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ec2bcbe7 | 1 | /* Interface to C preprocessor macro tables for GDB. |
9b254dd1 | 2 | Copyright (C) 2002, 2007, 2008 Free Software Foundation, Inc. |
ec2bcbe7 JB |
3 | Contributed by Red Hat, Inc. |
4 | ||
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 9 | the Free Software Foundation; either version 3 of the License, or |
ec2bcbe7 JB |
10 | (at your option) any later version. |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
ec2bcbe7 JB |
19 | |
20 | #ifndef MACROTAB_H | |
21 | #define MACROTAB_H | |
22 | ||
aa84d1bb AC |
23 | struct obstack; |
24 | struct bcache; | |
ec2bcbe7 JB |
25 | |
26 | /* How do we represent a source location? I mean, how should we | |
27 | represent them within GDB; the user wants to use all sorts of | |
28 | ambiguous abbreviations, like "break 32" and "break foo.c:32" | |
29 | ("foo.c" may have been #included into several compilation units), | |
30 | but what do we disambiguate those things to? | |
31 | ||
32 | - Answer 1: "Filename and line number." (Or column number, if | |
33 | you're picky.) That's not quite good enough. For example, the | |
34 | same source file can be #included into several different | |
35 | compilation units --- which #inclusion do you mean? | |
36 | ||
37 | - Answer 2: "Compilation unit, filename, and line number." This is | |
38 | a pretty good answer; GDB's `struct symtab_and_line' basically | |
39 | embodies this representation. But it's still ambiguous; what if a | |
40 | given compilation unit #includes the same file twice --- how can I | |
41 | set a breakpoint on line 12 of the fifth #inclusion of "foo.c"? | |
42 | ||
43 | - Answer 3: "Compilation unit, chain of #inclusions, and line | |
44 | number." This is analogous to the way GCC reports errors in | |
45 | #include files: | |
46 | ||
47 | $ gcc -c base.c | |
48 | In file included from header2.h:8, | |
49 | from header1.h:3, | |
50 | from base.c:5: | |
51 | header3.h:1: parse error before ')' token | |
52 | $ | |
53 | ||
54 | GCC tells you exactly what path of #inclusions led you to the | |
55 | problem. It gives you complete information, in a way that the | |
56 | following would not: | |
57 | ||
58 | $ gcc -c base.c | |
59 | header3.h:1: parse error before ')' token | |
60 | $ | |
61 | ||
62 | Converting all of GDB to use this is a big task, and I'm not really | |
63 | suggesting it should be a priority. But this module's whole | |
64 | purpose is to maintain structures describing the macro expansion | |
65 | process, so I think it's appropriate for us to take a little care | |
66 | to do that in a complete fashion. | |
67 | ||
68 | In this interface, the first line of a file is numbered 1, not 0. | |
69 | This is the same convention the rest of GDB uses. */ | |
70 | ||
71 | ||
72 | /* A table of all the macro definitions for a given compilation unit. */ | |
73 | struct macro_table; | |
74 | ||
75 | ||
76 | /* A source file that participated in a compilation unit --- either a | |
77 | main file, or an #included file. If a file is #included more than | |
78 | once, the presence of the `included_from' and `included_at_line' | |
79 | members means that we need to make one instance of this structure | |
80 | for each #inclusion. Taken as a group, these structures form a | |
81 | tree mapping the #inclusions that contributed to the compilation | |
82 | unit, with the main source file as its root. | |
83 | ||
f8302a57 JB |
84 | Beware --- not every source file mentioned in a compilation unit's |
85 | symtab structures will appear in the #inclusion tree! As of Oct | |
86 | 2002, GCC does record the effect of #line directives in the source | |
87 | line info, but not in macro info. This means that GDB's symtabs | |
88 | (built from the former, among other things) may mention filenames | |
89 | that the #inclusion tree (built from the latter) doesn't have any | |
90 | record of. See macroscope.c:sal_macro_scope for how to accomodate | |
91 | this. | |
92 | ||
ec2bcbe7 JB |
93 | It's worth noting that libcpp has a simpler way of representing all |
94 | this, which we should consider switching to. It might even be | |
95 | suitable for ordinary non-macro line number info. | |
96 | ||
97 | Suppose you take your main source file, and after each line | |
98 | containing an #include directive you insert the text of the | |
99 | #included file. The result is a big file that pretty much | |
100 | corresponds to the full text the compiler's going to see. There's | |
101 | a one-to-one correspondence between lines in the big file and | |
102 | per-inclusion lines in the source files. (Obviously, #include | |
103 | directives that are #if'd out don't count. And you'll need to | |
