Hi Richard, Pietro, Thanks for the feedback. I tested Pietro’s suggestion with a minimal reproducer and a local dummy plugin.
I compiled hello.c with: - -g -grecord-gcc-switches -fplugin=<absolute-path> Then repeated with: 1. -fdebug-prefix-map=/tmp/gcc_plugin_map_test3=REMAP 2. -fdebug-prefix-map targeting the plugin directory specifically 3. -ffile-prefix-map=/tmp/gcc_plugin_map_test3=REMAP 4. -fmacro-prefix-map=/tmp/gcc_plugin_map_test3=REMAP 5. -fdebug-prefix-map + -ffile-prefix-map 6. Control: -gno-record-gcc-switches Validation: - Checked DW_AT_producer via readelf --debug-dump=info. Findings: - In cases (1)–(5), DW_AT_producer still contained the absolute plugin path from -fplugin=.... - Only case (6) removed -fplugin from DW_AT_producer. So in this environment (GCC 13.3.0), the prefix-map options do not rewrite/sanitize the plugin path when GCC switch recording is enabled. Thanks, Jaihind Yadav -----Original Message----- From: Pietro Monteiro <[email protected]> Sent: Sunday, August 16, 2026 8:06 PM To: Richard Biener <[email protected]>; Jaihind Yadav <[email protected]> Cc: [email protected]; [email protected] Subject: Re: RFC: Should -fplugin and -fplugin-arg options be excluded from DW_AT_producer recording? WARNING: This email originated from outside of Qualcomm. Please be wary of any links or attachments, and do not enable macros. On Fri, Aug 14, 2026, at 2:16 AM, Richard Biener via Gcc wrote: > On Wed, Aug 12, 2026 at 12:40 PM Jaihind Yadav > <[email protected]> wrote: >> >> Hi, >> >> >> >> While investigating a build-path leakage issue, I noticed that >> >> -fplugin=<path> and -fplugin-arg-* options are currently recorded in >> >> DW_AT_producer when -grecord-gcc-switches is enabled. >> >> >> >> As a result, an absolute plugin path may become embedded in debug >> >> metadata. >> >> >> >> For example: >> >> >> >> gcc -g -grecord-gcc-switches \ >> >> -fplugin=/path/to/plugin.so \ >> >> -c hello.c >> >> >> >> produces an object file whose DW_AT_producer contains: >> >> >> >> GNU C23 ... -g -fplugin=/path/to/plugin.so >> >> >> >> In my case, the recorded path was an absolute build-system path to a >> >> GCC plugin: >> >> >> >> -fplugin=/local/.../scripts/gcc-plugins/stackleak_plugin.so >> >> >> >> This introduces host-specific path information into the generated >> >> artifact and may negatively affect reproducibility. >> >> >> >> I noticed that GCC already has the NoDWARFRecord mechanism for >> options >> >> that should not be recorded in the producer string. Looking through >> the >> >> history, it appears that this mechanism was introduced partly to >> address >> >> reproducibility concerns involving path-containing options, and there >> >> are also examples where specific options are intentionally excluded >> from >> >> producer-string recording. >> >> >> >> As an experiment, I modified: >> >> >> >> gcc/common.opt >> >> >> >> and marked: >> >> >> >> -fplugin= >> >> -fplugin-arg-* >> >> >> >> with NoDWARFRecord. >> >> >> >> With this change: >> >> >> >> Before: >> >> DW_AT_producer: >> >> GNU C23 ... -g \ >> >> -fplugin=/local/.../stackleak_plugin.so >> >> >> >> After: >> >> DW_AT_producer: >> >> GNU C23 ... -g >> >> >> >> The plugin is still loaded correctly, plugin arguments are still >> passed, >> >> and generated code/debug information remain unchanged. The only >> observed >> >> difference is that plugin-related command-line options are no longer >> >> recorded in DW_AT_producer. >> >> >> >> The tradeoff appears to be: >> >> >> >> Benefits: >> >> - Avoids recording host-specific absolute plugin paths. >> >> - Improves reproducibility of producer strings. >> >> - Reduces leakage of local build environment details. >> >> >> >> Downsides: >> >> - Reduces provenance information available from DW_AT_producer. >> >> - Makes it harder to determine from the binary alone which GCC plugin >> >> (and plugin arguments) were used during compilation. >> >> >> >> Before preparing a formal patch submission, I would like feedback on >> the >> >> policy aspect: >> >> >> >> Should -fplugin and -fplugin-arg-* be treated similarly to other >> >> path-sensitive options and be excluded from producer-string >> >> recording? > > No, they should not be excluded as they are clearly affecting the > compilation. Is there not a standard plugin search path so the build > systems can use -fplugin=<name>.so without path? Can you test the effect of -fdebug-prefix-map and other path options on plugin path recording? https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html#index-fdebug-prefix-map pietro >> >> >> >> or >> >> >> >> Is preserving plugin provenance in DW_AT_producer considered more >> >> valuable than avoiding path leakage and reproducibility issues? >> >> >> >> Comments and guidance would be appreciated. >> >> >> >> Thanks, >> >> Jaihind Yadav >> >>
