Commit | Line | Data |
---|---|---|
abae3014 | 1 | @page |
fc17ed5b TTN |
2 | @node Miscellaneous Tools |
3 | @chapter Miscellaneous Tools | |
4 | ||
5 | Programming is more fun with a good tools. This chapter describes snarfing | |
6 | tools, and the @code{guile-tools} program which can be used to invoke the rest | |
7 | of the tools (which are self-documenting). Some of these are used in Guile | |
8 | development, too. Imagine that! | |
9 | ||
10 | @menu | |
11 | * Snarfing:: Grepping the source in various ways. | |
12 | * Executable Modules:: Modules callable via guile-tools. | |
13 | @end menu | |
14 | ||
15 | @c --------------------------------------------------------------------------- | |
16 | @node Snarfing | |
17 | @section Snarfing | |
18 | @cindex snarfing | |
19 | ||
20 | Because it's easier to maintain documentation, code, and other metainfo in one | |
21 | source file than in many files, there have evolved many methods for grepping | |
22 | source to lift and separate these kinds of info, in the process generating | |
23 | docs or fragments of source or what have you. This is known generally as | |
24 | @dfn{snarfing}, which comes from the verb ``to snarf'', here meaning ``to | |
25 | unceremoniously extract information from a somewhat unwilling source.'' | |
26 | ||
27 | This section documents the installed program @code{guile-snarf} which does | |
28 | @dfn{init snarfing}, and also touches upon guile's doc snarfing process which | |
29 | is not yet finalized (i.e., doc snarfing programs are not installed at this | |
30 | time). | |
31 | ||
32 | @menu | |
33 | * Init Snarfing with guile-snarf:: Exposing C subrs and friends to Scheme. | |
34 | * Doc Snarfing:: Generating GDFv2 or texi from source. | |
35 | @end menu | |
36 | ||
37 | @c --------------------------------------------------------------------------- | |
38 | @node Init Snarfing with guile-snarf | |
39 | @subsection Init Snarfing with guile-snarf | |
40 | @c NOTE: This node and two subnodes are adapted from ../sources/snarf.texi. | |
41 | @cindex snarfing, init | |
42 | @cindex primitive functions | |
43 | @cindex subrs, defining | |
44 | ||
45 | When writing C code for use with Guile, you typically define a set of C | |
46 | functions, and then make some of them visible to the Scheme world by | |
47 | calling the @code{scm_c_define_gsubr} function; a C function published in | |
48 | this way is called a @dfn{subr}. If you have many subrs to publish, it | |
49 | can sometimes be annoying to keep the list of calls to | |
50 | @code{scm_c_define_gsubr} in sync with the list of function definitions. | |
51 | Frequently, a programmer will define a new subr in C, recompile the | |
52 | application, and then discover that the Scheme interpreter cannot see | |
53 | the subr, because of a missed call to @code{scm_c_define_gsubr}. | |
54 | ||
55 | Guile provides the @code{guile-snarf} command to manage this problem. | |
56 | Using this tool, you can keep all the information needed to define the | |
57 | subr alongside the function definition itself; @code{guile-snarf} will | |
58 | extract this information from your source code, and automatically | |
59 | generate a file of calls to @code{scm_c_define_gsubr} which you can | |
60 | @code{#include} into an initialization function. | |
61 | ||
62 | @menu | |
63 | * How guile-snarf works:: Using @code{guile-snarf}, with example. | |
64 | * Macros guile-snarf recognizes:: How to mark up code for @code{guile-snarf}. | |
65 | @end menu | |
66 | ||
67 | @c --------------------------------------------------------------------------- | |
68 | @node How guile-snarf works | |
