How do I read target dependencies from a file? - makefile

Question

So, I've got that makefile project that has a huge list of object files that need to be compiled.
I already ran into problems on Win32 because the input string is too large. I figured out that instead of passing the files 1-by-1 to the linker, I could read the object files to be linked from a file by passing #filename to the linker.
In my makefile: Is there a method how the dependencies could be read out of a file? Something like that:
main.lib: #dependency_file_name
where dependency_file_name holds the list of needed .obj files needed to create the lib.
Please keep in mind, that putting the contents of the file into a variable also doesn't work since I've got that problem with a too long input string also when using the list of dependencies as a variable.
In addition: the method shall be portable (Linux, Win32)
Edit: currently, the structure of my makefiles is as follows:
# slurp in some global settings
include /path/to/global/settings
all: prepare_target mylib cleanup_target
prepare_target:
# do preparing work (setup temp files etc)
cleanup_target:
# do cleanup work (delete temp files etc)
mylib: \
file1.obj \
file2.obj \
... \
file215.obj
# this file holds the dependencies for each .obj file
include file_with_obj_file_dependencies
There are really 215 C files to be compiled into this lib. As I said: when feeding this list to the linker, I need to do it via a file because the string is too large for the command line.
I'm free to change whatever is needed in the makefile: it's generated from a VisualStudio vcxproj and I own the generation templates.
file_with_obj_dependencies looks as this:
file1.obj: \
file1.c \
file1.h \
file2.obj: \
file2.c \
file2.h \
... \
file215.obj \
file215.c \
file215.h \

Answer 1

On Windows I tend to use cygwin. It's the closest environment I've found to unix. This makes your Makefiles portable. I haven't come across any limiting command-line length limits. Here is an example with over ¾ of a million command-line arguments:
a := 1 2 3 4 5 6 7 8 9 a b c d e f
.PHONY: test
test:
#echo $(foreach A,$a,$(foreach B,$a,$(foreach C,$a,$(foreach D,$a,$(foreach E,$a,$A$B$C$D$E))))) | wc -wc
(the wc is so that you don't have to wait for the 5,000,000 or so characters to scroll by.)
So, for the limited win32 tools, use bash to write the intermediate command-line-parameters file, then pass that to link.exe (say) prefixed with an #.
Something like:
mylib.lib:
echo $^ >$#-tmp
link -o $# #$#-tmp
(Are you sure you need the intermediate file? 215 source files doesn't seem too onerous.)