| blob | c7144a0ba29b0f70beb69c0948e8ecdec0466edb |
2 FIXINCLUDES OPERATION
3 =====================
5 See also: http://autogen.SourceForge.net/fixinc.html
7 The set of fixes required was distilled down to just the data required
8 to specify what needed to happen for each fix. Those data were edited
9 into a file named fixincludes/inclhack.def. A program called AutoGen
10 (http://autogen.SourceForge.net) uses these definitions to instantiate
11 several different templates that then produces code for a fixinclude
12 program (fixincl.x) and a shell script to test its functioning. On
13 certain platforms (viz. those that do not have functional bidirectional
14 pipes), the fixincl program is split into two. This should only concern
15 you on DOS and BeOS.
17 Regards,
18 Bruce <bkorb@gnu.org>
22 GCC MAINTAINER INFORMATION
23 ==========================
25 If you are having some problem with a system header that is either
26 broken by the manufacturer, or is broken by the fixinclude process,
27 then you will need to alter or add information to the include fix
28 definitions file, ``inclhack.def''. Please also send relevant
29 information to gcc-bugs@gcc.gnu.org, gcc-patches@gcc.gnu.org and,
30 please, to me: bkorb@gnu.org.
32 To make your fix, you will need to do several things:
34 1. Obtain access to the AutoGen program on some platform. It does
35 not have to be your build platform, but it is more convenient.
37 2. Edit "inclhack.def" to reflect the changes you need to make.
38 See below for information on how to make those changes.
40 3. Run the "genfixes" shell script to produce a new copy of
41 the "fixincl.x" file.
43 4. Rebuild the compiler and check the header causing the issue.
44 Make sure it is now properly handled. Add tests to the
45 "test_text" entry(ies) that validate your fix. This will
46 help ensure that future fixes won't negate your work.
48 5. Go into the fixincludes build directory and type, "make check".
49 You are guaranteed to have issues printed out as a result.
50 Look at the diffs produced. Make sure you have not clobbered
51 the proper functioning of a different fix. Make sure your
52 fix is properly tested and it does what it is supposed to do.
54 6. Now that you have the right things happening, synchronize the
55 $(srcdir)/tests/base directory with the $(builddir)/tests/res
56 directory. The output of "make check" will be some diffs that
57 should give you some hints about what to do.
59 7. Rerun "make check" and verify that there are no issues left.
62 MAKING CHANGES TO INCLHACK.DEF
63 ==============================
65 0. If you are not the fixincludes maintainer, please send that
66 person email about any changes you may want to make. Thanks!
68 1. Every fix must have a "hackname" that is compatible with C syntax
69 for variable names and is unique without regard to alphabetic case.
70 Please keep them alphabetical by this name. :-)
72 2. If the problem is known to exist only in certain files, then
73 identify the files with "files = " entries. If you use fnmatch(3C)
74 wild card characters in a "files" entry, be certain that the first
75 "files" entry has no such character. Otherwise, the "make check"
76 machinery will attempt to create files with those characters in the
77 name. That is inconvenient.
79 3. It is relatively expensive to fire off a process to fix a source
80 file, therefore write apply tests to avoid unnecessary fix
81 processes. The preferred apply tests are "select", "bypass", "mach"
82 and "c-test" because they are performed internally:
84 * select - Run a regex on the contents of the file being considered.
85 All such regex-es must match. Matching is done with
86 extended regular expressions.
88 * bypass - Run a regex on the contents of the file being considered.
89 No such regex may match.
91 * c_test - call a function in fixtests.c. See that file.
93 * files - the "fnmatch" pattern of the file(s) to examine for
94 the issue. There may be several copies of this attribute.
95 If the header lives in a /usr/include subdirectory, be
96 sure to include that subdirectory in the name. e.g. net/if.h
98 * mach - Match the output of config.guess against a series of fnmatch
99 patterns. It must match at least one of the patterns, unless
100 "not-machine" has also been specified. In that case, the
101 config.guess output must not match any of the patterns.
