Insulate calling conventions in PNaCl bitcode files.

Creates a bitcode-local enumeration for calling conventions for the PNaCl bitcode file, so that the bitcode file is better protected from (accidental) changes in LLVM code.

Also removes invokes from the bitcode.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3497
R=dschuff@chromium.org, mseaborn@chromium.org

Review URL: https://codereview.chromium.org/17118002

1 files changed, 12 insertions, 26 deletions

diff --git a/lib/Bitcode/NaCl/Writer/NaClBitcodeWriter.cpp b/lib/Bitcode/NaCl/Writer/NaClBitcodeWriter.cpp
index e286d2852a..c5c469255b 100644
--- a/lib/Bitcode/NaCl/Writer/NaClBitcodeWriter.cpp
+++ b/lib/Bitcode/NaCl/Writer/NaClBitcodeWriter.cpp
@@ -181,6 +181,13 @@ static unsigned GetEncodedSynchScope(SynchronizationScope SynchScope) {
   llvm_unreachable("Invalid synch scope");
 }
 
+static unsigned GetEncodedCallingConv(CallingConv::ID conv) {
+  switch (conv) {
+  case CallingConv::C: return naclbitc::C_CallingConv;
+  }
+  report_fatal_error("Calling convention not supported by PNaCL bitcode");
+}
+
 static void WriteStringRecord(unsigned Code, StringRef Str,
                               unsigned AbbrevToUse,
                               NaClBitstreamWriter &Stream) {
@@ -610,7 +617,7 @@ static void WriteModuleInfo(const Module *M, const NaClValueEnumerator &VE,
     // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
     //             section, visibility, gc, unnamed_addr]
     Vals.push_back(VE.getTypeID(F->getType()));
-    Vals.push_back(F->getCallingConv());
+    Vals.push_back(GetEncodedCallingConv(F->getCallingConv()));
     Vals.push_back(F->isDeclaration());
     Vals.push_back(getEncodedLinkage(F));
     Vals.push_back(VE.getAttributeID(F->getAttributes()));
@@ -1374,31 +1381,9 @@ static void WriteInstruction(const Instruction &I, unsigned InstID,
       Vals.push_back(VE.getValueID(I.getOperand(i)));
     break;
 
-  case Instruction::Invoke: {
-    const InvokeInst *II = cast<InvokeInst>(&I);
-    const Value *Callee(II->getCalledValue());
-    PointerType *PTy = cast<PointerType>(Callee->getType());
-    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
-    Code = naclbitc::FUNC_CODE_INST_INVOKE;
-
-    Vals.push_back(VE.getAttributeID(II->getAttributes()));
-    Vals.push_back(II->getCallingConv());
-    Vals.push_back(VE.getValueID(II->getNormalDest()));
-    Vals.push_back(VE.getValueID(II->getUnwindDest()));
-    PushValueAndType(Callee, InstID, Vals, VE);
-
-    // Emit value #'s for the fixed parameters.
-    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
-      pushValue(I.getOperand(i), InstID, Vals, VE);  // fixed param.
-
-    // Emit type/value pairs for varargs params.
-    if (FTy->isVarArg()) {
-      for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
-           i != e; ++i)
-        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
-    }
+  case Instruction::Invoke:
+    report_fatal_error("Invoke is not allowed in PNaCl bitcode");
     break;
-  }
   case Instruction::Resume:
     Code = naclbitc::FUNC_CODE_INST_RESUME;
     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
@@ -1516,7 +1501,8 @@ static void WriteInstruction(const Instruction &I, unsigned InstID,
     Code = naclbitc::FUNC_CODE_INST_CALL;
 
     Vals.push_back(VE.getAttributeID(CI.getAttributes()));
-    Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
+    Vals.push_back((GetEncodedCallingConv(CI.getCallingConv()) << 1)
+                   | unsigned(CI.isTailCall()));
     PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
 
     // Emit value #'s for the fixed parameters.