Configury: Consolidate CHECK_ATTRIBUTE_VISIBILITY macro.
The CHECK_ATTRIBUTE_VISIBILITY macro is now centralized in visibility.m4 and used by libatomic, libgfortran, libgomp, and libitm.
The CHECK_ATTRIBUTE_VISIBILITY macro was duplicated across multiple libraries (libatomic, libgfortran, libgomp, and libitm). This commit centralizes the macro in a new file, config/visibility.m4, and updates the libraries to use the common definition. This change reduces redundancy and simplifies maintenance.
In Details
The commit consolidates the CHECK_ATTRIBUTE_VISIBILITY macro, which is used to determine whether attribute visibility is supported by the compiler. The macro was previously duplicated in libatomic, libgfortran, libgomp, and libitm. The consolidated macro is now located in config/visibility.m4, and the libraries are updated to use GCC_CHECK_ATTRIBUTE_VISIBILITY instead of their নিজস্ব copies. This involves changes to configure.ac, acinclude.m4, and Makefile.in in each library.
For Context
When building software, the configure script is a critical step that checks for dependencies and configures the build environment. Autoconf is a tool that helps generate these configure scripts. This commit modifies the Autoconf configuration to consolidate a macro called CHECK_ATTRIBUTE_VISIBILITY. This macro checks whether the compiler supports visibility attributes, which control symbol visibility in shared libraries. By centralizing this macro, the build process becomes more maintainable and consistent across different parts of the GCC project.