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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 gcc/fixinc/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 fixinc 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, syncronize 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,
73 then name each such file with a "files = " entry.
75 3. It is relatively expensive to fire off a process to fix a source
76 file, therefore write apply tests to avoid unnecessary fix
77 processes. The preferred apply tests are "select", "bypass" and
78 "c_test" because they are performed internally. The available
79 tests are:
81 * select - Run a regex on the contents of the file being considered.
82 All such regex-es must match.
84 * bypass - Run a regex on the contents of the file being considered.
85 No such regex may match.
87 * c_test - call a function in fixtests.c. See that file.
89 The next two tests are relatively slow because they must be handled
90 in a separate shell process. Some platforms do not support server
91 shells, so the whole process is even slower and more cumbersome there.
93 * mach - Match the output of config.conf against a series of globbing
94 patterns. It must match at least one of the patterns, unless
95 "not-machine" has also been specified. If that has been
96 specified, then the config.conf output may not match any of
97 the patterns.
99 * test - These should be arguments to the program, "/bin/test".
100 You may perform multiple commands, if you enclose them
101 in backquotes and echo out valid test arguments. For
102 example, you might echo out '0 -eq 1' if you want a false
103 result, or '0 -eq 0' for a true result.
105 These tests are required to:
107 1. Be positive for all header files that require the fix.
109 It is desireable to:
111 2. Be negative as often as possible whenever the fix is not
112 required, avoiding the process overhead.
114 It is nice if:
116 3. The expression is as simple as possible to both
117 process and understand by people. :-)
119 Please take advantage of the fact AutoGen will glue
120 together string fragments. It helps. Also take note
121 that double quote strings and single quote strings have
122 different formation rules. Double quote strings are a
123 tiny superset of ANSI-C string syntax. Single quote
124 strings follow shell single quote string formation
125 rules, except that the backslash is processed before
126 '\\', '\'' and '#' characters (using C character syntax).
128 Each test must pass or the fix is not applied. For example,
129 all "select" expressions must be found and not one "bypass"
130 selection may be found.
132 Examples of test specifications:
134 hackname = broken_assert_stdio;
135 files = assert.h;
136 select = stderr;
137 bypass = "include.*stdio.h";
139 The ``broken_assert_stdio'' fix will be applied only to a file
140 named "assert.h" if it contains the string "stderr" _and_ it
141 does _not_ contain the expression "include.*stdio.h".
143 hackname = no_double_slash;
144 c_test = "double_slash";
146 The ``no_double_slash'' fix will be applied if the
147 ``double_slash_test()'' function says to. See ``fixtests.c''
148 for documentation on how to include new functions into that
149 module.
151 4. There are currently four methods of fixing a file:
153 1. a series of sed expressions. Each will be an individual
154 "-e" argument to a single invocation of sed.
156 2. a shell script. These scripts are _required_ to read all
157 of stdin in order to avoid pipe stalls. They may choose to
158 discard the input.
160 3. Replacement text. If the replacement is empty, then no
161 fix is applied. Otherwise, the replacement text is
162 written to the output file and no further fixes are
163 applied. If you really want a no-op file, replace the
164 file with a comment.
166 Replacement text "fixes" must be first in this file!!
168 4. A C language subroutine method for both tests and fixes.
169 See ``fixtests.c'' for instructions on writing C-language
170 applicability tests and ``fixfixes.c'' for C-language fixing.
171 These files also contain tables that describe the currently
172 implemented fixes and tests.
174 If at all possible, you should try to use one of the C language
175 fixes as it is far more efficient. There are currently five
176 such fixes, three of which are very special purpose:
178 i) char_macro_def - This function repairs the definition of an
179 ioctl macro that presumes CPP macro substitution within
180 pairs of single quote characters.
182 ii) char_macro_use - This function repairs the usage of ioctl
183 macros that no longer can wrap an argument with single quotes.
185 iii) machine_name - This function will look at "#if", "#ifdef",
186 "#ifndef" and "#elif" directive lines and replace the first
187 occurrence of a non-reserved name that is traditionally
188 pre-defined by the native compiler.
190 The next two are for general use:
192 iv) wrap - wraps the entire file with "#ifndef", "#define" and
193 "#endif" self-exclusionary text. It also, optionally, inserts
194 a prolog after the "#define" and an epilog just before the
195 "#endif". You can use this for a fix as follows:
197 c_fix = wrap;
198 c_fix_arg = "/* prolog text */";
199 c_fix_arg = "/* epilog text */";
201 If you want an epilog without a prolog, set the first "c_fix_arg"
202 to the empty string. Both or the second "c_fix_arg"s may be
203 omitted and the file will still be wrapped.
