Fix diagnostic style issues (#7982)

Remove trailing `.`s and leading capitalization from diagnostics, and
separate clauses with `;` rather than `.`, per
https://docs.carbon-lang.dev/toolchain/docs/diagnostics.html#diagnostic-message-style-guide

toolchain/check/eval.cpp

@@ -2549,7 +2549,7 @@ static auto MakeConstantForBuiltinCall(EvalContext& eval_context,
 
       if (index_val.isNegative()) {
         CARBON_DIAGNOSTIC(StringAtIndexNegative, Error,
-                          "index `{0}` is negative.", TypedInt);
+                          "index `{0}` is negative", TypedInt);
         context.emitter().Emit(
             loc_id, StringAtIndexNegative,
             {.type = eval_context.insts().Get(index_id).type_id(),
@@ -2560,7 +2560,7 @@ static auto MakeConstantForBuiltinCall(EvalContext& eval_context,
       if (index_val.getZExtValue() >= string_value.size()) {
         CARBON_DIAGNOSTIC(
             StringAtIndexOutOfBounds, Error,
-            "string index `{0}` is out of bounds; string has length {1}.",
+            "string index `{0}` is out of bounds; string has length {1}",
             TypedInt, size_t);
         context.emitter().Emit(
             loc_id, StringAtIndexOutOfBounds,

toolchain/check/function.cpp

@@ -684,14 +684,14 @@ static auto CheckDefaults(Context& context, SemIR::Function& function)
     // Finished processing this tuple-pattern, emit diagnostics if any.
     if (!state->patterns_missing_defaults.empty()) {
       CARBON_DIAGNOSTIC(RequiredPatternDefaultValueMissing, Error,
-                        "this pattern is missing a required default value.");
+                        "this pattern is missing a required default value");
       CARBON_DIAGNOSTIC_LABEL(RequiredPatternDefaultValueFirstDefault, Info,
                               "all patterns to the right of this first pattern "
                               "with a default value must also specify a "
-                              "default value.");
+                              "default value");
       CARBON_DIAGNOSTIC_LABEL(
           RequiredPatternDefaultValueMissingAdditional, Primary,
-          "this pattern is also missing a required default value.");
+          "this pattern is also missing a required default value");
       auto inst_ref = llvm::ArrayRef(state->patterns_missing_defaults);
       auto builder = context.emitter().Build(
           inst_ref.consume_front(), RequiredPatternDefaultValueMissing);

toolchain/check/testdata/function/declaration/default_values.carbon

@@ -44,12 +44,12 @@ library "[[@TEST_NAME]]";
 
 class C {}
 
-// CHECK:STDERR: fail_required_default_values_missing.carbon:[[@LINE+7]]:35-38: error: this pattern is missing a required default value. [RequiredPatternDefaultValueMissing]
-// CHECK:STDERR: fail_required_default_values_missing.carbon:[[@LINE+6]]:24-27: note: all patterns to the right of this first pattern with a default value must also specify a default value. [RequiredPatternDefaultValueFirstDefault]
+// CHECK:STDERR: fail_required_default_values_missing.carbon:[[@LINE+7]]:35-38: error: this pattern is missing a required default value [RequiredPatternDefaultValueMissing]
+// CHECK:STDERR: fail_required_default_values_missing.carbon:[[@LINE+6]]:24-27: note: all patterns to the right of this first pattern with a default value must also specify a default value [RequiredPatternDefaultValueFirstDefault]
 // CHECK:STDERR:
-// CHECK:STDERR: fail_required_default_values_missing.carbon:[[@LINE+4]]:23-39: error: this pattern is missing a required default value. [RequiredPatternDefaultValueMissing]
-// CHECK:STDERR: fail_required_default_values_missing.carbon:[[@LINE+3]]:53-56: note: this pattern is also missing a required default value. [RequiredPatternDefaultValueMissingAdditional]
-// CHECK:STDERR: fail_required_default_values_missing.carbon:[[@LINE+2]]:12-15: note: all patterns to the right of this first pattern with a default value must also specify a default value. [RequiredPatternDefaultValueFirstDefault]
+// CHECK:STDERR: fail_required_default_values_missing.carbon:[[@LINE+4]]:23-39: error: this pattern is missing a required default value [RequiredPatternDefaultValueMissing]
+// CHECK:STDERR: fail_required_default_values_missing.carbon:[[@LINE+3]]:53-56: note: this pattern is also missing a required default value [RequiredPatternDefaultValueMissingAdditional]
+// CHECK:STDERR: fail_required_default_values_missing.carbon:[[@LINE+2]]:12-15: note: all patterns to the right of this first pattern with a default value must also specify a default value [RequiredPatternDefaultValueFirstDefault]
 // CHECK:STDERR:
 fn Z(v: C, x: C = {}, (y: C = {}, z: C), w: C = {}, k: C);
 
