Makefile.mk: portable Makefile.m32

Update bare GNU Make `Makefile.m32` to:

- Move objects into a subdirectory.
- Add support for MS-DOS. Tested with DJGPP.
- Add support for Watt-32 (on MS-DOS).
- Add support for AmigaOS.
- Rename `Makefile.m32` to `Makefile.mk`
- Replace `ARCH` with `TRIPLET`.
- Build `tool_hugehelp.c` proper (when tools are available).
- Drop MS-DOS compatibility macro `USE_ZLIB` (replaced by `HAVE_LIBZ`)
- Add support for `ZLIB_LIBS` to override `-lz`.
- Omit object files when building examples.
- Default `CC` to `gcc` once again, for convenience. (Caveat: compiler
  name `cc` cannot be set now.)
- Set `-DCURL_NO_OLDIES` for examples, like autotools does.
- Delete `makefile.dj` files. Notice the configuration details and
  defaults are not retained with the new method.
- Delete `makefile.amiga` files. A successful build needs a few custom
  options. We're also not retaining all build details from the existing
  Amiga make files.
- Rename `Makefile.m32` to `Makefile.mk` to reflect that they are not
  Windows/MinGW32-specific anymore.
- Add support for new `CFG` options: `-map`, `-debug`, `-trackmem`
- Set `-DNDEBUG` by default.
- Allow using `-DOS=...` in all `lib/config-*.h` headers, syncing this
  with `config-win32.h`.
- Look for zlib parts in `ZLIB_PATH/include` and `ZLIB_PATH/lib`
  instead of bare `ZLIB_PATH`.

Note that existing build configurations for MS-DOS and AmigaOS likely
become incompatible with this change.

Example AmigaOS configuration:
```
export CROSSPREFIX=/opt/amiga/bin/m68k-amigaos-
export CC=gcc
export CPPFLAGS='-DHAVE_PROTO_BSDSOCKET_H'
export CFLAGS='-mcrt=clib2'
export LDFLAGS="${CFLAGS}"
export LIBS='-lnet -lm'
make -C lib -f Makefile.mk
make -C src -f Makefile.mk
```

Example MS-DOS configuration:
```
export CROSSPREFIX=/opt/djgpp/bin/i586-pc-msdosdjgpp-
export WATT_PATH=/opt/djgpp/net/watt
export ZLIB_PATH=/opt/djgpp
export OPENSSL_PATH=/opt/djgpp
export OPENSSL_LIBS='-lssl -lcrypt'
export CFG=-zlib-ssl
make -C lib -f Makefile.mk
make -C src -f Makefile.mk
```

Closes curl#9764

.github/scripts/spellcheck.words

@@ -160,6 +160,7 @@ dir
 distro
 distro's
 distros
+DJGPP
 dlist
 DLL
 dll
@@ -226,6 +227,7 @@ FreeDOS
 FreeRTOS
 freshmeat
 Frexx
+FS
 fseek
 FTPing
 fuzzer

Makefile.dist

@@ -31,25 +31,25 @@ ssl:
 	make
 
 mingw32:
-	$(MAKE) -C lib -f Makefile.m32
-	$(MAKE) -C src -f Makefile.m32
+	$(MAKE) -C lib -f Makefile.mk
+	$(MAKE) -C src -f Makefile.mk
 
 mingw32-clean:
-	$(MAKE) -C lib -f Makefile.m32 clean
-	$(MAKE) -C src -f Makefile.m32 clean
-	$(MAKE) -C docs/examples -f Makefile.m32 clean
+	$(MAKE) -C lib -f Makefile.mk clean
+	$(MAKE) -C src -f Makefile.mk clean
+	$(MAKE) -C docs/examples -f Makefile.mk clean
 
