[llvm] r240717 - Debug Info: Add basic test coverage for the DWARF encoding of bitfields.

[Adrian Prantl]

Author: adrian
Date: Thu Jun 25 18:19:19 2015
New Revision: 240717

URL: http://llvm.org/viewvc/llvm-project?rev=240717&view=rev
Log:
Debug Info: Add basic test coverage for the DWARF encoding of bitfields.

While looking at a couple of bugs in the debug info output for bitfields
I noticed that there wasn't a single regression test to test my changes
against, so here's a start.

Added:
    llvm/trunk/test/DebugInfo/bitfields.ll

Added: llvm/trunk/test/DebugInfo/bitfields.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/bitfields.ll?rev=240717&view=auto
==============================================================================
--- llvm/trunk/test/DebugInfo/bitfields.ll (added)
+++ llvm/trunk/test/DebugInfo/bitfields.ll Thu Jun 25 18:19:19 2015
@@ -0,0 +1,104 @@
+; RUN: %llc_dwarf -mtriple x86_64-apple-macosx -O0 -filetype=obj -o %t_le.o %s
+; RUN: llvm-dwarfdump -debug-dump=info %t_le.o | FileCheck %s --check-prefix=CHECK-LE
+; RUN: %llc_dwarf -mtriple aarch64_be-gnu-linux -O0 -filetype=obj -o %t_be.o %s
+; RUN: llvm-dwarfdump -debug-dump=info %t_be.o | FileCheck %s --check-prefix=CHECK-BE
+
+; Produced at -O0 from:
+; struct bitfield {
+;   int a : 2;
+;   int b : 32;
+;   int c : 1;
+;   int d : 28;
+; };
+; struct bitfield b;
+
+; Note that DWARF 2 counts bit offsets backwards from the high end of
+; the storage unit to the high end of the bit field.
+
+; CHECK-LE: DW_TAG_member
+; CHECK-LE-NEXT: DW_AT_name{{.*}}"a"
+; CHECK-LE-NOT: DW_TAG_member
+; CHECK-LE:      DW_AT_byte_size  {{.*}} (0x04)
+; CHECK-LE-NEXT: DW_AT_bit_size   {{.*}} (0x02)
+; CHECK-LE-NEXT: DW_AT_bit_offset {{.*}} (0x1e)
+; CHECK-LE-NEXT: DW_AT_data_member_location {{.*}} 00
+
+; CHECK-LE: DW_TAG_member
+; CHECK-LE-NEXT: DW_AT_name{{.*}}"b"
+; CHECK-LE-NOT: DW_TAG_member
+; CHECK-LE:      DW_AT_data_member_location {{.*}} 04
+
+; CHECK-LE: DW_TAG_member
+; CHECK-LE-NEXT: DW_AT_name{{.*}}"c"
+; CHECK-LE-NOT: DW_TAG_member
+; CHECK-LE:      DW_AT_byte_size  {{.*}} (0x04)
+; CHECK-LE-NEXT: DW_AT_bit_size   {{.*}} (0x01)
+; CHECK-LE-NEXT: DW_AT_bit_offset {{.*}} (0x1f)
+; CHECK-LE-NEXT: DW_AT_data_member_location {{.*}} 08
+
+; CHECK-LE: DW_TAG_member
+; CHECK-LE-NEXT: DW_AT_name{{.*}}"d"
+; CHECK-LE-NOT: DW_TAG_member
+; CHECK-LE:      DW_AT_byte_size  {{.*}} (0x04)
+; CHECK-LE-NEXT: DW_AT_bit_size   {{.*}} (0x1c)
+; CHECK-LE-NEXT: DW_AT_bit_offset {{.*}} (0x03)
+; CHECK-LE-NEXT: DW_AT_data_member_location {{.*}} 08
+
+; CHECK-BE: DW_TAG_member
+; CHECK-BE-NEXT: DW_AT_name{{.*}}"a"
+; CHECK-BE-NOT: DW_TAG_member
