1 /* Definitions for using variables in GNU Make.
2 Copyright (C) 1988-2022 Free Software Foundation, Inc.
3 This file is part of GNU Make.
4
5 GNU Make is free software; you can redistribute it and/or modify it under the
6 terms of the GNU General Public License as published by the Free Software
7 Foundation; either version 3 of the License, or (at your option) any later
8 version.
9
10 GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
11 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
12 A PARTICULAR PURPOSE. See the GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License along with
15 this program. If not, see <https://www.gnu.org/licenses/>. */
16
17 #include "hash.h"
18
19 struct file;
20
21 /* Codes in a variable definition saying where the definition came from.
22 Increasing numeric values signify less-overridable definitions. */
23 enum variable_origin
24 {
25 o_default, /* Variable from the default set. */
26 o_env, /* Variable from environment. */
27 o_file, /* Variable given in a makefile. */
28 o_env_override, /* Variable from environment, if -e. */
29 o_command, /* Variable given by user. */
30 o_override, /* Variable from an 'override' directive. */
31 o_automatic, /* Automatic variable -- cannot be set. */
32 o_invalid /* Core dump time. */
33 };
34
35 enum variable_flavor
36 {
37 f_bogus, /* Bogus (error) */
38 f_simple, /* Simple definition (:= or ::=) */
39 f_recursive, /* Recursive definition (=) */
40 f_expand, /* POSIX :::= assignment */
41 f_append, /* Appending definition (+=) */
42 f_conditional, /* Conditional definition (?=) */
43 f_shell, /* Shell assignment (!=) */
44 f_append_value /* Append unexpanded value */
45 };
46
47 enum variable_export
48 {
49 v_default = 0, /* Decide in target_environment. */
50 v_export, /* Export this variable. */
51 v_noexport, /* Don't export this variable. */
52 v_ifset /* Export it if it has a non-default value. */
53 };
54
55 /* Structure that represents one variable definition.
56 Each bucket of the hash table is a chain of these,
57 chained through 'next'. */
58
59 #define EXP_COUNT_BITS 15 /* This gets all the bitfields into 32 bits */
60 #define EXP_COUNT_MAX ((1<<EXP_COUNT_BITS)-1)
61
62 struct variable
63 {
64 char *name; /* Variable name. */
65 char *value; /* Variable value. */
66 floc fileinfo; /* Where the variable was defined. */
67 unsigned int length; /* strlen (name) */
68 unsigned int recursive:1; /* Gets recursively re-evaluated. */
69 unsigned int append:1; /* Nonzero if an appending target-specific
70 variable. */
71 unsigned int conditional:1; /* Nonzero if set with a ?=. */
72 unsigned int per_target:1; /* Nonzero if a target-specific variable. */
73 unsigned int special:1; /* Nonzero if this is a special variable. */
74 unsigned int exportable:1; /* Nonzero if the variable _could_ be
75 exported. */
76 unsigned int expanding:1; /* Nonzero if currently being expanded. */
77 unsigned int private_var:1; /* Nonzero avoids inheritance of this
78 target-specific variable. */
79 unsigned int exp_count:EXP_COUNT_BITS;
80 /* If >1, allow this many self-referential
81 expansions. */
82 enum variable_flavor
83 flavor ENUM_BITFIELD (3); /* Variable flavor. */
84 enum variable_origin
85 origin ENUM_BITFIELD (3); /* Variable origin. */
86 enum variable_export
87 export ENUM_BITFIELD (2); /* Export control. */
88 };
89
90 /* Structure that represents a variable set. */
91
92 struct variable_set
93 {
94 struct hash_table table; /* Hash table of variables. */
95 };
96
97 /* Structure that represents a list of variable sets. */
98
99 struct variable_set_list
100 {
101 struct variable_set_list *next; /* Link in the chain. */
102 struct variable_set *set; /* Variable set. */
103 int next_is_parent; /* True if next is a parent target. */
104 };
105
106 /* Structure used for pattern-specific variables. */
107
108 struct pattern_var
109 {
110 struct pattern_var *next;
111 const char *suffix;
112 const char *target;
113 size_t len;
114 struct variable variable;
115 };
116
117 extern unsigned long long env_recursion;
118 extern char *variable_buffer;
119 extern struct variable_set_list *current_variable_set_list;
120 extern struct variable *default_goal_var;
121 extern struct variable shell_var;
122
123 /* expand.c */
124 #ifndef SIZE_MAX
125 # define SIZE_MAX ((size_t)~(size_t)0)
126 #endif
127
128 char *variable_buffer_output (char *ptr, const char *string, size_t length);
129 char *variable_expand (const char *line);
130 char *variable_expand_for_file (const char *line, struct file *file);
131 char *allocated_variable_expand_for_file (const char *line, struct file *file);
132 #define allocated_variable_expand(line) \
133 allocated_variable_expand_for_file (line, (struct file *) 0)
