Skip MCJIT unit tests if LLVM is not configured for native compilation

[broadwaylamb]

Summary

When running MCJIT unit test, ensure that the host target is something LLVM can generate code for.

Without this change, the tests could fail if LLVM was configured for cross-compilation e. g. from x86 to ARM.

[broadwaylamb]

llvm/unittests/ExecutionEngine/MCJIT/MCJITTestAPICommon.h

39 ↗

(On Diff #218417)

This was not in the upstream. I tried to fix these tests by changing this line to sys::getProcessTriple() and committed it to my local git repo, and now reverted it, so Arcanist has caught this change.

The upstream uses sys::getProcessTriple(), so please ignore this change.

[broadwaylamb]

llvm/unittests/ExecutionEngine/MCJIT/MCJITTestAPICommon.h

39 ↗

(On Diff #218417)

Correction: I tried to fix these tests by changing this line to sys::getDefaultTargetTriple(), and here reverted it back to sys::getProcessTriple().

[broadwaylamb]

Replaced an accidental tab with spaces

[dblaikie]

llvm/unittests/ExecutionEngine/MCJIT/MCJITTestAPICommon.h

58 ↗

(On Diff #218426)

Please use 'nullptr' rather than '0' for a null pointer constant.

[broadwaylamb]

Use nullptr instead of 0

[dblaikie]

Seems reasonable to me - do you need me to commit this for you?

[broadwaylamb]

llvm/unittests/ExecutionEngine/MCJIT/MCJITTestAPICommon.h

58 ↗

(On Diff #218426)

I'm not sure I understand how Phabricator works: does the most recent diff get composed with the older one, or rather replaces it?

[broadwaylamb]

In D67089#1656158, @dblaikie wrote:

Seems reasonable to me - do you need me to commit this for you?

I don't have commit access, so yes

llvm/trunk/unittests/ExecutionEngine/MCJIT/MCJITTestAPICommon.h

 
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/IR/LegacyPassManager.h"
 #include "llvm/InitializePasses.h"
 #include "llvm/Support/Host.h"
 #include "llvm/Support/TargetSelect.h"
+#include "llvm/Support/TargetRegistry.h"
 
 // Used to skip tests on unsupported architectures and operating systems.
 // To skip a test, add this macro at the top of a test-case in a suite that
 // inherits from MCJITTestBase. See MCJITTest.cpp for examples.
 #define SKIP_UNSUPPORTED_PLATFORM \
   do \
-    if (!ArchSupportsMCJIT() || !OSSupportsMCJIT()) \
+    if (!ArchSupportsMCJIT() || !OSSupportsMCJIT() || !HostCanBeTargeted()) \
       return; \
   while(0)
 
 namespace llvm {
 
 class MCJITTestAPICommon {
 protected:
   MCJITTestAPICommon()
     : HostTriple(sys::getProcessTriple())
   {
     InitializeNativeTarget();
     InitializeNativeTargetAsmPrinter();
 
     // FIXME: It isn't at all clear why this is necesasry, but without it we
     // fail to initialize the AssumptionCacheTracker.
     initializeAssumptionCacheTrackerPass(*PassRegistry::getPassRegistry());
 
 #ifdef _WIN32
     // On Windows, generate ELF objects by specifying "-elf" in triple
     HostTriple += "-elf";
 #endif // _WIN32
     HostTriple = Triple::normalize(HostTriple);
   }
 
+  bool HostCanBeTargeted() {
+    std::string Error;
+    return TargetRegistry::lookupTarget(HostTriple, Error) != nullptr;
+  }
+
   /// Returns true if the host architecture is known to support MCJIT
   bool ArchSupportsMCJIT() {
     Triple Host(HostTriple);
     // If ARCH is not supported, bail
     if (!is_contained(SupportedArchs, Host.getArch()))
       return false;
 
     // If ARCH is supported and has no specific sub-arch support