How can I configure my makefile for debug and release builds

Question

I have the following makefile for my project  and I d like to configure it for release and debug builds  In my code  I have lots of  ifdef DEBUG macros in place  so it s simply a matter of setting this macro and adding the -g3 -gdwarf2 flags to the compilers  How can I do this     CC    g   -g3 -gdwarf2   cc    gcc -g3 -gdwarf2  all  executable  executable  CommandParser tab o CommandParser yy o Command o     g   -g -o output CommandParser yy o CommandParser tab o Command o -lfl  CommandParser yy o  CommandParser l      flex -o CommandParser yy c CommandParser l     gcc -g -c CommandParser yy c  CommandParser tab o  CommandParser y     bison -d CommandParser y     g   -g -c CommandParser tab c  Command o  Command cpp     g   -g -c Command cpp  clean      rm -f CommandParser tab   CommandParser yy   output   o   Just to clarify  when I say release debug builds  I want to be able to just type make and get a release build or make debug and get a debug build  without manually commenting out things in the makefile

User · Answer

Completing the answers from earlier    You need to reference the variables you define info in your commands     DEBUG    1 ifeq  DEBUG  1      CFLAGS  -g3 -gdwarf2 -DDEBUG else     CFLAGS -DNDEBUG endif  CXX   g     CFLAGS  CC   gcc   CFLAGS   all  executable  executable  CommandParser tab o CommandParser yy o Command o       CXX  -o output CommandParser yy o CommandParser tab o Command o -lfl  CommandParser yy o  CommandParser l      flex -o CommandParser yy c CommandParser l       CC  -c CommandParser yy c  CommandParser tab o  CommandParser y     bison -d CommandParser y       CXX  -c CommandParser tab c  Command o  Command cpp       CXX  -c Command cpp  clean      rm -f CommandParser tab   CommandParser yy   output   o

User · Answer

You could also add something simple to your Makefile such as  ifeq    DEBUG  1     OPTS   -g endif   Then compile it for debugging   make DEBUG 1

User · Answer

If by configure release build  you mean you only need one config per makefile  then it is simply a matter and decoupling CC and CFLAGS   CFLAGS -DDEBUG  CFLAGS -O2 -DNDEBUG CC g   -g3 -gdwarf2   CFLAGS    Depending on whether you can use gnu makefile  you can use conditional to make this a bit fancier  and control it from the command line   DEBUG    1 ifeq    DEBUG   1      CFLAGS  -DDEBUG else     CFLAGS -DNDEBUG endif   o   c       CC  -c   lt  -o      CFLAGS    and then use   make DEBUG 0 make DEBUG 1   If you need to control both configurations at the same time  I think it is better to have build directories  and one build directory   config

User · Answer

This question has appeared often when searching for a similar problem  so I feel a fully implemented solution is warranted  Especially since I  and I would assume others  have struggled piecing all the various answers together   Below is a sample Makefile which supports multiple build types in separate directories  The example illustrated shows debug and release builds   Supports       separate project directories for specific builds easy selection of a default target build silent prep target to create directories needed for building the project build-specific compiler configuration flags GNU Make s natural method of determining if project requires a rebuild pattern rules rather than the obsolete suffix rules         Compiler flags   CC       gcc CFLAGS   -Wall -Werror -Wextra      Project files   SRCS   file1 c file2 c file3 c file4 c OBJS     SRCS  c  o  EXE    exefile      Debug build settings   DBGDIR   debug DBGEXE     DBGDIR    EXE  DBGOBJS     addprefix   DBGDIR      OBJS   DBGCFLAGS   -g -O0 -DDEBUG      Release build settings   RELDIR   release RELEXE     RELDIR    EXE  RELOBJS     addprefix   RELDIR      OBJS   RELCFLAGS   -O3 -DNDEBUG   PHONY  all clean debug prep release remake    Default build all  prep release      Debug rules   debug    DBGEXE     DBGEXE     DBGOBJS        CC    CFLAGS    DBGCFLAGS  -o   DBGEXE        DBGDIR    o    c       CC  -c   CFLAGS    DBGCFLAGS  -o      lt       Release rules   release    RELEXE     RELEXE     RELOBJS        CC    CFLAGS    RELCFLAGS  -o   RELEXE        RELDIR    o    c       CC  -c   CFLAGS    RELCFLAGS  -o      lt       Other rules   prep       mkdir -p   DBGDIR    RELDIR   remake  clean all  clean      rm -f   RELEXE    RELOBJS    DBGEXE    DBGOBJS

User · Answer

Note that you can also make your Makefile simpler  at the same time    DEBUG    1 ifeq  DEBUG  1      CFLAGS  -g3 -gdwarf2 -DDEBUG else     CFLAGS -DNDEBUG endif  CXX   g     CFLAGS  CC   gcc   CFLAGS   EXECUTABLE   output OBJECTS   CommandParser tab o CommandParser yy o Command o LIBRARIES   -lfl  all    EXECUTABLE     EXECUTABLE     OBJECTS        CXX  -o         LIBRARIES     yy o    l      flex -o    yy c   lt        CC  -c    yy c    tab o    y     bison -d   lt        CXX  -c    tab c    o    cpp       CXX  -c   lt   clean      rm -f   EXECUTABLE    OBJECTS    yy c   tab c   Now you don t have to repeat filenames all over the place  Any  l files will get passed through flex and gcc  any  y files will get passed through bison and g    and any  cpp files through just g     Just list the  o files you expect to end up with  and Make will do the work of figuring out which rules can satisfy the needs     for the record       The name of the target file  the one before the colon    lt  The name of the first  or only  prerequisite file  the first one after the colon     The names of all the prerequisite files  space separated     The stem  the bit which matches the   wildcard in the rule definition

User · Answer

you can have a variable   DEBUG   0   then you can use a conditional statement     ifeq    DEBUG  1     else    endif

User · Answer

You can use Target-specific Variable Values  Example   CXXFLAGS   -g3 -gdwarf2 CCFLAGS   -g3 -gdwarf2  all  executable  debug  CXXFLAGS    -DDEBUG -g debug  CCFLAGS    -DDEBUG -g debug  executable  executable  CommandParser tab o CommandParser yy o Command o       CXX  -o output CommandParser yy o CommandParser tab o Command o -lfl  CommandParser yy o  CommandParser l      flex -o CommandParser yy c CommandParser l       CC  -c CommandParser yy c   Remember to use   CXX  or   CC  in all your compile commands   Then   make debug  will have extra flags like -DDEBUG and -g where as  make  will not   On a side note  you can make your Makefile a lot more concise like other posts had suggested

[makefile] How can I configure my makefile for debug and release builds?

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