[PATCH] D11179: [asan] Invalid debug info for promotable allocas

[Kuba Brecka]

kubabrecka updated this revision to Diff 29881.
kubabrecka added a comment.

Addressing review comments.  I checked that the test passes in a release (RelWithDebInfo) build.


http://reviews.llvm.org/D11179

Files:
  lib/Transforms/Instrumentation/AddressSanitizer.cpp
  test/Instrumentation/AddressSanitizer/debug_info_noninstrumented_alloca.ll

Index: test/Instrumentation/AddressSanitizer/debug_info_noninstrumented_alloca.ll
===================================================================
--- test/Instrumentation/AddressSanitizer/debug_info_noninstrumented_alloca.ll
+++ test/Instrumentation/AddressSanitizer/debug_info_noninstrumented_alloca.ll
@@ -0,0 +1,26 @@
+; This test checks that non-instrumented allocas stay in the first basic block.
+; Only first-basic-block allocas are considered stack slots, and moving them
+; breaks debug info.
+
+; RUN: opt < %s -asan -asan-module -S | FileCheck %s
+
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.10.0"
+
+define i32 @foo() sanitize_address {
+entry:
+  ; Regular alloca, will get instrumented (forced by the ptrtoint below).
+  %instrumented = alloca i32, align 4
+
+  ; Won't be instrumented because of asan-skip-promotable-allocas.
+  %non_instrumented = alloca i32, align 4
+  store i32 0, i32* %non_instrumented, align 4
+  %value = load i32, i32* %non_instrumented, align 4
+
+  %ptr = ptrtoint i32* %instrumented to i64
+  ret i32 %value
+}
+
+; CHECK: entry:
+; CHECK: %non_instrumented = alloca i32, align 4
+; CHECK: load i32, i32* @__asan_option_detect_stack_use_after_return
Index: lib/Transforms/Instrumentation/AddressSanitizer.cpp
===================================================================
--- lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -525,6 +525,7 @@
   ShadowMapping Mapping;
 
   SmallVector<AllocaInst *, 16> AllocaVec;
+  SmallVector<AllocaInst *, 16> NonInstrumentedStaticAllocaVec;
   SmallVector<Instruction *, 8> RetVec;
   unsigned StackAlignment;
 
@@ -625,7 +626,10 @@
 
   /// \brief Collect Alloca instructions we want (and can) handle.
   void visitAllocaInst(AllocaInst &AI) {
-    if (!ASan.isInterestingAlloca(AI)) return;
+    if (!ASan.isInterestingAlloca(AI)) {
+      if (AI.isStaticAlloca()) NonInstrumentedStaticAllocaVec.push_back(&AI);
+      return;
+    }
 
     StackAlignment = std::max(StackAlignment, AI.getAlignment());
     if (ASan.isDynamicAlloca(AI))
@@ -1734,6 +1738,8 @@
   IRBuilder<> IRB(InsBefore);
   IRB.SetCurrentDebugLocation(EntryDebugLocation);
 
+  for (auto *AI : NonInstrumentedStaticAllocaVec) AI->moveBefore(InsBefore);
+
   SmallVector<ASanStackVariableDescription, 16> SVD;
   SVD.reserve(AllocaVec.size());
   for (AllocaInst *AI : AllocaVec) {


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D11179.29881.patch
Type: text/x-patch
Size: 2463 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20150716/d657d9cc/attachment.bin>