104 | append a newline to any file that doesn't end in one, to avoid | |
105 | splicing the last #included line with the next line of the | |
106 | #including file.) | |
107 | ||
108 | Libcpp calls line numbers in this big imaginary file "logical line | |
109 | numbers", and has a data structure called a "line map" that can map | |
110 | logical line numbers onto actual source filenames and line numbers, | |
111 | and also tell you the chain of #inclusions responsible for any | |
112 | particular logical line number. Basically, this means you can pass | |
113 | around a single line number and some kind of "compilation unit" | |
114 | object and you get nice, unambiguous source code locations that | |
115 | distinguish between multiple #inclusions of the same file, etc. | |
116 | ||
117 | Pretty neat, huh? */ | |
118 | ||
119 | struct macro_source_file | |
120 | { | |
121 | ||
122 | /* The macro table for the compilation unit this source location is | |
123 | a part of. */ | |
124 | struct macro_table *table; | |
125 | ||
126 | /* A source file --- possibly a header file. */ | |
127 | const char *filename; | |
128 | ||
129 | /* The location we were #included from, or zero if we are the | |
130 | compilation unit's main source file. */ | |
131 | struct macro_source_file *included_by; | |
132 | ||
133 | /* If `included_from' is non-zero, the line number in that source | |
134 | file at which we were included. */ | |
135 | int included_at_line; | |
136 | ||
137 | /* Head of a linked list of the source files #included by this file; | |
138 | our children in the #inclusion tree. This list is sorted by its | |
139 | elements' `included_at_line' values, which are unique. (The | |
140 | macro splay tree's ordering function needs this property.) */ | |
141 | struct macro_source_file *includes; | |
142 | ||
143 | /* The next file #included by our `included_from' file; our sibling | |
144 | in the #inclusion tree. */ | |
145 | struct macro_source_file *next_included; | |
146 | }; | |
147 | ||
148 | ||
149 | /* Create a new, empty macro table. Allocate it in OBSTACK, or use | |
150 | xmalloc if OBSTACK is zero. Use BCACHE to store all macro names, | |
151 | arguments, definitions, and anything else that might be the same | |
152 | amongst compilation units in an executable file; if BCACHE is zero, | |
153 | don't cache these things. | |
154 | ||
32623386 JB |
155 | Note that, if either OBSTACK or BCACHE are non-zero, then removing |
156 | information from the table may leak memory. Neither obstacks nor | |
157 | bcaches really allow you to remove information, so although we can | |
158 | update the data structure to record the change, we can't free the | |
159 | old data. At the moment, since we only provide obstacks and | |
160 | bcaches for macro tables for symtabs, this isn't a problem; only | |
161 | odd debugging information makes a definition and then deletes it at | |
162 | the same source location (although 'gcc -DFOO -UFOO -DFOO=2' does | |
163 | do that in GCC 4.1.2.). */ | |
ec2bcbe7 JB |
164 | struct macro_table *new_macro_table (struct obstack *obstack, |
165 | struct bcache *bcache); | |
166 | ||
167 | ||
168 | /* Free TABLE, and any macro definitions, source file structures, | |
169 | etc. it owns. This will raise an internal error if TABLE was | |
170 | allocated on an obstack, or if it uses a bcache. */ | |
171 | void free_macro_table (struct macro_table *table); | |
172 | ||
173 | ||
174 | /* Set FILENAME as the main source file of TABLE. Return a source | |
175 | file structure describing that file; if we record the #definition | |
176 | of macros, or the #inclusion of other files into FILENAME, we'll | |
177 | use that source file structure to indicate the context. | |
178 | ||
179 | The "main source file" is the one that was given to the compiler; | |
180 | all other source files that contributed to the compilation unit are | |
181 | #included, directly or indirectly, from this one. | |
182 | ||
183 | The macro table makes its own copy of FILENAME; the caller is | |
184 | responsible for freeing FILENAME when it is no longer needed. */ | |
185 | struct macro_source_file *macro_set_main (struct macro_table *table, | |
186 | const char *filename); | |
187 | ||
188 | ||
189 | /* Return the main source file of the macro table TABLE. */ | |
190 | struct macro_source_file *macro_main (struct macro_table *table); | |
191 | ||
192 | ||
193 | /* Record a #inclusion. | |
194 | Record in SOURCE's macro table that, at line number LINE in SOURCE, | |
195 | we #included the file INCLUDED. Return a source file structure we | |
196 | can use for symbols #defined or files #included into that. If we've | |
197 | already created a source file structure for this #inclusion, return | |