69 | @subsubsection How guile-snarf works | |
70 | @cindex guile-snarf invocation | |
71 | @cindex guile-snarf example | |
72 | ||
b5bb4262 | 73 | Usage: guile-snarf [-d | -D] [-o OUTFILE] INFILE [CPP-OPTIONS ...] |
fc17ed5b | 74 | |
d5e1d82d TTN |
75 | What @code{guile-snarf} does: |
76 | ||
77 | Process INFILE using the C pre-processor and some other programs. | |
033aa07c MV |
78 | Write output to a file named OUTFILE or to the standard output when no |
79 | OUTFILE has been specified or when OUTFILE is @code{-}. When writing | |
80 | to a file, ignore lines from the input matching the following grep(1) | |
81 | regular expression: | |
d5e1d82d TTN |
82 | |
83 | @example | |
84 | ^#include ".*OUTFILE" | |
85 | @end example | |
86 | ||
87 | If there are errors during processing, delete OUTFILE and exit with | |
88 | non-zero status. | |
89 | ||
b5bb4262 TTN |
90 | Optional arg "-d" means grep INFILE for deprecated macros and |
91 | issue a warning if any are found. Alternatively, "-D" means | |
92 | do the same thing but signal error and exit with non-zero status. | |
d5e1d82d TTN |
93 | |
94 | If env var CPP is set, use its value instead of the C pre-processor | |
a2448fb1 | 95 | determined at Guile configure-time. |
d5e1d82d | 96 | |
033aa07c MV |
97 | During snarfing, the pre-processor macro @code{SCM_MAGIC_SNARFER} is |
98 | defined. | |
99 | ||
d5e1d82d | 100 | @xref{Macros guile-snarf recognizes}, for a list of the special (some would |
b5bb4262 | 101 | say magic) cpp macros you can use, including the list of deprecated macros. |
fc17ed5b TTN |
102 | |
103 | For example, here is how you might define a new subr called | |
104 | @code{clear-image}, implemented by the C function @code{clear_image}: | |
105 | ||
106 | @example | |
107 | @group | |
108 | #include <libguile.h> | |
109 | ||
110 | SCM_DEFINE (clear_image, "clear-image", 1, 0, 0, | |
111 | (SCM image_smob), | |
112 | "Clear the image.") | |
113 | #define FUNC_NAME s_clear_image | |
114 | @{ | |
115 | /* C code to clear the image... */ | |
116 | @} | |
117 | #undef FUNC_NAME | |
118 | ||
119 | void | |
120 | init_image_type () | |
121 | @{ | |
122 | #include "image-type.x" | |
123 | @} | |
124 | @end group | |
125 | @end example | |
126 | ||
127 | The @code{SCM_DEFINE} declaration says that the C function | |
128 | @code{clear_image} implements a Scheme subr called @code{clear-image}, | |
129 | which takes one required argument (type @code{SCM} named | |
130 | @code{image_smob}), no optional arguments, and no tail argument. | |
131 | @xref{Doc Snarfing}, for info on the docstring. | |
132 | ||
133 | This works in concert with @code{FUNC_NAME} to also define a static | |
134 | array of characters named @code{s_clear_image}, initialized to the | |
135 | string "clear-image". The body of @code{clear_image} may use the array | |
136 | in error messages, instead of writing out the literal string; this may | |
137 | save string space on some systems. | |
138 | ||
139 | Assuming the text above lives in a file named @file{image-type.c}, you will | |
140 | need to execute the following command to prepare this file for compilation: | |
141 | ||
142 | @example | |
d5e1d82d | 143 | guile-snarf image-type.c |
fc17ed5b TTN |
144 | @end example |
145 | ||
146 | This scans @file{image-type.c} for @code{SCM_DEFINE} | |
147 | declarations, and writes to @file{image-type.x} the output: | |
148 | ||
149 | @example | |
150 | scm_c_define_gsubr (s_clear_image, 1, 0, 0, (SCM (*)() ) clear_image); | |
151 | @end example | |
152 | ||
153 | When compiled normally, @code{SCM_DEFINE} is a macro which expands to a | |
154 | declaration of the @code{s_clear_image} string. | |
155 | ||