@@ -58,11 +58,11 @@ library "[[@TEST_NAME]]";
 
 class C {}
 
-// CHECK:STDERR: fail_nesting_required_default_values_missing.carbon:[[@LINE+6]]:36-47: error: this pattern is missing a required default value. [RequiredPatternDefaultValueMissing]
-// CHECK:STDERR: fail_nesting_required_default_values_missing.carbon:[[@LINE+5]]:25-28: note: all patterns to the right of this first pattern with a default value must also specify a default value. [RequiredPatternDefaultValueFirstDefault]
+// CHECK:STDERR: fail_nesting_required_default_values_missing.carbon:[[@LINE+6]]:36-47: error: this pattern is missing a required default value [RequiredPatternDefaultValueMissing]
+// CHECK:STDERR: fail_nesting_required_default_values_missing.carbon:[[@LINE+5]]:25-28: note: all patterns to the right of this first pattern with a default value must also specify a default value [RequiredPatternDefaultValueFirstDefault]
 // CHECK:STDERR:
-// CHECK:STDERR: fail_nesting_required_default_values_missing.carbon:[[@LINE+3]]:24-48: error: this pattern is missing a required default value. [RequiredPatternDefaultValueMissing]
-// CHECK:STDERR: fail_nesting_required_default_values_missing.carbon:[[@LINE+2]]:13-16: note: all patterns to the right of this first pattern with a default value must also specify a default value. [RequiredPatternDefaultValueFirstDefault]
+// CHECK:STDERR: fail_nesting_required_default_values_missing.carbon:[[@LINE+3]]:24-48: error: this pattern is missing a required default value [RequiredPatternDefaultValueMissing]
+// CHECK:STDERR: fail_nesting_required_default_values_missing.carbon:[[@LINE+2]]:13-16: note: all patterns to the right of this first pattern with a default value must also specify a default value [RequiredPatternDefaultValueFirstDefault]
 // CHECK:STDERR:
 fn F(a: C, (b: C = {}, (c: C = {}, (d: C, e: C))));
 

toolchain/check/testdata/lambda/lambda.carbon

@@ -238,8 +238,8 @@ fn F() {
 library "[[@TEST_NAME]]";
 
 fn F() {
-  // CHECK:STDERR: fail_default_values.carbon:[[@LINE+3]]:34-39: error: this pattern is missing a required default value. [RequiredPatternDefaultValueMissing]
-  // CHECK:STDERR: fail_default_values.carbon:[[@LINE+2]]:15-20: note: all patterns to the right of this first pattern with a default value must also specify a default value. [RequiredPatternDefaultValueFirstDefault]
+  // CHECK:STDERR: fail_default_values.carbon:[[@LINE+3]]:34-39: error: this pattern is missing a required default value [RequiredPatternDefaultValueMissing]
+  // CHECK:STDERR: fail_default_values.carbon:[[@LINE+2]]:15-20: note: all patterns to the right of this first pattern with a default value must also specify a default value [RequiredPatternDefaultValueFirstDefault]
   // CHECK:STDERR:
   (fn (unused x: i32 = 1, unused y: i32) {});
 }

toolchain/check/testdata/operators/overloaded/string_indexing.carbon

@@ -14,7 +14,7 @@
 library "[[@TEST_NAME]]";
 
 fn TestLiteralNegativeIndex() {
-  // CHECK:STDERR: fail_literal_negative_index.carbon:[[@LINE+2]]:24-33: error: index `-1` is negative. [StringAtIndexNegative]
+  // CHECK:STDERR: fail_literal_negative_index.carbon:[[@LINE+2]]:24-33: error: index `-1` is negative [StringAtIndexNegative]
   // CHECK:STDERR:
   let unused c: char = "Test"[-1];
 }
@@ -23,7 +23,7 @@ fn TestLiteralNegativeIndex() {
 library "[[@TEST_NAME]]";
 
