This probes for:
checking whether C compiler accepts -Werror=unknown-warning-option... yes checking whether C compiler accepts -Wno-suggest-attribute=format... yes checking whether C compiler accepts -fno-strict-aliasing... yes checking whether C compiler accepts -Wall... yes checking whether C compiler accepts -Wextra... yes checking whether C compiler accepts -Wundef... yes checking whether C compiler accepts -Wnested-externs... yes checking whether C compiler accepts -Wwrite-strings... yes checking whether C compiler accepts -Wpointer-arith... yes checking whether C compiler accepts -Wmissing-declarations... yes checking whether C compiler accepts -Wmissing-prototypes... yes checking whether C compiler accepts -Wstrict-prototypes... yes checking whether C compiler accepts -Wredundant-decls... yes checking whether C compiler accepts -Wno-unused-parameter... yes checking whether C compiler accepts -Wno-missing-field-initializers... yes checking whether C compiler accepts -Wdeclaration-after-statement... yes checking whether C compiler accepts -Wformat=2... yes checking whether C compiler accepts -Wold-style-definition... yes checking whether C compiler accepts -Wcast-align... yes checking whether C compiler accepts -Wformat-nonliteral... yes checking whether C compiler accepts -Wformat-security... yes checking whether C compiler accepts -Wsign-compare... yes checking whether C compiler accepts -Wstrict-aliasing... yes checking whether C compiler accepts -Wshadow... yes checking whether C compiler accepts -Winline... yes checking whether C compiler accepts -Wpacked... yes checking whether C compiler accepts -Wmissing-format-attribute... yes checking whether C compiler accepts -Wmissing-noreturn... yes checking whether C compiler accepts -Winit-self... yes checking whether C compiler accepts -Wredundant-decls... (cached) yes checking whether C compiler accepts -Wmissing-include-dirs... yes checking whether C compiler accepts -Wunused-but-set-variable... no checking whether C compiler accepts -Warray-bounds... yes checking whether C compiler accepts -Wimplicit-function-declaration... yes checking whether C compiler accepts -Wreturn-type... yes checking whether C compiler accepts -Wswitch-enum... yes checking whether C compiler accepts -Wswitch-default... yes checking whether C compiler accepts -Wno-suggest-attribute=format... no checking whether C compiler accepts -Wno-error=unused-parameter... yes checking whether C compiler accepts -Wno-error=missing-field-initializers... yes checking whether C compiler accepts -Werror=unknown-warning-option... (cached) yes checking whether the linker accepts -Wl,--no-as-needed... no checking whether the linker accepts -Wl,--fatal-warnings... no checking whether the linker accepts -Wl,-fatal_warnings... yes checking whether the linker accepts -Wl,-fatal_warnings... yes
This probes for: