mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-10-01 14:25:53 +01:00
David BlaikieandDana Jansens
a179bd461b
This adds just enough debug info for i32/int parameters and return
values, with a path forward for adding DWARF type metadata for other
types.
As it happens, return type information is carried separately from
parameter information:
* Return type information is carried in the `type` of the `DISubprogram`
(as a `DISubroutineType` - which does carry parameter type information
as well, but that's unused when the DWARF is emitted by LLVM)
* Parameter information is carried by `DILocalVariable`s with a non-zero
`arg` value (representing the order of function parameters)
In the absence of locations for the parameters (future work), nothing
would usually keep the `DILocalVariable` live/reachable when emitting
DWARF - so for cases where this can happen (for clang, this happens in
optimized builds where all references to the parameter variable might be
optimized away) the variables can be "retained" in a list on the
`DISubprogram` - achieved by passing `AlwaysPreserve` parameter to
`createParameterVariable` (adds them to a list, then that list gets
attached to the `DISubprogram` when it's finalized later)
For now, any unsupported types are emitted as `void*` (except void
return, which is implemented as void) as a placeholder.
Given this example:
```
import Core library "io";
class MyClass {
}
fn Unsupported(v: MyClass) {
}
fn Ret() -> i32 {
return 42;
}
fn Arg(x: i32) {
Core.Print(x);
}
fn Run() {
}
```
this is the resulting DWARF:
```
DW_TAG_compile_unit
DW_AT_name ("test.carbon")
DW_TAG_subprogram
DW_AT_name ("Unsupported")
DW_TAG_formal_parameter
DW_AT_type (0x00000066 "void *")
DW_TAG_subprogram
DW_AT_name ("Ret")
DW_AT_type (0x00000062 "int")
DW_TAG_subprogram
DW_AT_name ("Arg")
DW_TAG_formal_parameter
DW_AT_type (0x00000062 "int")
DW_TAG_subprogram
DW_AT_name ("Run")
DW_TAG_base_type
DW_AT_name ("int")
DW_TAG_pointer_type
```
And the debugger:
```
(gdb) p Ret()
$1 = 42
(gdb) p Arg(4)
4
$2 = void
```
I'm not sure if there's a way this logic should be merged with the logic
for making the `llvm::Function` type (which the `DISubroutineType`
building code was inspired by/copied from) - since they're done at
different times/places, I don't think there's an easy way to do it in
one pass, but maybe the code can be shared (even if it's run twice) in
some generic `SemIR::Function` type walker.
---------
Co-authored-by: Dana Jansens <danakj@orodu.net>
109 lines
5.1 KiB
Plaintext
109 lines
5.1 KiB
Plaintext
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
|
|
// Exceptions. See /LICENSE for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
// INCLUDE-FILE: toolchain/testing/testdata/min_prelude/full.carbon
|
|
//
|
|
// AUTOUPDATE
|
|
// TIP: To test this file alone, run:
|
|
// TIP: bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/lower/testdata/function/generic/call_different_impls.carbon
|
|
// TIP: To dump output, run:
|
|
// TIP: bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/lower/testdata/function/generic/call_different_impls.carbon
|
|
|
|
import Core library "io";
|
|
|
|
interface I {
|
|
fn F();
|
|
}
|
|
class X {}
|
|
impl X as I {
|
|
fn F() { Core.Print(1); }
|
|
}
|
|
class Y {}
|
|
impl Y as I {
|
|
fn F() { Core.Print(2); }
|
|
}
|
|
|
|
// Cannot coalesce the lowering for G specifics, as they call different functions.
|
|
// Check different functions are still emitted when trying to deduplicate emitted definitons.
|
|
fn G(T:! I) { T.F(); }
|
|
|
|
fn Run() {
|
|
G(X);
|
|
G(Y);
|
|
}
|
|
|
|
// CHECK:STDOUT: ; ModuleID = 'call_different_impls.carbon'
|
|
// CHECK:STDOUT: source_filename = "call_different_impls.carbon"
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: @printf.int.format = private unnamed_addr constant [4 x i8] c"%d\0A\00", align 1
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: ; Function Attrs: nounwind
|
|
// CHECK:STDOUT: define void @"_CF.X.Main:I.Main"() #0 !dbg !4 {
|
|
// CHECK:STDOUT: entry:
|
|
// CHECK:STDOUT: %Print.call = call i32 (ptr, ...) @printf(ptr @printf.int.format, i32 1), !dbg !7
|
|
// CHECK:STDOUT: ret void, !dbg !8
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: ; Function Attrs: nounwind
|
|
// CHECK:STDOUT: define void @"_CF.Y.Main:I.Main"() #0 !dbg !9 {
|
|
// CHECK:STDOUT: entry:
|
|
// CHECK:STDOUT: %Print.call = call i32 (ptr, ...) @printf(ptr @printf.int.format, i32 2), !dbg !10
|
|
// CHECK:STDOUT: ret void, !dbg !11
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: ; Function Attrs: nounwind
|
|
// CHECK:STDOUT: define void @main() #0 !dbg !12 {
|
|
// CHECK:STDOUT: entry:
|
|
// CHECK:STDOUT: call void @_CG.Main.4d3c36eeac175c1f(), !dbg !13
|
|
// CHECK:STDOUT: call void @_CG.Main.7abe23e63361d139(), !dbg !14
|
|
// CHECK:STDOUT: ret void, !dbg !15
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: declare i32 @printf(ptr, ...)
