Strip Android version when looking up toolchain paths.

[jmgao]

Summary

Android target triples can include a version number in the abi field
(e.g. 'aarch64-linux-android21'), used for checking for availability.
However, the driver was searching for toolchain binaries using the
passed in triple as a prefix.

[t.p.northover]

This could do with a test in test/Driver.

[jmgao]

Add test.

[t.p.northover]

I think that looks good. Thanks for adding the test!

Tim.

[jmgao]

Thanks for the review!

lib/Driver/Driver.cpp

std::string Driver::GetFilePath(const char *Name, const ToolChain &TC) const {
 
   return Name;
 }
 
 void Driver::generatePrefixedToolNames(
     const char *Tool, const ToolChain &TC,
     SmallVectorImpl<std::string> &Names) const {
   // FIXME: Needs a better variable than DefaultTargetTriple
-  Names.emplace_back(DefaultTargetTriple + "-" + Tool);
+  StringRef Triple = DefaultTargetTriple;
+
+  // On Android, the target triple can include a version number that needs to
+  // be stripped.
+  if (TC.getTriple().isAndroid()) {
+    Triple = Triple.rtrim("0123456789");
+  }
+
+  Names.emplace_back((Triple + "-" + Tool).str());
   Names.emplace_back(Tool);
 
   // Allow the discovery of tools prefixed with LLVM's default target triple.
   std::string LLVMDefaultTargetTriple = llvm::sys::getDefaultTargetTriple();
   if (LLVMDefaultTargetTriple != DefaultTargetTriple)
     Names.emplace_back(LLVMDefaultTargetTriple + "-" + Tool);
 }
 

test/Driver/android-triple-version.c

+// Android's target triples can contain a version number in the environment
+// field (e.g. arm-linux-androideabi9).
+// Make sure that any version is stripped when finding toolchain binaries.
+
+// RUN: env "PATH=%S/Inputs/android_triple_version/bin" \
+// RUN:     %clang -### -target arm-linux-androideabi %s 2>&1 | FileCheck %s
+// RUN: env "PATH=%S/Inputs/android_triple_version/bin" \
+// RUN:     %clang -### -target arm-linux-androideabi9 %s 2>&1 | FileCheck %s
+
+// CHECK: arm-linux-androideabi-ld