[pw_fuzzer] Fix OSS-Fuzz coverage: emit absolute source paths for the FuzzTest toolchain#72705
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mergify[bot] merged 1 commit intoJun 23, 2026
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…ed relative_paths) Pigweed's $dir_pw_build:relative_paths config (-ffile-prefix-map) rewrites the chip_pw_fuzztest toolchain's source paths to repo-relative (src/..., out/...). OSS-Fuzz's coverage report resolves only absolute paths (llvm-cov -path-equivalence=/,$OUT), so the FuzzTest binaries' relative paths break report generation, which aborts on an out-of-tree path (out/usr/include/glib-2.0/...). The legacy chip fuzz targets use chip's own (non-pigweed) toolchain with no relative_paths (absolute paths), which coverage already handled. Drop relative_paths under oss_fuzz so chip_pw_fuzztest records absolute paths. Verified by reproducing the OSS-Fuzz coverage build (infra/helper.py build_fuzzers --sanitizer coverage + coverage): the report now generates.
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This pull request updates the chip_pw_fuzztest toolchain configuration in build/toolchain/pw_fuzzer/BUILD.gn to remove Pigweed's relative_paths config when building for OSS-Fuzz (oss_fuzz is true). This ensures absolute paths are retained, preventing issues with OSS-Fuzz coverage report generation which relies on absolute paths. There are no review comments, and I have no feedback to provide.
andy31415
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Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## master #72705 +/- ##
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+ Coverage 56.09% 56.76% +0.66%
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Files 1640 1634 -6
Lines 112467 112660 +193
Branches 13318 13143 -175
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+ Hits 63087 63948 +861
+ Misses 49380 48712 -668 ☔ View full report in Codecov by Harness. 🚀 New features to boost your workflow:
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PR #72705: Size comparison from 44fb474 to cc7abd8 Full report (33 builds for bl602, bl702, bl702l, cc13x4_26x4, cc32xx, efr32, esp32, nrfconnect, psoc6, qpg, realtek, stm32, telink)
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Summary
Problem
After the pw_fuzzer / Google FuzzTest OSS-Fuzz integration (#72573) landed, OSS-Fuzz's periodic coverage build started failing during report generation (the
address/undefinedbuilds andcheck_buildare unaffected):llvm-cov -path-equivalence=/,$OUT— i.e. it expects absolute paths (the builder's$SRCis copied into$OUT/$SRC).chip_pw_fuzztesttoolchain inherits pigweed's$dir_pw_build:relative_pathsconfig, whose-ffile-prefix-maptransforms rewrite source paths to repo-relative (src/..., out-dir files toout/...). So the FuzzTest binaries record relative paths that don't remap, and the report aborts on an out-of-tree path.relative_paths, so they record absolute paths — which is why coverage worked before the integration.Solution
Drop the
relative_pathsconfig from thechip_pw_fuzztesttoolchain undeross_fuzz, so it records absolute source paths like the legacy chip fuzz targets. Local builds are unchanged (they keeprelative_paths; local coverage resolves relative paths from the repo root).Related issues
Follow-up to #72573 (the FuzzTest OSS-Fuzz integration that introduced the regression).
Testing
Reproduced the OSS-Fuzz coverage build end-to-end against this change:
AssertionErrorabove (non-zero exit).Successfully generated clang code coverage report; the FuzzTest sources now resolve and the previously-fatalglibpath no longer appears in the summary.