This is needed in particular for hardening flags.
CC=${CC:-gcc}
CXX=${CXX:-g++}
CFLAGS=${CFLAGS:--O2}
+CPPFLAGS=${CPPFLAGS:-}
CXXFLAGS=${CXXFLAGS:-\$(CFLAGS)}
LDFLAGS=${LDFLAGS:-}
XAPIAN_CONFIG=${XAPIAN_CONFIG:-xapian-config}
CC The C compiler to use
CFLAGS Flags to pass to the C compiler
+ CPPFLAGS Flags to pass to the C preprocessor
CXX The C++ compiler to use
CXXFLAGS Flags to pass to the C compiler
LDFLAGS Flags to pass when linking
# Default FLAGS for C compiler (can be overridden by user such as "make CFLAGS=-g")
CFLAGS = ${CFLAGS}
+# Default FLAGS for C preprocessor (can be overridden by user such as "make CPPFLAGS=-I/usr/local/include")
+CPPFLAGS = ${CPPFLAGS}
+
# Default FLAGS for C++ compiler (can be overridden by user such as "make CXXFLAGS=-g")
CXXFLAGS = ${CXXFLAGS}