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[DWARFv5] llvm-mc support for new unit header.
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This is for running the assembler with -g (to emit DWARF describing
the assembler source).

Differential Revision: http://reviews.llvm.org/D30475

llvm-svn: 296541
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@pogo59
pogo59 committed Feb 28, 2017
1 parent 7d7409e commit dccb4fe
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Showing 4 changed files with 42 additions and 23 deletions.
14 changes: 9 additions & 5 deletions llvm/lib/MC/MCDwarf.cpp
View file
Expand Up @@ -674,19 +674,23 @@ static void EmitGenDwarfInfo(MCStreamer *MCOS,
// The 2 byte DWARF version.
MCOS->EmitIntValue(context.getDwarfVersion(), 2);

// The DWARF v5 header has unit type, address size, abbrev offset.
// Earlier versions have abbrev offset, address size.
const MCAsmInfo &AsmInfo = *context.getAsmInfo();
int AddrSize = AsmInfo.getPointerSize();
if (context.getDwarfVersion() >= 5) {
MCOS->EmitIntValue(dwarf::DW_UT_compile, 1);
MCOS->EmitIntValue(AddrSize, 1);
}
// The 4 byte offset to the debug abbrevs from the start of the .debug_abbrev,
// it is at the start of that section so this is zero.
if (AbbrevSectionSymbol == nullptr)
MCOS->EmitIntValue(0, 4);
else
MCOS->EmitSymbolValue(AbbrevSectionSymbol, 4,
AsmInfo.needsDwarfSectionOffsetDirective());

const MCAsmInfo *asmInfo = context.getAsmInfo();
int AddrSize = asmInfo->getPointerSize();
// The 1 byte size of an address.
MCOS->EmitIntValue(AddrSize, 1);
if (context.getDwarfVersion() <= 4)
MCOS->EmitIntValue(AddrSize, 1);

// Second part: the compile_unit DIE.

Expand Down
37 changes: 22 additions & 15 deletions llvm/test/MC/ARM/dwarf-asm-multiple-sections.s
View file
@@ -1,11 +1,14 @@
// RUN: llvm-mc < %s -triple=armv7-linux-gnueabi -filetype=obj -o %t -g -dwarf-version 5 -fdebug-compilation-dir=/tmp
// RUN: llvm-dwarfdump %t | FileCheck -check-prefix DWARF -check-prefix DWARF45 %s
// RUN: llvm-objdump -r %t | FileCheck -check-prefix RELOC -check-prefix RELOC5 %s
// RUN: llvm-mc < %s -triple=armv7-linux-gnueabi -filetype=obj -o %t -g -fdebug-compilation-dir=/tmp
// RUN: llvm-dwarfdump %t | FileCheck -check-prefix DWARF -check-prefix DWARF4 %s
// RUN: llvm-objdump -r %t | FileCheck -check-prefix RELOC %s
// RUN: llvm-dwarfdump %t | FileCheck -check-prefix DWARF -check-prefix DWARF45 %s
// RUN: llvm-objdump -r %t | FileCheck -check-prefix RELOC -check-prefix RELOC4 %s
// RUN: llvm-mc < %s -triple=armv7-linux-gnueabi -filetype=obj -o %t -g -dwarf-version 3 -fdebug-compilation-dir=/tmp
// RUN: llvm-dwarfdump %t | FileCheck -check-prefix DWARF -check-prefix DWARF3 %s
// RUN: llvm-mc < %s -triple=armv7-linux-gnueabi -filetype=obj -o %t -g -dwarf-version 2 2>&1 | FileCheck -check-prefix VERSION %s
// RUN: not llvm-mc < %s -triple=armv7-linux-gnueabi -filetype=obj -o %t -g -dwarf-version 1 2>&1 | FileCheck -check-prefix DWARF1 %s
// RUN: not llvm-mc < %s -triple=armv7-linux-gnueabi -filetype=obj -o %t -g -dwarf-version 5 2>&1 | FileCheck -check-prefix DWARF5 %s
// RUN: not llvm-mc < %s -triple=armv7-linux-gnueabi -filetype=obj -o %t -g -dwarf-version 6 2>&1 | FileCheck -check-prefix DWARF6 %s
.section .text, "ax"
a:
mov r0, r0
Expand All @@ -18,9 +21,9 @@ b:
// DWARF: Abbrev table for offset: 0x00000000
// DWARF: [1] DW_TAG_compile_unit DW_CHILDREN_yes
// DWARF3: DW_AT_stmt_list DW_FORM_data4
// DWARF4: DW_AT_stmt_list DW_FORM_sec_offset
// DWARF45: DW_AT_stmt_list DW_FORM_sec_offset
// DWARF3: DW_AT_ranges DW_FORM_data4
// DWARF4: DW_AT_ranges DW_FORM_sec_offset
// DWARF45: DW_AT_ranges DW_FORM_sec_offset
// DWARF: DW_AT_name DW_FORM_string
// DWARF: DW_AT_comp_dir DW_FORM_string
// DWARF: DW_AT_producer DW_FORM_string
Expand All @@ -29,8 +32,8 @@ b:
// DWARF: .debug_info contents:
// DWARF: 0x{{[0-9a-f]+}}: DW_TAG_compile_unit [1]
// DWARF-NOT: DW_TAG_
// DWARF3: DW_AT_ranges [DW_FORM_data4] (0x00000000
// DWARF4: DW_AT_ranges [DW_FORM_sec_offset] (0x00000000
// DWARF3: DW_AT_ranges [DW_FORM_data4] (0x00000000
// DWARF45: DW_AT_ranges [DW_FORM_sec_offset] (0x00000000

