[gas] Emit v2 .debug_line for -gdwarf-2
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Commit Message
Currently, when using -gdwarf-2, gas emits a v3 .debug_line contribution.
Fix this by emitting a v3 .debug_line contribution instead.
gas/ChangeLog:
2023-01-31 Tom de Vries <tdevries@suse.de>
PR 23941
* dwarf2dbg.c (DWARF2_LINE_VERSION): Set to 2 for -gdwarf-2.
(DWARF2_LINE_OPCODE_BASE): Handle DWARF2_LINE_VERSION == 2.
(dwarf2_directive_loc): Bump dwarf_level when encountering
v3 .loc options.
(out_debug_line): Don't output v3 standard opcodes for v2.
* testsuite/gas/i386/debug1.d: Update.
* testsuite/gas/i386/dwarf2-line-1.d: Update.
* testsuite/gas/i386/dwarf2-line-4.d: Update.
---
gas/dwarf2dbg.c | 27 ++++++++++++++++++--------
gas/testsuite/gas/i386/debug1.d | 7 ++-----
gas/testsuite/gas/i386/dwarf2-line-1.d | 7 ++-----
gas/testsuite/gas/i386/dwarf2-line-4.d | 7 ++-----
4 files changed, 25 insertions(+), 23 deletions(-)
base-commit: 594a01c217143dce2f1f3181bcca4047b4a44107
Comments
On Jan 31 2023, Tom de Vries via Binutils wrote:
> Fix this by emitting a v3 .debug_line contribution instead.
s/v3/v2/?
> diff --git a/gas/dwarf2dbg.c b/gas/dwarf2dbg.c
> index c7d9e8ef72f..e6c411426af 100644
> --- a/gas/dwarf2dbg.c
> +++ b/gas/dwarf2dbg.c
> @@ -88,7 +88,7 @@
>
> /* This implementation outputs version 3 .debug_line information. */
> #ifndef DWARF2_LINE_VERSION
> -#define DWARF2_LINE_VERSION (dwarf_level > 3 ? dwarf_level : 3)
> +#define DWARF2_LINE_VERSION dwarf_level
Seems like the comment is no longer accurate.
On 1/31/23 12:55, Andreas Schwab wrote:
> On Jan 31 2023, Tom de Vries via Binutils wrote:
>
>> Fix this by emitting a v3 .debug_line contribution instead.
>
> s/v3/v2/?
>
Hi Andreas,
thanks for the review.
Fixed the typo.
>> diff --git a/gas/dwarf2dbg.c b/gas/dwarf2dbg.c
>> index c7d9e8ef72f..e6c411426af 100644
>> --- a/gas/dwarf2dbg.c
>> +++ b/gas/dwarf2dbg.c
>> @@ -88,7 +88,7 @@
>>
>> /* This implementation outputs version 3 .debug_line information. */
>> #ifndef DWARF2_LINE_VERSION
>> -#define DWARF2_LINE_VERSION (dwarf_level > 3 ? dwarf_level : 3)
>> +#define DWARF2_LINE_VERSION dwarf_level
>
> Seems like the comment is no longer accurate.
>
I've updated the comment, and I've also updated the macro definition to:
...
#define DWARF2_LINE_VERSION DWARF2_VERSION
...
In gas/config/tc-ia64.h we override DWARF2_VERSION, and using
DWARF2_VERSION rather than dwarf_level for DWARF2_LINE_VERSION makes
sure that we keep the same version in .debug_info and .debug_line (well,
as long as DWARF2_LINE_VERSION isn't overridden).
Thanks,
- Tom
Hi Tom,
> I've updated the comment, and I've also updated the macro definition to:
> ...
> #define DWARF2_LINE_VERSION DWARF2_VERSION
Does this mean that DWARF2_LINE_VERSION is now redundant, and
could just be replaced with DWARF2_VERSION ?
Anyway, patch approved - please apply.
Cheers
Nick
On 1/31/23 14:38, Nick Clifton wrote:
> Hi Tom,
>
>> I've updated the comment, and I've also updated the macro definition to:
>> ...
>> #define DWARF2_LINE_VERSION DWARF2_VERSION
>
> Does this mean that DWARF2_LINE_VERSION is now redundant, and
> could just be replaced with DWARF2_VERSION ?
>
I suppose so, though when using DWARF2_LINE_VERSION it's immediate clear
what it means. With using DWARF2_VERSION when dealing .debug_lines, you
need to know/remember/lookup that the version is the same for the two.
> Anyway, patch approved - please apply.
Thanks, I'll commit then.
