[z/OS][pg] Throw error when using -pg on z/OS

[francii]

Summary

Throw an error when trying to compile with -pg on z/OS,
as the platform does not support gprof.

[SeanP]

clang/include/clang/Basic/DiagnosticDriverKinds.td

241 ↗

(On Diff #474406)

Rather than saying "on z/OS" you should say "by the target '%1'" and pass in the triple. There must be the equivalent message already. If not rename the message too (eg. err_option_unsupported_target).

[francii]

Use existing error

[francii]

This comment was removed by francii.

clang/test/Driver/zos-profiling-error.c

8

I will add the missing e in error: momentarily.

[francii]

Fix test case

[MaskRay]

clang/test/Driver/zos-profiling-error.c

4

Prefer --target= for new tests. Consider reusing clang/test/Driver/p.c and adding the code to clang/lib/Driver/ToolChains/Clang.cpp instead

[MaskRay]

clang/test/Driver/zos-profiling-error.c

4

Sorry, the code is not needed since clang/lib/Driver/ToolChains/Clang.cpp rejects -p for most OSes now.

[francii]

Remove -p references

[MaskRay]

See clang/lib/Driver/ToolChains/Clang.cpp:6191 if (TC.SupportsProfiling()) {. You can define SupportsProfiling as false for zos. It's a -Wunused-command-line-argument warning, not an error, but may be good enough.

-p has already been handled, so the subject Throw Error When Using -p or -pg on z/OS should be updated. Note that we don't capitalize every word, just the first word.

[MaskRay]

Most targets reject -p now. It's unnecessary to have another z/OS specific diagnostic. So this patch can be abandoned.

% fclang -p a.cc
clang-16: error: unsupported option '-p' for target 'x86_64-unknown-linux-gnu'

[hubert.reinterpretcast]

In D137756#4018666, @MaskRay wrote:

Most targets reject -p now. It's unnecessary to have another z/OS specific diagnostic. So this patch can be abandoned.

% fclang -p a.cc
clang-16: error: unsupported option '-p' for target 'x86_64-unknown-linux-gnu'

@francii, if you can confirm:

1. that there is a test that covers that error for z/OS, and
2. any comments in the code associated with generating the error above do not misrepresent the rationale for why -p is unsupported on z/OS,

then I'm good with leaving it at that.

Otherwise, we should make this into an NFC patch that adds the test/adjusts the comments.

[francii]

In D137756#4023531, @hubert.reinterpretcast wrote:

In D137756#4018666, @MaskRay wrote:

Most targets reject -p now. It's unnecessary to have another z/OS specific diagnostic. So this patch can be abandoned.

% fclang -p a.cc
clang-16: error: unsupported option '-p' for target 'x86_64-unknown-linux-gnu'

@francii, if you can confirm:

1. that there is a test that covers that error for z/OS, and
2. any comments in the code associated with generating the error above do not misrepresent the rationale for why -p is unsupported on z/OS,

then I'm good with leaving it at that.

Otherwise, we should make this into an NFC patch that adds the test/adjusts the comments.

1. There is no test for z/OS. clang/test/Driver/p.c exists but does not contain a z/OS test case.
2. There are no comments explaining why -p is unsupported. Removing support for -p came with D138255, which simply states that -p is only supported on AIX and OpenBSD.

[francii]

clang/lib/Driver/ToolChains/ZOS.cpp

22 ↗

(On Diff #480130)

@MaskRay we still need -pg to error-out on z/OS. Should the check for this be moved to clang/lib/Driver/ToolChains/Clang.cpp instead?

[MaskRay]

clang/lib/Driver/ToolChains/ZOS.cpp

22 ↗

(On Diff #480130)

Sounds reasonable to move -pg diagnostic beside -p.

[francii]

Move check to Clang.cpp

[MaskRay]

Thanks!

clang/test/Driver/zos-profiling-error.c

2

Delete this comment. It does not help reading the test.

4

Use --target=

-target is legacy.

[francii]

Rebase and test case update

[francii]

Update test case verbosity

clang/lib/Driver/ToolChains/Clang.cpp

   if (Arg *A = Args.getLastArgNoClaim(options::OPT_p)) {
     if (TC.getTriple().isOSAIX()) {
       CmdArgs.push_back("-pg");
     } else if (!TC.getTriple().isOSOpenBSD()) {
       D.Diag(diag::err_drv_unsupported_opt_for_target)
           << A->getAsString(Args) << TripleStr;
     }
   }
+  if (Arg *A = Args.getLastArgNoClaim(options::OPT_pg)) {
+    if (TC.getTriple().isOSzOS()) {
+      D.Diag(diag::err_drv_unsupported_opt_for_target)
+          << A->getAsString(Args) << TripleStr;
+    }
+  }
 
   if (Args.getLastArg(options::OPT_fapple_kext) ||
       (Args.hasArg(options::OPT_mkernel) && types::isCXX(InputType)))
     CmdArgs.push_back("-fapple-kext");
 
   Args.AddLastArg(CmdArgs, options::OPT_altivec_src_compat);
   Args.AddLastArg(CmdArgs, options::OPT_flax_vector_conversions_EQ);
   Args.AddLastArg(CmdArgs, options::OPT_fobjc_sender_dependent_dispatch);

clang/test/Driver/zos-profiling-error.c

+// RUN: %clang 2>&1 -### --target=s390x-none-zos -pg -S %s | FileCheck -check-prefix=FAIL-PG-NAME %s
+// FAIL-PG-NAME: error: unsupported option '-pg' for target 's390x-none-zos'