134 char *expand_argument (const char *str, const char *end);
135 char *variable_expand_string (char *line, const char *string, size_t length);
136 char *initialize_variable_output (void);
137 void install_variable_buffer (char **bufp, size_t *lenp);
138 void restore_variable_buffer (char *buf, size_t len);
139
140 /* function.c */
141 int handle_function (char **op, const char **stringp);
142 int pattern_matches (const char *pattern, const char *percent, const char *str);
143 char *subst_expand (char *o, const char *text, const char *subst,
144 const char *replace, size_t slen, size_t rlen,
145 int by_word);
146 char *patsubst_expand_pat (char *o, const char *text, const char *pattern,
147 const char *replace, const char *pattern_percent,
148 const char *replace_percent);
149 char *patsubst_expand (char *o, const char *text, char *pattern, char *replace);
150 char *func_shell_base (char *o, char **argv, int trim_newlines);
151 void shell_completed (int exit_code, int exit_sig);
152
153 /* expand.c */
154 char *recursively_expand_for_file (struct variable *v, struct file *file);
155 #define recursively_expand(v) recursively_expand_for_file (v, NULL)
156
157 /* variable.c */
158 struct variable_set_list *create_new_variable_set (void);
159 void free_variable_set (struct variable_set_list *);
160 struct variable_set_list *push_new_variable_scope (void);
161 void pop_variable_scope (void);
162 void define_automatic_variables (void);
163 void initialize_file_variables (struct file *file, int reading);
164 void print_file_variables (const struct file *file);
165 void print_target_variables (const struct file *file);
166 void merge_variable_set_lists (struct variable_set_list **to_list,
167 struct variable_set_list *from_list);
168 struct variable *do_variable_definition (const floc *flocp,
169 const char *name, const char *value,
170 enum variable_origin origin,
171 enum variable_flavor flavor,
172 int target_var);
173 char *parse_variable_definition (const char *line,
174 struct variable *v);
175 struct variable *assign_variable_definition (struct variable *v, const char *line);
176 struct variable *try_variable_definition (const floc *flocp, const char *line,
177 enum variable_origin origin,
178 int target_var);
179 void init_hash_global_variable_set (void);
180 void hash_init_function_table (void);
181 void define_new_function(const floc *flocp, const char *name,
182 unsigned int min, unsigned int max, unsigned int flags,
183 gmk_func_ptr func);
184 struct variable *lookup_variable (const char *name, size_t length);
185 struct variable *lookup_variable_in_set (const char *name, size_t length,
186 const struct variable_set *set);
187
188 struct variable *define_variable_in_set (const char *name, size_t length,
189 const char *value,
190 enum variable_origin origin,
191 int recursive,
192 struct variable_set *set,
193 const floc *flocp);
194
195 /* Define a variable in the current variable set. */
196
197 #define define_variable(n,l,v,o,r) \
198 define_variable_in_set((n),(l),(v),(o),(r),\
199 current_variable_set_list->set,NILF)
200
201 /* Define a variable with a constant name in the current variable set. */
202
203 #define define_variable_cname(n,v,o,r) \
204 define_variable_in_set((n),(sizeof (n) - 1),(v),(o),(r),\
205 current_variable_set_list->set,NILF)
206
207 /* Define a variable with a location in the current variable set. */
208
209 #define define_variable_loc(n,l,v,o,r,f) \
210 define_variable_in_set((n),(l),(v),(o),(r),\
211 current_variable_set_list->set,(f))
212
213 /* Define a variable with a location in the global variable set. */
214
215 #define define_variable_global(n,l,v,o,r,f) \
216 define_variable_in_set((n),(l),(v),(o),(r),NULL,(f))
217
218 /* Define a variable in FILE's variable set. */
219
220 #define define_variable_for_file(n,l,v,o,r,f) \
221 define_variable_in_set((n),(l),(v),(o),(r),(f)->variables->set,NILF)
222
223 void undefine_variable_in_set (const char *name, size_t length,
224 enum variable_origin origin,
225 struct variable_set *set);
226
227 /* Remove variable from the current variable set. */
228
229 #define undefine_variable_global(n,l,o) \
230 undefine_variable_in_set((n),(l),(o),NULL)
231
232 /* Warn that NAME is an undefined variable. */
233
234 #define warn_undefined(n,l) do{\
235 if (warn_undefined_variables_flag) \
236 error (reading_file, (l), \
237 _("warning: undefined variable '%.*s'"), \
238 (int)(l), (n)); \
239 }while(0)
240
241 char **target_environment (struct file *file, int recursive);
242
243 struct pattern_var *create_pattern_var (const char *target,
244 const char *suffix);
245
246 extern int export_all_variables;
247
248 #define MAKELEVEL_NAME "MAKELEVEL"
249 #define MAKELEVEL_LENGTH (CSTRLEN (MAKELEVEL_NAME))