Apply fix for clang crashing on invalid -Wa,-march= values

Merge commit df08b2fe8b35 from llvm git (by Dimitry Andric):

  [AArch64] Avoid crashing on invalid -Wa,-march= values

  As reported in https://bugs.freebsd.org/260078, the gnutls Makefiles
  pass -Wa,-march=all to compile a number of assembly files. Clang does
  not support this -march value, but because of a mistake in handling
  the arguments, an unitialized Arg pointer is dereferenced, which can
  cause a segfault.

  Work around this by adding a check if the local WaMArch variable is
  initialized, and if so, using its value in the diagnostic message.

  Reviewed By: tschuett

  Differential Revision: https://reviews.llvm.org/D114677

PR:		260078
Reported by:	bz
MFC after:	3 days
This commit is contained in:
Dimitry Andric 2021-12-05 18:54:13 +01:00
parent b25ba58adc
commit a9cd5c30d6

View File

@ -191,7 +191,7 @@ void aarch64::getAArch64TargetFeatures(const Driver &D,
bool success = true;
// Enable NEON by default.
Features.push_back("+neon");
llvm::StringRef WaMArch = "";
llvm::StringRef WaMArch;
if (ForAS)
for (const auto *A :
Args.filtered(options::OPT_Wa_COMMA, options::OPT_Xassembler))
@ -201,7 +201,7 @@ void aarch64::getAArch64TargetFeatures(const Driver &D,
// Call getAArch64ArchFeaturesFromMarch only if "-Wa,-march=" or
// "-Xassembler -march" is detected. Otherwise it may return false
// and causes Clang to error out.
if (WaMArch.size())
if (!WaMArch.empty())
success = getAArch64ArchFeaturesFromMarch(D, WaMArch, Args, Features);
else if ((A = Args.getLastArg(options::OPT_march_EQ)))
success = getAArch64ArchFeaturesFromMarch(D, A->getValue(), Args, Features);
@ -222,8 +222,15 @@ void aarch64::getAArch64TargetFeatures(const Driver &D,
success = getAArch64MicroArchFeaturesFromMcpu(
D, getAArch64TargetCPU(Args, Triple, A), Args, Features);
if (!success)
D.Diag(diag::err_drv_clang_unsupported) << A->getAsString(Args);
if (!success) {
auto Diag = D.Diag(diag::err_drv_clang_unsupported);
// If "-Wa,-march=" is used, 'WaMArch' will contain the argument's value,
// while 'A' is uninitialized. Only dereference 'A' in the other case.
if (!WaMArch.empty())
Diag << "-march=" + WaMArch.str();
else
Diag << A->getAsString(Args);
}
if (Args.getLastArg(options::OPT_mgeneral_regs_only)) {
Features.push_back("-fp-armv8");