 mingw32-vclean mingw32-distclean:
-	$(MAKE) -C lib -f Makefile.m32 vclean
-	$(MAKE) -C src -f Makefile.m32 vclean
-	$(MAKE) -C docs/examples -f Makefile.m32 vclean
+	$(MAKE) -C lib -f Makefile.mk vclean
+	$(MAKE) -C src -f Makefile.mk vclean
+	$(MAKE) -C docs/examples -f Makefile.mk vclean
 
 mingw32-examples%:
-	$(MAKE) -C docs/examples -f Makefile.m32 CFG=$@
+	$(MAKE) -C docs/examples -f Makefile.mk CFG=$@
 
 mingw32%:
-	$(MAKE) -C lib -f Makefile.m32 CFG=$@
-	$(MAKE) -C src -f Makefile.m32 CFG=$@
+	$(MAKE) -C lib -f Makefile.mk CFG=$@
+	$(MAKE) -C src -f Makefile.mk CFG=$@
 
 vc:
 	cd winbuild
@@ -59,9 +59,9 @@ vc-x64:
 	cd winbuild
 	nmake /f Makefile.vc MACHINE=x64
 
-djgpp:
-	$(MAKE) -C lib -f Makefile.dj
-	$(MAKE) -C src -f Makefile.dj
+djgpp%:
+	$(MAKE) -C lib -f Makefile.mk CFG=$@ CROSSPREFIX=i586-pc-msdosdjgpp-
+	$(MAKE) -C src -f Makefile.mk CFG=$@ CROSSPREFIX=i586-pc-msdosdjgpp-
 
 cygwin:
 	./configure
@@ -71,9 +71,9 @@ cygwin-ssl:
 	./configure --with-openssl
 	make
 
-amiga:
-	cd ./lib && make -f makefile.amiga
-	cd ./src && make -f makefile.amiga
+amiga%:
+	$(MAKE) -C lib -f Makefile.mk CFG=$@ CROSSPREFIX=m68k-amigaos-
+	$(MAKE) -C src -f Makefile.mk CFG=$@ CROSSPREFIX=m68k-amigaos-
 
 unix: all
 

docs/INSTALL.md

@@ -182,7 +182,7 @@ make targets available to build libcurl with more features, use:
    and SSPI support.
 
 If you have any problems linking libraries or finding header files, be sure
-to verify that the provided `Makefile.m32` files use the proper paths, and
+to verify that the provided `Makefile.mk` files use the proper paths, and
 adjust as necessary. It is also possible to override these paths with
 environment variables, for example:
 
