Linker syntax : Linker does not use all of the linkers's flag during the linking

Question

I have study makefile projec. I am using the gnu gcc and as linker, I use the gcc with the following argument:

linkerCmdLine=$(exe) -Wl,--start-group -nostdlib -Map=test_mapfile.map -l:libc.a -l:libgcc.a -l:libm.a -Wl,--end-group -o $(output)

During the linking process, the linker does not use all of this flags: The flag -Map=test_mapfile.map is not used.

Why??

There is a project settings file and in this one is also stored the linker settings.

\“linkerCmdLine\\=$(exe) -Wl, --start-group -nostdlib -Map\\=./99_output/PUZ_GPF.map --gc-sections -l\\:libc.a -l\\:libgcc.a -l\\:libm.a -Wl,--end-group -o $(output)\”

How must I store the settings correct?

Edited:

With the the map file works fine, but I have actually problem with the linker file. I use only the following flag:

"linkerCmdLine=$(exe) -Wl, --script=C:/workspace/test_project/test_linker_file.ld -static -o $(output)”

I get this error in the console window:

arm-none-eabi-gcc.exe: error: unrecognized command line option '--script=C:/workspace/test_project/test_linker_file.ld'

I don't understand why, because the map file and the .ld file belong to the linker flags.

Answer 1

The -Wl, prefix only passes the current argument, with commas separating linker arguments. So in order to pass -z defs , you would use -Wl,-z,defs .

This mechanism only works for true flags, ie when the position in the command line is irrelevant. The -l parameters are not flags, and the gcc compiler driver collects them into a separate list and passes them in a single block.

So this technique doesn't work for the exact commandline you want. On the other hand, the -nostdlib inhibits the -lc -lgcc -lm that would be the default.

Normally there is a provision in the gcc specs (the script for the compiler driver) to use --start-group and --end-group around the standard libraries when linking statically (which appears to be what you want to do).

So I think that

linkerCmdLine=$(exe) -Wl,-Map=test_mapfile.map -static -o $(output)

should work for your case.