1 Port of GNU Make to 32-bit protected mode on MSDOS and MS-Windows.
3 Builds with DJGPP v2 port of GNU C/C++ compiler and utilities.
6 New (since 3.74) DOS-specific features:
8 1. Supports long filenames when run from DOS box on Windows 9x.
10 2. Supports both stock DOS COMMAND.COM and Unix-style shells
11 (details in ``Notes'' below).
13 3. Supports DOS drive letters in dependencies and pattern rules.
15 4. Better support for DOS-style backslashes in pathnames (but see
18 5. The $(shell) built-in can run arbitrary complex commands,
19 including pipes and redirection, even when COMMAND.COM is your
22 6. Can be built without floating-point code (see below).
24 7. Supports signals in child programs and restores the original
25 directory if the child was interrupted.
27 8. Can be built without (a previous version of) Make.
29 9. The build process requires only standard tools. (Optional
30 targets like "install:" and "clean:" still need additional
31 programs, though, see below.)
36 1. Unzip the archive, preserving the directory structure (-d switch
37 if you use PKUNZIP). If you build Make on Windows 95, use an
38 unzip program that supports long filenames in zip files.
40 If you are unpacking an official GNU source distribution, use
41 either DJTAR (which is part of the DJGPP development
42 environment), or the DJGPP port of GNU Tar.
44 2. Invoke the `configure.bat' batch file.
46 If you are building Make in-place, i.e. in the same directory
47 where its sources are kept, just type "configure.bat" and press
48 [Enter]. Otherwise, you need to supply the path to the source
49 directory as an argument to the batch file, like this:
51 c:\djgpp\gnu\make-%VERSION%\configure.bat c:/djgpp/gnu/make-%VERSION%
53 Note the forward slashes in the source path argument: you MUST
56 3. If configure.bat doesn't find a working Make, it will suggest to
57 use the `dosbuild.bat' batch file to build Make. Either do as it
58 suggests or install another Make program (a pre-compiled binary
59 should be available from the usual DJGPP sites) and rerun
62 4. If you will need to run Make on machines without an FPU, you
63 might consider building a version of Make which doesn't issue
64 floating-point instructions (they don't help much on MSDOS
65 anyway). To this end, edit the Makefile created by
66 configure.bat and add -DNO_FLOAT to the value of CPPFLAGS.
70 If you are building from outside of the source directory, you
71 need to tell Make where the sources are, like this:
73 make srcdir=c:/djgpp/gnu/make-%VERSION%
75 (configure.bat will tell you this when it finishes). You MUST
76 use a full, not relative, name of the source directory here, or
79 6. After Make finishes, if you have a Unix-style shell installed,
80 you can use the `install' target to install the package. You
81 will also need GNU Fileutils and GNU Sed for this (they should
82 be available from the DJGPP sites).
84 Without a Unix-style shell, you will have to install programs
85 and the docs manually. Copy make.exe to a directory on your
86 PATH, make.i* info files to your Info directory, and update the
87 file `dir' in your Info directory by adding the following item
90 * Make: (make.info). The GNU make utility.
92 If you have the `install-info' program (from the GNU Texinfo
93 package), it will do that for you if you invoke it like this:
95 install-info --info-dir=c:/djgpp/info c:/djgpp/info/make.info
97 (If your Info directory is other than C:\DJGPP\INFO, change this
100 7. The `clean' targets also require Unix-style shell, and GNU Sed
101 and `rm' programs (the latter from Fileutils).
110 This is probably the most significant improvement, first
111 introduced in the port of GNU Make 3.75.
113 The original behavior of GNU Make is to invoke commands
114 directly, as long as they don't include characters special to
115 the shell or internal shell commands, because that is faster.
116 When shell features like redirection or filename wildcards are
117 involved, Make calls the shell.