@@ -210,7 +210,7 @@ set LDFLAGS=-Lc:/openldapsdk/lib/mscvc
 set LIBS=-lldapsdk -lldapssl -lldapx
 ```
 
-If you want to enable LDAPS support then set LDAPS=1.
+If you want to enable LDAPS support then append `-ldaps` to the make target.
 
 ## Cygwin
 
@@ -220,6 +220,30 @@ executable in `/bin/` or you will see the configure fail toward the end.
 
 Run `make`
 
+## MS-DOS
+
+Requires DJGPP in the search path and pointing to the Watt-32 stack via
+`WATT_PATH=c:/djgpp/net/watt`.
+
+Run `make -f Makefile.dist djgpp` in the root curl dir.
+
+For build configuration options, please see the MinGW32 section.
+
+Notes:
+
+ - DJGPP 2.04 beta has a `sscanf()` bug so the URL parsing is not done
+   properly. Use DJGPP 2.03 until they fix it.
+
+ - Compile Watt-32 (and OpenSSL) with the same version of DJGPP. Otherwise
+   things go wrong because things like FS-extensions and `errno` values have
+   been changed between releases.
+
+## AmigaOS
+
+Run `make -f Makefile.dist amiga` in the root curl dir.
+
+For build configuration options, please see the MinGW32 section.
+
 ## Disabling Specific Protocols in Windows builds
 
 The configure utility, unfortunately, is not available for the Windows

docs/examples/Makefile.am

@@ -24,8 +24,8 @@
 
 AUTOMAKE_OPTIONS = foreign nostdinc
 
-EXTRA_DIST = README.md Makefile.example Makefile.inc Makefile.m32 \
-  makefile.dj $(COMPLICATED_EXAMPLES) .checksrc
+EXTRA_DIST = README.md Makefile.example Makefile.inc Makefile.mk \
+  $(COMPLICATED_EXAMPLES) .checksrc
 
 # Specify our include paths here, and do it relative to $(top_srcdir) and
 # $(top_builddir), to ensure that these paths which belong to the library

docs/examples/Makefile.m32 → docs/examples/Makefile.mk

@@ -22,37 +22,53 @@
 #
 #***************************************************************************
 
-# Build libcurl via lib/Makefile.m32 first.
+# Build libcurl via lib/Makefile.mk first.
 
 PROOT := ../..
 
+ifeq ($(findstring -static,$(CFG)),)
+  DYN := 1
+endif
+
+### Common
+
+include $(PROOT)/lib/Makefile.mk
+
+### Local
+
+CPPFLAGS += -DCURL_NO_OLDIES
 LDFLAGS  += -L$(PROOT)/lib
-LIBS     += -lcurl
+LIBS     := -lcurl $(LIBS)
 
-ifeq ($(findstring -static,$(CFG)),)
+ifdef DYN
   curl_DEPENDENCIES += $(PROOT)/lib/libcurl.dll.a
-  DYN := 1
 else
   curl_DEPENDENCIES := $(PROOT)/lib/libcurl.a
-  CPPFLAGS += -DCURL_STATICLIB
-  LDFLAGS += -static
+  ifdef WIN32
+    CPPFLAGS += -DCURL_STATICLIB
+    LDFLAGS += -static
+  endif
 endif
 
-LIBS += -lws2_32
+ifdef WIN32
+  LIBS += -lws2_32
+endif
 
 ### Sources and targets
 
 # Provides check_PROGRAMS
 include Makefile.inc
 
-TARGETS := $(patsubst %,%.exe,$(strip $(check_PROGRAMS) synctime))
-TOCLEAN := $(TARGETS:.exe=.o)
+ifdef WIN32
+check_PROGRAMS += synctime
+endif
 
-### Local rules
+TARGETS := $(patsubst %,%$(BIN_EXT),$(strip $(check_PROGRAMS)))
+TOCLEAN := $(TARGETS)
 
-%.exe: %.o $(curl_DEPENDENCIES)
-	$(CC) $(LDFLAGS) $(CURL_LDFLAGS_BIN) -o $@ $< $(LIBS)
+### Rules
 
-### Global script
+%$(BIN_EXT): %.c $(curl_DEPENDENCIES)
+	$(CC) $(CFLAGS) $(CPPFLAGS) $(LDFLAGS) $(CURL_LDFLAGS_BIN) $< -o $@ $(LIBS)
 
-include $(PROOT)/lib/Makefile.m32
+all: $(TARGETS)

lib/Makefile.am

@@ -25,9 +25,9 @@ AUTOMAKE_OPTIONS = foreign nostdinc
 
 CMAKE_DIST = CMakeLists.txt curl_config.h.cmake
 
-EXTRA_DIST = Makefile.m32 config-win32.h config-win32ce.h config-plan9.h   \
- config-riscos.h config-mac.h curl_config.h.in makefile.dj config-dos.h    \
- libcurl.plist libcurl.rc config-amigaos.h makefile.amiga config-win32ce.h \
+EXTRA_DIST = Makefile.mk config-win32.h config-win32ce.h config-plan9.h    \
+ config-riscos.h config-mac.h curl_config.h.in config-dos.h                \
+ libcurl.plist libcurl.rc config-amigaos.h config-win32ce.h                \
  config-os400.h setup-os400.h $(CMAKE_DIST) setup-win32.h .checksrc
 
 lib_LTLIBRARIES = libcurl.la