How to get the preprocessor output as part of the compilation process?

[Konstantin Andreev]

Hi, Valdis. It wasn't me who asked the question, so I can't comment on the Frank's goal.

> And in fact, what you may want to do is have your script invoke gcc twice, once with -E, and then a second time with -c, ...

Certainly. That is exactly what I have proposed. Nothing wrong with this.

Regards, Konstantin

Valdis Klētnieks, 10 Dec 2019 06:17 MSK:
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> And in fact, what you may want to do is have your script invoke gcc twice, once with -E, and then a second time with -c, because otherwise the build will die the first time it tries to link together two or more non-existent .o files.
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> Using 'make -k' might also work, but will leave the build log output littered with a lot of error messages.
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> Or explain why you're doing this - there may be a simpler way to achieve your goal. For instance, if you're trying to build a cross-reference of what .c files include what .h directly or indirectly, there's already specialized tools for doing that sort of thing, such as 'cxref'.

Konstantin Andreev, 09 Dec 2019 13:10 MSK:
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> The universal approach that always works in this and many similar cases is just to replace the instrumented binary by your interception shell script.
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> E.g. rename gcc to gcc.hide (generally, moving into another location may not work) and setup 'gcc' script that does what you want: replaces `-c' with the `-E', replaces `-o' argument, etc ..., calls gcc.hide to preprocess source then calls gcc.hide with original non-modified command line.
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> This is cumbersome process, you can break some things, ...