Fix line numbers for code inlined from __nodebug__ functions.

Instructions from __nodebug__ functions don't have file:line
information even when inlined into no-nodebug functions. As a result,
intrinsics (SSE and other) from <*intrin.h> clang headers _never_
have file:line information.

With this change, an instruction without !dbg metadata gets one from
the call instruction when inlined.

Fixes PR19001.

llvm-svn: 210459

1 files changed, 7 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/Utils/InlineFunction.cpp b/llvm/lib/Transforms/Utils/InlineFunction.cpp
index e01d0c38ec4..d93db5dc1ef 100644
--- a/llvm/lib/Transforms/Utils/InlineFunction.cpp
+++ b/llvm/lib/Transforms/Utils/InlineFunction.cpp
@@ -466,7 +466,13 @@ static void fixupLineNumbers(Function *Fn, Function::iterator FI,
     for (BasicBlock::iterator BI = FI->begin(), BE = FI->end();
          BI != BE; ++BI) {
       DebugLoc DL = BI->getDebugLoc();
-      if (!DL.isUnknown()) {
+      if (DL.isUnknown()) {
+        // If the inlined instruction has no line number, make it look as if it
+        // originates from the call location. This is important for
+        // ((__always_inline__, __nodebug__)) functions which must use caller
+        // location for all instructions in their function body.
+        BI->setDebugLoc(TheCallDL);
+      } else {
         BI->setDebugLoc(updateInlinedAtInfo(DL, TheCallDL, BI->getContext()));
         if (DbgValueInst *DVI = dyn_cast<DbgValueInst>(BI)) {
           LLVMContext &Ctx = BI->getContext();