From f4a702c079674120bbc95c3474602334274c6046 Mon Sep 17 00:00:00 2001
From: Alexey Samsonov <vonosmas@gmail.com>
Date: Mon, 9 Jun 2014 21:53:47 +0000
Subject: Generate better location ranges for some register-described
 variables.

Don't terminate location ranges for register-described variables
at the end of machine basic block if this register is never modified
in the function body, except for the prologue and epilogue. Prologue
location is guessed by FrameSetup flags on MachineInstructions, while
epilogue location is deduced from debug locations of instructions
in the basic blocks ending with return instructions.

This patch is mostly targeted to fix non-trivial debug locations for
variables addressed via stack and frame pointers.

It is not really a generic fix. We can still produce poor debug info
for register-described variables if this register *is* modified somewhere
in the function, but in unrelated places. This might be the case for the debug
info in optimized binaries (e.g. for local variables in inlined functions).
LiveDebugVariables pass in CodeGen attempts to fix this problem by adjusting
DBG_VALUE instructions, but this pass is tied to greedy register allocator,
which is used in optimized builds only. Proper fix would likely involve
generalizing LiveDebugVariables to all register allocators. See more discussion
in http://reviews.llvm.org/D3933 review thread.

I'm proceeding with this patch to fix immediate severe problems and
important cases, e.g. fix completely broken debug info with AddressSanitizer
and fix PR19307 (missing debug info for by-value std::string arguments).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210492 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/DebugInfo/X86/debug-loc-asan.ll   | 186 +++++++++++++++++++++++++++++++++
 test/DebugInfo/X86/debug-loc-offset.ll | 132 ++++++++++++++---------
 test/DebugInfo/X86/pr19307.ll          | 147 ++++++++++++++++++++++++++
 3 files changed, 417 insertions(+), 48 deletions(-)
 create mode 100644 test/DebugInfo/X86/debug-loc-asan.ll
 create mode 100644 test/DebugInfo/X86/pr19307.ll

(limited to 'test/DebugInfo/X86')

