PNaCl ABI: Strip out calling conventions from functions and calls

Always use the standard C calling conventions.  Disallow "fastcc" etc.

BUG=https://code.google.com/p/nativeclient/issues/detail?id=2346
TEST=*.ll tests + PNaCl toolchain trybots

Review URL: https://codereview.chromium.org/16529004

3 files changed, 20 insertions, 6 deletions

diff --git a/lib/Analysis/NaCl/PNaClABIVerifyFunctions.cpp b/lib/Analysis/NaCl/PNaClABIVerifyFunctions.cpp
index 167cad15d0..a59f6f6682 100644
--- a/lib/Analysis/NaCl/PNaClABIVerifyFunctions.cpp
+++ b/lib/Analysis/NaCl/PNaClABIVerifyFunctions.cpp
@@ -255,11 +255,14 @@ const char *PNaClABIVerifyFunctions::checkInstruction(const Instruction *Inst) {
       break;
     }
 
-    case Instruction::Call:
-      if (cast<CallInst>(Inst)->isInlineAsm())
+    case Instruction::Call: {
+      const CallInst *Call = cast<CallInst>(Inst);
+      if (Call->isInlineAsm())
         return "inline assembly";
-      if (!cast<CallInst>(Inst)->getAttributes().isEmpty())
+      if (!Call->getAttributes().isEmpty())
         return "bad call attributes";
+      if (Call->getCallingConv() != CallingConv::C)
+        return "bad calling convention";
 
       // Intrinsic calls can have multiple pointer arguments and
       // metadata arguments, so handle them specially.
@@ -281,6 +284,7 @@ const char *PNaClABIVerifyFunctions::checkInstruction(const Instruction *Inst) {
       if (!isNormalizedPtr(Inst->getOperand(PtrOperandIndex)))
         return "bad function callee operand";
       break;
+    }
 
     case Instruction::Switch: {
       // SwitchInst represents switch cases using array and vector
diff --git a/lib/Analysis/NaCl/PNaClABIVerifyModule.cpp b/lib/Analysis/NaCl/PNaClABIVerifyModule.cpp
index 91f71c949c..477bc50ec9 100644
--- a/lib/Analysis/NaCl/PNaClABIVerifyModule.cpp
+++ b/lib/Analysis/NaCl/PNaClABIVerifyModule.cpp
@@ -383,6 +383,12 @@ bool PNaClABIVerifyModule::runOnModule(Module &M) {
             << "Function " << MI->getName() << " has disallowed attributes:"
             << getAttributesAsString(MI->getAttributes()) << "\n";
       }
+      if (MI->getCallingConv() != CallingConv::C) {
+        Reporter->addError()
+            << "Function " << MI->getName()
+            << " has disallowed calling convention: "
+            << MI->getCallingConv() << "\n";
+      }
     }
 
     checkGlobalValueCommon(MI);
diff --git a/lib/Transforms/NaCl/StripAttributes.cpp b/lib/Transforms/NaCl/StripAttributes.cpp
index f5ec0423b4..476c500756 100644
--- a/lib/Transforms/NaCl/StripAttributes.cpp
+++ b/lib/Transforms/NaCl/StripAttributes.cpp
@@ -8,12 +8,14 @@
 //===----------------------------------------------------------------------===//
 //
 // This pass strips out attributes that are not supported by PNaCl's
-// stable ABI.  Currently, this strips out attributes from functions
-// and function calls.
+// stable ABI.  Currently, this strips out:
+//
+//  * Function and argument attributes from functions and function
+//    calls.
+//  * Calling conventions from functions and function calls.
 //
 // TODO(mseaborn): Strip out the following too:
 //
-//  * Calling conventions from functions and function calls.
 //  * "nuw" and "nsw" arithmetic attributes.
 //  * "align" attributes from integer memory accesses.
 //
@@ -131,6 +133,7 @@ static void CheckAttributes(AttributeSet Attrs) {
 bool StripAttributes::runOnFunction(Function &Func) {
   CheckAttributes(Func.getAttributes());
   Func.setAttributes(AttributeSet());
+  Func.setCallingConv(CallingConv::C);
 
   for (Function::iterator BB = Func.begin(), E = Func.end();
        BB != E; ++BB) {
@@ -140,6 +143,7 @@ bool StripAttributes::runOnFunction(Function &Func) {
       if (Call) {
         CheckAttributes(Call.getAttributes());
         Call.setAttributes(AttributeSet());
+        Call.setCallingConv(CallingConv::C);
       }
     }
   }