[OpenCL] Eliminate warning when declaring OpenCL builtin functions.

OpenCL builtin functions are usually declared in header files.
Currently clang emits warning for OpenCL builtin functions
which have the same name as standard C library functions.

This commit eliminates such warnings by not adding the C standard
includes following the restriction from OpenCL v1.2 s6.9.f.

Patch by Liu Yaxun (Sam)!

Review: http://reviews.llvm.org/D16692

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@259491 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Sema/SemaLookup.cpp b/lib/Sema/SemaLookup.cpp
index f28cd27e85cc95488153cd3dc514417d5d043bc7..93d503e20b5b45feab2d2ee7484d36f96cb2e097 100644 (file)
--- a/lib/Sema/SemaLookup.cpp
+++ b/lib/Sema/SemaLookup.cpp
@@ -684,9 +684,9 @@ static bool LookupBuiltin(Sema &S, LookupResult &R) {
 
       // If this is a builtin on this (or all) targets, create the decl.
       if (unsigned BuiltinID = II->getBuiltinID()) {
-        // In C++, we don't have any predefined library functions like
-        // 'malloc'. Instead, we'll just error.
-        if (S.getLangOpts().CPlusPlus &&
+        // In C++ and OpenCL (spec v1.2 s6.9.f), we don't have any predefined
+        // library functions like 'malloc'. Instead, we'll just error.
+        if ((S.getLangOpts().CPlusPlus || S.getLangOpts().OpenCL) &&
             S.Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))
           return false;
 

diff --git a/test/SemaOpenCL/builtin.cl b/test/SemaOpenCL/builtin.cl
new file mode 100644 (file)
index 0000000..e5f56e2
--- /dev/null
+++ b/test/SemaOpenCL/builtin.cl
@@ -0,0 +1,3 @@
+// RUN: %clang_cc1 %s -verify -pedantic -fsyntax-only
+
+float __attribute__((overloadable)) acos(float); // expected-no-diagnostics