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[Driver] Let -fno-integrated-as -gdwarf-5 use -fdwarf-directory-asm 

While GNU as only allows the directory form of the .file directive for DWARF v5,
the integrated assembler prefers the directory form on all DWARF versions
(-fdwarf-directory-asm).

We currently set CC1 -fno-dwarf-directory-asm for -fno-integrated-as -gdwarf-5
which may cause the directory entry 0 and the filename entry 0 to be incorrect
(see D105662 and the example below). This patch makes -fno-integrated-as -gdwarf-5 use
-fdwarf-directory-asm as well.

```
cd /tmp/c

before
% clang -g -gdwarf-5 -fno-integrated-as e/a.c -S -o - | grep '\.file.*0'
        .file   0 "/tmp/c/e/a.c" md5 0x97e31cee64b4e58a4af8787512d735b6
% clang -g -gdwarf-5 -fno-integrated-as e/a.c -c
% llvm-dwarfdump a.o | grep include_directories
include_directories[  0] = "/tmp/c/e"

after
% clang -g -gdwarf-5 -fno-integrated-as e/a.c -S -o - | grep '\.file.*0'
        .file   0 "/tmp/c" "e/a.c" md5 0x97e31cee64b4e58a4af8787512d735b6
% clang -g -gdwarf-5 -fno-integrated-as e/a.c -c
% llvm-dwarfdump a.o | grep include_directories
include_directories[  0] = "/tmp/c"
```

Reviewed By: #debug-info, dblaikie, osandov

Differential Revision: https://reviews.llvm.org/D105835
This commit is contained in:
Fangrui Song 2021-07-12 15:46:20 -07:00
parent f2832c2295
commit 51fc742ce7
2 changed files with 19 additions and 11 deletions
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19
clang/lib/Driver/ToolChains/Clang.cpp
View File

@ -490,14 +490,6 @@ static bool ShouldEnableAutolink(const ArgList &Args, const ToolChain &TC,
Default);
}
static bool ShouldDisableDwarfDirectory(const ArgList &Args,
const ToolChain &TC) {
bool UseDwarfDirectory =
Args.hasFlag(options::OPT_fdwarf_directory_asm,
options::OPT_fno_dwarf_directory_asm, TC.useIntegratedAs());
return !UseDwarfDirectory;
}
// Convert an arg of the form "-gN" or "-ggdbN" or one of their aliases
// to the corresponding DebugInfoKind.
static codegenoptions::DebugInfoKind DebugLevelToInfoKind(const Arg &A) {
@ -4175,6 +4167,14 @@ static void renderDebugOptions(const ToolChain &TC, const Driver &D,
}
}
// To avoid join/split of directory+filename, the integrated assembler prefers
// the directory form of .file on all DWARF versions. GNU as doesn't allow the
// form before DWARF v5.
if (!Args.hasFlag(options::OPT_fdwarf_directory_asm,
options::OPT_fno_dwarf_directory_asm,
TC.useIntegratedAs() || EffectiveDWARFVersion >= 5))
CmdArgs.push_back("-fno-dwarf-directory-asm");
// Decide how to render forward declarations of template instantiations.
// SCE wants full descriptions, others just get them in the name.
if (DebuggerTuning == llvm::DebuggerKind::SCE)
@ -5506,9 +5506,6 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
CmdArgs.push_back("-fno-gnu-keywords");
}
if (ShouldDisableDwarfDirectory(Args, TC))
CmdArgs.push_back("-fno-dwarf-directory-asm");
if (!ShouldEnableAutolink(Args, TC, JA))
CmdArgs.push_back("-fno-autolink");

11
clang/test/Driver/debug-options.c
View File

@ -424,3 +424,14 @@
// GDWARF64_VER: error: invalid argument '-gdwarf64' only allowed with 'DWARFv3 or greater'
// GDWARF64_32ARCH: error: invalid argument '-gdwarf64' only allowed with '64 bit architecture'
// GDWARF64_ELF: error: invalid argument '-gdwarf64' only allowed with 'ELF platforms'
/// Default to -fno-dwarf-directory-asm for -fno-integrated-as before DWARF v5.
// RUN: %clang -### -target x86_64 -c -gdwarf-2 %s 2>&1 | FileCheck --check-prefix=DIRECTORY %s
// RUN: %clang -### -target x86_64 -c -gdwarf-5 %s 2>&1 | FileCheck --check-prefix=DIRECTORY %s
// RUN: %clang -### -target x86_64 -c -gdwarf-4 -fno-integrated-as %s 2>&1 | FileCheck --check-prefix=NODIRECTORY %s
// RUN: %clang -### -target x86_64 -c -gdwarf-5 -fno-integrated-as %s 2>&1 | FileCheck --check-prefix=DIRECTORY %s
// RUN: %clang -### -target x86_64 -c -gdwarf-4 -fno-dwarf-directory-asm %s 2>&1 | FileCheck --check-prefix=NODIRECTORY %s
// DIRECTORY-NOT: "-fno-dwarf-directory-asm"
// NODIRECTORY: "-fno-dwarf-directory-asm"