; N]*);
@@ -10,7 +10,7 @@

 fn F(T:! type, U:! type) {
  var p: T*;
-  // CHECK:STDERR: fail_type_param_mismatch.carbon:[[@LINE+3]]:3: ERROR: Package `Core` implicitly referenced here, but not found.
+  // CHECK:STDERR: fail_type_param_mismatch.carbon:[[@LINE+3]]:3: error: package `Core` implicitly referenced here, but not found
  // CHECK:STDERR:   let n: U = *p;
  // CHECK:STDERR:   ^~~~~~~~~~~~~~
  let n: U = *p;
@@ -24,18 +24,18 @@ library "[[@TEST_NAME]]";

 fn F(T:! type, U:! type) -> T*;

-// CHECK:STDERR: fail_different_return_type.carbon:[[@LINE+7]]:1: ERROR: Function redeclaration differs because return type is `U*`.
+// CHECK:STDERR: fail_different_return_type.carbon:[[@LINE+7]]:1: error: function redeclaration differs because return type is `U*`
 // CHECK:STDERR: fn F(T:! type, U:! type) -> U* {
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_different_return_type.carbon:[[@LINE-5]]:1: Previously declared with return type `T*`.
+// CHECK:STDERR: fail_different_return_type.carbon:[[@LINE-5]]:1: previously declared with return type `T*`
 // CHECK:STDERR: fn F(T:! type, U:! type) -> T*;
 // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // CHECK:STDERR:
 fn F(T:! type, U:! type) -> U* {
-  // CHECK:STDERR: fail_different_return_type.carbon:[[@LINE+7]]:10: ERROR: 1 argument(s) passed to function expecting 2 argument(s).
+  // CHECK:STDERR: fail_different_return_type.carbon:[[@LINE+7]]:10: error: 1 argument(s) passed to function expecting 2 argument(s).
  // CHECK:STDERR:   return F(T);
  // CHECK:STDERR:          ^~
-  // CHECK:STDERR: fail_different_return_type.carbon:[[@LINE-13]]:1: Calling function declared here.
+  // CHECK:STDERR: fail_different_return_type.carbon:[[@LINE-13]]:1: calling function declared here
  // CHECK:STDERR: fn F(T:! type, U:! type) -> T*;
  // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // CHECK:STDERR:
@@ -48,18 +48,18 @@ library "[[@TEST_NAME]]";

 fn F(T:! type, U:! type) -> T*;

-// CHECK:STDERR: fail_reorder.carbon:[[@LINE+7]]:6: ERROR: Redeclaration differs at parameter 1.
+// CHECK:STDERR: fail_reorder.carbon:[[@LINE+7]]:6: error: redeclaration differs at parameter 1
 // CHECK:STDERR: fn F(U:! type, T:! type) -> T* {
 // CHECK:STDERR:      ^
-// CHECK:STDERR: fail_reorder.carbon:[[@LINE-5]]:6: Previous declaration's corresponding parameter here.
+// CHECK:STDERR: fail_reorder.carbon:[[@LINE-5]]:6: previous declaration's corresponding parameter here
 // CHECK:STDERR: fn F(T:! type, U:! type) -> T*;
 // CHECK:STDERR:      ^
 // CHECK:STDERR:
 fn F(U:! type, T:! type) -> T* {
-  // CHECK:STDERR: fail_reorder.carbon:[[@LINE+7]]:10: ERROR: 1 argument(s) passed to function expecting 2 argument(s).
+  // CHECK:STDERR: fail_reorder.carbon:[[@LINE+7]]:10: error: 1 argument(s) passed to function expecting 2 argument(s).
  // CHECK:STDERR:   return F(T);
  // CHECK:STDERR:          ^~
-  // CHECK:STDERR: fail_reorder.carbon:[[@LINE-13]]:1: Calling function declared here.
+  // CHECK:STDERR: fail_reorder.carbon:[[@LINE-13]]:1: calling function declared here
  // CHECK:STDERR: fn F(T:! type, U:! type) -> T*;
  // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // CHECK:STDERR:
@@ -72,18 +72,18 @@ library "[[@TEST_NAME]]";

 fn F(T:! type, U:! type) -> T*;

-// CHECK:STDERR: fail_rename.carbon:[[@LINE+7]]:6: ERROR: Redeclaration differs at parameter 1.
+// CHECK:STDERR: fail_rename.carbon:[[@LINE+7]]:6: error: redeclaration differs at parameter 1
 // CHECK:STDERR: fn F(U:! type, T:! type) -> U* {
 // CHECK:STDERR:      ^
-// CHECK:STDERR: fail_rename.carbon:[[@LINE-5]]:6: Previous declaration's corresponding parameter here.
+// CHECK:STDERR: fail_rename.carbon:[[@LINE-5]]:6: previous declaration's corresponding parameter here
 // CHECK:STDERR: fn F(T:! type, U:! type) -> T*;
 // CHECK:STDERR:      ^
 // CHECK:STDERR:
 fn F(U:! type, T:! type) -> U* {
-  // CHECK:STDERR: fail_rename.carbon:[[@LINE+6]]:10: ERROR: 1 argument(s) passed to function expecting 2 argument(s).
+  // CHECK:STDERR: fail_rename.carbon:[[@LINE+6]]:10: error: 1 argument(s) passed to function expecting 2 argument(s).
  // CHECK:STDERR:   return F(T);
  // CHECK:STDERR:          ^~
-  // CHECK:STDERR: fail_rename.carbon:[[@LINE-13]]:1: Calling function declared here.
+  // CHECK:STDERR: fail_rename.carbon:[[@LINE-13]]:1: calling function declared here
  // CHECK:STDERR: fn F(T:! type, U:! type) -> T*;
  // CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  return F(T);