The most useful thing you could have shown us, you didn't provide: make will print the compile command that it invokes, and looking at that will.
You can use the -U option with gcc, but it won't undefine a macro defined in your source code. If compiler initially assumes MYDEF undefined, it will define it once it start And I hope your test case will work, if you pass MYDEF to -D and - U.
An Introduction to GCC - for the GNU compilers gcc and g++ To define a macro with a value, the -D command-line option can be used in the form -D NAME.
Some options control the preprocessor and others the compiler itself. multiple single-letter options may not be grouped: '-dr' is very different from '-d -r'.
The gcc program accepts options and file names as operands. names; therefore multiple single-letter options may not be grouped: dv is very different from -d -v.
GNU D Compiler. before the compiler starts handling command-line arguments . thel3l.me_lang_mask: The language mask used for option parsing.
Otherwise, read compiler arguments and switches from the text file cmdfile. The file This option should be used with caution and as a last resort to improve performance. . CC: dmd normally runs the linker by looking for gcc along the PATH.
gcc is very popular compiler in Linux world. gcc provides interpreter and In this tutorial we will examine popular compiler options like error, . In this example we will use -D option with the macro name which is MYMACRO.