diff --git a/test/DebugInfo/X86/debug-loc-asan.ll b/test/DebugInfo/X86/debug-loc-asan.ll
new file mode 100644
index 0000000000..5f201ad163
--- /dev/null
+++ b/test/DebugInfo/X86/debug-loc-asan.ll
@@ -0,0 +1,186 @@
+; RUN: llc -O0 -mtriple=x86_64-unknown-linux-gnu < %s | FileCheck %s
+
+; Verify that we have correct debug info for local variables in code
+; instrumented with AddressSanitizer.
+
+; Generated from the source file test.cc:
+; int bar(int y) {
+;   return y + 2;
+; }
+; with "clang++ -S -emit-llvm -fsanitize=address -O0 -g test.cc"
+
+; First, argument variable "y" resides in %rdi:
+; CHECK: DEBUG_VALUE: bar:y <- RDI
+
+; Then its address is stored in a location on a stack:
+; CHECK: movq %rdi, [[OFFSET:[0-9]+]](%rsp)
+; CHECK-NEXT: [[START_LABEL:.Ltmp[0-9]+]]
+; CHECK-NEXT: DEBUG_VALUE: bar:y <- [RSP+[[OFFSET]]]
+; This location should be valid until the end of the function.
+
+; CHECK: .Ldebug_loc{{[0-9]+}}:
+; We expect two location ranges for the variable.
+
+; First, it is stored in %rdi:
+; CHECK:      .Lset{{[0-9]+}} = .Lfunc_begin0-.Lfunc_begin0
+; CHECK-NEXT: .quad .Lset{{[0-9]+}}
+; CHECK-NEXT: .Lset{{[0-9]+}} = [[START_LABEL]]-.Lfunc_begin0
+; CHECK-NEXT: .quad .Lset{{[0-9]+}}
+; CHECK: DW_OP_reg5
+
+; Then it's addressed via %rsp:
+; CHECK:      .Lset{{[0-9]+}} = [[START_LABEL]]-.Lfunc_begin0
+; CHECK-NEXT: .quad .Lset{{[0-9]+}}
+; CHECK-NEXT: .Lset{{[0-9]+}} = .Lfunc_end0-.Lfunc_begin0
+; CHECK-NEXT: .quad .Lset{{[0-9]+}}
+; CHECK: DW_OP_breg7
+; CHECK-NEXT: [[OFFSET]]
+; CHECK: DW_OP_deref
+
+; ModuleID = 'test.cc'
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@llvm.global_ctors = appending global [1 x { i32, void ()* }] [{ i32, void ()* } { i32 1, void ()* @asan.module_ctor }]
+@__asan_option_detect_stack_use_after_return = external global i32
+@__asan_gen_ = private unnamed_addr constant [16 x i8] c"1 32 4 6 y.addr\00", align 1
+
+; Function Attrs: nounwind sanitize_address uwtable
+define i32 @_Z3bari(i32 %y) #0 {
+entry:
+  %MyAlloca = alloca [64 x i8], align 32
+  %0 = ptrtoint [64 x i8]* %MyAlloca to i64
+  %1 = load i32* @__asan_option_detect_stack_use_after_return
+  %2 = icmp ne i32 %1, 0
+  br i1 %2, label %3, label %5
+
+; <label>:3                                       ; preds = %entry
+  %4 = call i64 @__asan_stack_malloc_0(i64 64, i64 %0)
+  br label %5
+
+; <label>:5                                       ; preds = %entry, %3
+  %6 = phi i64 [ %0, %entry ], [ %4, %3 ]
+  %7 = add i64 %6, 32
+  %8 = inttoptr i64 %7 to i32*
+  %9 = inttoptr i64 %6 to i64*
+  store i64 1102416563, i64* %9
+  %10 = add i64 %6, 8
+  %11 = inttoptr i64 %10 to i64*
+  store i64 ptrtoint ([16 x i8]* @__asan_gen_ to i64), i64* %11
+  %12 = add i64 %6, 16
+  %13 = inttoptr i64 %12 to i64*
+  store i64 ptrtoint (i32 (i32)* @_Z3bari to i64), i64* %13
+  %14 = lshr i64 %6, 3
+  %15 = add i64 %14, 2147450880
+  %16 = add i64 %15, 0
+  %17 = inttoptr i64 %16 to i64*
+  store i64 -868083100587789839, i64* %17
+  %18 = ptrtoint i32* %8 to i64
+  %19 = lshr i64 %18, 3
+  %20 = add i64 %19, 2147450880
+  %21 = inttoptr i64 %20 to i8*
+  %22 = load i8* %21
+  %23 = icmp ne i8 %22, 0
+  call void @llvm.dbg.declare(metadata !{i32* %8}, metadata !12)
+  br i1 %23, label %24, label %30
+
+; <label>:24                                      ; preds = %5
+  %25 = and i64 %18, 7
+  %26 = add i64 %25, 3
+  %27 = trunc i64 %26 to i8
+  %28 = icmp sge i8 %27, %22
+  br i1 %28, label %29, label %30
+
+; <label>:29                                      ; preds = %24
+  call void @__asan_report_store4(i64 %18)
+  call void asm sideeffect "", ""()
+  unreachable
+
+; <label>:30                                      ; preds = %24, %5
+  store i32 %y, i32* %8, align 4
+  %31 = ptrtoint i32* %8 to i64, !dbg !13
+  %32 = lshr i64 %31, 3, !dbg !13
+  %33 = add i64 %32, 2147450880, !dbg !13
+  %34 = inttoptr i64 %33 to i8*, !dbg !13
+  %35 = load i8* %34, !dbg !13
+  %36 = icmp ne i8 %35, 0, !dbg !13
+  br i1 %36, label %37, label %43, !dbg !13
+
+; <label>:37                                      ; preds = %30
+  %38 = and i64 %31, 7, !dbg !13
+  %39 = add i64 %38, 3, !dbg !13
+  %40 = trunc i64 %39 to i8, !dbg !13
+  %41 = icmp sge i8 %40, %35, !dbg !13
+  br i1 %41, label %42, label %43
+
+; <label>:42                                      ; preds = %37
+  call void @__asan_report_load4(i64 %31), !dbg !13
+  call void asm sideeffect "", ""()
+  unreachable
+
+; <label>:43                                      ; preds = %37, %30
+  %44 = load i32* %8, align 4, !dbg !13
+  %add = add nsw i32 %44, 2, !dbg !13
+  store i64 1172321806, i64* %9, !dbg !13
+  %45 = icmp ne i64 %6, %0, !dbg !13
+  br i1 %45, label %46, label %53, !dbg !13
+
+; <label>:46                                      ; preds = %43
+  %47 = add i64 %15, 0, !dbg !13
+  %48 = inttoptr i64 %47 to i64*, !dbg !13
+  store i64 -723401728380766731, i64* %48, !dbg !13
+  %49 = add i64 %6, 56, !dbg !13
+  %50 = inttoptr i64 %49 to i64*, !dbg !13
+  %51 = load i64* %50, !dbg !13
+  %52 = inttoptr i64 %51 to i8*, !dbg !13
+  store i8 0, i8* %52, !dbg !13
+  br label %56, !dbg !13
+
+; <label>:53                                      ; preds = %43
+  %54 = add i64 %15, 0, !dbg !13
+  %55 = inttoptr i64 %54 to i64*, !dbg !13
+  store i64 0, i64* %55, !dbg !13
+  br label %56, !dbg !13
+
+; <label>:56                                      ; preds = %53, %46
+  ret i32 %add, !dbg !13
+}
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.declare(metadata, metadata) #1
+
+define internal void @asan.module_ctor() {
+  call void @__asan_init_v3()
+  ret void
+}
+
+declare void @__asan_init_v3()
+
+declare void @__asan_report_load4(i64)
+
+declare void @__asan_report_store4(i64)
+
+declare i64 @__asan_stack_malloc_0(i64, i64)
+
+attributes #0 = { nounwind sanitize_address uwtable "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 }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!9, !10}
+!llvm.ident = !{!11}
+
+!0 = metadata !{i32 786449, metadata !1, i32 4, metadata !"clang version 3.5.0 (209308)", i1 false, metadata !"", i32 0, metadata !2, metadata !2, metadata !3, metadata !2, metadata !2, metadata !"", i32 1} ; [ DW_TAG_compile_unit ] [/llvm_cmake_gcc/test.cc] [DW_LANG_C_plus_plus]
+!1 = metadata !{metadata !"test.cc", metadata !"/llvm_cmake_gcc"}
+!2 = metadata !{}
+!3 = metadata !{metadata !4}
+!4 = metadata !{i32 786478, metadata !1, metadata !5, metadata !"bar", metadata !"bar", metadata !"_Z3bari", i32 1, metadata !6, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, i32 (i32)* @_Z3bari, null, null, metadata !2, i32 1} ; [ DW_TAG_subprogram ] [line 1] [def] [bar]
+!5 = metadata !{i32 786473, metadata !1}          ; [ DW_TAG_file_type ] [/llvm_cmake_gcc/test.cc]
+!6 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !7, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!7 = metadata !{metadata !8, metadata !8}
+!8 = metadata !{i32 786468, null, null, metadata !"int", i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
+!9 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
+!10 = metadata !{i32 2, metadata !"Debug Info Version", i32 1}
+!11 = metadata !{metadata !"clang version 3.5.0 (209308)"}
+!12 = metadata !{i32 786689, metadata !4, metadata !"y", metadata !5, i32 16777217, metadata !8, i32 0, i32 0, i64 2} ; [ DW_TAG_arg_variable ] [y] [line 1]
+!13 = metadata !{i32 2, i32 0, metadata !4, null}
+
diff --git a/test/DebugInfo/X86/debug-loc-offset.ll b/test/DebugInfo/X86/debug-loc-offset.ll
index 3f4d39da76..244aa53aa4 100644
--- a/test/DebugInfo/X86/debug-loc-offset.ll
+++ b/test/DebugInfo/X86/debug-loc-offset.ll
@@ -3,20 +3,23 @@
 
