On 12/16/2021 3:40 AM, lsix--- via Gcc-patches wrote:
From: Lancelot SIX <lancelot....@amd.com>
Currently libiberty fails to demangle the name of cloned functions if
the clone-type-identifier contains numbers.
This can be observed with the following example:
$ cat > ex.cc <<EOT
void foo (float *, float *)
__attribute__((target_clones("avx2,avx,sse4.1,default")));
void foo (float *, float *) {}
EOT
$ gcc -c ex.cc
$ nm -C ex.o | grep foo
0000000000000000 i foo(float*, float*)
0000000000000026 t foo(float*, float*) [clone .avx.1]
0000000000000013 t _Z3fooPfS_.avx2.0
0000000000000000 t foo(float*, float*) [clone .default.3]
0000000000000000 W foo(float*, float*) [clone .resolver]
0000000000000039 t _Z3fooPfS_.sse4_1.2
In this example, gcc creates clones for the FOO function, each matching
one of the specified targets. When inspecting the binary, nm (and other
libiberty-based tools, including gdb) fails to demangle the symbol names
if the clone identifier contains numbers.
Form my understanding of the mangling convention[1], clone names are
part of vendor-specific suffixes and do not have rule preventing them
from containing digits.
This commit proposes to fix the demangling. With this commit (ported to
binutils), nm gives the following output:
$ nm-new -C ex.o | grep foo
0000000000000000 i foo(float*, float*)
0000000000000026 t foo(float*, float*) [clone .avx.1]
0000000000000013 t foo(float*, float*) [clone .avx2.0]
0000000000000000 t foo(float*, float*) [clone .default.3]
0000000000000000 W foo(float*, float*) [clone .resolver]
0000000000000039 t foo(float*, float*) [clone .sse4_1.2]
Tested on x86_86-linux with 'make check-libiberty'.
[1] https://itanium-cxx-abi.github.io/cxx-abi/abi.html#mangling
libiberty/ChangeLog:
* cp-demangle.c (d_clone_suffix): Support digits in clone tag
names.
* testsuite/demangle-expected: Check demangling of clone symbols
with digits in name.
Thanks. Installed on the trunk.
jeff
