How do I compile a c99-to-c89 converter with clang?

I'm trying to compile ffmpeg on windows for VisualStudio and one of the steps is to compile c99-to-c89 code with clang according to this post. I was able to create clang.exe, but how do I compile the c99-to-c89 code?

I changed the makefile a bit in c99-to-c89 so the variable CC

now points to the compiler clang.exe 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 the command make

i get clang: error: unsupported use of internal gcc -Z option '-Z7'

. I think the problem is in CFLAGS

and LDFLAGS

, but I don't know how to fix it because there is a lack of knowledge in the makefile and clang.