$ perl indentmk.pl crud.mk > indented-crud.mk

$ cat crud.mk
CC                      *= gcc
CCTYPE          *= GCC
.IF "$(CCTYPE)" == "GCC"
GCC_MAJOR_VERSION *= 12
.IF  "$(GCC_MAJOR_VERSION)" == "4"
CFLAGS          += -static-libgcc
LIBC            += -static-libgcc
.ELSE
GCC_MAJOR_VERSION *= 42
.ENDIF
.ENDIF
.IF "$(CCTYPE)" == "GCC"
$(XCOPY) $(CCHOME)\bin\*dll ..\t\$(NULL)
.ENDIF


$ cat indented-crud.mk
CC                      *= gcc
CCTYPE          *= GCC
.IF "$(CCTYPE)" == "GCC"
        GCC_MAJOR_VERSION *= 12
        .IF  "$(GCC_MAJOR_VERSION)" == "4"
                CFLAGS          += -static-libgcc
                LIBC            += -static-libgcc
        .ELSE
                GCC_MAJOR_VERSION *= 42
        .ENDIF
.ENDIF
.IF "$(CCTYPE)" == "GCC"
        $(XCOPY) $(CCHOME)\bin\*dll ..\t\$(NULL)
.ENDIF