 ; From the code:
 
-; bar.cpp
+; debug-loc-offset1.cc
 ; int bar (int b) {
 ;   return b+4;
 ; }
 
-; foo.cpp
+; debug-loc-offset2.cc
 ; struct A {
-;   int a;
-;   int b;
-;   int c;
+;   int var;
+;   virtual char foo();
 ; };
 
-; int a (struct A var) {
-;   return var.a;
+; void baz(struct A a) {
+;   int z = 2;
+;   if (a.var > 2)
+;     z++;
+;   if (a.foo() == 'a')
+;     z++;
 ; }
 
 ; Compiled separately for i386-pc-linux-gnu and linked together.
@@ -38,78 +41,111 @@
 
 ; CHECK: DW_TAG_subprogram
 ; CHECK-NOT: DW_TAG
-; CHECK: DW_AT_MIPS_linkage_name [DW_FORM_strp]{{.*}}"_Z1a1A"
+; CHECK: DW_AT_MIPS_linkage_name [DW_FORM_strp]{{.*}}"_Z3baz1A"
 ; CHECK-NOT: {{DW_TAG|NULL}}
 ; CHECK: DW_TAG_formal_parameter
-; CHECK-NEXT: DW_AT_name [DW_FORM_strp]{{.*}}"var"
+; CHECK-NEXT: DW_AT_name [DW_FORM_strp]{{.*}}"a"
 ; CHECK: DW_AT_location [DW_FORM_sec_offset]   (0x00000000)
+
+; CHECK: DW_TAG_variable
+; CHECK: DW_AT_location [DW_FORM_exprloc]
 ; CHECK-NOT: DW_AT_location
 
 ; CHECK: .debug_loc contents:
 ; CHECK: 0x00000000: Beginning address offset: 0x0000000000000000
-; CHECK:                Ending address offset: 0x0000000000000009
-
+; CHECK:                Ending address offset: 0x000000000000001a
 
-%struct.A = type { i32, i32, i32 }
+%struct.A = type { i32 (...)**, i32 }
 
 ; Function Attrs: nounwind
 define i32 @_Z3bari(i32 %b) #0 {
 entry:
   %b.addr = alloca i32, align 4
   store i32 %b, i32* %b.addr, align 4
-  call void @llvm.dbg.declare(metadata !{i32* %b.addr}, metadata !25), !dbg !26
-  %0 = load i32* %b.addr, align 4, !dbg !27
-  %add = add nsw i32 %0, 4, !dbg !27
-  ret i32 %add, !dbg !27
+  call void @llvm.dbg.declare(metadata !{i32* %b.addr}, metadata !21), !dbg !22
+  %0 = load i32* %b.addr, align 4, !dbg !23
+  %add = add nsw i32 %0, 4, !dbg !23
+  ret i32 %add, !dbg !23
 }
 
 ; Function Attrs: nounwind readnone
 declare void @llvm.dbg.declare(metadata, metadata) #1
 
-; Function Attrs: nounwind
-define i32 @_Z1a1A(%struct.A* byval align 4 %var) #0 {
+define void @_Z3baz1A(%struct.A* %a) #2 {
 entry:
-  call void @llvm.dbg.declare(metadata !{%struct.A* %var}, metadata !28), !dbg !29
-  %a = getelementptr inbounds %struct.A* %var, i32 0, i32 0, !dbg !30
-  %0 = load i32* %a, align 4, !dbg !30
-  ret i32 %0, !dbg !30
+  %z = alloca i32, align 4
+  call void @llvm.dbg.declare(metadata !{%struct.A* %a}, metadata !24), !dbg !25
+  call void @llvm.dbg.declare(metadata !{i32* %z}, metadata !26), !dbg !27
+  store i32 2, i32* %z, align 4, !dbg !27
+  %var = getelementptr inbounds %struct.A* %a, i32 0, i32 1, !dbg !28
+  %0 = load i32* %var, align 4, !dbg !28
+  %cmp = icmp sgt i32 %0, 2, !dbg !28
+  br i1 %cmp, label %if.then, label %if.end, !dbg !28
+
+if.then:                                          ; preds = %entry
+  %1 = load i32* %z, align 4, !dbg !30
+  %inc = add nsw i32 %1, 1, !dbg !30
+  store i32 %inc, i32* %z, align 4, !dbg !30
+  br label %if.end, !dbg !30
+
+if.end:                                           ; preds = %if.then, %entry
+  %call = call signext i8 @_ZN1A3fooEv(%struct.A* %a), !dbg !31
+  %conv = sext i8 %call to i32, !dbg !31
+  %cmp1 = icmp eq i32 %conv, 97, !dbg !31
+  br i1 %cmp1, label %if.then2, label %if.end4, !dbg !31
+
+if.then2:                                         ; preds = %if.end
+  %2 = load i32* %z, align 4, !dbg !33
+  %inc3 = add nsw i32 %2, 1, !dbg !33
+  store i32 %inc3, i32* %z, align 4, !dbg !33
+  br label %if.end4, !dbg !33
+
+if.end4:                                          ; preds = %if.then2, %if.end
+  ret void, !dbg !34
 }
 
+declare signext i8 @_ZN1A3fooEv(%struct.A*) #2
+
 attributes #0 = { nounwind "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" }
 
 !llvm.dbg.cu = !{!0, !9}
-!llvm.module.flags = !{!22, !23}
-!llvm.ident = !{!24, !24}
+!llvm.module.flags = !{!18, !19}
+!llvm.ident = !{!20, !20}
 
