2 files changed, 89 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index c963c51ec63..f8f62a9273d 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -1111,7 +1111,7 @@ bool llvm::replaceDbgDeclareForAlloca(AllocaInst *AI, Value *NewAllocaAddress,
   if (!DIVar)
     return false;
 
-  // Create a copy of the original DIDescriptor for user variable, appending
+  // Create a copy of the original DIDescriptor for user variable, prepending
   // "deref" operation to a list of address elements, as new llvm.dbg.declare
   // will take a value storing address of the memory for variable, not
   // alloca itself.
@@ -1121,7 +1121,7 @@ bool llvm::replaceDbgDeclareForAlloca(AllocaInst *AI, Value *NewAllocaAddress,
       NewDIExpr.push_back(DIExpr.getElement(i));
     }
   }
-  NewDIExpr.push_back(dwarf::DW_OP_deref);
+  NewDIExpr.insert(NewDIExpr.begin(), dwarf::DW_OP_deref);
 
   // Insert llvm.dbg.declare in the same basic block as the original alloca,
   // and remove old llvm.dbg.declare.
diff --git a/llvm/test/DebugInfo/block-asan.ll b/llvm/test/DebugInfo/block-asan.ll
new file mode 100644
index 00000000000..43f9e7f653c
--- /dev/null
+++ b/llvm/test/DebugInfo/block-asan.ll
@@ -0,0 +1,87 @@
+; RUN: opt -S -asan %s | FileCheck %s
+
+; The IR of this testcase is generated from the following C code:
+; void bar (int);
+;
+; void foo() {
+;   __block int x;
+;   bar(x);
+; }
+; by compiling it with 'clang -emit-llvm -g -S' and then by manually
+; adding the sanitize_address attribute to the @foo() function (so
+; that ASAN accepts to instrument the function in the above opt run).
+
+; Check that the location of the ASAN instrumented __block variable is
+; correct.
+; CHECK: [ DW_TAG_expression ] [DW_OP_deref] [DW_OP_plus 8] [DW_OP_deref] [DW_OP_plus 24]
+
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+
+%struct.__block_byref_x = type { i8*, %struct.__block_byref_x*, i32, i32, i32 }
+
+; Function Attrs: nounwind ssp uwtable
+define void @foo() #0 {
+entry:
+  %x = alloca %struct.__block_byref_x, align 8
+  call void @llvm.dbg.declare(metadata !{%struct.__block_byref_x* %x}, metadata !12, metadata !22), !dbg !23
+  %byref.isa = getelementptr inbounds %struct.__block_byref_x* %x, i32 0, i32 0, !dbg !24
+  store i8* null, i8** %byref.isa, !dbg !24
+  %byref.forwarding = getelementptr inbounds %struct.__block_byref_x* %x, i32 0, i32 1, !dbg !24
+  store %struct.__block_byref_x* %x, %struct.__block_byref_x** %byref.forwarding, !dbg !24
+  %byref.flags = getelementptr inbounds %struct.__block_byref_x* %x, i32 0, i32 2, !dbg !24
+  store i32 0, i32* %byref.flags, !dbg !24
+  %byref.size = getelementptr inbounds %struct.__block_byref_x* %x, i32 0, i32 3, !dbg !24
+  store i32 32, i32* %byref.size, !dbg !24
+  %forwarding = getelementptr inbounds %struct.__block_byref_x* %x, i32 0, i32 1, !dbg !25
+  %0 = load %struct.__block_byref_x** %forwarding, !dbg !25
+  %x1 = getelementptr inbounds %struct.__block_byref_x* %0, i32 0, i32 4, !dbg !25
+  %1 = load i32* %x1, align 4, !dbg !25
+  call void @bar(i32 %1), !dbg !25
+  %2 = bitcast %struct.__block_byref_x* %x to i8*, !dbg !26
+  call void @_Block_object_dispose(i8* %2, i32 8) #3, !dbg !26
+  ret void, !dbg !26
+}
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
+
+declare void @bar(i32) #2
+
+declare void @_Block_object_dispose(i8*, i32)