103 The next test is relatively slow because it must be handled in a
104 separate shell process. Some platforms do not support server shells,
105 so the whole process is even slower and more cumbersome there.
107 * test - These should be arguments to the program, "/bin/test".
108 You may perform multiple commands, if you enclose them
109 in backquotes and echo out valid test arguments. For
110 example, you might echo out '0 -eq 1' if you want a false
111 result, or '0 -eq 0' for a true result.
113 These tests are required to:
115 1. Be positive for all header files that require the fix.
117 It is desirable to:
119 2. Be negative as often as possible whenever the fix is not
120 required, avoiding the process overhead.
122 It is nice if:
124 3. The expression is as simple as possible to both
125 process and understand by people. :-)
127 Please take advantage of the fact AutoGen will glue
128 together string fragments. It helps. Also take note
129 that double quote strings and single quote strings have
130 different formation rules. Double quote strings are a
131 tiny superset of ANSI-C string syntax. Single quote
132 strings follow shell single quote string formation
133 rules, except that the backslash is processed before
134 '\\', '\'' and '#' characters (using C character syntax).
136 Each test must pass or the fix is not applied. For example,
137 all "select" expressions must be found and not one "bypass"
138 selection may be found.
140 Examples of test specifications:
142 hackname = broken_assert_stdio;
143 files = assert.h;
144 select = stderr;
145 bypass = "include.*stdio.h";
147 The ``broken_assert_stdio'' fix will be applied only to a file
148 named "assert.h" if it contains the string "stderr" _and_ it
149 does _not_ contain the expression "include.*stdio.h".
151 hackname = no_double_slash;
152 c_test = "double_slash";
154 The ``no_double_slash'' fix will be applied if the
155 ``double_slash_test()'' function says to. See ``fixtests.c''
156 for documentation on how to include new functions into that
157 module.
159 4. There are currently four methods of fixing a file:
161 1. a series of sed expressions. Each will be an individual
162 "-e" argument to a single invocation of sed.
164 2. a shell script. These scripts are _required_ to read all
165 of stdin in order to avoid pipe stalls. They may choose to
166 discard the input.
168 3. Replacement text. If the replacement is empty, then no
169 fix is applied. Otherwise, the replacement text is
170 written to the output file and no further fixes are
171 applied. If you really want a no-op file, replace the
172 file with a comment.
174 Replacement text "fixes" must be first in this file!!
176 4. A C language subroutine method for both tests and fixes.
177 See ``fixtests.c'' for instructions on writing C-language
178 applicability tests and ``fixfixes.c'' for C-language fixing.
179 These files also contain tables that describe the currently
180 implemented fixes and tests.
182 If at all possible, you should try to use one of the C language
183 fixes as it is far more efficient. There are currently five
184 such fixes, three of which are very special purpose:
186 i) char_macro_def - This function repairs the definition of an
187 ioctl macro that presumes CPP macro substitution within
188 pairs of single quote characters.
190 ii) char_macro_use - This function repairs the usage of ioctl
191 macros that no longer can wrap an argument with single quotes.
193 iii) machine_name - This function will look at "#if", "#ifdef",
194 "#ifndef" and "#elif" directive lines and replace the first
195 occurrence of a non-reserved name that is traditionally
196 pre-defined by the native compiler.
198 The next two are for general use:
200 iv) wrap - wraps the entire file with "#ifndef", "#define" and
201 "#endif" self-exclusionary text. It also, optionally, inserts
202 a prolog after the "#define" and an epilog just before the
203 "#endif". You can use this for a fix as follows:
205 c_fix = wrap;
206 c_fix_arg = "/* prolog text */";
207 c_fix_arg = "/* epilog text */";
209 If you want an epilog without a prolog, set the first "c_fix_arg"
210 to the empty string. Both or the second "c_fix_arg"s may be
211 omitted and the file will still be wrapped.
213 THERE IS A SPECIAL EXCEPTION TO THIS, HOWEVER:
215 If the regular expression '#if.*__need' is found, then it is
216 assumed that the file needs to be read and interpreted more
217 than once. However, the prolog and epilog text (if any) will
218 be inserted.
