1/* Definitions for using variables in GNU Make.
2Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
31998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software
4Foundation, Inc.
5This file is part of GNU Make.
6
7GNU Make is free software; you can redistribute it and/or modify it under the
8terms of the GNU General Public License as published by the Free Software
9Foundation; either version 2, or (at your option) any later version.
10
11GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
12WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
13A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
14
15You should have received a copy of the GNU General Public License along with
16GNU Make; see the file COPYING.  If not, write to the Free Software
17Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.  */
18
19#include "hash.h"
20
21/* Codes in a variable definition saying where the definition came from.
22   Increasing numeric values signify less-overridable definitions.  */
23enum 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
35enum variable_flavor
36  {
37    f_bogus,            /* Bogus (error) */
38    f_simple,           /* Simple definition (:=) */
39    f_recursive,        /* Recursive definition (=) */
40    f_append,           /* Appending definition (+=) */
41    f_conditional       /* Conditional definition (?=) */
42  };
43
44/* Structure that represents one variable definition.
45   Each bucket of the hash table is a chain of these,
46   chained through `next'.  */
47
48#define EXP_COUNT_BITS  15      /* This gets all the bitfields into 32 bits */
49#define EXP_COUNT_MAX   ((1<<EXP_COUNT_BITS)-1)
50
51struct variable
52  {
53    char *name;			/* Variable name.  */
54    int length;			/* strlen (name) */
55    char *value;		/* Variable value.  */
56    struct floc fileinfo;       /* Where the variable was defined.  */
57    unsigned int recursive:1;	/* Gets recursively re-evaluated.  */
58    unsigned int append:1;	/* Nonzero if an appending target-specific
59                                   variable.  */
60    unsigned int conditional:1; /* Nonzero if set with a ?=. */
61    unsigned int per_target:1;	/* Nonzero if a target-specific variable.  */
62    unsigned int special:1;     /* Nonzero if this is a special variable. */
63    unsigned int exportable:1;  /* Nonzero if the variable _could_ be
64                                   exported.  */
65    unsigned int expanding:1;	/* Nonzero if currently being expanded.  */
66    unsigned int exp_count:EXP_COUNT_BITS;
67                                /* If >1, allow this many self-referential
68                                   expansions.  */
69    enum variable_flavor
70      flavor ENUM_BITFIELD (3);	/* Variable flavor.  */
71    enum variable_origin
72      origin ENUM_BITFIELD (3);	/* Variable origin.  */
73    enum variable_export
74      {
75	v_export,		/* Export this variable.  */
76	v_noexport,		/* Don't export this variable.  */
77	v_ifset,		/* Export it if it has a non-default value.  */
78	v_default		/* Decide in target_environment.  */
79      } export ENUM_BITFIELD (2);
80  };
81
82/* Structure that represents a variable set.  */
83
84struct variable_set
85  {
86    struct hash_table table;	/* Hash table of variables.  */
87  };
88
89/* Structure that represents a list of variable sets.  */
90
91struct variable_set_list
92  {
93    struct variable_set_list *next;	/* Link in the chain.  */
94    struct variable_set *set;		/* Variable set.  */
95  };
96
97/* Structure used for pattern-specific variables.  */
98
99struct pattern_var
100  {
101    struct pattern_var *next;
102    char *target;
103    unsigned int len;
104    char *suffix;
105    struct variable variable;
106  };
107
108extern char *variable_buffer;
109extern struct variable_set_list *current_variable_set_list;
110
111/* expand.c */
112extern char *variable_buffer_output PARAMS ((char *ptr, char *string, unsigned int length));
113extern char *variable_expand PARAMS ((char *line));
114extern char *variable_expand_for_file PARAMS ((char *line, struct file *file));
115extern char *allocated_variable_expand_for_file PARAMS ((char *line, struct file *file));
116#define	allocated_variable_expand(line) \
117  allocated_variable_expand_for_file (line, (struct file *) 0)
118extern char *expand_argument PARAMS ((const char *str, const char *end));
119extern char *variable_expand_string PARAMS ((char *line, char *string,
