Use function attribute "trap-func-name" and remove TargetOptions::TrapFuncName.

This commit changes normal isel and fast isel to read the user-defined trap
function name from function attribute "trap-func-name" attached to llvm.trap or
llvm.debugtrap instead of from TargetOptions::TrapFuncName. This is needed to
use clang's command line option "-ftrap-function" for LTO and enable changing
the trap function name on a per-call-site basis.

Out-of-tree projects currently using TargetOptions::TrapFuncName to specify the
trap function name should attach attribute "trap-func-name" to the call sites
of llvm.trap and llvm.debugtrap instead.

rdar://problem/21225723

Differential Revision: http://reviews.llvm.org/D10832


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241305 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/SelectionDAG/FastISel.cpp

@@ -1350,7 +1350,7 @@ bool FastISel::selectInstruction(const Instruction *I) {
 
     // Don't handle Intrinsic::trap if a trap funciton is specified.
     if (F && F->getIntrinsicID() == Intrinsic::trap &&
-        !TM.Options.getTrapFunctionName().empty())
+        Call->hasFnAttr("trap-func-name"))
       return false;
   }
 

lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

@@ -4780,7 +4780,10 @@ SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) {
 
   case Intrinsic::debugtrap:
   case Intrinsic::trap: {
-    StringRef TrapFuncName = TM.Options.getTrapFunctionName();
+    StringRef TrapFuncName =
+        I.getAttributes()
+            .getAttribute(AttributeSet::FunctionIndex, "trap-func-name")
+            .getValueAsString();
     if (TrapFuncName.empty()) {
       ISD::NodeType Op = (Intrinsic == Intrinsic::trap) ?
         ISD::TRAP : ISD::DEBUGTRAP;

lib/CodeGen/TargetOptionsImpl.cpp

@@ -47,10 +47,3 @@ bool TargetOptions::LessPreciseFPMAD() const {
 bool TargetOptions::HonorSignDependentRoundingFPMath() const {
   return !UnsafeFPMath && HonorSignDependentRoundingFPMathOption;
 }
-
-/// getTrapFunctionName - If this returns a non-empty string, this means isel
-/// should lower Intrinsic::trap to a call to the specified function name
-/// instead of an ISD::TRAP node.
-StringRef TargetOptions::getTrapFunctionName() const {
-  return TrapFuncName;
-}