Emit relocations for DW_AT_location entries on systems which need it. This is

a recommit of r127757. Fixes PR9493. Patch by Paul Robinson!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158957 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 111 insertions, 0 deletions

diff --git a/test/DebugInfo/X86/DW_AT_location-reference.ll b/test/DebugInfo/X86/DW_AT_location-reference.ll
new file mode 100644
index 0000000..3be9aba
--- /dev/null
+++ b/test/DebugInfo/X86/DW_AT_location-reference.ll
@@ -0,0 +1,111 @@
+; RUN: llc -O1 -mtriple=x86_64-apple-darwin < %s | FileCheck -check-prefix=DARWIN %s
+; RUN: llc -O1 -mtriple=x86_64-pc-linux-gnu < %s | FileCheck -check-prefix=LINUX %s
+; PR9493
+; Adapted from the original test case in r127757.
+; We use 'llc -O1' to induce variable 'x' to live in different locations.
+; We don't actually care where 'x' lives, or what exact optimizations get
+; used, as long as 'x' moves around we're fine.
+
+; // The variable 'x' lives in different locations, so it needs an entry in
+; // the .debug_loc table section, referenced by DW_AT_location.
+; // This ref is not relocatable on Darwin, and is relocatable elsewhere.
+; extern int g(int, int);
+; extern int a;
+; 
+; void f(void) {
+;   int x;
+;   a = g(0, 0);
+;   x = 1;
+;   while (x & 1) { x *= a; }
+;   a = g(x, 0);
+;   x = 2;
+;   while (x & 2) { x *= a; }
+;   a = g(0, x);
+; }
+
+; // The 'x' variable and its symbol reference location
+; DARWIN:      DW_TAG_variable
+; DARWIN-NEXT: ## DW_AT_name
+; DARWIN-NEXT: .long Lset{{[0-9]+}}
+; DARWIN-NEXT: ## DW_AT_decl_file
+; DARWIN-NEXT: ## DW_AT_decl_line
+; DARWIN-NEXT: ## DW_AT_type
+; DARWIN-NEXT: Lset{{[0-9]+}} = Ldebug_loc{{[0-9]+}}-Lsection_debug_loc ## DW_AT_location
+; DARWIN-NEXT: .long Lset{{[0-9]+}}
+
+; LINUX:      DW_TAG_variable
+; LINUX-NEXT: # DW_AT_name
+; LINUX-NEXT: # DW_AT_decl_file
+; LINUX-NEXT: # DW_AT_decl_line
+; LINUX-NEXT: # DW_AT_type
+; LINUX-NEXT: .long .Ldebug_loc{{[0-9]+}} # DW_AT_location
+
+
+; ModuleID = 'simple.c'
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-n32"
+
+@a = external global i32
+
+define void @f() nounwind {
+entry:
+  %call = tail call i32 @g(i32 0, i32 0) nounwind, !dbg !8
+  store i32 %call, i32* @a, align 4, !dbg !8, !tbaa !9
+  tail call void @llvm.dbg.value(metadata !12, i64 0, metadata !5), !dbg !13
+  br label %while.body
+
+while.body:                                       ; preds = %entry, %while.body
+  %x.017 = phi i32 [ 1, %entry ], [ %mul, %while.body ]
+  %mul = mul nsw i32 %call, %x.017, !dbg !14
+  %and = and i32 %mul, 1, !dbg !14
+  %tobool = icmp eq i32 %and, 0, !dbg !14
+  br i1 %tobool, label %while.end, label %while.body, !dbg !14
+
+while.end:                                        ; preds = %while.body
+  tail call void @llvm.dbg.value(metadata !{i32 %mul}, i64 0, metadata !5), !dbg !14
+  %call4 = tail call i32 @g(i32 %mul, i32 0) nounwind, !dbg !15
+  store i32 %call4, i32* @a, align 4, !dbg !15, !tbaa !9
+  tail call void @llvm.dbg.value(metadata !16, i64 0, metadata !5), !dbg !17
+  br label %while.body9
+
+while.body9:                                      ; preds = %while.end, %while.body9
+  %x.116 = phi i32 [ 2, %while.end ], [ %mul12, %while.body9 ]
+  %mul12 = mul nsw i32 %call4, %x.116, !dbg !18
+  %and7 = and i32 %mul12, 2, !dbg !18
+  %tobool8 = icmp eq i32 %and7, 0, !dbg !18
+  br i1 %tobool8, label %while.end13, label %while.body9, !dbg !18
+
+while.end13:                                      ; preds = %while.body9
+  tail call void @llvm.dbg.value(metadata !{i32 %mul12}, i64 0, metadata !5), !dbg !18
+  %call15 = tail call i32 @g(i32 0, i32 %mul12) nounwind, !dbg !19
+  store i32 %call15, i32* @a, align 4, !dbg !19, !tbaa !9
+  ret void, !dbg !20
+}
+
+declare i32 @g(i32, i32)
+
+declare void @llvm.dbg.value(metadata, i64, metadata) nounwind readnone
+
+!llvm.dbg.sp = !{!0}
+!llvm.dbg.lv.f = !{!5}
+
+!0 = metadata !{i32 589870, i32 0, metadata !1, metadata !"f", metadata !"f", metadata !"", metadata !1, i32 4, metadata !3, i1 false, i1 true, i32 0, i32 0, i32 0, i32 256, i1 true, void ()* @f} ; [ DW_TAG_subprogram ]
+!1 = metadata !{i32 589865, metadata !"simple.c", metadata !"/home/rengol01/temp/tests/dwarf/relocation", metadata !2} ; [ DW_TAG_file_type ]
+!2 = metadata !{i32 589841, i32 0, i32 12, metadata !"simple.c", metadata !"/home/rengol01/temp/tests/dwarf/relocation", metadata !"clang version 3.0 (trunk)", i1 true, i1 true, metadata !"", i32 0} ; [ DW_TAG_compile_unit ]
+!3 = metadata !{i32 589845, metadata !1, metadata !"", metadata !1, i32 0, i64 0, i64 0, i32 0, i32 0, i32 0, metadata !4, i32 0, i32 0} ; [ DW_TAG_subroutine_type ]
+!4 = metadata !{null}
+!5 = metadata !{i32 590080, metadata !6, metadata !"x", metadata !1, i32 5, metadata !7, i32 0} ; [ DW_TAG_auto_variable ]
+!6 = metadata !{i32 589835, metadata !0, i32 4, i32 14, metadata !1, i32 0} ; [ DW_TAG_lexical_block ]
+!7 = metadata !{i32 589860, metadata !2, metadata !"int", null, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ]
+!8 = metadata !{i32 6, i32 3, metadata !6, null}
+!9 = metadata !{metadata !"int", metadata !10}
+!10 = metadata !{metadata !"omnipotent char", metadata !11}
+!11 = metadata !{metadata !"Simple C/C++ TBAA", null}
+!12 = metadata !{i32 1}
+!13 = metadata !{i32 7, i32 3, metadata !6, null}
+!14 = metadata !{i32 8, i32 3, metadata !6, null}
+!15 = metadata !{i32 9, i32 3, metadata !6, null}
+!16 = metadata !{i32 2}
+!17 = metadata !{i32 10, i32 3, metadata !6, null}
+!18 = metadata !{i32 11, i32 3, metadata !6, null}
+!19 = metadata !{i32 12, i32 3, metadata !6, null}
+!20 = metadata !{i32 13, i32 1, metadata !6, null}