119 This port supports both DOS shells (the stock COMMAND.COM and its
120 4DOS/NDOS replacements), and Unix-style shells (tested with the
121 venerable Stewartson's `ms_sh' 2.3 and the DJGPP port of `bash' by
122 Daisuke Aoyama <jack@st.rim.or.jp>).
124 When the $SHELL variable points to a Unix-style shell, Make
125 works just like you'd expect on Unix, calling the shell for any
126 command that involves characters special to the shell or
127 internal shell commands. The only difference is that, since
128 there is no standard way to pass command lines longer than the
129 infamous DOS 126-character limit, this port of Make writes the
130 command line to a temporary disk file and then invokes the shell
133 If $SHELL points to a DOS-style shell, however, Make will not
134 call it automatically, as it does with Unix shells. Stock
135 COMMAND.COM is too dumb and would unnecessarily limit the
136 functionality of Make. For example, you would not be able to
137 use long command lines in commands that use redirection or
138 pipes. Therefore, when presented with a DOS shell, this port of
139 Make will emulate most of the shell functionality, like
140 redirection and pipes, and shall only call the shell when a
141 batch file or a command internal to the shell is invoked. (Even
142 when a command is an internal shell command, Make will first
143 search the $PATH for it, so that if a Makefile calls `mkdir',
144 you can install, say, a port of GNU `mkdir' and have it called
147 The key to all this is the extended functionality of `spawn' and
148 `system' functions from the DJGPP library; this port just calls
149 `system' where it would invoke the shell on Unix. The most
150 important aspect of these functions is that they use a special
151 mechanism to pass long (up to 16KB) command lines to DJGPP
152 programs. In addition, `system' emulates some internal
153 commands, like `cd' (so that you can now use forward slashes
154 with it, and can also change the drive if the directory is on
155 another drive). Another aspect worth mentioning is that you can
156 call Unix shell scripts directly, provided that the shell whose
157 name is mentioned on the first line of the script is installed
158 anywhere along the $PATH. It is impossible to tell here
159 everything about these functions; refer to the DJGPP library
160 reference for more details.
162 The $(shell) built-in is implemented in this port by calling
163 `popen'. Since `popen' calls `system', the above considerations
164 are valid for $(shell) as well. In particular, you can put
165 arbitrary complex commands, including pipes and redirection,
166 inside $(shell), which is in many cases a valid substitute for
167 the Unix-style command substitution (`command`) feature.
170 2. "SHELL=/bin/sh" -- or is it?
172 Many Unix Makefiles include a line which sets the SHELL, for
173 those versions of Make which don't have this as the default.
174 Since many DOS systems don't have `sh' installed (in fact, most
175 of them don't even have a `/bin' directory), this port takes
176 such directives with a grain of salt. It will only honor such a
177 directive if the basename of the shell name (like `sh' in the
178 above example) can indeed be found in the directory that is
179 mentioned in the SHELL= line (`/bin' in the above example), or
180 in the current working directory, or anywhere on the $PATH (in
181 that order). If the basename doesn't include a filename
182 extension, Make will look for any known extension that indicates
183 an executable file (.exe, .com, .bat, .btm, .sh, and even .sed
184 and .pl). If any such file is found, then $SHELL will be
185 defined to the exact pathname of that file, and that shell will
186 hence be used for the rest of processing. But if the named
187 shell is *not* found, the line which sets it will be effectively
188 ignored, leaving the value of $SHELL as it was before. Since a
189 lot of decisions that this port makes depend on the gender of
190 the shell, I feel it doesn't make any sense to tailor Make's
191 behavior to a shell which is nowhere to be found.
193 Note that the above special handling of "SHELL=" only happens
194 for Makefiles; if you set $SHELL in the environment or on the
195 Make command line, you are expected to give the complete
196 pathname of the shell, including the filename extension.
