Change getProcessTriple to return different archs in universal binary

[jpienaar]

Summary

With the current approach that cmake makes uses for universal binaries
getProcessTriple was returning the same value whether or not being run on
x86_64 or arm. This resulted in failures if one ran the tools/tests with
arch-x86_64 or arch -arm64 (depending on LLVM_HOST_TRIPLE that was set at build
time). Change getProcessTriple to consider the architecture being compiled when
populating triple.

I'm not sure if this is best approach but LLVM_HOST_TRIPLE is fixed per
compilation given current universal binary approach and this is noninvasive
while enabling usage inside universal binary so easy to change.

[mehdi_amini]

llvm/lib/Support/Host.cpp

1936

Is the test useful here?

[jpienaar]

llvm/lib/Support/Host.cpp

1936

I think so, my rationale was if there were subtarget set then I'd not be clobbering it here to just set same target.

[lhames]

@jpienaar @jroelofs Sorry that I missed this at the time.

@jpienaar -- does Jon's patch dc078e6eaacf work for you?

[jpienaar]

In D140806#4564255, @lhames wrote:

@jpienaar @jroelofs Sorry that I missed this at the time.

@jpienaar -- does Jon's patch dc078e6eaacf work for you?

Ah missed your response. I'll check tomorrow.

llvm/lib/Support/Host.cpp

std::string sys::getProcessTriple() {
   std::string TargetTripleString = updateTripleOSVersion(LLVM_HOST_TRIPLE);
   Triple PT(Triple::normalize(TargetTripleString));
 
   if (sizeof(void *) == 8 && PT.isArch32Bit())
     PT = PT.get64BitArchVariant();
   if (sizeof(void *) == 4 && PT.isArch64Bit())
     PT = PT.get32BitArchVariant();
 
+#if defined(__APPLE__)
+    // Handle current CMake universal binary compilation.
+#if defined(__aarch64__)
+  if (PT.getArch() != llvm::Triple::aarch64)
+    PT.setArch(llvm::Triple::aarch64);
+#elif defined(__x86_64__) || defined(_M_X64)
+  if (PT.getArch() != llvm::Triple::x86_64)
+    PT.setArch(llvm::Triple::x86_64);
+#endif
+#endif
+
   return PT.str();
 }

llvm/unittests/Support/Host.cpp

TEST_F(HostTest, getMacOSHostVersion) {
   } else {
     // Don't compare the 'Micro' version, as it's always '0' for the 'Darwin'
     // triples.
     ASSERT_EQ(SystemVersion.getMajor(), HostVersion.getMajor());
     ASSERT_EQ(SystemVersion.getMinor(), HostVersion.getMinor());
   }
 }
 
+TEST_F(HostTest, getMacOSHostArch) {
+  llvm::Triple HostTriple(llvm::sys::getProcessTriple());
+  if (!HostTriple.isMacOSX())
+    GTEST_SKIP();
+  std::string HostTripleStr = HostTriple.normalize();
+
+  const char *SwVersPath = "/usr/bin/arch";
+  StringRef argv[] = {SwVersPath};
+  std::unique_ptr<char[]> Buffer;
+  off_t Size;
+  ASSERT_EQ(runAndGetCommandOutput(SwVersPath, argv, Buffer, Size), true);
+  StringRef ArchStr = StringRef(Buffer.get(), Size).rtrim();
+
+  if (ArchStr == "i386")
+    ASSERT_EQ(StringRef(HostTripleStr).starts_with("x86"), true);
+  if (ArchStr == "arm64")
+    ASSERT_EQ(StringRef(HostTripleStr).starts_with("arm"), true);
+}
+
 // Helper to return AIX system version. Must return void to use ASSERT_*.
 static void getAIXSystemVersion(VersionTuple &SystemVersion) {
   const char *ExePath = "/usr/bin/oslevel";
   StringRef argv[] = {ExePath};
   std::unique_ptr<char[]> Buffer;
   off_t Size;
   ASSERT_EQ(runAndGetCommandOutput(ExePath, argv, Buffer, Size), true);
   StringRef SystemVersionStr = StringRef(Buffer.get(), Size).rtrim();