Bug 102248 – [CMake] Do not regenerate LLIntAssembly.h on every incremental build

• Component: Tools / Tests
• Status: RESOLVED FIXED

[Thiago Marcos P. Santos]

SSIA.

[Thiago Marcos P. Santos]

Created attachment 174196 [details]
Patch

[Raphael Kubo da Costa (:rakuco)]

FWIW, we've worked together on this one so LGTM.

[Laszlo Gombos]

Just an idea - would it be possible to remove LLIntOffsetsExtractor as a dependency for this generator ? - It seems that the Qt port is using that approach.

-DEPENDS LLIntOffsetsExtractor ${LLINT_ASM} ${OFFLINE_ASM}
+DEPENDS ${LLINT_ASM} ${OFFLINE_ASM}

[Thiago Marcos P. Santos]

(In reply to comment #3)
> Just an idea - would it be possible to remove LLIntOffsetsExtractor as a dependency for this generator ? - It seems that the Qt port is using that approach.
> 
> -DEPENDS LLIntOffsetsExtractor ${LLINT_ASM} ${OFFLINE_ASM}
> +DEPENDS ${LLINT_ASM} ${OFFLINE_ASM}

This is wrong. LLIntOffsetsExtractor is a real dependency.

The problem here is that sometimes the dependencies of LLIntOffsetsExtractor changes and it is rebuilt, but the exact same binary as before is generated (like when you add some code #ifdef'ed for a platform other than yours). This is fine and happens all the time with regular source code.

asm.rb, which in this case acts like a compiler, does some checksum magic and LLIntAssembly.h is not regenerated if LLIntOffsetsExtractor checksum matches the older version. asm.rb breaks the build system, because in this case a dependency (LLIntOffsetsExtractor) will be always newer than the dependent (LLIntAssembly.h). I'm fixing this by touching the LLIntAssembly.h.

[WebKit Review Bot]

Comment on attachment 174196 [details]
Patch

Clearing flags on attachment: 174196

Committed r134793: <http://trac.webkit.org/changeset/134793>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.