[Clang][AIX][p]Enable -p Functionality

This patch enables `-p` functionality into Clang on AIX and Linux
To create parity with GCC.

The purpose of the `-p` flag is similar to that of `-pg`, but the
results are analyzed with the `prof` tool as opposed to the `gprof` tool.
More details can be found in this RFC post:
https://discourse.llvm.org/t/rfc-add-p-driver-support-to-clang/66013?u=francii

On AIX, compiling with `-p` links against `mcrt0.o`
and produces a mon.out file analyzed with the `prof` tool,
while `-pg` links against `gcrt0.o` and produces a `gmon.out`file
analyzed with the `gprof` tool. The differences are therefore
only a concern when linking, so calling `-p` will push `-pg` to cc1.

An AIX test for `-p` already exists, and I recently
another test was added here:
llvm@dc9846c
As such, there is no AIX test case attached to this patch.

Reviewed By: daltenty

Differential Revision: https://reviews.llvm.org/D137753

Author: SanitizedMemory

clang/include/clang/Driver/Options.td

@@ -4179,6 +4179,7 @@ def pedantic_errors : Flag<["-", "--"], "pedantic-errors">, Group<pedantic_Group
   MarshallingInfoFlag<DiagnosticOpts<"PedanticErrors">>;
 def pedantic : Flag<["-", "--"], "pedantic">, Group<pedantic_Group>, Flags<[CC1Option,FlangOption,FC1Option]>,
   HelpText<"Warn on language extensions">, MarshallingInfoFlag<DiagnosticOpts<"Pedantic">>;
+def p : Flag<["-"], "p">, HelpText<"Enable mcount instrumentation with prof">;
 def pg : Flag<["-"], "pg">, HelpText<"Enable mcount instrumentation">, Flags<[CC1Option]>,
   MarshallingInfoFlag<CodeGenOpts<"InstrumentForProfiling">>;
 def pipe : Flag<["-", "--"], "pipe">,
@@ -4225,7 +4226,6 @@ defm pthread : BoolOption<"", "pthread",
   LangOpts<"POSIXThreads">, DefaultFalse,
   PosFlag<SetTrue, [], "Support POSIX threads in generated code">,
   NegFlag<SetFalse>, BothFlags<[CC1Option]>>;
-def p : Flag<["-"], "p">;
 def pie : Flag<["-"], "pie">, Group<Link_Group>;
 def static_pie : Flag<["-"], "static-pie">, Group<Link_Group>;
 def read__only__relocs : Separate<["-"], "read_only_relocs">;

clang/lib/Driver/ToolChains/AIX.cpp

@@ -271,7 +271,7 @@ void aix::Linker::ConstructJob(Compilation &C, const JobAction &JA,
 
     CmdArgs.push_back("-lc");
 
-    if (Args.hasArg(options::OPT_pg)) {
+    if (Args.hasArg(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

@@ -6331,7 +6331,9 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     }
   }
   if (Arg *A = Args.getLastArgNoClaim(options::OPT_p)) {
-    if (!TC.getTriple().isOSAIX() && !TC.getTriple().isOSOpenBSD()) {
+    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;
     }

clang/test/Driver/aix-ld.c

@@ -135,6 +135,8 @@
 // CHECK-LD32-PROF-NOT: "--no-as-needed"
 // CHECK-LD32-PROF-NOT: "-lm"
 // CHECK-LD32-PROF:     "-lc"
+// CHECK-LD32-PROF:     "-L[[SYSROOT]]/lib/profiled"
+// CHECK-LD32-PROF:     "-L[[SYSROOT]]/usr/lib/profiled"
 
 // Check powerpc64-ibm-aix7.1.0.0, 64-bit. Enable profiling.
 // RUN: %clang %s -### 2>&1 \
@@ -162,6 +164,8 @@
 // CHECK-LD64-PROF-NOT: "--no-as-needed"
 // CHECK-LD64-PROF-NOT: "-lm"
 // CHECK-LD64-PROF:     "-lc"
+// CHECK-LD64-PROF:     "-L[[SYSROOT]]/lib/profiled"
+// CHECK-LD64-PROF:     "-L[[SYSROOT]]/usr/lib/profiled
 
 // Check powerpc-ibm-aix7.1.0.0, 32-bit. Enable g-profiling.
 // RUN: %clang %s -### 2>&1 \