[cfe-commits] r102464 - in /cfe/trunk: lib/AST/ASTContext.cpp test/Sema/attr-regparm.c

[Eli Friedman]

Author: efriedma
Date: Tue Apr 27 16:07:06 2010
New Revision: 102464

URL: http://llvm.org/viewvc/llvm-project?rev=102464&view=rev
Log:
Fix for PR6953: per gcc, regparm and noreturn affect the compatibility of
function types.

This could potentially have unexpected side-effects, so look here if there are
new regressions.


Modified:
    cfe/trunk/lib/AST/ASTContext.cpp
    cfe/trunk/test/Sema/attr-regparm.c

Modified: cfe/trunk/lib/AST/ASTContext.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ASTContext.cpp?rev=102464&r1=102463&r2=102464&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ASTContext.cpp (original)
+++ cfe/trunk/lib/AST/ASTContext.cpp Tue Apr 27 16:07:06 2010
@@ -4311,21 +4311,16 @@
     allLTypes = false;
   if (getCanonicalType(retType) != getCanonicalType(rbase->getResultType()))
     allRTypes = false;
-  // FIXME: double check this
-  // FIXME: should we error if lbase->getRegParmAttr() != 0 &&
-  //                           rbase->getRegParmAttr() != 0 &&
-  //                           lbase->getRegParmAttr() != rbase->getRegParmAttr()?
+
+  // Check misc function attributes
   FunctionType::ExtInfo lbaseInfo = lbase->getExtInfo();
   FunctionType::ExtInfo rbaseInfo = rbase->getExtInfo();
-  unsigned RegParm = lbaseInfo.getRegParm() == 0 ? rbaseInfo.getRegParm() :
-      lbaseInfo.getRegParm();
-  bool NoReturn = lbaseInfo.getNoReturn() || rbaseInfo.getNoReturn();
-  if (NoReturn != lbaseInfo.getNoReturn() ||
-      RegParm != lbaseInfo.getRegParm())
-    allLTypes = false;
-  if (NoReturn != rbaseInfo.getNoReturn() ||
-      RegParm != rbaseInfo.getRegParm())
-    allRTypes = false;
+  // Per gcc, compatible functions must have compatible regparm and noreturn
+  // attributes.
+  unsigned RegParm = lbaseInfo.getRegParm();
+  bool NoReturn = lbaseInfo.getNoReturn();
+  if (NoReturn != rbaseInfo.getNoReturn() || RegParm != rbaseInfo.getRegParm())
+    return QualType();
   CallingConv lcc = lbaseInfo.getCC();
   CallingConv rcc = rbaseInfo.getCC();
   // Compatible functions must have compatible calling conventions

Modified: cfe/trunk/test/Sema/attr-regparm.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/attr-regparm.c?rev=102464&r1=102463&r2=102464&view=diff
==============================================================================
--- cfe/trunk/test/Sema/attr-regparm.c (original)
+++ cfe/trunk/test/Sema/attr-regparm.c Tue Apr 27 16:07:06 2010
@@ -1,7 +1,11 @@
 // RUN: %clang_cc1 -triple i386-apple-darwin9 -fsyntax-only -verify %s
 
-__attribute((regparm(2))) int x(void);
-__attribute((regparm(1.0))) int x(void); // expected-error{{'regparm' attribute requires integer constant}}
-__attribute((regparm(-1))) int x(void); // expected-error{{'regparm' parameter must be between 0 and 3 inclusive}}
-__attribute((regparm(5))) int x(void); // expected-error{{'regparm' parameter must be between 0 and 3 inclusive}}
-__attribute((regparm(5,3))) int x(void); // expected-error{{attribute requires 1 argument(s)}}
+__attribute((regparm(2))) int a(void);
+__attribute((regparm(1.0))) int b(void); // expected-error{{'regparm' attribute requires integer constant}}
+__attribute((regparm(-1))) int c(void); // expected-error{{'regparm' parameter must be between 0 and 3 inclusive}}
+__attribute((regparm(5))) int d(void); // expected-error{{'regparm' parameter must be between 0 and 3 inclusive}}
+__attribute((regparm(5,3))) int e(void); // expected-error{{attribute requires 1 argument(s)}}
+int f(void);
+__attribute((regparm(0))) int f(void);
+__attribute((regparm(1))) int g(void); // expected-note{{previous declaration is here}}
+__attribute((regparm(2))) int g(void); // expected-error{{conflicting types for 'g'}}