156 | Note that the output file name matches the @code{#include} from the | |
157 | input file. Also, you still need to provide all the same information | |
158 | you would if you were using @code{scm_c_define_gsubr} yourself, but you | |
159 | can place the information near the function definition itself, so it is | |
160 | less likely to become incorrect or out-of-date. | |
161 | ||
162 | If you have many files that @code{guile-snarf} must process, you should | |
d5e1d82d | 163 | consider using a fragment like the following in your Makefile: |
fc17ed5b TTN |
164 | |
165 | @example | |
d5e1d82d | 166 | snarfcppopts = $(DEFS) $(INCLUDES) $(CPPFLAGS) $(CFLAGS) |
fc17ed5b TTN |
167 | .SUFFIXES: .x |
168 | .c.x: | |
d5e1d82d | 169 | guile-snarf -o $@ $< $(snarfcppopts) |
fc17ed5b TTN |
170 | @end example |
171 | ||
172 | This tells make to run @code{guile-snarf} to produce each needed | |
173 | @file{.x} file from the corresponding @file{.c} file. | |
174 | ||
d5e1d82d TTN |
175 | Aside from the required argument INFILE, @code{guile-snarf} passes its |
176 | command-line arguments directly to the C preprocessor, which it uses to | |
177 | extract the information it needs from the source code. this means you can pass | |
178 | normal compilation flags to @code{guile-snarf} to define preprocessor symbols, | |
179 | add header file directories, and so on. | |
fc17ed5b TTN |
180 | |
181 | @c --------------------------------------------------------------------------- | |
182 | @node Macros guile-snarf recognizes | |
183 | @subsubsection Macros guile-snarf recognizes | |
184 | @cindex guile-snarf recognized macros | |
b5bb4262 | 185 | @cindex guile-snarf deprecated macros |
fc17ed5b TTN |
186 | |
187 | Here are the macros you can use in your source code from which | |
188 | @code{guile-snarf} can construct initialization code: | |
189 | ||
190 | @example | |
191 | /* procedures */ | |
192 | SCM_DEFINE (FNAME, PRIMNAME, REQ, OPT, VAR, ARGLIST, DOCSTRING) | |
193 | ||
194 | SCM_PROC (RANAME, STR, REQ, OPT, VAR, CFN) | |
195 | SCM_REGISTER_PROC (RANAME, STR, REQ, OPT, VAR, CFN) | |
196 | ||
197 | SCM_GPROC (RANAME, STR, REQ, OPT, VAR, CFN, GF) | |
198 | ||
199 | /* everything else */ | |
200 | SCM_SYMBOL (c_name, scheme_name) | |
201 | SCM_GLOBAL_SYMBOL (c_name, scheme_name) | |
202 | ||
203 | SCM_KEYWORD (c_name, scheme_name) | |
204 | SCM_GLOBAL_KEYWORD (c_name, scheme_name) | |
205 | ||
206 | SCM_VARIABLE (c_name, scheme_name) | |
207 | SCM_GLOBAL_VARIABLE (c_name, scheme_name) | |
208 | ||
209 | SCM_VARIABLE_INIT (c_name, scheme_name, init_val) | |
210 | SCM_GLOBAL_VARIABLE_INIT (c_name, scheme_name, init_val) | |
211 | @end example | |
212 | ||
213 | @c i like things dense, but maybe someone else will reformat this | |
214 | @c into an easier-to-read list. also, all-upcase to me is a form | |
215 | @c of quoting, so @var{} is not necessary there. --ttn | |
216 | REQ and OPT are numbers indicating required and optional argument | |
217 | counts, respectively; VAR is a number that, if non-zero, means the | |
218 | function will accept any remaining arguments as a list; DOCSTRING is a | |
219 | string (use @code{\n\} at eol for multi-line); FNAME is a C-language | |
220 | identifier, CFN and GF and @var{c_name} likewise; PRIMNAME is a string | |
221 | denoting the name available to Scheme code, STR and @var{scheme_name} | |
222 | likewise; RANAME is the name of the static string (must match that | |
223 | declared by the associated definition of cpp macro @var{FUNC_NAME}); | |
224 | ARGLIST is an argument list (in parentheses); and lastly, @var{init_val} | |
225 | is a expression suitable for initializing a new variable. | |