+; CHECK-BE:      DW_AT_byte_size  {{.*}} (0x04)
+; CHECK-BE-NEXT: DW_AT_bit_size   {{.*}} (0x02)
+; CHECK-BE-NEXT: DW_AT_bit_offset {{.*}} (0x00)
+; CHECK-BE-NEXT: DW_AT_data_member_location {{.*}} 00
+
+; CHECK-BE: DW_TAG_member
+; CHECK-BE-NEXT: DW_AT_name{{.*}}"b"
+; CHECK-BE-NOT: DW_TAG_member
+; CHECK-BE:      DW_AT_data_member_location {{.*}} 04
+
+; CHECK-BE: DW_TAG_member
+; CHECK-BE-NEXT: DW_AT_name{{.*}}"c"
+; CHECK-BE-NOT: DW_TAG_member
+; CHECK-BE:      DW_AT_byte_size  {{.*}} (0x04)
+; CHECK-BE-NEXT: DW_AT_bit_size   {{.*}} (0x01)
+; CHECK-BE-NEXT: DW_AT_bit_offset {{.*}} (0x00)
+; CHECK-BE-NEXT: DW_AT_data_member_location {{.*}} 08
+
+; CHECK-BE: DW_TAG_member
+; CHECK-BE-NEXT: DW_AT_name{{.*}}"d"
+; CHECK-BE-NOT: DW_TAG_member
+; CHECK-BE:      DW_AT_byte_size  {{.*}} (0x04)
+; CHECK-BE-NEXT: DW_AT_bit_size   {{.*}} (0x1c)
+; CHECK-BE-NEXT: DW_AT_bit_offset {{.*}} (0x01)
+; CHECK-BE-NEXT: DW_AT_data_member_location {{.*}} 08
+
+; ModuleID = 'bitfields.c'
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx"
+
+%struct.bitfield = type <{ i8, [3 x i8], i64 }>
+
+ at b = common global %struct.bitfield zeroinitializer, align 4
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!13, !14, !15}
+!llvm.ident = !{!16}
+
+!0 = !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.7.0 (trunk 240548) (llvm/trunk 240554)", isOptimized: false, runtimeVersion: 0, emissionKind: 1, enums: !2, retainedTypes: !2, subprograms: !2, globals: !3, imports: !2)
+!1 = !DIFile(filename: "bitfields.c", directory: "/")
+!2 = !{}
+!3 = !{!4}
+!4 = !DIGlobalVariable(name: "b", scope: !0, file: !5, line: 8, type: !6, isLocal: false, isDefinition: true, variable: %struct.bitfield* @b)
+!5 = !DIFile(filename: "bitfields.c", directory: "/")
+!6 = !DICompositeType(tag: DW_TAG_structure_type, name: "bitfield", file: !5, line: 1, size: 96, align: 32, elements: !7)
+!7 = !{!8, !10, !11, !12}
+!8 = !DIDerivedType(tag: DW_TAG_member, name: "a", scope: !6, file: !5, line: 2, baseType: !9, size: 2, align: 32)
+!9 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!10 = !DIDerivedType(tag: DW_TAG_member, name: "b", scope: !6, file: !5, line: 3, baseType: !9, size: 32, align: 32, offset: 32)
+!11 = !DIDerivedType(tag: DW_TAG_member, name: "c", scope: !6, file: !5, line: 4, baseType: !9, size: 1, align: 32, offset: 64)
+!12 = !DIDerivedType(tag: DW_TAG_member, name: "d", scope: !6, file: !5, line: 5, baseType: !9, size: 28, align: 32, offset: 65)
+!13 = !{i32 2, !"Dwarf Version", i32 2}
+!14 = !{i32 2, !"Debug Info Version", i32 3}
+!15 = !{i32 1, !"PIC Level", i32 2}
+!16 = !{!"clang version 3.7.0 (trunk 240548) (llvm/trunk 240554)"}