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Re: [PATCH GCC]Add 'force-dwarf-lexical-blocks' command line option
- From: pinskia at gmail dot com
- To: "Herman, Andrei" <Andrei_Herman at codesourcery dot com>
- Cc: "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>, "Herman_Andrei at mentor dot com" <Herman_Andrei at relay1 dot mentorg dot com>
- Date: Wed, 7 May 2014 02:36:39 -0700
- Subject: Re: [PATCH GCC]Add 'force-dwarf-lexical-blocks' command line option
- Authentication-results: sourceware.org; auth=none
- References: <FEC4CADEDABC9E40A1EC17465AAC8402AE41BF45 at EU-MBX-04 dot mgc dot mentorg dot com>
> On May 7, 2014, at 2:32 AM, "Herman, Andrei" <Andrei_Herman@codesourcery.com> wrote:
> Currently GCC only emits DWARF debug information (DW_TAG_lexical_block DIEs)
> for compound statements containing significant local declarations.
> However, code coverage tools that process the DWARF debug information to
> implement block/path coverage need more complete lexical block information.
> This patch adds the necessary functionality under the control of a new
> command line argument: -fforce-dwarf-lexical-blocks.
> When this flag is set, a DW_TAG_lexical_block DIE will be emitted for every
> function body, loop body, switch body, case statement, if-then and if-else
> statement, even if the body is a single statement.
> Likewise, a lexical block will be emitted for the first label of a labeled
> statement. This block ends at the end of the current lexical scope, or when
> a break, continue, goto or return statement is encountered at the same lexical
> scope level.
> Consequently, any case in a switch statement that does not flow through to
> the next case, will have its own dwarf lexical block.
> The complete change proposal contains 4 patches (attached first 3):
> 1. Add command line option -fforce-dwarf-lexical-blocks
This option since it is specific to the c frontend should go into c.opt instead of common.opt. Unless you are going to extend this to Ada, Java and fortran.
> 2. Use of flag_force_dwarf_blocks
> 3. Create label scopes
> A forth patch, extending the proposed functionality to C++ will be submitted in a separate message.
> Attached are the proposed ChangeLog additions, named according to the directory each one belongs to.
> Best regards,
> Andrei Herman
> Mentor Graphics Corporation
> Israel branch