How to compile c99-to-c89 convertor with clang? - makefile

Question

I'm trying to compile ffmpeg in windows for VisualStudio and one of the step is to compile c99-to-c89 code with clang according to this post. I managed to create clang.exe but how I compile c99-to-c89 code with it?
I changed a little bit the makefile in c99-to-c89 so CC variable points now to clang.exe compiler and not cl.exe
EXT=.exe
all: c99conv$(EXT) c99wrap$(EXT)
CLANGDIR=C:/build
CC=C:/build/bin/Release/clang.exe
CFLAGS=-nologo -Z7 -D_CRT_SECURE_NO_WARNINGS=1 -Dpopen=_popen -Dunlink=_unlink -Dstrdup=_strdup -Dsnprintf=_snprintf -I. -I$(CLANGDIR)/tools/clang/include
LDFLAGS=-nologo -Z7 $(CLANGDIR)/lib/Release/libclang.lib
clean:
rm -f c99conv$(EXT) c99wrap$(EXT) convert.o compilewrap.o
rm -f unit.c.c unit2.c.c
test1: c99conv$(EXT)
$(CC) -P unit.c -Fiunit.prev.c
./c99conv unit.prev.c unit.post.c
diff -u unit.{prev,post}.c
test2: c99conv$(EXT)
$(CC) -P unit2.c -Fiunit2.prev.c
./c99conv unit2.prev.c unit2.post.c
diff -u unit2.{prev,post}.c
test3: c99conv$(EXT)
$(CC) $(CFLAGS) -P -Ficonvert.prev.c convert.c
./c99conv convert.prev.c convert.post.c
diff -u convert.{prev,post}.c
c99conv$(EXT): convert.o
$(CC) -Fe$# $< $(LDFLAGS) $(LIBS)
c99wrap$(EXT): compilewrap.o
$(CC) -Fe$# $< $(LDFLAGS)
%.o: %.c
$(CC) $(CFLAGS) -Fo$# -c $<
but when I run make command I get clang: error: unsupported use of internal gcc -Z option '-Z7'. I guess the problem in CFLAGS and LDFLAGS but I don't know how to fix it because the lack of knowledge in makefile and clang.

Answer 1

If someone still needs, the guys from libav provided me with this link to download the binaries c99conv.exe, c99wrap.exe, makedef

Answer 2

c99conv wust be compilled with msvc compiller, but it uses libraries from LLVM. Actualy, converter uses clang as a parser C99 sources.
Therefore clang needs to be compilled with MSVC (because MSVC will link libclang with c99conv).
So, just lead the build instructions from article you link.
Run visual studio command promt.
Run msys shell from mingw.
Tune Makefile.w32 for your environment
Compile c99conv with Makefile.w32
make -f Makefile.w32