[PATCH 2/3] perf clang: Add support for recent clang versions

[Sandipan Das]

The clang API calls used by perf have changed in recent
releases and builds succeed with libclang-3.9 only. This
introduces compatibility with libclang-4.0 and above.

Without this patch, we will see the following compilation
errors with libclang-4.0+:

 util/c++/clang.cpp: In function ‘clang::CompilerInvocation* 
perf::createCompilerInvocation(llvm::opt::ArgStringList, llvm::StringRef&, 
clang::DiagnosticsEngine&)’:
 util/c++/clang.cpp:62:33: error: ‘IK_C’ was not declared in this scope
   Opts.Inputs.emplace_back(Path, IK_C);
                                  ^~~~
 util/c++/clang.cpp: In function ‘std::unique_ptr<llvm::Module> 
perf::getModuleFromSource(llvm::opt::ArgStringList, llvm::StringRef, 
llvm::IntrusiveRefCntPtr<clang::vfs::FileSystem>)’:
 util/c++/clang.cpp:75:26: error: no matching function for call to 
‘clang::CompilerInstance::setInvocation(clang::CompilerInvocation*)’
   Clang.setInvocation(&*CI);
                           ^
 In file included from util/c++/clang.cpp:14:0:
 /usr/include/clang/Frontend/CompilerInstance.h:231:8: note: candidate: void 
clang::CompilerInstance::setInvocation(std::shared_ptr<clang::CompilerInvocation>)
    void setInvocation(std::shared_ptr<CompilerInvocation> Value);
         ^~~~~~~~~~~~~

Fixes: 00b86691c77c ("perf clang: Add builtin clang support ant test case")
Signed-off-by: Sandipan Das <sandi...@linux.vnet.ibm.com>
---
 tools/perf/util/c++/clang.cpp | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/c++/clang.cpp b/tools/perf/util/c++/clang.cpp
index 1bfc946e37dc..bf31ceab33bd 100644
--- a/tools/perf/util/c++/clang.cpp
+++ b/tools/perf/util/c++/clang.cpp
@@ -9,6 +9,7 @@
  * Copyright (C) 2016 Huawei Inc.
  */
 
+#include "clang/Basic/Version.h"
 #include "clang/CodeGen/CodeGenAction.h"
 #include "clang/Frontend/CompilerInvocation.h"
 #include "clang/Frontend/CompilerInstance.h"
@@ -58,7 +59,8 @@ createCompilerInvocation(llvm::opt::ArgStringList CFlags, 
StringRef& Path,
 
        FrontendOptions& Opts = CI->getFrontendOpts();
        Opts.Inputs.clear();
-       Opts.Inputs.emplace_back(Path, IK_C);
+       Opts.Inputs.emplace_back(Path,
+                       FrontendOptions::getInputKindForExtension("c"));
        return CI;
 }
 
@@ -71,10 +73,17 @@ getModuleFromSource(llvm::opt::ArgStringList CFlags,
 
        Clang.setVirtualFileSystem(&*VFS);
 
+#if CLANG_VERSION_MAJOR < 4
        IntrusiveRefCntPtr<CompilerInvocation> CI =
                createCompilerInvocation(std::move(CFlags), Path,
                                         Clang.getDiagnostics());
        Clang.setInvocation(&*CI);
+#else
+       std::shared_ptr<CompilerInvocation> CI(
+               createCompilerInvocation(std::move(CFlags), Path,
+                                        Clang.getDiagnostics()));
+       Clang.setInvocation(CI);
+#endif
 
        std::unique_ptr<CodeGenAction> Act(new EmitLLVMOnlyAction(&*LLVMCtx));
        if (!Clang.ExecuteAction(*Act))
-- 
2.14.3