Emscripten - how to use my makefile with emcc instead of gcc? - html

Question

I have a project in C called triple where you can add, delete and match some Triplets. The idea now is to transform it to html using emcc and emmake.
I tried to compile it with:
emmake make
And then use:
emcc triple.o -s WASM=1 -o triple.html
But I get the error :
WARNING:root:triple.o is not valid LLVM bitcode
ERROR:root:no input files
note that input files without a known suffix are ignored, make sure
your input files end with one of: ('.c', '.C', '.i', '.cpp', '.cxx',
'.cc', '.c++', '.CPP', '.CXX', '.CC', '.C++', '.ii', '.m', '.mi',
'.mm', '.mii', '/dev/null', '.bc', '.o', '.obj', '.lo', '.dylib',
'.so', '.a', '.ll', '.h', '.hxx', '.hpp', '.hh', '.H', '.HXX', '.HPP',
'.HH')
What am I missing? Is there another way to use the make file with emcc instead with gcc?
Here is the make file I am using.
CC=emcc
triple : triple.o insert.o match.o Delete.o printList.o writeList.o
$(CC) -o triple triple.o insert.o match.o Delete.o printList.o
writeList.o
triple.o : triple.c
$(CC) -g -c triple.c
insert.o : insert.c
$(CC) -g -c insert.c
match.o : match.c
$(CC) -g -c match.c
Delete.o : Delete.c
$(CC) -g -c Delete.c
printList.o : printList.c
$(CC) -g -c printList.c
writeList.o : writeList.c
$(CC) -g -c writeList.c

Answer 1

The emcc program is a compiler front-end. This means it takes source code as input. You do not need to compile the code first with GCC. The emscripten website says it best: "use Emscripten Compiler Frontend (emcc) as a drop-in replacement for gcc in your existing project."
If you have the source there seems to be no good reason to compile to LLVM first.
What you need to do is simply replace any reference to gcc in your Makefile with emcc.
Even better - add a CC variable and use this. eg
CC=emcc
then replace all references to the compiler with $(CC). the $ bit is how to access a variable in a Makefile. Using a variable means you can easily change the compiler later.

Answer 2

You haven't specified an output target for the .o lines, so I think it will build to a.o.
Try modifying your makefile to say:
$(CC) -g -c triple.c -o triple.o