Fix unnecessary rebuilds caused by hip_prof_gen.py updating source file #2532
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hip_prof_gen.py writes the generated hip_prof_str.h to both the build directory and the source directory. Since the source file is written after the build output, it has a newer mtime (~19ns later). Ninja sees the source file as 'newer' than the build output and triggers a rebuild on every invocation. Reproducer (before fix): cd build/core/clr/build rm -f hipamd/include/hip/amd_detail/hip_prof_str.h ninja gen-prof-api-str-header ninja gen-prof-api-str-header -d explain # Output shows rebuild even though nothing changed: # ninja explain: recorded mtime of .../hip_prof_str.h older than # most recent input .../hip_prof_str.h (807560042 vs 826560006) Fix: Only write to the source file if content actually changed, avoiding unnecessary mtime updates that trigger rebuilds.
shadidashmiz
approved these changes
Jan 12, 2026
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hip_prof_gen.pywrites the generatedhip_prof_str.hto both the build directory and the source directory. Thehip_prof_str.hin the source directory (which is also an input tohip_prof_gen.py) thus gets its mtime updated. Ninja sees the source file as 'newer' than the build output and triggers a rebuild on every invocation.This is particularly problematic in TheRock, where this can triggers rebuilds of downstream components.
Fix: Only write to the source file if content actually changed, avoiding unnecessary mtime updates that trigger rebuilds.
Test Plan
Reproducer (before fix):
Test Result
No rebuild happens
Submission Checklist