Fix spurious rebuilds for phony targets with validations#2729
Merged
jhasse merged 4 commits intoninja-build:masterfrom Mar 3, 2026
Merged
Fix spurious rebuilds for phony targets with validations#2729jhasse merged 4 commits intoninja-build:masterfrom
jhasse merged 4 commits intoninja-build:masterfrom
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Phony targets with no inputs are considered dirty if their output is missing. However, phony targets used as anchors for validation dependencies (e.g. from GN groups) often have no regular inputs but should not force a rebuild if the validations are clean. This change updates RecomputeOutputDirty to check if a phony target has validation dependencies. If so, it is treated similarly to a target with inputs: it is only dirty if its dependencies are dirty, not automatically dirty because the output file is missing. This fixes an issue where targets depending on a phony validation anchor would rebuild on every run.
digit-google
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Feb 15, 2026
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Thank you, this looks fine, @jhasse please take a look.
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Phony targets with no inputs are considered dirty if their output is missing. However, phony targets used as anchors for validation dependencies (e.g. from GN groups) often have no regular inputs but should not force a rebuild if the validations are clean.
This change updates RecomputeOutputDirty to check if a phony target has validation dependencies. If so, it is treated similarly to a target with inputs: it is only dirty if its dependencies are dirty, not automatically dirty because the output file is missing.
This fixes an issue where targets depending on a phony validation anchor would rebuild on every run.