- Tom
@@ -88,7 +88,7 @@
/* This implementation outputs version 3 .debug_line information. */
#ifndef DWARF2_LINE_VERSION
-#define DWARF2_LINE_VERSION (dwarf_level > 3 ? dwarf_level : 3)
+#define DWARF2_LINE_VERSION dwarf_level
#endif
/* The .debug_rnglists has only been in DWARF version 5. */
@@ -119,7 +119,7 @@
Note: If you want to change this, you'll have to update the
"standard_opcode_lengths" table that is emitted below in
out_debug_line(). */
-#define DWARF2_LINE_OPCODE_BASE 13
+#define DWARF2_LINE_OPCODE_BASE (DWARF2_LINE_VERSION == 2 ? 10 : 13)
#ifndef DWARF2_LINE_BASE
/* Minimum line offset in a special line info. opcode. This value
@@ -1328,11 +1328,15 @@ dwarf2_directive_loc (int dummy ATTRIBUTE_UNUSED)
}
else if (strcmp (p, "prologue_end") == 0)
{
+ if (dwarf_level < 3)
+ dwarf_level = 3;
current.flags |= DWARF2_FLAG_PROLOGUE_END;
*input_line_pointer = c;
}
else if (strcmp (p, "epilogue_begin") == 0)
{
+ if (dwarf_level < 3)
+ dwarf_level = 3;
current.flags |= DWARF2_FLAG_EPILOGUE_BEGIN;
*input_line_pointer = c;
}
@@ -1352,6 +1356,8 @@ dwarf2_directive_loc (int dummy ATTRIBUTE_UNUSED)
}
else if (strcmp (p, "isa") == 0)
{
+ if (dwarf_level < 3)
+ dwarf_level = 3;
(void) restore_line_pointer (c);
value = get_absolute_expression ();
if (value >= 0)
@@ -2479,12 +2485,17 @@ out_debug_line (segT line_seg)
out_byte (0); /* DW_LNS_set_basic_block */
out_byte (0); /* DW_LNS_const_add_pc */
out_byte (1); /* DW_LNS_fixed_advance_pc */
- out_byte (0); /* DW_LNS_set_prologue_end */
- out_byte (0); /* DW_LNS_set_epilogue_begin */
- out_byte (1); /* DW_LNS_set_isa */
- /* We have emitted 12 opcode lengths, so make that this
- matches up to the opcode base value we have been using. */
- gas_assert (DWARF2_LINE_OPCODE_BASE == 13);
+ if (DWARF2_LINE_VERSION >= 3)
+ {
+ out_byte (0); /* DW_LNS_set_prologue_end */
+ out_byte (0); /* DW_LNS_set_epilogue_begin */
+ out_byte (1); /* DW_LNS_set_isa */
+ /* We have emitted 12 opcode lengths, so make that this
+ matches up to the opcode base value we have been using. */
+ gas_assert (DWARF2_LINE_OPCODE_BASE == 13);
+ }
+ else
+ gas_assert (DWARF2_LINE_OPCODE_BASE == 10);
out_dir_and_file_list (line_seg, sizeof_offset);
@@ -6,13 +6,13 @@ Raw dump of debug contents of section \.z?debug_line:
Offset: (0x)?0
Length: .*
- DWARF Version: 3
+ DWARF Version: 2
Prologue Length: .*
Minimum Instruction Length: 1
Initial value of 'is_stmt': 1
Line Base: -5
Line Range: 14
- Opcode Base: 13
+ Opcode Base: 10
Opcodes:
Opcode 1 has 0 args
@@ -24,9 +24,6 @@ Raw dump of debug contents of section \.z?debug_line:
Opcode 7 has 0 args
Opcode 8 has 0 args
Opcode 9 has 1 arg
- Opcode 10 has 0 args
- Opcode 11 has 0 args
- Opcode 12 has 1 arg
The Directory Table \(offset 0x.*\):
.*
@@ -6,13 +6,13 @@ Raw dump of debug contents of section \.z?debug_line:
Offset: (0x)?0
Length: .*
- DWARF Version: 3
+ DWARF Version: 2
Prologue Length: .*
Minimum Instruction Length: 1
Initial value of 'is_stmt': 1
Line Base: -5
Line Range: 14
- Opcode Base: 13
+ Opcode Base: 10
Opcodes:
Opcode 1 has 0 args
@@ -24,9 +24,6 @@ Raw dump of debug contents of section \.z?debug_line:
Opcode 7 has 0 args
Opcode 8 has 0 args
Opcode 9 has 1 arg
- Opcode 10 has 0 args
- Opcode 11 has 0 args
- Opcode 12 has 1 arg
The Directory Table \(offset 0x.*\):
.*
@@ -6,13 +6,13 @@ Raw dump of debug contents of section \.z?debug_line:
Offset: (0x)?0
Length: .*
- DWARF Version: 3
+ DWARF Version: 2
Prologue Length: .*
Minimum Instruction Length: 1
Initial value of 'is_stmt': 1
Line Base: -5
Line Range: 14
- Opcode Base: 13
+ Opcode Base: 10
Opcodes:
Opcode 1 has 0 args
@@ -24,9 +24,6 @@ Raw dump of debug contents of section \.z?debug_line:
Opcode 7 has 0 args
Opcode 8 has 0 args
Opcode 9 has 1 arg
- Opcode 10 has 0 args
- Opcode 11 has 0 args
- Opcode 12 has 1 arg
The Directory Table is empty\.