[Clang][AIX][p] Manually Claim -p in front end

The current implementation of `-p` does not claim the argument once it
is passed. Since it pushes `-pg` directly, it is only ever referred to
again when linking. As a result, when compiling with `-S`, the compiler
warns that `-p` goes unused even though that is not the case.

With this patch, if both `-p` and `-pg` are passed, the argument that is
passed second will take precedence. `-p` will still throw an error on
unsupported platforms, regardless of precedence.

This revision includes a test case, which has been placed in
`clang/test/Driver/zos-profiling-error.c`. As a result,
`zos-profiling-error.c` has been renamed to `ibm-profiling.c`. This
revision also passes `clang/test/Driver/aix-ld.c`.

Differential Revision: https://reviews.llvm.org/D145021

clang/lib/Driver/ToolChains/AIX.cpp

@@ -164,14 +164,14 @@ void aix::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   }
 
   auto getCrt0Basename = [&Args, IsArch32Bit] {
-    // Enable gprofiling when "-pg" is specified.
-    if (Args.hasArg(options::OPT_pg))
-      return IsArch32Bit ? "gcrt0.o" : "gcrt0_64.o";
-    // Enable profiling when "-p" is specified.
-    else if (Args.hasArg(options::OPT_p))
+    if (Arg *A = Args.getLastArgNoClaim(options::OPT_p, options::OPT_pg)) {
+      // Enable gprofiling when "-pg" is specified.
+      if (A->getOption().matches(options::OPT_pg))
+        return IsArch32Bit ? "gcrt0.o" : "gcrt0_64.o";
+      // Enable profiling when "-p" is specified.
       return IsArch32Bit ? "mcrt0.o" : "mcrt0_64.o";
-    else
-      return IsArch32Bit ? "crt0.o" : "crt0_64.o";
+    }
+    return IsArch32Bit ? "crt0.o" : "crt0_64.o";
   };
 
   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles,
@@ -271,7 +271,7 @@ void aix::Linker::ConstructJob(Compilation &C, const JobAction &JA,
 
     CmdArgs.push_back("-lc");
 
-    if (Args.hasArg(options::OPT_p, options::OPT_pg)) {
+    if (Args.hasArgNoClaim(options::OPT_p, options::OPT_pg)) {
       CmdArgs.push_back(Args.MakeArgString((llvm::Twine("-L") + D.SysRoot) +
                                            "/lib/profiled"));
       CmdArgs.push_back(Args.MakeArgString((llvm::Twine("-L") + D.SysRoot) +

clang/lib/Driver/ToolChains/Clang.cpp

@@ -6322,20 +6322,26 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
             << A->getAsString(Args) << TripleStr;
     }
   }
-  if (Arg *A = Args.getLastArgNoClaim(options::OPT_p)) {
-    if (TC.getTriple().isOSAIX()) {
-      CmdArgs.push_back("-pg");
-    } else if (!TC.getTriple().isOSOpenBSD()) {
+
+  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 (Arg *A = Args.getLastArgNoClaim(options::OPT_pg)) {
-    if (TC.getTriple().isOSzOS()) {
+  if (Arg *A = Args.getLastArgNoClaim(options::OPT_p)) {
+    if (!(TC.getTriple().isOSAIX() || TC.getTriple().isOSOpenBSD())) {
       D.Diag(diag::err_drv_unsupported_opt_for_target)
           << A->getAsString(Args) << TripleStr;
     }
   }
+  if (Arg *A = Args.getLastArgNoClaim(options::OPT_p, options::OPT_pg)) {
+    if (A->getOption().matches(options::OPT_p)) {
+      A->claim();
+      if (TC.getTriple().isOSAIX() && !Args.hasArgNoClaim(options::OPT_pg))
+        CmdArgs.push_back("-pg");
+    }
+  }
 
   if (Args.getLastArg(options::OPT_fapple_kext) ||
       (Args.hasArg(options::OPT_mkernel) && types::isCXX(InputType)))

clang/test/Driver/ibm-profiling.c

@@ -0,0 +1,27 @@
+// Check that -pg throws an error on z/OS.
+// RUN: %clang -### 2>&1 --target=s390x-none-zos -S -pg %s | FileCheck -check-prefix=FAIL-PG-NAME %s
+// FAIL-PG-NAME: error: unsupported option '-pg' for target 's390x-none-zos'
+
+// Check that -p is still used when not linking on AIX.
+// RUN: %clang -### 2>&1 --target=powerpc-ibm-aix7.1.0.0 -S -p -S %s \
+// RUN:   | FileCheck --check-prefix=CHECK %s
+// CHECK-NOT: warning: argument unused during compilation: '-p'
+
+// Check precedence: -pg is unused when passed first on AIX.
+// RUN: %clang -### 2>&1 --target=powerpc-ibm-aix7.1.0.0 --sysroot %S/Inputs/aix_ppc_tree -pg -p %s \
+// RUN:        | FileCheck --check-prefix=CHECK2 %s
+// CHECK2-NOT: warning: argument unused during compilation: '-p' [-Wunused-command-line-argument]
+// CHECK2:     "-isysroot" "[[SYSROOT:[^"]+]]"
+// CHECK2:     "[[SYSROOT]]/usr/lib{{/|\\\\}}mcrt0.o"
+// CHECK2:     "-L[[SYSROOT]]/lib/profiled"
+// CHECK2:     "-L[[SYSROOT]]/usr/lib/profiled"
+
+// Check precedence: -p is unused when passed first on AIX.
+// RUN: %clang -### 2>&1 --target=powerpc-ibm-aix7.1.0.0 --sysroot %S/Inputs/aix_ppc_tree -p -pg %s \
+// RUN:        | FileCheck --check-prefix=CHECK3 %s
+// CHECK3: warning: argument unused during compilation: '-p' [-Wunused-command-line-argument]
+// CHECK3:     "-isysroot" "[[SYSROOT:[^"]+]]"
+// CHECK3:     "[[SYSROOT]]/usr/lib{{/|\\\\}}gcrt0.o"
+// CHECK3:     "-L[[SYSROOT]]/lib/profiled"
+// CHECK3:     "-L[[SYSROOT]]/usr/lib/profiled"
+