From: Simon Marchi <simark@simark.ca>
To: Guinevere Larsen <blarsen@redhat.com>, gdb-patches@sourceware.org
Subject: Re: [PATCH] gdb/dwarf2: Add support for DW_LNS_set_epilogue_begin in line-table
Date: Wed, 10 Jan 2024 11:57:26 -0500 [thread overview]
Message-ID: <3cf538c1-c8a9-404f-a2d2-86fd3d39fb5b@simark.ca> (raw)
In-Reply-To: <20231221102925.377720-1-blarsen@redhat.com>
On 12/21/23 05:29, Guinevere Larsen wrote:
> This commit adds a mechanism for GDB to detect the linetable opcode
> DW_LNS_set_epilogue_begin. This opcode is set by compilers to indicate
> that a certain instruction marks the point where the frame is destroyed.
>
> While the standard allows for multiple points marked with epilogue_begin
> in the same function, for performance reasons, the function that
> searches for the epilogue address will only find the last address that
> sets this flag for a given block.
>
> This commit also changes amd64_stack_frame_destroyed_p_1 to attempt to
> use the epilogue begin directly, and only if an epilogue can't be found
> will it attempt heuristics based on the current instruction.
>
> Finally, this commit also changes the dwarf assembler to be able to emit
> epilogue-begin instructions, to make it easier to test this patch
Starting with this commit, I see:
FAIL: gdb.base/unwind-on-each-insn-amd64.exp: foo: instruction 6: $fba_value == $fn_fba
FAIL: gdb.base/unwind-on-each-insn-amd64.exp: foo: instruction 6: check frame-id matches
FAIL: gdb.base/unwind-on-each-insn-amd64.exp: foo: instruction 6: bt 2
FAIL: gdb.base/unwind-on-each-insn-amd64.exp: foo: instruction 6: up
FAIL: gdb.base/unwind-on-each-insn-amd64.exp: foo: instruction 6: $sp_value == $::main_sp
FAIL: gdb.base/unwind-on-each-insn-amd64.exp: foo: instruction 6: $fba_value == $::main_fba
FAIL: gdb.base/unwind-on-each-insn-amd64.exp: foo: instruction 6: [string equal $fid $::main_fid]
Do you see it?
Simon
next prev parent reply other threads:[~2024-01-10 16:57 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-21 10:29 Guinevere Larsen
2023-12-22 16:34 ` Tom Tromey
2023-12-22 16:56 ` Guinevere Larsen
2024-01-02 9:24 ` Guinevere Larsen
2024-01-10 16:57 ` Simon Marchi [this message]
2024-01-10 17:01 ` Guinevere Larsen
2024-01-10 17:59 ` Tom Tromey
2024-01-11 17:02 ` Tom Tromey
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