 fn TestLiteralOutOfBounds() {
-  // CHECK:STDERR: fail_literal_out_of_bounds.carbon:[[@LINE+2]]:24-32: error: string index `4` is out of bounds; string has length 4. [StringAtIndexOutOfBounds]
+  // CHECK:STDERR: fail_literal_out_of_bounds.carbon:[[@LINE+2]]:24-32: error: string index `4` is out of bounds; string has length 4 [StringAtIndexOutOfBounds]
   // CHECK:STDERR:
   let unused c: char = "Test"[4];
 }

toolchain/driver/link_driver.cpp

@@ -122,7 +122,7 @@ auto LinkDriver::Link(DriverEnv& driver_env) -> DriverResult {
       auto path_or_error = std::move(prelude_builder).Build();
       if (!path_or_error.ok()) {
         CARBON_DIAGNOSTIC(LinkCarbonPreludeBuildFailed, Error,
-                          "Failed to build Carbon prelude during linking: {0}",
+                          "failed to build Carbon prelude during linking: {0}",
                           std::string);
         driver_env.emitter.Emit(LinkCarbonPreludeBuildFailed,
                                 path_or_error.error().message());

toolchain/lex/lex.cpp

@@ -1502,21 +1502,21 @@ auto Lexer::LexWordAsDollarIntLiteralToken(llvm::StringRef word,
   auto diagnose_invalid_char = [&]() {
     CARBON_DIAGNOSTIC(
         InvalidCharacterInDollarIntLiteral, Error,
-        "Positional parameters can only contain digits after `$`");
+        "positional parameters can only contain digits after `$`");
     emitter_.Emit(word.begin() + 1, InvalidCharacterInDollarIntLiteral);
     return LexTokenWithPayload(TokenKind::Error, word.size(), byte_offset);
   };
 
   if (word.size() < 2) {
     CARBON_DIAGNOSTIC(DollarIntLiteralMissingNumber, Error,
-                      "Expected digits after `$`");
+                      "expected digits after `$`");
     emitter_.Emit(word.begin() + 1, DollarIntLiteralMissingNumber);
     return LexTokenWithPayload(TokenKind::Error, word.size(), byte_offset);
   }
   if (word[1] == '0' && word.size() > 2) {
     CARBON_DIAGNOSTIC(
         DollarIntLiteralLeadingZero, Error,
-        "Leading zeroes are not allowed in positional parameters");
+        "leading zeroes are not allowed in positional parameters");
     emitter_.Emit(word.begin() + 1, DollarIntLiteralLeadingZero);
     return LexTokenWithPayload(TokenKind::Error, word.size(), byte_offset);
   }

toolchain/lex/testdata/dollar_int_literals.carbon

@@ -26,36 +26,36 @@ $999999999999
 // CHECK:STDOUT: - filename: fail_invalid.carbon
 // CHECK:STDOUT:   tokens:
 
