Local variables whose address is taken and passed on to a call are described
in debug info using their stack slots instead of as an indirection of param reg + 0
offset. This is done by detecting FrameIndexSDNodes in SelectionDAG and generating
FrameIndexDbgValues for them. This ultimately generates DBG_VALUEs with stack
location operands.
Differential Revision: http://reviews.llvm.org/D23283
llvm-svn: 278703
diff --git a/llvm/test/DebugInfo/X86/debug-loc-frame.ll b/llvm/test/DebugInfo/X86/debug-loc-frame.ll
new file mode 100644
index 0000000..0462c66
--- /dev/null
+++ b/llvm/test/DebugInfo/X86/debug-loc-frame.ll
@@ -0,0 +1,113 @@
+; REQUIRES: object-emission
+
+; Check that when variables are allocated on the stack we generate debug locations
+; for the stack location directly instead of generating a register+offset indirection.
+
+; RUN: %llc_dwarf -O2 -filetype=obj -disable-post-ra < %s | llvm-dwarfdump - | FileCheck %s
+;
+; int data = 17;
+; int sum = 0;
+; int zero = 0;
+; int *ptr;
+;
+; extern void foo(int i, int *p);
+;
+; int main()
+; {
+; int val;
+; val = data;
+; foo(1, &val);
+; foo(2, &data);
+; return zero;
+; }
+;
+; CHECK: .debug_info contents
+; CHECK: DW_TAG_subprogram
+; CHECK-NOT: NULL
+; CHECK: DW_TAG_variable
+; CHECK: DW_AT_location [DW_FORM_sec_offset] ([[DEBUGLOCOFFSET:0x[0-9a-f]+]]){{[[:space:]].*}}"val"
+
+; See that 'val' has at least one location entry with a DW_op_breg? operand.
+; The DWARF DW_op_breg* ops are encoded from 0x70 to 0x8f, but checking for an
+; op in the range from 0x70 to 0x7f should suffice because that range covers
+; all integer GPRs.
+;
+; CHECK: .debug_loc contents:
+; CHECK-NOT: .debug{{.*}} contents
+; CHECK: [[DEBUGLOCOFFSET]]: Beginning
+; CHECK-NOT: {{0x[0-9a-f]+}}: Beginning
+; CHECK: Location description: 7{{[0-9a-f] .*}}
+
+; ModuleID = 'frame.c'
+source_filename = "frame.c"
+
+@data = global i32 17, align 4
+@sum = local_unnamed_addr global i32 0, align 4
+@zero = local_unnamed_addr global i32 0, align 4
+@ptr = common local_unnamed_addr global i32* null, align 8
+
+; Function Attrs: nounwind uwtable
+define i32 @main() local_unnamed_addr !dbg !13 {
+entry:
+ %val = alloca i32, align 4
+ %0 = bitcast i32* %val to i8*, !dbg !18
+ call void @llvm.lifetime.start(i64 4, i8* %0), !dbg !18
+ %1 = load i32, i32* @data, align 4, !dbg !19, !tbaa !20
+ tail call void @llvm.dbg.value(metadata i32 %1, i64 0, metadata !17, metadata !24), !dbg !25
+ store i32 %1, i32* %val, align 4, !dbg !26, !tbaa !20
+ tail call void @llvm.dbg.value(metadata i32* %val, i64 0, metadata !17, metadata !27), !dbg !25
+ call void @foo(i32 1, i32* nonnull %val), !dbg !28
+ call void @foo(i32 2, i32* nonnull @data), !dbg !29
+ %2 = load i32, i32* @zero, align 4, !dbg !30, !tbaa !20
+ call void @llvm.lifetime.end(i64 4, i8* %0), !dbg !31
+ ret i32 %2, !dbg !32
+}
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.start(i64, i8* nocapture)
+
+declare void @foo(i32, i32*) local_unnamed_addr
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.end(i64, i8* nocapture)
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.value(metadata, i64, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!10, !11}
+!llvm.ident = !{!12}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.9.0 (trunk 273961)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3)
+!1 = !DIFile(filename: "frame.c", directory: "/home/user/test")
+!2 = !{}
+!3 = !{!4, !6, !7, !8}
+!4 = distinct !DIGlobalVariable(name: "data", scope: !0, file: !1, line: 1, type: !5, isLocal: false, isDefinition: true, variable: i32* @data)
+!5 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!6 = distinct !DIGlobalVariable(name: "sum", scope: !0, file: !1, line: 2, type: !5, isLocal: false, isDefinition: true, variable: i32* @sum)
+!7 = distinct !DIGlobalVariable(name: "zero", scope: !0, file: !1, line: 3, type: !5, isLocal: false, isDefinition: true, variable: i32* @zero)
+!8 = distinct !DIGlobalVariable(name: "ptr", scope: !0, file: !1, line: 4, type: !9, isLocal: false, isDefinition: true, variable: i32** @ptr)
+!9 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !5, size: 64, align: 64)
+!10 = !{i32 2, !"Dwarf Version", i32 4}
+!11 = !{i32 2, !"Debug Info Version", i32 3}
+!12 = !{!"clang version 3.9.0 (trunk 273961)"}
+!13 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 8, type: !14, isLocal: false, isDefinition: true, scopeLine: 9, isOptimized: true, unit: !0, variables: !16)
+!14 = !DISubroutineType(types: !15)
+!15 = !{!5}
+!16 = !{!17}
+!17 = !DILocalVariable(name: "val", scope: !13, file: !1, line: 10, type: !5)
+!18 = !DILocation(line: 10, column: 3, scope: !13)
+!19 = !DILocation(line: 11, column: 9, scope: !13)
+!20 = !{!21, !21, i64 0}
+!21 = !{!"int", !22, i64 0}
+!22 = !{!"omnipotent char", !23, i64 0}
+!23 = !{!"Simple C/C++ TBAA"}
+!24 = !DIExpression()
+!25 = !DILocation(line: 10, column: 7, scope: !13)
+!26 = !DILocation(line: 11, column: 7, scope: !13)
+!27 = !DIExpression(DW_OP_deref)
+!28 = !DILocation(line: 12, column: 3, scope: !13)
+!29 = !DILocation(line: 13, column: 3, scope: !13)
+!30 = !DILocation(line: 14, column: 10, scope: !13)
+!31 = !DILocation(line: 15, column: 1, scope: !13)
+!32 = !DILocation(line: 14, column: 3, scope: !13)