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: ; Function Attrs: nounwind
|
|
// CHECK:STDOUT: define linkonce_odr void @_CG.Main.4d3c36eeac175c1f() #0 !dbg !16 {
|
|
// CHECK:STDOUT: entry:
|
|
// CHECK:STDOUT: call void @"_CF.X.Main:I.Main"(), !dbg !17
|
|
// CHECK:STDOUT: ret void, !dbg !18
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: ; Function Attrs: nounwind
|
|
// CHECK:STDOUT: define linkonce_odr void @_CG.Main.7abe23e63361d139() #0 !dbg !19 {
|
|
// CHECK:STDOUT: entry:
|
|
// CHECK:STDOUT: call void @"_CF.Y.Main:I.Main"(), !dbg !20
|
|
// CHECK:STDOUT: ret void, !dbg !21
|
|
// CHECK:STDOUT: }
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: ; uselistorder directives
|
|
// CHECK:STDOUT: uselistorder ptr @printf, { 1, 0 }
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: attributes #0 = { nounwind }
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
|
|
// CHECK:STDOUT: !llvm.dbg.cu = !{!2}
|
|
// CHECK:STDOUT:
|
|
// CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
|
|
// CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
|
|
// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
|
|
// CHECK:STDOUT: !3 = !DIFile(filename: "call_different_impls.carbon", directory: "")
|
|
// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "F", linkageName: "_CF.X.Main:I.Main", scope: null, file: !3, line: 20, type: !5, spFlags: DISPFlagDefinition, unit: !2)
|
|
// CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
|
|
// CHECK:STDOUT: !6 = !{null}
|
|
// CHECK:STDOUT: !7 = !DILocation(line: 20, column: 12, scope: !4)
|
|
// CHECK:STDOUT: !8 = !DILocation(line: 20, column: 3, scope: !4)
|
|
// CHECK:STDOUT: !9 = distinct !DISubprogram(name: "F", linkageName: "_CF.Y.Main:I.Main", scope: null, file: !3, line: 24, type: !5, spFlags: DISPFlagDefinition, unit: !2)
|
|
// CHECK:STDOUT: !10 = !DILocation(line: 24, column: 12, scope: !9)
|
|
// CHECK:STDOUT: !11 = !DILocation(line: 24, column: 3, scope: !9)
|
|
// CHECK:STDOUT: !12 = distinct !DISubprogram(name: "Run", linkageName: "main", scope: null, file: !3, line: 31, type: !5, spFlags: DISPFlagDefinition, unit: !2)
|
|
// CHECK:STDOUT: !13 = !DILocation(line: 32, column: 3, scope: !12)
|
|
// CHECK:STDOUT: !14 = !DILocation(line: 33, column: 3, scope: !12)
|
|
// CHECK:STDOUT: !15 = !DILocation(line: 31, column: 1, scope: !12)
|
|
// CHECK:STDOUT: !16 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.4d3c36eeac175c1f", scope: null, file: !3, line: 29, type: !5, spFlags: DISPFlagDefinition, unit: !2)
|
|
// CHECK:STDOUT: !17 = !DILocation(line: 29, column: 15, scope: !16)
|
|
// CHECK:STDOUT: !18 = !DILocation(line: 29, column: 1, scope: !16)
|
|
// CHECK:STDOUT: !19 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.7abe23e63361d139", scope: null, file: !3, line: 29, type: !5, spFlags: DISPFlagDefinition, unit: !2)
|
|
// CHECK:STDOUT: !20 = !DILocation(line: 29, column: 15, scope: !19)
|
|
// CHECK:STDOUT: !21 = !DILocation(line: 29, column: 1, scope: !19)
|