diagnose errors when a builtin that require constant arguments don't have them.

For example, on:

#include <emmintrin.h>
int foo(int N) {
 __m128i white2;
 white2 = _mm_slli_si128(white2, N);
 return 0;
} 

we used to get:
fatal error: error in backend: Cannot yet select: intrinsic %llvm.x86.sse2.psll.dq

now we get:
/Users/sabre/t.c:4:11: error: argument to '__builtin_ia32_pslldqi128' must be a
      constant integer
 white2 = _mm_slli_si128(white2, N);
          ^~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /Users/sabre/t.c:1:
/Volumes/Projects/cvs/llvm/Debug+Asserts/lib/clang/2.9/include/emmintrin.h:781:13: note: instantiated from:
  ((__m128i)__builtin_ia32_pslldqi128((__m128i)(VEC), (IMM)*8))
            ^                                         ~~~~~~~
1 error generated.




git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@115374 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 18 insertions, 0 deletions

diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index c4e86875ed..4b1f423028 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -131,6 +131,24 @@ ExprResult
 Sema::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
   ExprResult TheCallResult(Owned(TheCall));
 
+  // Find out if any arguments are required to be integer constant expressions.
+  unsigned ICEArguments = 0;
+  ASTContext::GetBuiltinTypeError Error;
+  Context.GetBuiltinType(BuiltinID, Error, &ICEArguments);
+  if (Error != ASTContext::GE_None)
+    ICEArguments = 0;  // Don't diagnose previously diagnosed errors.
+  
+  // If any arguments are required to be ICE's, check and diagnose.
+  for (unsigned ArgNo = 0; ICEArguments != 0; ++ArgNo) {
+    // Skip arguments not required to be ICE's.
+    if ((ICEArguments & (1 << ArgNo)) == 0) continue;
+    
+    llvm::APSInt Result;
+    if (SemaBuiltinConstantArg(TheCall, ArgNo, Result))
+      return true;
+    ICEArguments &= ~(1 << ArgNo);
+  }
+  
   switch (BuiltinID) {
   case Builtin::BI__builtin___CFStringMakeConstantString:
     assert(TheCall->getNumArgs() == 1 &&