Avoid clobbering user variables in autotools files #747
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The user variable CCASFLAGS should never be set in configure.ac, and the default AM_CCASFLAGS already has AM_CPPFLAGS added so it ends up appearing in the command line twice. Remove setting both of these variables so using the user variable from the command line will do the right thing and there is less noise in the build logs.
Enabling debug mode was convoluted and added cognitive load.
This change simplifies how the configuration option --enable-debug works
by simply adding -DUNW_DEBUG=1 to the preprocesor flags via a specific
confiuration variable, accomplishing the folowing goals.
- don't clobber the CPPFLAGS user variable
- don't mess with -DNDEBUG which has other meanings orthogonal
to libunwind debug mode
- don't hide the definition of the ABI-changing build-time option
behind an ifdef in an internal header file
In addition I added a warning to confogure --help to point out that
enabling the option changes the ABI. Caveat lector.
Replaced defining the user variable CPPFLAGS in configure.ac with UNW_REMOTE_CPPFLAGS and UNW_TARGET_CPPFLAGS.
Replaced the clobbering of the user variable CFLAGS in configure.ac with UNW_EXTRA_CFLAGS.
bregma
changed the title
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configure.acand the variousMakefile.amfiles were clobbering user variables CFLAGS, CPPFLAGS, and CCASFLAGS. This causes trouble when a user want to set those variables from the command line during a build (eg.make CFLAGS="-g -O0").This change replaces that clobber with various UNW_ variables propagated through the system.
Closes #744
Closes #743