198 | the same structure we created last time. | |
199 | ||
200 | The first line of the source file has a line number of 1, not 0. | |
201 | ||
202 | The macro table makes its own copy of INCLUDED; the caller is | |
203 | responsible for freeing INCLUDED when it is no longer needed. */ | |
204 | struct macro_source_file *macro_include (struct macro_source_file *source, | |
205 | int line, | |
206 | const char *included); | |
207 | ||
208 | ||
209 | /* Find any source file structure for a file named NAME, either | |
210 | included into SOURCE, or SOURCE itself. Return zero if we have | |
211 | none. NAME is only the final portion of the filename, not the full | |
212 | path. e.g., `stdio.h', not `/usr/include/stdio.h'. If NAME | |
213 | appears more than once in the inclusion tree, return the | |
214 | least-nested inclusion --- the one closest to the main source file. */ | |
215 | struct macro_source_file *(macro_lookup_inclusion | |
216 | (struct macro_source_file *source, | |
217 | const char *name)); | |
218 | ||
219 | ||
220 | /* Record an object-like #definition (i.e., one with no parameter list). | |
221 | Record in SOURCE's macro table that, at line number LINE in SOURCE, | |
222 | we #defined a preprocessor symbol named NAME, whose replacement | |
223 | string is REPLACEMENT. This function makes copies of NAME and | |
224 | REPLACEMENT; the caller is responsible for freeing them. */ | |
225 | void macro_define_object (struct macro_source_file *source, int line, | |
226 | const char *name, const char *replacement); | |
227 | ||
228 | ||
229 | /* Record an function-like #definition (i.e., one with a parameter list). | |
230 | ||
231 | Record in SOURCE's macro table that, at line number LINE in SOURCE, | |
232 | we #defined a preprocessor symbol named NAME, with ARGC arguments | |
233 | whose names are given in ARGV, whose replacement string is REPLACEMENT. If | |
234 | the macro takes a variable number of arguments, then ARGC should be | |
235 | one greater than the number of named arguments, and ARGV[ARGC-1] | |
236 | should be the string "...". This function makes its own copies of | |
237 | NAME, ARGV, and REPLACEMENT; the caller is responsible for freeing | |
238 | them. */ | |
239 | void macro_define_function (struct macro_source_file *source, int line, | |
240 | const char *name, int argc, const char **argv, | |
241 | const char *replacement); | |
242 | ||
243 | ||
244 | /* Record an #undefinition. | |
245 | Record in SOURCE's macro table that, at line number LINE in SOURCE, | |
246 | we removed the definition for the preprocessor symbol named NAME. */ | |
247 | void macro_undef (struct macro_source_file *source, int line, | |
248 | const char *name); | |
249 | ||
250 | ||
251 | /* Different kinds of macro definitions. */ | |
252 | enum macro_kind | |
253 | { | |
254 | macro_object_like, | |
255 | macro_function_like | |
256 | }; | |
257 | ||
258 | ||
259 | /* A preprocessor symbol definition. */ | |
260 | struct macro_definition | |
261 | { | |
262 | /* The table this definition lives in. */ | |
263 | struct macro_table *table; | |
264 | ||
265 | /* What kind of macro it is. */ | |
266 | enum macro_kind kind; | |
267 | ||
268 | /* If `kind' is `macro_function_like', the number of arguments it | |
269 | takes, and their names. The names, and the array of pointers to | |
270 | them, are in the table's bcache, if it has one. */ | |
271 | int argc; | |
272 | const char * const *argv; | |
273 | ||
274 | /* The replacement string (body) of the macro. This is in the | |
275 | table's bcache, if it has one. */ | |
276 | const char *replacement; | |
277 | }; | |
278 | ||
279 | ||
280 | /* Return a pointer to the macro definition for NAME in scope at line | |
281 | number LINE of SOURCE. If LINE is -1, return the definition in | |
282 | effect at the end of the file. The macro table owns the structure; | |
283 | the caller need not free it. Return zero if NAME is not #defined | |
284 | at that point. */ | |
285 | struct macro_definition *(macro_lookup_definition | |
286 | (struct macro_source_file *source, | |
287 | int line, const char *name)); | |
288 | ||
289 | ||
290 | /* Return the source location of the definition for NAME in scope at | |
291 | line number LINE of SOURCE. Set *DEFINITION_LINE to the line | |
292 | number of the definition, and return a source file structure for | |
293 | the file. Return zero if NAME has no definition in scope at that | |
294 | point, and leave *DEFINITION_LINE unchanged. */ | |
295 | struct macro_source_file *(macro_definition_location | |
296 | (struct macro_source_file *source, | |
297 | int line, | |
298 | const char *name, | |
299 | int *definition_line)); | |
300 | ||
301 | ||
302 | #endif /* MACROTAB_H */ |