198 The default value of $SHELL is computed as on Unix (see the Make
199 manual for details), except that if $SHELL is not defined in the
200 environment, $COMSPEC is used. Also, if an environment variable
201 named $MAKESHELL is defined, it takes precedence over both
202 $COMSPEC and $SHELL. Note that, unlike Unix, $SHELL in the
203 environment *is* used to set the shell (since on MSDOS, it's
204 unlikely that the interactive shell will not be suitable for
205 Makefile processing).
207 The bottom line is that you can now write Makefiles where some
208 of the targets require a real (i.e. Unix-like) shell, which will
209 nevertheless work when such shell is not available (provided, of
210 course, that the commands which should always work, don't
211 require such a shell). More important, you can convert Unix
212 Makefiles to MSDOS and leave the line which sets the shell
213 intact, so that people who do have Unixy shell could use it for
214 targets which aren't converted to DOS (like `install' and
215 `uninstall', for example).
218 3. Default directories.
220 GNU Make knows about standard directories where it searches for
221 library and include files mentioned in the Makefile. Since
222 MSDOS machines don't have standard places for these, this port
223 will search ${DJDIR}/lib and ${DJDIR}/include respectively.
224 $DJDIR is defined automatically by the DJGPP startup code as the
225 root of the DJGPP installation tree (unless you've tampered with
226 the DJGPP.ENV file). This should provide reasonable default
227 values, unless you moved parts of DJGPP to other directories.
230 4. Letter-case in filenames.
232 If you run Make on Windows 9x, you should be aware of the
233 letter-case issue. Make is internally case-sensitive, but all
234 file operations are case-insensitive on Windows 9x, so
235 e.g. files `FAQ', `faq' and `Faq' all refer to the same file, as
236 far as Windows is concerned. The underlying DJGPP C library
237 functions honor the letter-case of the filenames they get from
238 the OS, except that by default, they down-case 8+3 DOS filenames
239 which are stored in upper case in the directory and would break
240 many Makefiles otherwise. (The details of which filenames are
241 converted to lower case are explained in the DJGPP libc docs,
242 under the `_preserve_fncase' and `_lfn_gen_short_fname'
243 functions, but as a thumb rule, any filename that is stored in
244 upper case in the directory, is a valid DOS 8+3 filename and
245 doesn't include characters invalid on MSDOS FAT filesystems,
246 will be automatically down-cased.) User reports that I have
247 indicate that this default behavior is generally what you'd
248 expect; however, your input is most welcome.
250 In any case, if you hit a situation where you must force Make to
251 get the 8+3 DOS filenames in upper case, set FNCASE=y in the
252 environment or in the Makefile.
255 5. DOS-style pathnames.
257 There are a lot of places throughout the program sources which
258 make implicit assumptions about the pathname syntax. In
259 particular, the directories are assumed to be separated by `/',
260 and any pathname which doesn't begin with a `/' is assumed to be
261 relative to the current directory. This port attempts to
262 support DOS-style pathnames which might include the drive letter
263 and use backslashes instead of forward slashes. However, this
264 support is not complete; I feel that pursuing this support too
265 far might break some more important features, particularly if
266 you use a Unix-style shell (where a backslash is a quote
267 character). I only consider support of backslashes desirable
268 because some Makefiles invoke non-DJGPP programs which don't
269 understand forward slashes. A notable example of such programs
270 is the standard programs which come with MSDOS. Otherwise, you
271 are advised to stay away from backslashes whenever possible. In
272 particular, filename globbing won't work on pathnames with
273 backslashes, because the GNU `glob' library doesn't support them
274 (backslash is special in filename wildcards, and I didn't want
277 One feature which *does* work with backslashes is the filename-
278 related built-in functions such as $(dir), $(notdir), etc.
279 Drive letters in pathnames are also fully supported.
286 Bugs that are clearly related to the MSDOS/DJGPP port should be
287 reported first on the comp.os.msdos.djgpp news group (if you cannot
288 post to Usenet groups, write to the DJGPP mailing list,
289 <djgpp@delorie.com>, which is an email gateway into the above news
290 group). For other bugs, please follow the procedure explained in
291 the "Bugs" chapter of the Info docs. If you don't have an Info
292 reader, look up that chapter in the `make.i1' file with any text
297 Eli Zaretskii <eliz@is.elta.co.il>