cmake: Let libsecp256k1 manage config-specific C flags

CMakeLists.txt

@@ -428,15 +428,12 @@ target_compile_definitions(core_interface_debug INTERFACE
 )
 # We leave assertions on.
 if(MSVC)
-  remove_c_flag_from_all_configs(/DNDEBUG)
   remove_cxx_flag_from_all_configs(/DNDEBUG)
 else()
-  remove_c_flag_from_all_configs(-DNDEBUG)
   remove_cxx_flag_from_all_configs(-DNDEBUG)
 
-  # Adjust flags used by the C/CXX compiler during RELEASE builds.
+  # Adjust flags used by the CXX compiler during RELEASE builds.
   # Prefer -O2 optimization level. (-O3 is CMake's default for Release for many compilers.)
-  replace_c_flag_in_config(Release -O3 -O2)
   replace_cxx_flag_in_config(Release -O3 -O2)
 
   are_flags_overridden(CMAKE_CXX_FLAGS_DEBUG cxx_flags_debug_overridden)
@@ -446,6 +443,7 @@ else()
     if(compiler_supports_g3)
       replace_cxx_flag_in_config(Debug -g -g3)
     endif()
+    unset(compiler_supports_g3)
 
     try_append_cxx_flags("-ftrapv" RESULT_VAR compiler_supports_ftrapv)
     if(compiler_supports_ftrapv)
@@ -462,24 +460,6 @@ else()
     )
   endif()
   unset(cxx_flags_debug_overridden)
-
-  are_flags_overridden(CMAKE_C_FLAGS_DEBUG c_flags_debug_overridden)
-  if(NOT c_flags_debug_overridden)
-    # Redefine flags used by the C compiler during DEBUG builds.
-    if(compiler_supports_g3)
-      replace_c_flag_in_config(Debug -g -g3)
-    endif()
-
-    string(PREPEND CMAKE_C_FLAGS_DEBUG "-O0 ")
-
-    set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG}"
-      CACHE STRING
-      "Flags used by the C compiler during DEBUG builds."
-      FORCE
-    )
-  endif()
-  unset(compiler_supports_g3)
-  unset(c_flags_debug_overridden)
 endif()
 
 include(optional)

cmake/module/ProcessConfigurations.cmake

@@ -84,23 +84,6 @@ function(set_default_config config)
   endif()
 endfunction()
 
-function(remove_c_flag_from_all_configs flag)
-  get_all_configs(all_configs)
-  foreach(config IN LISTS all_configs)
-    string(TOUPPER "${config}" config_uppercase)
-    set(flags "${CMAKE_C_FLAGS_${config_uppercase}}")
-    separate_arguments(flags)
-    list(FILTER flags EXCLUDE REGEX "${flag}")
-    list(JOIN flags " " new_flags)
-    set(CMAKE_C_FLAGS_${config_uppercase} "${new_flags}" PARENT_SCOPE)
-    set(CMAKE_C_FLAGS_${config_uppercase} "${new_flags}"
-      CACHE STRING
-      "Flags used by the C compiler during ${config_uppercase} builds."
-      FORCE
-    )
-  endforeach()
-endfunction()
-
 function(remove_cxx_flag_from_all_configs flag)
   get_all_configs(all_configs)
   foreach(config IN LISTS all_configs)
@@ -118,17 +101,6 @@ function(remove_cxx_flag_from_all_configs flag)
   endforeach()
 endfunction()
 
-function(replace_c_flag_in_config config old_flag new_flag)
-  string(TOUPPER "${config}" config_uppercase)
-  string(REGEX REPLACE "(^| )${old_flag}( |$)" "\\1${new_flag}\\2" new_flags "${CMAKE_C_FLAGS_${config_uppercase}}")
-  set(CMAKE_C_FLAGS_${config_uppercase} "${new_flags}" PARENT_SCOPE)
-  set(CMAKE_C_FLAGS_${config_uppercase} "${new_flags}"
-    CACHE STRING
-    "Flags used by the C compiler during ${config_uppercase} builds."
-    FORCE
-  )
-endfunction()
-
 function(replace_cxx_flag_in_config config old_flag new_flag)
   string(TOUPPER "${config}" config_uppercase)
   string(REGEX REPLACE "(^| )${old_flag}( |$)" "\\1${new_flag}\\2" new_flags "${CMAKE_CXX_FLAGS_${config_uppercase}}")