When used in a compound expression FP_CONTRACT should proceed all explicit

declarations and statements. Emit an error if the FP_CONTRACT is used
later in a compound statement.

llvm-svn: 166383

clang/include/clang/Basic/DiagnosticParseKinds.td

@@ -729,6 +729,10 @@ def warn_pragma_unused_expected_var : Warning<
   "expected '#pragma unused' argument to be a variable name">;
 def warn_pragma_unused_expected_punc : Warning<
   "expected ')' or ',' in '#pragma unused'">;
+// - #pragam fp_contract
+def err_pragma_fp_contract_scope : Error<
+  "'#pragma fp_contract' should only appear at file scope or at the start of a "
+  "compound expression">; 
 
 // OpenCL Section 6.8.g
 def err_not_opencl_storage_class_specifier : Error<

clang/lib/Parse/ParseStmt.cpp

@@ -280,9 +280,10 @@ Retry:
     return StmtEmpty();
 
   case tok::annot_pragma_fp_contract:
-    ProhibitAttributes(Attrs);
-    HandlePragmaFPContract();
-    return StmtEmpty();
+    Diag(Tok, diag::err_pragma_fp_contract_scope);
+    ConsumeToken();
+    return StmtError();
+
 
   case tok::annot_pragma_opencl_extension:
     ProhibitAttributes(Attrs);
@@ -728,6 +729,10 @@ StmtResult Parser::ParseCompoundStatementBody(bool isStmtExpr) {
 
   StmtVector Stmts;
 
+  // Parse FP_CONTRACT if present.
+  if (Tok.is(tok::annot_pragma_fp_contract))
+    HandlePragmaFPContract();
+
   // "__label__ X, Y, Z;" is the GNU "Local Label" extension.  These are
   // only allowed at the start of a compound stmt regardless of the language.
   while (Tok.is(tok::kw___label__)) {

clang/test/CodeGen/fp-contract-pragma.cpp

@@ -39,7 +39,6 @@ template<typename T> class fp_contract_4 {
   float method(float a, float b, float c) {
     #pragma STDC FP_CONTRACT ON
     return a * b + c;
-    #pragma STDC FP_CONTRACT OFF    
   }
 };
 

clang/test/Parser/pragma-fp-contract.c

@@ -0,0 +1,6 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+void f1(void) {
+  int x = 0;
+/* expected-error {{'#pragma fp_contract' should only appear at file scope or at the start of a compound expression}} */ #pragma STDC FP_CONTRACT ON
+}