// DWARF: 0x{{[0-9a-f]+}}: DW_TAG_label [2] *
// DWARF-NEXT: DW_AT_name [DW_FORM_string] ("a")
Expand All @@ -46,10 +49,10 @@ b:


// DWARF: .debug_line contents:
// DWARF: 0x0000000000000000 11 0 1 0 0 is_stmt
// DWARF-NEXT: 0x0000000000000004 11 0 1 0 0 is_stmt end_sequence
// DWARF-NEXT: 0x0000000000000000 15 0 1 0 0 is_stmt
// DWARF-NEXT: 0x0000000000000004 15 0 1 0 0 is_stmt end_sequence
// DWARF: 0x0000000000000000 14 0 1 0 0 is_stmt
// DWARF-NEXT: 0x0000000000000004 14 0 1 0 0 is_stmt end_sequence
// DWARF-NEXT: 0x0000000000000000 18 0 1 0 0 is_stmt
// DWARF-NEXT: 0x0000000000000004 18 0 1 0 0 is_stmt end_sequence


// DWARF: .debug_ranges contents:
Expand All @@ -61,10 +64,14 @@ b:



// Offsets are different in DWARF v5 due to different header layout.
// RELOC: RELOCATION RECORDS FOR [.rel.debug_info]:
// RELOC-NEXT: 00000006 R_ARM_ABS32 .debug_abbrev
// RELOC-NEXT: 0000000c R_ARM_ABS32 .debug_line
// RELOC-NEXT: 00000010 R_ARM_ABS32 .debug_ranges
// RELOC4-NEXT: 00000006 R_ARM_ABS32 .debug_abbrev
// RELOC4-NEXT: 0000000c R_ARM_ABS32 .debug_line
// RELOC4-NEXT: 00000010 R_ARM_ABS32 .debug_ranges
// RELOC5-NEXT: 00000008 R_ARM_ABS32 .debug_abbrev
// RELOC5-NEXT: 0000000d R_ARM_ABS32 .debug_line
// RELOC5-NEXT: 00000011 R_ARM_ABS32 .debug_ranges
// RELOC-NEXT: R_ARM_ABS32 .text
// RELOC-NEXT: R_ARM_ABS32 foo

Expand All @@ -81,4 +88,4 @@ b:
// VERSION: {{.*}} warning: DWARF2 only supports one section per compilation unit

// DWARF1: Dwarf version 1 is not supported.
// DWARF5: Dwarf version 5 is not supported.
// DWARF6: Dwarf version 6 is not supported.
12 changes: 10 additions & 2 deletions llvm/test/MC/ELF/gen-dwarf.s
View file
Expand Up @@ -3,7 +3,8 @@
// RUN: llvm-mc -g -dwarf-version 2 -triple i686-pc-linux-gnu %s -filetype=asm -o - | FileCheck --check-prefix=ASM --check-prefix=DWARF2 %s
// RUN: llvm-mc -g -dwarf-version 3 -triple i686-pc-linux-gnu %s -filetype=asm -o - | FileCheck --check-prefix=ASM --check-prefix=DWARF3 %s
// RUN: llvm-mc -g -triple i686-pc-linux-gnu %s -filetype=asm -o - | FileCheck --check-prefix=ASM --check-prefix=DWARF4 %s
// RUN: not llvm-mc -g -dwarf-version 5 -triple i686-pc-linux-gnu %s -filetype=asm -o - 2>&1 | FileCheck --check-prefix=DWARF5 %s
// RUN: llvm-mc -g -dwarf-version 5 -triple i686-pc-linux-gnu %s -filetype=asm -o - 2>&1 | FileCheck --check-prefix=DWARF5 %s
// RUN: not llvm-mc -g -dwarf-version 6 -triple i686-pc-linux-gnu %s -filetype=asm -o - 2>&1 | FileCheck --check-prefix=DWARF6 %s


// Test that on ELF:
Expand Down Expand Up @@ -35,6 +36,8 @@ foo:

// ASM: .section .debug_abbrev
// ASM-NEXT: [[ABBREV_LABEL:.Ltmp[0-9]+]]
// DWARF5: .section .debug_abbrev
// DWARF5-NEXT: [[ABBREV_LABEL:.Ltmp[0-9]+]]

// Second instance of the section has the CU
// ASM: .section .debug_info
Expand All @@ -43,6 +46,11 @@ foo:
// DWARF3: .short 3
// DWARF4: .short 4
// ASM-NEXT: .long [[ABBREV_LABEL]]
// DWARF5: .short 5
// DWARF5-NEXT: .byte 1
// DWARF5-NEXT: .byte 4
// DWARF5-NEXT: .long [[ABBREV_LABEL]]

// First .byte 1 is the abbreviation number for the compile_unit abbrev
// ASM: .byte 1
// ASM-NEXT: .long [[LINE_LABEL:.L[a-z0-9]+]]
Expand All @@ -51,4 +59,4 @@ foo:
// ASM-NEXT: [[LINE_LABEL]]

// DWARF1: Dwarf version 1 is not supported.
// DWARF5: Dwarf version 5 is not supported.
// DWARF6: Dwarf version 6 is not supported.
2 changes: 1 addition & 1 deletion llvm/tools/llvm-mc/llvm-mc.cpp
View file
Expand Up @@ -516,7 +516,7 @@ int main(int argc, char **argv) {
Ctx.setGenDwarfForAssembly(GenDwarfForAssembly);
// Default to 4 for dwarf version.
unsigned DwarfVersion = MCOptions.DwarfVersion ? MCOptions.DwarfVersion : 4;
if (DwarfVersion < 2 || DwarfVersion > 4) {
if (DwarfVersion < 2 || DwarfVersion > 5) {
errs() << ProgName << ": Dwarf version " << DwarfVersion
<< " is not supported." << '\n';
return 1;
Expand Down

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