205 THERE IS A SPECIAL EXCEPTION TO THIS, HOWEVER:
207 If the regular expression '#if.*__need' is found, then it is
208 assumed that the file needs to be read and interpreted more
209 than once. However, the prolog and epilog text (if any) will
210 be inserted.
212 v) format - Replaces text selected with a regular expression with
213 a specialized formating string. The formatting works as follows:
214 The format text is copied to the output until a '%' character
215 is found. If the character after the '%' is another '%', then
216 one '%' is output and processing continues. If the following
217 character is not a digit, then the '%' and that character are
218 copied and processing continues. Finally, if the '%' *is*
219 followed by a digit, that digit is used as an index into the
220 regmatch_t array to replace the two characters with the matched
221 text. i.e.: "%0" is replaced by the full matching text, "%1"
222 is the first matching sub-expression, etc.
224 This is used as follows:
226 c_fix = format;
227 c_fix_arg = "#ifndef %1\n%0\n#endif";
228 c_fix_arg = "#define[ \t]+([A-Z][A-Z0-9a-z_]*).*";
230 This would wrap a traditional #define inside of a "#ifndef"/"#endif"
231 pair. The second "c_fix_arg" may be omitted *IF* there is
232 a select clause and the first one matches the text you want
233 replaced. You may delete text by supplying an empty string for
234 the format (the first "c_fix_arg").
236 Note: In general, a format c_fix may be used in place of one
237 sed expression. However, it will need to be rewritten by
238 hand. For example:
240 sed = 's@^#if __GNUC__ == 2 && __GNUC_MINOR__ >= 7$'
241 '@& || __GNUC__ >= 3@';
243 may be rewritten using a format c_fix as:
245 c_fix = format;
246 c_fix_arg = '%0 || __GNUC__ >= 3';
247 c_fix_arg = '^#if __GNUC__ == 2 && __GNUC_MINOR__ >= 7$';
249 Multiple sed substitution expressions probably ought to remain sed
250 expressions in order to maintain clarity. Also note that if the
251 second sed expression is the same as the first select expression,
252 then you may omit the second c_fix_arg. The select expression will
253 be picked up and used in its absence.
255 EXAMPLES OF FIXES:
256 ==================
258 hackname = AAA_ki_iface;
259 replace; /* empty replacement -> no fixing the file */
261 When this ``fix'' is invoked, it will prevent any fixes
262 from being applied.
264 ------------------
266 hackname = AAB_svr4_no_varargs;
267 replace = "/* This file was generated by fixincludes. */\n"
268 "#ifndef _SYS_VARARGS_H\n"
269 "#define _SYS_VARARGS_H\n\n"
271 "#ifdef __STDC__\n"
272 "#include <stdarg.h>\n"
273 "#else\n"
274 "#include <varargs.h>\n"
275 "#endif\n\n"
277 "#endif /* _SYS_VARARGS_H */\n";
279 When this ``fix'' is invoked, the replacement text will be
280 emitted into the replacement include file. No further fixes
281 will be applied.
283 ------------------
285 hackname = hpux11_fabsf;
286 files = math.h;
287 select = "^[ \t]*#[ \t]*define[ \t]+fabsf\\(.*";
288 bypass = "__cplusplus";
290 c_fix = format;
291 c_fix_arg = "#ifndef __cplusplus\n%0\n#endif";
293 test_text =
294 "# define fabsf(x) ((float)fabs((double)(float)(x)))\n";
296 This fix will ensure that the #define for fabs is wrapped
297 with C++ protection, providing the header is not already
298 C++ aware.
300 ------------------
302 5. Testing fixes.
304 The brute force method is, of course, to configure and build
305 GCC. But you can also:
307 cd ${top_builddir}/gcc
308 rm -rf fixinc.sh include/ stmp-fixinc
309 make stmp-fixinc
311 I would really recommend, however:
313 cd ${top_builddir}/gcc/fixinc
314 make check
316 To do this, you *must* have autogen installed on your system.
317 The "check" step will proceed to construct a shell script that
318 will exercise all the fixes, using the sample test_text
319 provided with each fix. Once done, the changes made will
320 be compared against the changes saved in the source directory.
321 If you are changing the tests or fixes, the change will likely
322 be highlighted.