-// CHECK:STDERR: fail_invalid.carbon:[[@LINE+2]]:2: error: Expected digits after `$` [DollarIntLiteralMissingNumber]
+// CHECK:STDERR: fail_invalid.carbon:[[@LINE+2]]:2: error: expected digits after `$` [DollarIntLiteralMissingNumber]
 // CHECK:STDERR:
 $
 // CHECK:STDOUT:   - { index:  1, kind:      "Error", line: {{ *}}[[@LINE-1]], column:   1, indent: 1, spelling: "$", has_leading_space: true }
-// CHECK:STDERR: fail_invalid.carbon:[[@LINE+2]]:2: error: Expected digits after `$` [DollarIntLiteralMissingNumber]
+// CHECK:STDERR: fail_invalid.carbon:[[@LINE+2]]:2: error: expected digits after `$` [DollarIntLiteralMissingNumber]
 // CHECK:STDERR:
 $ 1
 // CHECK:STDOUT:   - { index:  2, kind:      "Error", line: {{ *}}[[@LINE-1]], column:   1, indent: 1, spelling: "$", has_leading_space: true }
 // CHECK:STDOUT:   - { index:  3, kind: "IntLiteral", line: {{ *}}[[@LINE-2]], column:   3, indent: 1, spelling: "1", value: "1", has_leading_space: true }
-// CHECK:STDERR: fail_invalid.carbon:[[@LINE+2]]:2: error: Positional parameters can only contain digits after `$` [InvalidCharacterInDollarIntLiteral]
+// CHECK:STDERR: fail_invalid.carbon:[[@LINE+2]]:2: error: positional parameters can only contain digits after `$` [InvalidCharacterInDollarIntLiteral]
 // CHECK:STDERR:
 $foo
 // CHECK:STDOUT:   - { index:  4, kind:      "Error", line: {{ *}}[[@LINE-1]], column:   1, indent: 1, spelling: "$foo", has_leading_space: true }
-// CHECK:STDERR: fail_invalid.carbon:[[@LINE+2]]:2: error: Positional parameters can only contain digits after `$` [InvalidCharacterInDollarIntLiteral]
+// CHECK:STDERR: fail_invalid.carbon:[[@LINE+2]]:2: error: positional parameters can only contain digits after `$` [InvalidCharacterInDollarIntLiteral]
 // CHECK:STDERR:
 $1a32
 // CHECK:STDOUT:   - { index:  5, kind:      "Error", line: {{ *}}[[@LINE-1]], column:   1, indent: 1, spelling: "$1a32", has_leading_space: true }
-// CHECK:STDERR: fail_invalid.carbon:[[@LINE+2]]:2: error: Leading zeroes are not allowed in positional parameters [DollarIntLiteralLeadingZero]
+// CHECK:STDERR: fail_invalid.carbon:[[@LINE+2]]:2: error: leading zeroes are not allowed in positional parameters [DollarIntLiteralLeadingZero]
 // CHECK:STDERR:
 $00
 // CHECK:STDOUT:   - { index:  6, kind:      "Error", line: {{ *}}[[@LINE-1]], column:   1, indent: 1, spelling: "$00", has_leading_space: true }
-// CHECK:STDERR: fail_invalid.carbon:[[@LINE+2]]:2: error: Leading zeroes are not allowed in positional parameters [DollarIntLiteralLeadingZero]
+// CHECK:STDERR: fail_invalid.carbon:[[@LINE+2]]:2: error: leading zeroes are not allowed in positional parameters [DollarIntLiteralLeadingZero]
 // CHECK:STDERR:
 $025321
 // CHECK:STDOUT:   - { index:  7, kind:      "Error", line: {{ *}}[[@LINE-1]], column:   1, indent: 1, spelling: "$025321", has_leading_space: true }
-// CHECK:STDERR: fail_invalid.carbon:[[@LINE+2]]:2: error: Leading zeroes are not allowed in positional parameters [DollarIntLiteralLeadingZero]
+// CHECK:STDERR: fail_invalid.carbon:[[@LINE+2]]:2: error: leading zeroes are not allowed in positional parameters [DollarIntLiteralLeadingZero]
 // CHECK:STDERR:
 $0x12
 // CHECK:STDOUT:   - { index:  8, kind:      "Error", line: {{ *}}[[@LINE-1]], column:   1, indent: 1, spelling: "$0x12", has_leading_space: true }
-// CHECK:STDERR: fail_invalid.carbon:[[@LINE+2]]:2: error: Leading zeroes are not allowed in positional parameters [DollarIntLiteralLeadingZero]
+// CHECK:STDERR: fail_invalid.carbon:[[@LINE+2]]:2: error: leading zeroes are not allowed in positional parameters [DollarIntLiteralLeadingZero]
 // CHECK:STDERR:
 $0b1100
 // CHECK:STDOUT:   - { index:  9, kind:      "Error", line: {{ *}}[[@LINE-1]], column:   1, indent: 1, spelling: "$0b1100", has_leading_space: true }

toolchain/parse/handle_binding_pattern.cpp

@@ -133,7 +133,7 @@ auto HandleBindingPattern(Context& context) -> void {
     if (state.in_field_shorthand_pattern) {
       CARBON_DIAGNOSTIC(
           AnonymousBindingInStructPattern, Error,
-          "Anonymous binding found in struct pattern. Use `.field = "
+          "anonymous binding found in struct pattern; use `.field = "
           "_: field_type` or `unused field: field_type`");
       context.emitter().Emit(*context.position(),
                              AnonymousBindingInStructPattern);

toolchain/parse/handle_pattern_list.cpp

@@ -268,7 +268,7 @@ static auto HandlePatternList(Context& context, NodeKind node_kind,
   if (state.in_field_shorthand_pattern) {
     if (node_kind == NodeKind::TuplePatternStart) {
       CARBON_DIAGNOSTIC(NestedTuplePatternInStructPatternShortField, Error,
-                        "Tuple pattern in shorthand struct pattern field. Use "
+                        "tuple pattern in shorthand struct pattern field; use "
                         "`.field = (...)` instead");
       context.emitter().Emit(*context.position(),
                              NestedTuplePatternInStructPatternShortField);
@@ -276,7 +276,7 @@ static auto HandlePatternList(Context& context, NodeKind node_kind,
       context.ReturnErrorOnState();
     } else if (node_kind == NodeKind::StructPatternStart) {
       CARBON_DIAGNOSTIC(NestedStructPatternStructPatternShortField, Error,
-                        "Struct pattern in shorthand struct pattern field. Use "
+                        "struct pattern in shorthand struct pattern field; use "
                         "`.field = {{...}` instead");
       context.emitter().Emit(*context.position(),
                              NestedStructPatternStructPatternShortField);

toolchain/parse/testdata/struct/struct_pattern.carbon

@@ -206,31 +206,31 @@ let {"foo" = , .x = x:()} = {};
 
