[INLINER] allow inlining of address taken blocks

as long as their uses does not contain calls to functions that capture
the argument (potentially allowing the blockaddress to "escape" the
lifetime of the caller).

TODO:
- add more tests
- fix crash in llvm::updateCGAndAnalysisManagerForFunctionPass when
  invoking Transforms/Inline/blockaddress.ll

llvm-svn: 354079

1 files changed, 8 insertions, 0 deletions

diff --git a/llvm/lib/IR/BasicBlock.cpp b/llvm/lib/IR/BasicBlock.cpp
index 18e2fd89..7f2e762 100644
--- a/llvm/lib/IR/BasicBlock.cpp
+++ b/llvm/lib/IR/BasicBlock.cpp
@@ -442,6 +442,14 @@ BasicBlock *BasicBlock::splitBasicBlock(iterator I, const Twine &BBName) {
   return New;
 }
 
+bool BasicBlock::addressPotentiallyEscapesFunction() {
+  for (const Use& U : BlockAddress::get(this)->uses())
+    if (const CallInst* CI = dyn_cast<CallInst>(U))
+      if (!CI->paramHasAttr(U.getOperandNo(), Attribute::NoCapture))
+        return true;
+  return false;
+}
+
 void BasicBlock::replaceSuccessorsPhiUsesWith(BasicBlock *New) {
   Instruction *TI = getTerminator();
   if (!TI)