variable.h

   1 /* Definitions for using variables in GNU Make.
   2 Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
   3 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software
   4 Foundation, Inc.
   5 This file is part of GNU Make.
   6
   7 GNU Make is free software; you can redistribute it and/or modify it under the
   8 terms of the GNU General Public License as published by the Free Software
   9 Foundation; either version 2, or (at your option) any later version.
  10
  11 GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  13 A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License along with
  16 GNU Make; see the file COPYING.  If not, write to the Free Software
  17 Foundation, 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.  */
  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 (:=) */
  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
  51 struct 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
  84 struct variable_set
  85   {
  86     struct hash_table table;    /* Hash table of variables.  */
  87   };
  88
  89 /* Structure that represents a list of variable sets.  */
  90
  91 struct 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
  99 struct pattern_var
 100   {
 101     struct pattern_var *next;
 102     char *target;
 103     unsigned int len;
 104     char *suffix;
 105     struct variable variable;
 106   };
 107
 108 extern char *variable_buffer;
 109 extern struct variable_set_list *current_variable_set_list;
 110
 111 /* expand.c */
 112 extern char *variable_buffer_output PARAMS ((char *ptr, char *string, unsigned int length));
 113 extern char *variable_expand PARAMS ((char *line));
 114 extern char *variable_expand_for_file PARAMS ((char *line, struct file *file));
 115 extern 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)
 118 extern char *expand_argument PARAMS ((const char *str, const char *end));
 119 extern char *variable_expand_string PARAMS ((char *line, char *string,
 120                                              long length));
 121 extern void install_variable_buffer PARAMS ((char **bufp, unsigned int *lenp));
 122 extern void restore_variable_buffer PARAMS ((char *buf, unsigned int len));
 123
 124 /* function.c */
 125 extern int handle_function PARAMS ((char **op, char **stringp));
 126 extern int pattern_matches PARAMS ((char *pattern, char *percent, char *str));
 127 extern char *subst_expand PARAMS ((char *o, char *text, char *subst, char *replace,
 128                 unsigned int slen, unsigned int rlen, int by_word));
 129 extern char *patsubst_expand PARAMS ((char *o, char *text, char *pattern, char *replace,
 130                 char *pattern_percent, char *replace_percent));
 131
 132 /* expand.c */
 133 extern 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 */
 138 extern struct variable_set_list *create_new_variable_set PARAMS ((void));
 139 extern void free_variable_set PARAMS ((struct variable_set_list *));
 140 extern struct variable_set_list *push_new_variable_scope PARAMS ((void));
 141 extern void pop_variable_scope PARAMS ((void));
 142 extern void define_automatic_variables PARAMS ((void));
 143 extern void initialize_file_variables PARAMS ((struct file *file, int read));
 144 extern void print_file_variables PARAMS ((struct file *file));
 145 extern void print_variable_set PARAMS ((struct variable_set *set, char *prefix));
 146 extern void merge_variable_set_lists PARAMS ((struct variable_set_list **to_list, struct variable_set_list *from_list));
 147 extern 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));
 148 extern struct variable *parse_variable_definition PARAMS ((struct variable *v, char *line));
 149 extern struct variable *try_variable_definition PARAMS ((const struct floc *flocp, char *line, enum variable_origin origin, int target_var));
 150 extern void init_hash_global_variable_set PARAMS ((void));
 151 extern void hash_init_function_table PARAMS ((void));
 152 extern struct variable *lookup_variable PARAMS ((const char *name, unsigned int length));
 153 extern struct variable *lookup_variable_in_set PARAMS ((const char *name,
 154                                                         unsigned int length,
 155                                                         const struct variable_set *set));
 156
 157 extern 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
 193 extern char **target_environment PARAMS ((struct file *file));
 194
 195 extern struct pattern_var *create_pattern_var PARAMS ((char *target, char *suffix));
 196
 197 extern int export_all_variables;
 198
 199 #define MAKELEVEL_NAME "MAKELEVEL"
 200 #define MAKELEVEL_LENGTH (sizeof (MAKELEVEL_NAME) - 1)