 // --- fail_struct_pattern_nested_tuple_pattern.carbon
 
-// CHECK:STDERR: fail_struct_pattern_nested_tuple_pattern.carbon:[[@LINE+2]]:14: error: Tuple pattern in shorthand struct pattern field. Use `.field = (...)` instead [NestedTuplePatternInStructPatternShortField]
+// CHECK:STDERR: fail_struct_pattern_nested_tuple_pattern.carbon:[[@LINE+2]]:14: error: tuple pattern in shorthand struct pattern field; use `.field = (...)` instead [NestedTuplePatternInStructPatternShortField]
 // CHECK:STDERR:
 var {x: i32, (y: i32, z: i32)} = {};
 
 // --- fail_struct_pattern_nested_var_tuple_pattern.carbon
 
-// CHECK:STDERR: fail_struct_pattern_nested_var_tuple_pattern.carbon:[[@LINE+2]]:18: error: Tuple pattern in shorthand struct pattern field. Use `.field = (...)` instead [NestedTuplePatternInStructPatternShortField]
+// CHECK:STDERR: fail_struct_pattern_nested_var_tuple_pattern.carbon:[[@LINE+2]]:18: error: tuple pattern in shorthand struct pattern field; use `.field = (...)` instead [NestedTuplePatternInStructPatternShortField]
 // CHECK:STDERR:
 let {x: i32, var (y: i32, z: i32)} = {};
 
 // --- fail_struct_pattern_nested_struct_pattern.carbon
 
-// CHECK:STDERR: fail_struct_pattern_nested_struct_pattern.carbon:[[@LINE+2]]:13: error: Struct pattern in shorthand struct pattern field. Use `.field = {...}` instead [NestedStructPatternStructPatternShortField]
+// CHECK:STDERR: fail_struct_pattern_nested_struct_pattern.carbon:[[@LINE+2]]:13: error: struct pattern in shorthand struct pattern field; use `.field = {...}` instead [NestedStructPatternStructPatternShortField]
 // CHECK:STDERR:
 let{x: i32, {y: i32, z: i32}} = {};
 
 // --- fail_struct_pattern_unused_shorthand.carbon
 
-// CHECK:STDERR: fail_struct_pattern_unused_shorthand.carbon:[[@LINE+2]]:7: error: Anonymous binding found in struct pattern. Use `.field = _: field_type` or `unused field: field_type` [AnonymousBindingInStructPattern]
+// CHECK:STDERR: fail_struct_pattern_unused_shorthand.carbon:[[@LINE+2]]:7: error: anonymous binding found in struct pattern; use `.field = _: field_type` or `unused field: field_type` [AnonymousBindingInStructPattern]
 // CHECK:STDERR:
 var {_: i32} = {};
-// CHECK:STDERR: fail_struct_pattern_unused_shorthand.carbon:[[@LINE+2]]:11: error: Anonymous binding found in struct pattern. Use `.field = _: field_type` or `unused field: field_type` [AnonymousBindingInStructPattern]
+// CHECK:STDERR: fail_struct_pattern_unused_shorthand.carbon:[[@LINE+2]]:11: error: anonymous binding found in struct pattern; use `.field = _: field_type` or `unused field: field_type` [AnonymousBindingInStructPattern]
 // CHECK:STDERR:
 let {ref _: i32} = {};
-// CHECK:STDERR: fail_struct_pattern_unused_shorthand.carbon:[[@LINE+2]]:11: error: Anonymous binding found in struct pattern. Use `.field = _: field_type` or `unused field: field_type` [AnonymousBindingInStructPattern]
+// CHECK:STDERR: fail_struct_pattern_unused_shorthand.carbon:[[@LINE+2]]:11: error: anonymous binding found in struct pattern; use `.field = _: field_type` or `unused field: field_type` [AnonymousBindingInStructPattern]
 // CHECK:STDERR:
 let {var _: i32} = {};