tree ac5a06044a7ee4832fef6308830c6a1bdbc60dea
parent 8a553b8b6e6f8aa06723780a0354024d0cbde779
author commit-queue@webkit.org <commit-queue@webkit.org@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1585845546 +0000
committer commit-queue@webkit.org <commit-queue@webkit.org@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1585845546 +0000

Enable offlineasm debug annotations for GCC
https://bugs.webkit.org/show_bug.cgi?id=207119

Patch by Angelos Oikonomopoulos <angelos@igalia.com> on 2020-04-02
Reviewed by Darin Adler.

This simply reuses the existing code that generates debug
annotations, adding two workarounds for limitations in GCC and
GDB.

First, the .file directives that offlineasm inserts in inline asm
use file slots that conflict with those in the compilation unit
that includes LLIntAssembly.h (specifically,
LowLevelInterpreter.cpp). Clang's built-in assembler will
transparently fix that for us, but for GCC we need to
post-process the generated assembler.

Unfortunately, cmake doesn't allow us to introduce a compiler wrapper for a
single source file, so we need to create a separate target for it.  This
wrapping only happens when building with GCC and the user has explicitly
requested debug information, either by selecting a Debug/RelWithDebInfo build
or setting GCC_OFFLINEASM_SOURCE_MAP.

Second, GDB will only look at the line table for a compilation unit if
it can first resolve the address to one of the known symbols in the
file. Introduce marker symbols to work around this bug.

* CMakeLists.txt:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@259390 268f45cc-cd09-0410-ab3c-d52691b4dbfc