commit 0fe506bc5eff0b3b77632ff8db00165ae07830ee
author Reid Kleckner <rnk@google.com> Thu Sep 21 19:52:03 2017 +0000
committer Reid Kleckner <rnk@google.com> Thu Sep 21 19:52:03 2017 +0000
tree 540b10e2fd6b6ca76708216c9cdf21255da665db
parent 977996d25b1f7ca0d4f4d2c863537a95287f096e

Re-land r313825: "[IR] Add llvm.dbg.addr, a control-dependent version of llvm.dbg.declare"

The fix is to avoid invalidating our insertion point in
replaceDbgDeclare:
     Builder.insertDeclare(NewAddress, DIVar, DIExpr, Loc, InsertBefore);
+    if (DII == InsertBefore)
+      InsertBefore = &*std::next(InsertBefore->getIterator());
     DII->eraseFromParent();

I had to write a unit tests for this instead of a lit test because the
use list order matters in order to trigger the bug.

The reduced C test case for this was:
  void useit(int*);
  static inline void inlineme() {
    int x[2];
    useit(x);
  }
  void f() {
    inlineme();
    inlineme();
  }

llvm-svn: 313905

llvm/lib/IR/DIBuilder.cpp

diff --git a/llvm/lib/IR/DIBuilder.cpp b/llvm/lib/IR/DIBuilder.cpp
index 1a40d5c..88f5b36 100644
--- a/llvm/lib/IR/DIBuilder.cpp
+++ b/llvm/lib/IR/DIBuilder.cpp
@@ -24,6 +24,11 @@
 using namespace llvm;
 using namespace llvm::dwarf;
 
+cl::opt<bool>
+    UseDbgAddr("use-dbg-addr",
+                llvm::cl::desc("Use llvm.dbg.addr for all local variables"),
+                cl::init(false));
+
 DIBuilder::DIBuilder(Module &m, bool AllowUnresolvedNodes)
   : M(m), VMContext(M.getContext()), CUNode(nullptr),
       DeclareFn(nullptr), ValueFn(nullptr),
@@ -776,6 +781,11 @@
   return I;
 }
 
+static Function *getDeclareIntrin(Module &M) {
+  return Intrinsic::getDeclaration(&M, UseDbgAddr ? Intrinsic::dbg_addr
+                                                  : Intrinsic::dbg_declare);
+}
+
 Instruction *DIBuilder::insertDeclare(Value *Storage, DILocalVariable *VarInfo,
                                       DIExpression *Expr, const DILocation *DL,
                                       Instruction *InsertBefore) {
@@ -785,7 +795,7 @@
              VarInfo->getScope()->getSubprogram() &&
          "Expected matching subprograms");
   if (!DeclareFn)
-    DeclareFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_declare);
+    DeclareFn = getDeclareIntrin(M);
 
   trackIfUnresolved(VarInfo);
   trackIfUnresolved(Expr);
@@ -804,7 +814,7 @@
              VarInfo->getScope()->getSubprogram() &&
          "Expected matching subprograms");
   if (!DeclareFn)
-    DeclareFn = Intrinsic::getDeclaration(&M, Intrinsic::dbg_declare);
+    DeclareFn = getDeclareIntrin(M);
 
   trackIfUnresolved(VarInfo);
   trackIfUnresolved(Expr);