+
+attributes #0 = { nounwind ssp uwtable sanitize_address "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind readnone }
+attributes #2 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #3 = { nounwind }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!8, !9, !10}
+!llvm.ident = !{!11}
+
+!0 = metadata !{metadata !"0x11\0012\00clang version 3.6.0 (trunk 223120) (llvm/trunk 223119)\000\00\000\00\001", metadata !1, metadata !2, metadata !2, metadata !3, metadata !2, metadata !2} ; [ DW_TAG_compile_unit ] [/tmp/block.c] [DW_LANG_C99]
+!1 = metadata !{metadata !"block.c", metadata !"/tmp"}
+!2 = metadata !{}
+!3 = metadata !{metadata !4}
+!4 = metadata !{metadata !"0x2e\00foo\00foo\00\003\000\001\000\000\000\000\003", metadata !1, metadata !5, metadata !6, null, void ()* @foo, null, null, metadata !2} ; [ DW_TAG_subprogram ] [line 3] [def] [foo]
+!5 = metadata !{metadata !"0x29", metadata !1}    ; [ DW_TAG_file_type ] [/tmp/block.c]
+!6 = metadata !{metadata !"0x15\00\000\000\000\000\000\000", null, null, null, metadata !7, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!7 = metadata !{null}
+!8 = metadata !{i32 2, metadata !"Dwarf Version", i32 2}
+!9 = metadata !{i32 2, metadata !"Debug Info Version", i32 2}
+!10 = metadata !{i32 1, metadata !"PIC Level", i32 2}
+!11 = metadata !{metadata !"clang version 3.6.0 (trunk 223120) (llvm/trunk 223119)"}
+!12 = metadata !{metadata !"0x100\00x\004\000", metadata !4, metadata !5, metadata !13} ; [ DW_TAG_auto_variable ] [x] [line 4]
+!13 = metadata !{metadata !"0x13\00\000\00224\000\000\0016\000", metadata !1, metadata !5, null, metadata !14, null, null, null} ; [ DW_TAG_structure_type ] [line 0, size 224, align 0, offset 0] [def] [from ]
+!14 = metadata !{metadata !15, metadata !17, metadata !18, metadata !20, metadata !21}
+!15 = metadata !{metadata !"0xd\00__isa\000\0064\0064\000\000", metadata !1, metadata !5, metadata !16} ; [ DW_TAG_member ] [__isa] [line 0, size 64, align 64, offset 0] [from ]
+!16 = metadata !{metadata !"0xf\00\000\0064\0064\000\000", null, null, null} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [from ]
+!17 = metadata !{metadata !"0xd\00__forwarding\000\0064\0064\0064\000", metadata !1, metadata !5, metadata !16} ; [ DW_TAG_member ] [__forwarding] [line 0, size 64, align 64, offset 64] [from ]
+!18 = metadata !{metadata !"0xd\00__flags\000\0032\0032\00128\000", metadata !1, metadata !5, metadata !19} ; [ DW_TAG_member ] [__flags] [line 0, size 32, align 32, offset 128] [from int]
+!19 = metadata !{metadata !"0x24\00int\000\0032\0032\000\000\005", null, null} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
+!20 = metadata !{metadata !"0xd\00__size\000\0032\0032\00160\000", metadata !1, metadata !5, metadata !19} ; [ DW_TAG_member ] [__size] [line 0, size 32, align 32, offset 160] [from int]
+!21 = metadata !{metadata !"0xd\00x\000\0032\0032\00192\000", metadata !1, metadata !5, metadata !19} ; [ DW_TAG_member ] [x] [line 0, size 32, align 32, offset 192] [from int]
+!22 = metadata !{metadata !"0x102\0034\008\006\0034\0024"} ; [ DW_TAG_expression ] [DW_OP_plus 8] [DW_OP_deref] [DW_OP_plus 24]
+!23 = metadata !{i32 4, i32 15, metadata !4, null}
+!24 = metadata !{i32 4, i32 3, metadata !4, null}
+!25 = metadata !{i32 5, i32 3, metadata !4, null}
+!26 = metadata !{i32 6, i32 1, metadata !4, null}