-!0 = metadata !{i32 786449, metadata !1, i32 4, metadata !"clang version 3.5.0 (trunk 204264) (llvm/trunk 204286)", i1 false, metadata !"", i32 0, metadata !2, metadata !2, metadata !3, metadata !2, metadata !2, metadata !"", i32 1}
-!1 = metadata !{metadata !"bar.cpp", metadata !"/usr/local/google/home/echristo/tmp"}
+!0 = metadata !{i32 786449, metadata !1, i32 4, metadata !"clang version 3.5.0 (210479)", i1 false, metadata !"", i32 0, metadata !2, metadata !2, metadata !3, metadata !2, metadata !2, metadata !"", i32 1} ; [ DW_TAG_compile_unit ] [/llvm_cmake_gcc/debug-loc-offset1.cc] [DW_LANG_C_plus_plus]
+!1 = metadata !{metadata !"debug-loc-offset1.cc", metadata !"/llvm_cmake_gcc"}
 !2 = metadata !{}
 !3 = metadata !{metadata !4}
 !4 = metadata !{i32 786478, metadata !1, metadata !5, metadata !"bar", metadata !"bar", metadata !"_Z3bari", i32 1, metadata !6, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, i32 (i32)* @_Z3bari, null, null, metadata !2, i32 1} ; [ DW_TAG_subprogram ] [line 1] [def] [bar]
-!5 = metadata !{i32 786473, metadata !1}          ; [ DW_TAG_file_type ] [/usr/local/google/home/echristo/tmp/bar.cpp]
+!5 = metadata !{i32 786473, metadata !1}          ; [ DW_TAG_file_type ] [/llvm_cmake_gcc/debug-loc-offset1.cc]
 !6 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !7, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
 !7 = metadata !{metadata !8, metadata !8}
 !8 = metadata !{i32 786468, null, null, metadata !"int", i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
-!9 = metadata !{i32 786449, metadata !10, i32 4, metadata !"clang version 3.5.0 (trunk 204264) (llvm/trunk 204286)", i1 false, metadata !"", i32 0, metadata !2, metadata !11, metadata !17, metadata !2, metadata !2, metadata !"", i32 1}
-!10 = metadata !{metadata !"foo.cpp", metadata !"/usr/local/google/home/echristo/tmp"}
+!9 = metadata !{i32 786449, metadata !10, i32 4, metadata !"clang version 3.5.0 (210479)", i1 false, metadata !"", i32 0, metadata !2, metadata !11, metadata !13, metadata !2, metadata !2, metadata !"", i32 1} ; [ DW_TAG_compile_unit ] [/llvm_cmake_gcc/debug-loc-offset2.cc] [DW_LANG_C_plus_plus]
+!10 = metadata !{metadata !"debug-loc-offset2.cc", metadata !"/llvm_cmake_gcc"}
 !11 = metadata !{metadata !12}
-!12 = metadata !{i32 786451, metadata !10, null, metadata !"A", i32 1, i64 96, i64 32, i32 0, i32 0, null, metadata !13, i32 0, null, null, metadata !"_ZTS1A"} ; [ DW_TAG_structure_type ] [A] [line 1, size 96, align 32, offset 0] [def] [from ]
-!13 = metadata !{metadata !14, metadata !15, metadata !16}
-!14 = metadata !{i32 786445, metadata !10, metadata !"_ZTS1A", metadata !"a", i32 2, i64 32, i64 32, i64 0, i32 0, metadata !8} ; [ DW_TAG_member ] [a] [line 2, size 32, align 32, offset 0] [from int]
-!15 = metadata !{i32 786445, metadata !10, metadata !"_ZTS1A", metadata !"b", i32 3, i64 32, i64 32, i64 32, i32 0, metadata !8} ; [ DW_TAG_member ] [b] [line 3, size 32, align 32, offset 32] [from int]
-!16 = metadata !{i32 786445, metadata !10, metadata !"_ZTS1A", metadata !"c", i32 4, i64 32, i64 32, i64 64, i32 0, metadata !8} ; [ DW_TAG_member ] [c] [line 4, size 32, align 32, offset 64] [from int]
-!17 = metadata !{metadata !18}
-!18 = metadata !{i32 786478, metadata !10, metadata !19, metadata !"a", metadata !"a", metadata !"_Z1a1A", i32 7, metadata !20, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, i32 (%struct.A*)* @_Z1a1A, null, null, metadata !2, i32 7} ; [ DW_TAG_subprogram ] [line 7] [def] [a]
-!19 = metadata !{i32 786473, metadata !10}        ; [ DW_TAG_file_type ] [/usr/local/google/home/echristo/tmp/foo.cpp]
-!20 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !21, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
-!21 = metadata !{metadata !8, metadata !12}
-!22 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
-!23 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}
-!24 = metadata !{metadata !"clang version 3.5.0 (trunk 204264) (llvm/trunk 204286)"}
-!25 = metadata !{i32 786689, metadata !4, metadata !"b", metadata !5, i32 16777217, metadata !8, i32 0, i32 0} ; [ DW_TAG_arg_variable ] [b] [line 1]
-!26 = metadata !{i32 1, i32 0, metadata !4, null}
-!27 = metadata !{i32 2, i32 0, metadata !4, null}
-!28 = metadata !{i32 786689, metadata !18, metadata !"var", metadata !19, i32 16777223, metadata !"_ZTS1A", i32 0, i32 0}
-!29 = metadata !{i32 7, i32 0, metadata !18, null}
-!30 = metadata !{i32 8, i32 0, metadata !18, null} ; [ DW_TAG_imported_declaration ]
+!12 = metadata !{i32 786451, metadata !10, null, metadata !"A", i32 1, i64 0, i64 0, i32 0, i32 4, null, null, i32 0, null, null, metadata !"_ZTS1A"} ; [ DW_TAG_structure_type ] [A] [line 1, size 0, align 0, offset 0] [decl] [from ]
