Move dbg.declare intrinsics when merging and replacing allocas.
Place new and update dbg.declare calls immediately after the
corresponding alloca.
Current code in replaceDbgDeclareForAlloca puts the new dbg.declare
at the end of the basic block. LLVM codegen has problems emitting
debug info in a situation when dbg.declare appears after all uses of
the variable. This usually kinda works for inlining and ASan (two
users of this function) but not for SafeStack (see the pending change
in http://reviews.llvm.org/D13178).
llvm-svn: 248769
diff --git a/llvm/lib/Transforms/IPO/Inliner.cpp b/llvm/lib/Transforms/IPO/Inliner.cpp
index 07d3633..14b1767 100644
--- a/llvm/lib/Transforms/IPO/Inliner.cpp
+++ b/llvm/lib/Transforms/IPO/Inliner.cpp
@@ -228,6 +228,14 @@
DEBUG(dbgs() << " ***MERGED ALLOCA: " << *AI << "\n\t\tINTO: "
<< *AvailableAlloca << '\n');
+ // Move affected dbg.declare calls immediately after the new alloca to
+ // avoid the situation when a dbg.declare preceeds its alloca.
+ if (auto *L = LocalAsMetadata::getIfExists(AI))
+ if (auto *MDV = MetadataAsValue::getIfExists(AI->getContext(), L))
+ for (User *U : MDV->users())
+ if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(U))
+ DDI->moveBefore(AvailableAlloca->getNextNode());
+
AI->replaceAllUsesWith(AvailableAlloca);
if (Align1 != Align2) {
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 5efa128..adee3f6 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -1157,10 +1157,10 @@
DIExpr = Builder.createExpression(NewDIExpr);
}
- // Insert llvm.dbg.declare in the same basic block as the original alloca,
- // and remove old llvm.dbg.declare.
- BasicBlock *BB = AI->getParent();
- Builder.insertDeclare(NewAllocaAddress, DIVar, DIExpr, Loc, BB);
+ // Insert llvm.dbg.declare immediately after the original alloca, and remove
+ // old llvm.dbg.declare.
+ Builder.insertDeclare(NewAllocaAddress, DIVar, DIExpr, Loc,
+ AI->getNextNode());
DDI->eraseFromParent();
return true;
}