120                                             long length));
121extern void install_variable_buffer PARAMS ((char **bufp, unsigned int *lenp));
122extern void restore_variable_buffer PARAMS ((char *buf, unsigned int len));
123
124/* function.c */
125extern int handle_function PARAMS ((char **op, char **stringp));
126extern int pattern_matches PARAMS ((char *pattern, char *percent, char *str));
127extern char *subst_expand PARAMS ((char *o, char *text, char *subst, char *replace,
128		unsigned int slen, unsigned int rlen, int by_word));
129extern char *patsubst_expand PARAMS ((char *o, char *text, char *pattern, char *replace,
130		char *pattern_percent, char *replace_percent));
131
132/* expand.c */
133extern char *recursively_expand_for_file PARAMS ((struct variable *v,
134                                                  struct file *file));
135#define recursively_expand(v)   recursively_expand_for_file (v, NULL)
136
137/* variable.c */
138extern struct variable_set_list *create_new_variable_set PARAMS ((void));
139extern void free_variable_set PARAMS ((struct variable_set_list *));
140extern struct variable_set_list *push_new_variable_scope PARAMS ((void));
141extern void pop_variable_scope PARAMS ((void));
142extern void define_automatic_variables PARAMS ((void));
143extern void initialize_file_variables PARAMS ((struct file *file, int read));
144extern void print_file_variables PARAMS ((struct file *file));
145extern void print_variable_set PARAMS ((struct variable_set *set, char *prefix));
146extern void merge_variable_set_lists PARAMS ((struct variable_set_list **to_list, struct variable_set_list *from_list));
147extern struct variable *do_variable_definition PARAMS ((const struct floc *flocp, const char *name, char *value, enum variable_origin origin, enum variable_flavor flavor, int target_var));
148extern struct variable *parse_variable_definition PARAMS ((struct variable *v, char *line));
149extern struct variable *try_variable_definition PARAMS ((const struct floc *flocp, char *line, enum variable_origin origin, int target_var));
150extern void init_hash_global_variable_set PARAMS ((void));
151extern void hash_init_function_table PARAMS ((void));
152extern struct variable *lookup_variable PARAMS ((const char *name, unsigned int length));
153extern struct variable *lookup_variable_in_set PARAMS ((const char *name,
154                                                        unsigned int length,
155                                                        const struct variable_set *set));
156
157extern struct variable *define_variable_in_set
158    PARAMS ((const char *name, unsigned int length, char *value,
159             enum variable_origin origin, int recursive,
160             struct variable_set *set, const struct floc *flocp));
161
162/* Define a variable in the current variable set.  */
163
164#define define_variable(n,l,v,o,r) \
165          define_variable_in_set((n),(l),(v),(o),(r),\
166                                 current_variable_set_list->set,NILF)
167
168/* Define a variable with a location in the current variable set.  */
169
170#define define_variable_loc(n,l,v,o,r,f) \
171          define_variable_in_set((n),(l),(v),(o),(r),\
172                                 current_variable_set_list->set,(f))
173
174/* Define a variable with a location in the global variable set.  */
175
176#define define_variable_global(n,l,v,o,r,f) \
177          define_variable_in_set((n),(l),(v),(o),(r),NULL,(f))
178
179/* Define a variable in FILE's variable set.  */
180
181#define define_variable_for_file(n,l,v,o,r,f) \
182          define_variable_in_set((n),(l),(v),(o),(r),(f)->variables->set,NILF)
183
184/* Warn that NAME is an undefined variable.  */
185
186#define warn_undefined(n,l) do{\
187                              if (warn_undefined_variables_flag) \
188                                error (reading_file, \
189                                       _("warning: undefined variable `%.*s'"), \
190                                (int)(l), (n)); \
191                              }while(0)
192
193extern char **target_environment PARAMS ((struct file *file));
194
195extern struct pattern_var *create_pattern_var PARAMS ((char *target, char *suffix));
196
197extern int export_all_variables;
198
199#define MAKELEVEL_NAME "MAKELEVEL"
200#define MAKELEVEL_LENGTH (sizeof (MAKELEVEL_NAME) - 1)
201