[AIX] Clang's library integration support for 128-bit long double is incomplete on AIX.

[anjankgk]

Summary

Emit the unsupported option error until the Clang's library integration support for 128-bit long double is available for AIX.

[anjankgk]

Thanks for reviewing! Can someone with commit access help commit this pls?
Thanks in advance!

[cebowleratibm]

clang/lib/Driver/ToolChains/Clang.cpp

4845

It's not that AIX doesn't support 128-bit long double. The xlc compiler has -qldbl128, which links in different libraries for 128-bit. The XL compilers use -lc128 and -lC128 so there are binary compatibility concerns that need to be investigated.

I suggest this comment be updated accordingly.

[hubert.reinterpretcast]

clang/lib/Driver/ToolChains/Clang.cpp

4845

Note also to update the commit message.

[anjankgk]

Updated the comment

[cebowleratibm]

LGTM.

[anjankgk]

@cebowleratibm @Whitney Could either of you pls commit this?
Thanks!

[xgupta]

@anjankgk You need to provide your identity for commit in "your name <your email>" form.
see https://llvm.org/docs/DeveloperPolicy.html#obtaining-commit-access

Prior to obtaining commit access, it is common practice to request that someone with commit access commits on your behalf. When doing so, please provide the name and email address you would like to use in the Author property of the commit.

[anjankgk]

In D106074#2893249, @xgupta wrote:

@anjankgk You need to provide your identity for commit in "your name <your email>" form.
see https://llvm.org/docs/DeveloperPolicy.html#obtaining-commit-access

Prior to obtaining commit access, it is common practice to request that someone with commit access commits on your behalf. When doing so, please provide the name and email address you would like to use in the Author property of the commit.

Here's the info:
Anjan Kumar Guttahalli Krishna <[e-mail]>

Thank you!

[anjankgk]

Since Whitny and Chris are busy, I have requested Shimin to commit this in.
Thanks Shimin!

clang/lib/Driver/ToolChains/Clang.cpp

if (!Triple.isOSAIX())
       D.Diag(diag::err_drv_unsupported_opt_for_target)
           << A->getSpelling() << RawTriple.str();
     if (A->getOption().getID() == options::OPT_mabi_EQ_vec_extabi)
       CmdArgs.push_back("-mabi=vec-extabi");
     else
       CmdArgs.push_back("-mabi=vec-default");
   }
 
+  if (Arg *A = Args.getLastArg(options::OPT_mlong_double_128)) {
+    // AIX doesn't support 128-bit long double yet.
+    if (Triple.isOSAIX())
+      D.Diag(diag::err_drv_unsupported_opt_for_target)
+          << A->getSpelling() << RawTriple.str();
+  }
+
   if (Arg *A = Args.getLastArg(options::OPT_Wframe_larger_than_EQ)) {
     StringRef v = A->getValue();
     // FIXME: Validate the argument here so we don't produce meaningless errors
     // about -fwarn-stack-size=.
     if (v.empty())
       D.Diag(diag::err_drv_missing_argument) << A->getSpelling() << 1;
     else
       CmdArgs.push_back(Args.MakeArgString("-fwarn-stack-size=" + v));

clang/test/Driver/unsupported-option.c

 
 // RUN: not %clang -fprofile-generate --target=powerpc-ibm-aix %s 2>&1 | \
 // RUN: FileCheck %s --check-prefix=AIX-PROFILE-LTO
 // AIX-PROFILE-LTO: error: invalid argument '-fprofile-generate' only allowed with '-flto'
 
 // RUN: not %clang -fprofile-generate -flto=thin --target=powerpc64-ibm-aix %s 2>&1 | \
 // RUN: FileCheck %s --check-prefix=AIX-PROFILE-THINLTO
 // AIX-PROFILE-THINLTO: error: invalid argument '-fprofile-generate' only allowed with '-flto'
+
+// RUN: not %clang --target=powerpc-ibm-aix %s -mlong-double-128 2>&1 | \
+// RUN: FileCheck %s --check-prefix=AIX-LONGDOUBLE128-ERR
+// AIX-LONGDOUBLE128-ERR: error: unsupported option '-mlong-double-128' for target 'powerpc-ibm-aix'
+
+// RUN: not %clang --target=powerpc64-ibm-aix %s -mlong-double-128 2>&1 | \
+// RUN: FileCheck %s --check-prefix=AIX64-LONGDOUBLE128-ERR
+// AIX64-LONGDOUBLE128-ERR: error: unsupported option '-mlong-double-128' for target 'powerpc64-ibm-aix'