220 v) format - Replaces text selected with a regular expression with
221 a specialized formating string. The formatting works as follows:
222 The format text is copied to the output until a '%' character
223 is found. If the character after the '%' is another '%', then
224 one '%' is output and processing continues. If the following
225 character is not a digit, then the '%' and that character are
226 copied and processing continues. Finally, if the '%' *is*
227 followed by a digit, that digit is used as an index into the
228 regmatch_t array to replace the two characters with the matched
229 text. i.e.: "%0" is replaced by the full matching text, "%1"
230 is the first matching sub-expression, etc.
232 This is used as follows:
234 c_fix = format;
235 c_fix_arg = "#ifndef %1\n%0\n#endif";
236 c_fix_arg = "#define[ \t]+([A-Z][A-Z0-9a-z_]*).*";
238 This would wrap a one line #define inside of a "#ifndef"/"#endif"
239 pair. The second "c_fix_arg" may be omitted *IF* there is at least
240 one select clause and the first one identifies the text you wish to
241 reformat. It will then be used as the second "c_fix_arg". You may
242 delete the selected text by supplying an empty string for the
243 replacement format (the first "c_fix_arg").
245 Note: In general, a format c_fix may be used in place of one
246 sed expression. However, it will need to be rewritten by
247 hand. For example:
249 sed = 's@^#if __GNUC__ == 2 && __GNUC_MINOR__ >= 7$'
250 '@& || __GNUC__ >= 3@';
252 may be rewritten using a format c_fix as:
254 c_fix = format;
255 c_fix_arg = '%0 || __GNUC__ >= 3';
256 c_fix_arg = '^#if __GNUC__ == 2 && __GNUC_MINOR__ >= 7$';
258 Multiple sed substitution expressions probably ought to remain sed
259 expressions in order to maintain clarity. Also note that if the
260 second sed expression is the same as the first select expression,
261 then you may omit the second c_fix_arg. The select expression will
262 be picked up and used in its absence.
264 EXAMPLES OF FIXES:
265 ==================
267 hackname = AAA_ki_iface;
268 replace; /* empty replacement -> no fixing the file */
270 When this ``fix'' is invoked, it will prevent any fixes
271 from being applied.
273 ------------------
275 hackname = AAB_svr4_no_varargs;
276 replace = "/* This file was generated by fixincludes. */\n"
277 "#ifndef _SYS_VARARGS_H\n"
278 "#define _SYS_VARARGS_H\n\n"
280 "#ifdef __STDC__\n"
281 "#include <stdarg.h>\n"
282 "#else\n"
283 "#include <varargs.h>\n"
284 "#endif\n\n"
286 "#endif /* _SYS_VARARGS_H */\n";
288 When this ``fix'' is invoked, the replacement text will be
289 emitted into the replacement include file. No further fixes
290 will be applied.
292 ------------------
294 hackname = hpux11_fabsf;
295 files = math.h;
296 select = "^[ \t]*#[ \t]*define[ \t]+fabsf\\(.*";
297 bypass = "__cplusplus";
299 c_fix = format;
300 c_fix_arg = "#ifndef __cplusplus\n%0\n#endif";
302 test_text =
303 "# define fabsf(x) ((float)fabs((double)(float)(x)))\n";
305 This fix will ensure that the #define for fabs is wrapped
306 with C++ protection, providing the header is not already
307 C++ aware.
309 ------------------
311 5. Testing fixes.
313 The brute force method is, of course, to configure and build
314 GCC. But you can also:
316 cd ${top_builddir}/gcc
317 rm -rf include-fixed/ stmp-fixinc
318 make stmp-fixinc
320 I would really recommend, however:
322 cd ${top_builddir}/fixincludes
323 make check
325 To do this, you *must* have autogen installed on your system.
326 The "check" step will proceed to construct a shell script that
327 will exercise all the fixes, using the sample test_text
328 provided with each fix. Once done, the changes made will
329 be compared against the changes saved in the source directory.
330 If you are changing the tests or fixes, the change will likely
331 be highlighted.