llvm dev - Jul 2015 - [LLVMdev] Column information for the CodeView debug info format

Hello,

LLVM currently supports emission of CodeView's line table subsection.
However, we'd like to increase the fidelity of this debug info with column
information.  I was wondering if anybody had any pointers as to how
CodeView represents such information.

Thanks!

-- 
David Majnemer
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20150706/6cdf08b1/attachment.html>

The line number section you already emit looks like:

(0..3) SECREL relocation to function
(4..5) Section index of function
(6..7) Padding
(8..11) Code Size

The “Padding” field is actually a flags field, with one flag defined: bit 0 of
that field should be set if there is column info in this line number subsection.

The actual column info is emitted as part of the same chunks that contain the
line numbers for a given file name. Each chunk looks like:
(0..3) Offset of file in the file name table
(4..7) Count of line numbers (n)
(8..11) Size of chunk
(12..12+8*n) Line number records
(12+8*n..12+8*n+4*n) Column records (if column info flag was set)

Each column info record looks like:
(0..1) Start Column
(2..3) End Column

Note that the chunk includes all of the line number records before any of the
column records.

-Dave

From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On
Behalf Of David Majnemer
Sent: Monday, July 6, 2015 9:49 PM
To: llvmdev at cs.uiuc.edu
Cc: Jim Radigan <jradigan at microsoft.com>
Subject: [LLVMdev] Column information for the CodeView debug info format

Hello,

LLVM currently supports emission of CodeView's line table subsection. 
However, we'd like to increase the fidelity of this debug info with column
information.  I was wondering if anybody had any pointers as to how CodeView
represents such information.

Thanks!

--
David Majnemer
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20150708/bfeecf3f/attachment.html>

On Wed, Jul 8, 2015 at 10:54 AM, Dave Bartolomeo <
Dave.Bartolomeo at microsoft.com> wrote:
>  The line number section you already emit looks like:
>
>
>
> (0..3) SECREL relocation to function
>
> (4..5) Section index of function
>
> (6..7) Padding
>
> (8..11) Code Size
>
>
>
> The “Padding” field is actually a flags field, with one flag defined: bit
> 0 of that field should be set if there is column info in this line number
> subsection.
>
>
>
> The actual column info is emitted as part of the same chunks that contain
> the line numbers for a given file name. Each chunk looks like:
>
> (0..3) Offset of file in the file name table
>
> (4..7) Count of line numbers (n)
>
> (8..11) Size of chunk
>
> (12..12+8*n) Line number records
>
> (12+8*n..12+8*n+4*n) Column records (if column info flag was set)
>
>
>
> Each column info record looks like:
>
> (0..1) Start Column
>
> (2..3) End Column
>
>
>
> Note that the chunk includes all of the line number records before any of
> the column records.
>
Thanks! Should be implemented in r241764.

>
>
> -Dave
>
>
>
> *From:* llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at
cs.uiuc.edu] *On
> Behalf Of *David Majnemer
> *Sent:* Monday, July 6, 2015 9:49 PM
> *To:* llvmdev at cs.uiuc.edu
> *Cc:* Jim Radigan <jradigan at microsoft.com>
> *Subject:* [LLVMdev] Column information for the CodeView debug info format
>
>
>
> Hello,
>
>
>
> LLVM currently supports emission of CodeView's line table subsection.
> However, we'd like to increase the fidelity of this debug info with
column
> information.  I was wondering if anybody had any pointers as to how
> CodeView represents such information.
>
>
>
> Thanks!
>
>
>
> --
>
> David Majnemer
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20150710/ce347ff4/attachment.html>