226 | ||
227 | For procedures, you can use @code{SCM_DEFINE} for most purposes. Use | |
228 | @code{SCM_PROC} along with @code{SCM_REGISTER_PROC} when you don't want | |
229 | to be bothered with docstrings. Use @code{SCM_GPROC} for generic | |
230 | functions (@pxref{GOOPS,,,goops}). All procedures are declared | |
231 | @code{static} with return type @code{SCM}. | |
232 | ||
233 | For everything else, use the appropriate macro (@code{SCM_SYMBOL} for | |
234 | symbols, and so on). The "_GLOBAL_" variants omit @code{static} | |
235 | declaration. | |
236 | ||
237 | All these macros should be used at top-level, outside function bodies. | |
238 | Also, it's a good idea to define @var{FUNC_NAME} immediately after using | |
239 | @code{SCM_DEFINE} (and similar), and then the function body, and then | |
240 | @code{#undef FUNC_NAME}. | |
241 | ||
b5bb4262 | 242 | Here is the list of deprecated macros: |
d5e1d82d | 243 | |
b5bb4262 | 244 | @c reminder: sync w/ libguile/guile-snarf.in var `deprecated_list' |
d5e1d82d | 245 | @example |
b5bb4262 TTN |
246 | SCM_CONST_LONG |
247 | SCM_VCELL | |
248 | SCM_VCELL_INIT | |
249 | SCM_GLOBAL_VCELL | |
250 | SCM_GLOBAL_VCELL_INIT | |
d5e1d82d TTN |
251 | @end example |
252 | ||
b5bb4262 TTN |
253 | Some versions of guile (and guile-snarf) will continue to recognize them but |
254 | at some point they will no longer work. You can pass either @code{-d} or | |
255 | @code{-D} option to have guile-snarf warn or signal error, respectively, if | |
256 | any of these are found in the input file. | |
257 | ||
258 | @xref{How guile-snarf works}, and also libguile source, for examples. | |
259 | @xref{Subrs}, for details on argument passing and how to write C | |
260 | functions. | |
d5e1d82d | 261 | |
fc17ed5b TTN |
262 | @c --------------------------------------------------------------------------- |
263 | @node Doc Snarfing | |
264 | @subsection Doc Snarfing | |
265 | ||
266 | In addition to init snarfing (@pxref{Init Snarfing with guile-snarf}), | |
267 | the libguile sources are also subject to doc snarfing, by programs that | |
268 | are included in the distribution (but not installed at this time). The | |
269 | output is the file @file{guile-procedures.txt} which is installed, and | |
270 | subsequently used by module @code{(ice-9 documentation)}. | |
271 | ||
272 | Here is a list of what does what according to @file{libguile/Makefile.am}: | |
273 | ||
274 | @itemize | |
275 | @item guile-snarf-docs runs cpp defining SCM_MAGIC_SNARF_DOCS | |
276 | @item guile_filter_doc_snarfage parses guile-snarf-docs output to produce .doc | |
277 | @item ../scripts/snarf-check-and-output-texi makes guile.texi | |
278 | @item ../scripts/snarf-check-and-output-texi makes guile-procedures.txt | |
279 | @item guile-func-name-check checks source snarf-syntax integrity (optional?) | |
280 | @item guile-doc-snarf calls guile-snarf-docs (to make .doc) and guile-snarf | |
281 | @end itemize | |
282 | ||
283 | Note that for guile-1.4, a completely different approach was used! All this | |
284 | is rather byzantine, so for now @emph{NO} doc snarfing programs are installed. | |
285 | ||
286 | [fixme: Document further once doc snarfing is tamed somewhat. --ttn] | |
287 | ||
288 | @c --------------------------------------------------------------------------- | |
abae3014 | 289 | @node Executable Modules |
fc17ed5b | 290 | @section Executable Modules |
abae3014 TTN |
291 | @cindex guile-tools |
292 | @cindex modules, executable | |
293 | @cindex executable modules | |
294 | @cindex scripts | |
295 | ||
296 | When Guile is installed, in addition to the @code{(ice-9 FOO)} modules, | |
