- Will end up having 'CPPFLAGS=-DBAR -DCOOKIE'.
-
- Here is how the flags documented above are collected as
- augmentation of these variables:
-
- -Dxxx xxx is collected in CPPDEFINES
- -Ixxx xxx is collected in CPPINCLUDES
- -Wp,xxx collected in CPPFLAGS
- -Lxxx collected in LDFLAGS
- -lxxx collected in LDLIBS
- -Wp,xxx collected in LDLIBS
- -rpath xxx collected in LDLIBS
- -R xxx collected in LDLIBS
- -framework xxx collected in LDLIBS
- -static collected in LDLIBS
- -xxx collected in CFLAGS
- +xxx collected in CFLAGS
+ Backward compatibility note:
+
+ To be compatible with older configuration scripts, the
+ environment variables are ignored if compiling / linking
+ flags are given on the command line, except for these:
+
+ AR, CC, CXX, CROSS_COMPILE, HASHBANGPERL, PERL, RANLIB, RC
+ and WINDRES
+
+ For example, the following command will not see -DBAR:
+
+ CPPFLAGS=-DBAR ./config -DCOOKIE
+
+ However, the following will see both set variables:
+
+ CC=gcc CROSS_COMPILE=x86_64-w64-mingw32- \
+ ./config -DCOOKIE