+!13 = metadata !{metadata !14}
+!14 = metadata !{i32 786478, metadata !10, metadata !15, metadata !"baz", metadata !"baz", metadata !"_Z3baz1A", i32 6, metadata !16, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, void (%struct.A*)* @_Z3baz1A, null, null, metadata !2, i32 6} ; [ DW_TAG_subprogram ] [line 6] [def] [baz]
+!15 = metadata !{i32 786473, metadata !10}        ; [ DW_TAG_file_type ] [/llvm_cmake_gcc/debug-loc-offset2.cc]
+!16 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !17, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!17 = metadata !{null, metadata !12}
+!18 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
+!19 = metadata !{i32 2, metadata !"Debug Info Version", i32 1}
+!20 = metadata !{metadata !"clang version 3.5.0 (210479)"}
+!21 = metadata !{i32 786689, metadata !4, metadata !"b", metadata !5, i32 16777217, metadata !8, i32 0, i32 0} ; [ DW_TAG_arg_variable ] [b] [line 1]
+!22 = metadata !{i32 1, i32 0, metadata !4, null}
+!23 = metadata !{i32 2, i32 0, metadata !4, null}
+!24 = metadata !{i32 786689, metadata !14, metadata !"a", metadata !15, i32 16777222, metadata !"_ZTS1A", i32 8192, i32 0} ; [ DW_TAG_arg_variable ] [a] [line 6]
+!25 = metadata !{i32 6, i32 0, metadata !14, null}
+!26 = metadata !{i32 786688, metadata !14, metadata !"z", metadata !15, i32 7, metadata !8, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [z] [line 7]
+!27 = metadata !{i32 7, i32 0, metadata !14, null}
+!28 = metadata !{i32 8, i32 0, metadata !29, null} ; [ DW_TAG_imported_declaration ]
+!29 = metadata !{i32 786443, metadata !10, metadata !14, i32 8, i32 0, i32 0, i32 0} ; [ DW_TAG_lexical_block ] [/llvm_cmake_gcc/debug-loc-offset2.cc]
+!30 = metadata !{i32 9, i32 0, metadata !29, null}
+!31 = metadata !{i32 10, i32 0, metadata !32, null}
+!32 = metadata !{i32 786443, metadata !10, metadata !14, i32 10, i32 0, i32 0, i32 1} ; [ DW_TAG_lexical_block ] [/llvm_cmake_gcc/debug-loc-offset2.cc]
+!33 = metadata !{i32 11, i32 0, metadata !32, null}
+!34 = metadata !{i32 12, i32 0, metadata !14, null}
diff --git a/test/DebugInfo/X86/pr19307.ll b/test/DebugInfo/X86/pr19307.ll
new file mode 100644
index 0000000000..07e3a4255b
--- /dev/null
+++ b/test/DebugInfo/X86/pr19307.ll
@@ -0,0 +1,147 @@
+; RUN: llc -O0 -mtriple=x86_64-unknown-linux-gnu < %s | FileCheck %s
+
+; Generated from the source file pr19307.cc:
+; #include <string>
+; void parse_range(unsigned long long &offset, unsigned long long &limit,
+;                  std::string range) {
+;   if (range.compare(0, 6, "items=") != 0 || range[6] == '-')
+;     offset = 1;
+;   range.erase(0, 6);
+;   limit = 2;
+; }
+; with "clang++ -S -emit-llvm -O0 -g pr19307.cc"
+
+; Location of "range" string is spilled from %rdx to stack and is
+; addressed via %rbp.
+; CHECK: movq %rdx, {{[-0-9]+}}(%rbp)
+; CHECK-NEXT: [[START_LABEL:.Ltmp[0-9]+]]
+; This location should be valid until the end of the function.
+
+; Verify that we have proper range in debug_loc section:
+; CHECK: .Ldebug_loc{{[0-9]+}}:
+; CHECK: DW_OP_breg1
+; CHECK:      .Lset{{[0-9]+}} = [[START_LABEL]]-.Lfunc_begin0
+; CHECK-NEXT: .quad .Lset{{[0-9]+}}
+; CHECK-NEXT: .Lset{{[0-9]+}} = .Lfunc_end0-.Lfunc_begin0
+; CHECK-NEXT: .quad .Lset{{[0-9]+}}
+; CHECK: DW_OP_breg6
+; CHECK: DW_OP_deref
+
+; ModuleID = 'pr19307.cc'
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+%"class.std::basic_string" = type { %"struct.std::basic_string<char, std::char_traits<char>, std::allocator<char> >::_Alloc_hider" }
+%"struct.std::basic_string<char, std::char_traits<char>, std::allocator<char> >::_Alloc_hider" = type { i8* }
+
+@.str = private unnamed_addr constant [7 x i8] c"items=\00", align 1
+
+; Function Attrs: uwtable
+define void @_Z11parse_rangeRyS_Ss(i64* %offset, i64* %limit, %"class.std::basic_string"* %range) #0 {
+entry:
+  %offset.addr = alloca i64*, align 8
+  %limit.addr = alloca i64*, align 8
+  store i64* %offset, i64** %offset.addr, align 8
+  call void @llvm.dbg.declare(metadata !{i64** %offset.addr}, metadata !45), !dbg !46
+  store i64* %limit, i64** %limit.addr, align 8
+  call void @llvm.dbg.declare(metadata !{i64** %limit.addr}, metadata !47), !dbg !46
+  call void @llvm.dbg.declare(metadata !{%"class.std::basic_string"* %range}, metadata !48), !dbg !49
+  %call = call i32 @_ZNKSs7compareEmmPKc(%"class.std::basic_string"* %range, i64 0, i64 6, i8* getelementptr inbounds ([7 x i8]* @.str, i32 0, i32 0)), !dbg !50
+  %cmp = icmp ne i32 %call, 0, !dbg !50
+  br i1 %cmp, label %if.then, label %lor.lhs.false, !dbg !50
+
+lor.lhs.false:                                    ; preds = %entry
+  %call1 = call i8* @_ZNSsixEm(%"class.std::basic_string"* %range, i64 6), !dbg !52
+  %0 = load i8* %call1, !dbg !52
+  %conv = sext i8 %0 to i32, !dbg !52
+  %cmp2 = icmp eq i32 %conv, 45, !dbg !52
+  br i1 %cmp2, label %if.then, label %if.end, !dbg !52
+
+if.then:                                          ; preds = %lor.lhs.false, %entry
+  %1 = load i64** %offset.addr, align 8, !dbg !54
+  store i64 1, i64* %1, align 8, !dbg !54
+  br label %if.end, !dbg !54
+
+if.end:                                           ; preds = %if.then, %lor.lhs.false
+  %call3 = call %"class.std::basic_string"* @_ZNSs5eraseEmm(%"class.std::basic_string"* %range, i64 0, i64 6), !dbg !55
+  %2 = load i64** %limit.addr, align 8, !dbg !56
+  store i64 2, i64* %2, align 8, !dbg !56
+  ret void, !dbg !57
+}
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.declare(metadata, metadata) #1
+
+declare i32 @_ZNKSs7compareEmmPKc(%"class.std::basic_string"*, i64, i64, i8*) #2
+
+declare i8* @_ZNSsixEm(%"class.std::basic_string"*, i64) #2
+
+declare %"class.std::basic_string"* @_ZNSs5eraseEmm(%"class.std::basic_string"*, i64, i64) #2
+
+attributes #0 = { uwtable "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" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!42, !43}
+!llvm.ident = !{!44}
+
+!0 = metadata !{i32 786449, metadata !1, i32 4, metadata !"clang version 3.5.0 (209308)", i1 false, metadata !"", i32 0, metadata !2, metadata !3, metadata !12, metadata !2, metadata !21, metadata !"", i32 1} ; [ DW_TAG_compile_unit ] [/llvm_cmake_gcc/pr19307.cc] [DW_LANG_C_plus_plus]
+!1 = metadata !{metadata !"pr19307.cc", metadata !"/llvm_cmake_gcc"}
+!2 = metadata !{}
+!3 = metadata !{metadata !4, metadata !6, metadata !8}
+!4 = metadata !{i32 786451, metadata !5, null, metadata !"", i32 83, i64 0, i64 0, i32 0, i32 4, null, null, i32 0, null, null, metadata !"_ZTS11__mbstate_t"} ; [ DW_TAG_structure_type ] [line 83, size 0, align 0, offset 0] [decl] [from ]
+!5 = metadata !{metadata !"/usr/include/wchar.h", metadata !"/llvm_cmake_gcc"}
+!6 = metadata !{i32 786451, metadata !7, null, metadata !"lconv", i32 54, i64 0, i64 0, i32 0, i32 4, null, null, i32 0, null, null, metadata !"_ZTS5lconv"} ; [ DW_TAG_structure_type ] [lconv] [line 54, size 0, align 0, offset 0] [decl] [from ]
+!7 = metadata !{metadata !"/usr/include/locale.h", metadata !"/llvm_cmake_gcc"}
+!8 = metadata !{i32 786434, metadata !9, metadata !10, metadata !"basic_string<char, std::char_traits<char>, std::allocator<char> >", i32 1134, i64 0, i64 0, i32 0, i32 4, null, null, i32 0, null, null, metadata !"_ZTSSs"} ; [ DW_TAG_class_type ] [basic_string<char, std::char_traits<char>, std::allocator<char> >] [line 1134, size 0, align 0, offset 0] [decl] [from ]
+!9 = metadata !{metadata !"/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/basic_string.tcc", metadata !"/llvm_cmake_gcc"}
+!10 = metadata !{i32 786489, metadata !11, null, metadata !"std", i32 153} ; [ DW_TAG_namespace ] [std] [line 153]
+!11 = metadata !{metadata !"/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/x86_64-linux-gnu/bits/c++config.h", metadata !"/llvm_cmake_gcc"}
+!12 = metadata !{metadata !13}
+!13 = metadata !{i32 786478, metadata !1, metadata !14, metadata !"parse_range", metadata !"parse_range", metadata !"_Z11parse_rangeRyS_Ss", i32 3, metadata !15, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, void (i64*, i64*, %"class.std::basic_string"*)* @_Z11parse_rangeRyS_Ss, null, null, metadata !2, i32 4} ; [ DW_TAG_subprogram ] [line 3] [def] [scope 4] [parse_range]
+!14 = metadata !{i32 786473, metadata !1}         ; [ DW_TAG_file_type ] [/llvm_cmake_gcc/pr19307.cc]
+!15 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !16, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!16 = metadata !{null, metadata !17, metadata !17, metadata !19}
+!17 = metadata !{i32 786448, null, null, null, i32 0, i64 0, i64 0, i64 0, i32 0, metadata !18} ; [ DW_TAG_reference_type ] [line 0, size 0, align 0, offset 0] [from long long unsigned int]
+!18 = metadata !{i32 786468, null, null, metadata !"long long unsigned int", i32 0, i64 64, i64 64, i64 0, i32 0, i32 7} ; [ DW_TAG_base_type ] [long long unsigned int] [line 0, size 64, align 64, offset 0, enc DW_ATE_unsigned]
+!19 = metadata !{i32 786454, metadata !20, metadata !10, metadata !"string", i32 65, i64 0, i64 0, i64 0, i32 0, metadata !"_ZTSSs"} ; [ DW_TAG_typedef ] [string] [line 65, size 0, align 0, offset 0] [from _ZTSSs]
+!20 = metadata !{metadata !"/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/stringfwd.h", metadata !"/llvm_cmake_gcc"}
