Call the make command this way: make CFLAGS=-Dvar=42 And be sure to use $(CFLAGS) in your compile command in the Makefile. As @jørgensen mentioned, putting the variable assignment after the make command will override the CFLAGS value already defined in the Makefile. Alternatively, you could set -Dvar=42 in another variable than CFLAGS and then reuse … Read more
In fact all is explained in the doc: Finds whitespace-separated words in TEXT … means that one or more spaces have to separate the words. … that match PATTERN … means that it select only words that match a pattern (which can include some spaces). … and replaces them with REPLACEMENT. means that the selected … Read more
After re-reading the documentation on static pattern rules, I derived the following pattern rule which seems to work. $(OBJ_DEBUG): $(OBJDIR_DEBUG)/%.o: %.cpp $(CXX) $(CFLAGS_DEBUG) $(INC_DEBUG) -c $< -o $@ I’m not sure this is the best approach, and I’m open to suggestions.
If you are running make from the command line, use make CPPFLAGS=-DFOO which will add -DFOO to all compilations. See also CFLAGS, CXXFLAGS, LDFLAGS in the make manual.
The links posted are all good. For you particular case you can try this. Essentially all Makefiles follow this pattern. Everything else is shortcuts and macros. program: main.o dbAdapter.o gcc -o program main.o dbAdapter.o main.o: main.c dbAdapter.h gcc -c main.c dbAdapter.o dbAdapter.c dbAdapter.h gcc -c dbAdapter.c The key thing here is that the Makefile looks … Read more
According to autoconf manual (about AC_PROG_CC): If using the GNU C compiler, set shell variable GCC to ‘yes’. If output variable CFLAGS was not already set, set it to -g -O2 for the GNU C compiler (-O2 on systems where GCC does not accept -g), or -g for other compilers. If your package does not … Read more
I don’t know what the reason is, but if you move -lm to the end, it will compile. $ cc -o randomselection rfc3797.c MD5.c -lm rfc3797.c: In function ‘getinteger’: rfc3797.c:183:3: warning: format not a string literal and no format arguments [-Wformat-security]
Change your make target to this (adding semicolons): check: if [ -z “$(APP_NAME)” ]; then \ echo “Empty”; \ else \ echo “Not empty”; \ fi For evaluating a statement in a shell without newlines (newlines get eaten by the backslash \) you need to properly end it with a semicolon. You cannot use real … Read more
Incredibly, somehow everyone else missed the canonical way to do this, which has been around since 2 years before this thread began. 🙂 I wondered the same thing as the OP and was disappointed by the lack of proper (non-ugly) ways to do this when I read this thread. A few days later, while idly … Read more
If you export the variable to the shell and reference it as a shell variable, rather than a make variable, you will have better luck: define VAR1 /dev d 755 – – – – – endef define VAR2 /test d 777 – – – – – /test2 d 777 – – – – – endef … Read more