297 | a set of @dfn{executable modules} @code{(scripts BAR)} is also installed. | |
298 | Each is a regular Scheme module that has some additional packaging so | |
299 | that it can be called as a program in its own right, from the shell. For this | |
300 | reason, we sometimes use the term @dfn{script} in this context to mean the | |
301 | same thing. | |
302 | ||
fc17ed5b TTN |
303 | @c wow look at this hole^! variable-width font users eat your heart out. |
304 | ||
abae3014 TTN |
305 | As a convenience, the @code{guile-tools} wrapper program is installed along w/ |
306 | @code{guile}; it knows where a particular module is installed and calls it | |
307 | passing its args to the program. The result is that you need not augment your | |
308 | PATH. Usage is straightforward: | |
309 | ||
310 | @example | |
311 | guile-tools --help | |
312 | guile-tools --version | |
313 | guile-tools [OPTION] PROGRAM [ARGS ...] | |
314 | ||
315 | If PROGRAM is "list" or omitted, display contents of scripts dir, otherwise | |
316 | PROGRAM is run w/ ARGS. Options (only one of which may be used at a time): | |
317 | --scriptsdir DIR -- Look in DIR for scripts | |
318 | --guileversion VERS -- Look in $pkgdatadir/VERS/scripts for scripts | |
319 | --source -- Display PROGRAM source (ignore ARGS) to stdout | |
320 | @end example | |
321 | ||
322 | The modules are self-documenting. For example, to see the documentation for | |
323 | @code{lint}, use one (or both) of the shell commands: | |
324 | ||
325 | @example | |
326 | guile-tools display-commentary '(scripts lint)' | |
327 | guile-tools --source lint | |
328 | @end example | |
329 | ||
fc17ed5b | 330 | The rest of this section describes the packaging that goes into creating an |
abae3014 TTN |
331 | executable module. Feel free to skip to the next chapter. |
332 | ||
fc17ed5b | 333 | @subsection Writing Executable Modules |
abae3014 TTN |
334 | |
335 | @c adapted from scripts/README | |
336 | ||
337 | See template file @code{PROGRAM} for a quick start. | |
338 | ||
339 | Programs must follow the @dfn{executable module} convention, documented here: | |
340 | ||
341 | @itemize | |
342 | ||
343 | @item | |
344 | The file name must not end in ".scm". | |
345 | ||
346 | @item | |
347 | The file must be executable (chmod +x). | |
348 | ||
349 | @item | |
350 | The module name must be "(scripts PROGRAM)". A procedure named PROGRAM w/ | |
351 | signature "(PROGRAM . args)" must be exported. Basically, use some variant | |
352 | of the form: | |
353 | ||
354 | @example | |
fc17ed5b TTN |
355 | (define-module (scripts PROGRAM) |
356 | :export (PROGRAM)) | |
abae3014 TTN |
357 | @end example |
358 | ||
359 | Feel free to export other definitions useful in the module context. | |
360 | ||
361 | @item | |
362 | There must be the alias: | |
363 | ||
364 | @example | |
fc17ed5b | 365 | (define main PROGRAM) |
abae3014 TTN |
366 | @end example |
367 | ||
368 | However, `main' must NOT be exported. | |
369 | ||
370 | @item | |
371 | The beginning of the file must use the following invocation sequence: | |
372 | ||
373 | @example | |
fc17ed5b TTN |
374 | #!/bin/sh |
375 | main='(module-ref (resolve-module '\''(scripts PROGRAM)) '\'main')' | |
376 | exec $@{GUILE-guile@} -l $0 -c "(apply $main (cdr (command-line)))" "$@@" | |
377 | !# | |
abae3014 TTN |
378 | @end example |
379 | ||
380 | @end itemize | |
381 | ||
382 | Following these conventions allows the program file to be used as module | |
383 | @code{(scripts PROGRAM)} in addition to as a standalone executable. Please | |
384 | also include a helpful Commentary section w/ some usage info. | |
385 | ||
386 | @c tools.texi ends here |