Add list initialization for complex numbers in C.  Essentially, this allows "_Complex float x = {1.0f, 2.0f};".  See changes to docs/LanguageExtensions.html for a longer description.

<rdar://problem/9397672>.

llvm-svn: 140090
diff --git a/clang/lib/CodeGen/CGExprConstant.cpp b/clang/lib/CodeGen/CGExprConstant.cpp
index c0b7045..d7dfa25 100644
--- a/clang/lib/CodeGen/CGExprConstant.cpp
+++ b/clang/lib/CodeGen/CGExprConstant.cpp
@@ -742,6 +742,22 @@
   }
 
   llvm::Constant *VisitInitListExpr(InitListExpr *ILE) {
+    if (ILE->getType()->isAnyComplexType() && ILE->getNumInits() == 2) {
+      // Complex type with element initializers
+      Expr *Real = ILE->getInit(0);
+      Expr *Imag = ILE->getInit(1);
+      llvm::Constant *Complex[2];
+      Complex[0] = CGM.EmitConstantExpr(Real, Real->getType(), CGF);
+      if (!Complex[0])
+        return 0;
+      Complex[1] = CGM.EmitConstantExpr(Imag, Imag->getType(), CGF);
+      if (!Complex[1])
+        return 0;
+      llvm::StructType *STy =
+          cast<llvm::StructType>(ConvertType(ILE->getType()));
+      return llvm::ConstantStruct::get(STy, Complex);
+    }
+
     if (ILE->getType()->isScalarType()) {
       // We have a scalar in braces. Just use the first element.
       if (ILE->getNumInits() > 0) {