libga68: Honour user-set A68FLAGS in configure.
libga68's configure script now respects user-provided A68FLAGS, enabling reproducible builds.
The libga68 build process previously overwrote any user-specified A68FLAGS during configuration, preventing options like -ffile-prefix-map from being passed to the Algol 68 compiler. This change modifies configure.ac to default A68FLAGS only if it is unset, ensuring that user-defined flags are respected and aiding in the creation of reproducible builds.
In Details
The AC_PROG_A68 macro in libga68's configure.ac unconditionally assigned a default value to A68FLAGS after declaring it as a user variable. This prevented user-provided flags from being used, impacting reproducible builds by embedding the build directory in debug information. The change now defaults A68FLAGS only when unset, mirroring the behavior of GDCFLAGS in libphobos's configure script.
- libga68
- A library written in Algol 68, likely for a specific target or system that GCC supports.
- A68FLAGS
- A variable holding compiler flags for the Algol 68 compiler used to build libga68.
- configure.ac
- A file used by the Autoconf system to generate a shell script that configures the build environment for a package.
- Reproducible builds
- The ability to obtain the exact same build output from the same source code and build environment, regardless of when or where the build is performed.
- -ffile-prefix-map
- A compiler flag that remaps directory prefixes in file paths, useful for creating reproducible builds by ensuring that absolute paths do not appear in the output.