+!21 = metadata !{metadata !22, metadata !26, metadata !29, metadata !33, metadata !38, metadata !41}
+!22 = metadata !{i32 786490, metadata !23, metadata !25, i32 57} ; [ DW_TAG_imported_module ]
+!23 = metadata !{i32 786489, metadata !24, null, metadata !"__gnu_debug", i32 55} ; [ DW_TAG_namespace ] [__gnu_debug] [line 55]
+!24 = metadata !{metadata !"/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/debug/debug.h", metadata !"/llvm_cmake_gcc"}
+!25 = metadata !{i32 786489, metadata !24, metadata !10, metadata !"__debug", i32 49} ; [ DW_TAG_namespace ] [__debug] [line 49]
+!26 = metadata !{i32 786440, metadata !10, metadata !27, i32 66} ; [ DW_TAG_imported_declaration ]
+!27 = metadata !{i32 786454, metadata !5, null, metadata !"mbstate_t", i32 106, i64 0, i64 0, i64 0, i32 0, metadata !28} ; [ DW_TAG_typedef ] [mbstate_t] [line 106, size 0, align 0, offset 0] [from __mbstate_t]
+!28 = metadata !{i32 786454, metadata !5, null, metadata !"__mbstate_t", i32 95, i64 0, i64 0, i64 0, i32 0, metadata !"_ZTS11__mbstate_t"} ; [ DW_TAG_typedef ] [__mbstate_t] [line 95, size 0, align 0, offset 0] [from _ZTS11__mbstate_t]
+!29 = metadata !{i32 786440, metadata !10, metadata !30, i32 141} ; [ DW_TAG_imported_declaration ]
+!30 = metadata !{i32 786454, metadata !31, null, metadata !"wint_t", i32 141, i64 0, i64 0, i64 0, i32 0, metadata !32} ; [ DW_TAG_typedef ] [wint_t] [line 141, size 0, align 0, offset 0] [from unsigned int]
+!31 = metadata !{metadata !"/llvm_cmake_gcc/bin/../lib/clang/3.5.0/include/stddef.h", metadata !"/llvm_cmake_gcc"}
+!32 = metadata !{i32 786468, null, null, metadata !"unsigned int", i32 0, i64 32, i64 32, i64 0, i32 0, i32 7} ; [ DW_TAG_base_type ] [unsigned int] [line 0, size 32, align 32, offset 0, enc DW_ATE_unsigned]
+!33 = metadata !{i32 786440, metadata !34, metadata !36, i32 42} ; [ DW_TAG_imported_declaration ]
+!34 = metadata !{i32 786489, metadata !35, null, metadata !"__gnu_cxx", i32 69} ; [ DW_TAG_namespace ] [__gnu_cxx] [line 69]
+!35 = metadata !{metadata !"/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/cpp_type_traits.h", metadata !"/llvm_cmake_gcc"}
+!36 = metadata !{i32 786454, metadata !11, metadata !10, metadata !"size_t", i32 155, i64 0, i64 0, i64 0, i32 0, metadata !37} ; [ DW_TAG_typedef ] [size_t] [line 155, size 0, align 0, offset 0] [from long unsigned int]
+!37 = metadata !{i32 786468, null, null, metadata !"long unsigned int", i32 0, i64 64, i64 64, i64 0, i32 0, i32 7} ; [ DW_TAG_base_type ] [long unsigned int] [line 0, size 64, align 64, offset 0, enc DW_ATE_unsigned]
+!38 = metadata !{i32 786440, metadata !34, metadata !39, i32 43} ; [ DW_TAG_imported_declaration ]
+!39 = metadata !{i32 786454, metadata !11, metadata !10, metadata !"ptrdiff_t", i32 156, i64 0, i64 0, i64 0, i32 0, metadata !40} ; [ DW_TAG_typedef ] [ptrdiff_t] [line 156, size 0, align 0, offset 0] [from long int]
+!40 = metadata !{i32 786468, null, null, metadata !"long int", i32 0, i64 64, i64 64, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] [long int] [line 0, size 64, align 64, offset 0, enc DW_ATE_signed]
+!41 = metadata !{i32 786440, metadata !10, metadata !"_ZTS5lconv", i32 55} ; [ DW_TAG_imported_declaration ]
+!42 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
+!43 = metadata !{i32 2, metadata !"Debug Info Version", i32 1}
+!44 = metadata !{metadata !"clang version 3.5.0 (209308)"}
+!45 = metadata !{i32 786689, metadata !13, metadata !"offset", metadata !14, i32 16777219, metadata !17, i32 0, i32 0} ; [ DW_TAG_arg_variable ] [offset] [line 3]
+!46 = metadata !{i32 3, i32 0, metadata !13, null}
+!47 = metadata !{i32 786689, metadata !13, metadata !"limit", metadata !14, i32 33554435, metadata !17, i32 0, i32 0} ; [ DW_TAG_arg_variable ] [limit] [line 3]
+!48 = metadata !{i32 786689, metadata !13, metadata !"range", metadata !14, i32 50331652, metadata !19, i32 8192, i32 0} ; [ DW_TAG_arg_variable ] [range] [line 4]
+!49 = metadata !{i32 4, i32 0, metadata !13, null}
+!50 = metadata !{i32 5, i32 0, metadata !51, null}
+!51 = metadata !{i32 786443, metadata !1, metadata !13, i32 5, i32 0, i32 0, i32 0} ; [ DW_TAG_lexical_block ] [/llvm_cmake_gcc/pr19307.cc]
+!52 = metadata !{i32 5, i32 0, metadata !53, null}
+!53 = metadata !{i32 786443, metadata !1, metadata !51, i32 5, i32 0, i32 1, i32 1} ; [ DW_TAG_lexical_block ] [/llvm_cmake_gcc/pr19307.cc]
+!54 = metadata !{i32 6, i32 0, metadata !51, null}
+!55 = metadata !{i32 7, i32 0, metadata !13, null}
+!56 = metadata !{i32 8, i32 0, metadata !13, null} ; [ DW_TAG_imported_declaration ]
+!57 = metadata !{i32 9, i32 0, metadata !13, null}
+
-- 
cgit v1.2.3