Don't collect headers and macros from dependencies transitively#98
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chrisnovakovic merged 1 commit intoplease-build:masterfrom Nov 28, 2025
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…ncies Header files and macro definitions are currently collected from dependencies transitively, which is too aggressive. The only headers required to compile a C/C++ source file are the ones included by that source file, and the only macros that should be defined on the command line are the ones necessary to compile that source file. Collecting headers transitively pollutes the build environment (and increases the probability of unnecessary header name clashes); collecting macro definitions transitively risks causing action at a distance, especially for macros that change the meaning or behaviour of functions defined in the standard library (e.g. `_XOPEN_SOURCE`). Only collect headers exposed by direct dependencies, and don't collect macro definitions from dependencies at all. Fixes please-build#95.
toastwaffle
approved these changes
Nov 28, 2025
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Header files and macro definitions are currently collected from dependencies transitively, which is too aggressive. The only headers required to compile a C/C++ source file are the ones included by that source file, and the only macros that should be defined on the command line are the ones necessary to compile that source file. Collecting headers transitively pollutes the build environment (and increases the probability of unnecessary header name clashes); collecting macro definitions transitively risks causing action at a distance, especially for macros that change the visibility or behaviour of functions defined in the standard library (e.g.
_XOPEN_SOURCE).Only collect headers exposed by direct dependencies, and don't collect macro definitions from dependencies at all.
Fixes #95.