variable.h

   1 /* Definitions for using variables in GNU Make.
   2 Copyright (C) 1988-2012 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 <http://www.gnu.org/licenses/>.  */
  16
  17 #include "hash.h"
  18
  19 /* Codes in a variable definition saying where the definition came from.
  20    Increasing numeric values signify less-overridable definitions.  */
  21 enum variable_origin
  22   {
  23     o_default,          /* Variable from the default set.  */
  24     o_env,              /* Variable from environment.  */
  25     o_file,             /* Variable given in a makefile.  */
  26     o_env_override,     /* Variable from environment, if -e.  */
  27     o_command,          /* Variable given by user.  */
  28     o_override,         /* Variable from an 'override' directive.  */
  29     o_automatic,        /* Automatic variable -- cannot be set.  */
  30     o_invalid           /* Core dump time.  */
  31   };
  32
  33 enum variable_flavor
  34   {
  35     f_bogus,            /* Bogus (error) */
  36     f_simple,           /* Simple definition (:= or ::=) */
  37     f_recursive,        /* Recursive definition (=) */
  38     f_append,           /* Appending definition (+=) */
  39     f_conditional,      /* Conditional definition (?=) */
  40     f_shell             /* Shell assignment (!=) */
  41   };
  42
  43 /* Structure that represents one variable definition.
  44    Each bucket of the hash table is a chain of these,
  45    chained through 'next'.  */
  46
  47 #define EXP_COUNT_BITS  15      /* This gets all the bitfields into 32 bits */
  48 #define EXP_COUNT_MAX   ((1<<EXP_COUNT_BITS)-1)
  49
  50 struct variable
  51   {
  52     char *name;                 /* Variable name.  */
  53     char *value;                /* Variable value.  */
  54     struct floc fileinfo;       /* Where the variable was defined.  */
  55     int length;                 /* strlen (name) */
  56     unsigned int recursive:1;   /* Gets recursively re-evaluated.  */
  57     unsigned int append:1;      /* Nonzero if an appending target-specific
  58                                    variable.  */
  59     unsigned int conditional:1; /* Nonzero if set with a ?=. */
  60     unsigned int per_target:1;  /* Nonzero if a target-specific variable.  */
  61     unsigned int special:1;     /* Nonzero if this is a special variable.  */
  62     unsigned int exportable:1;  /* Nonzero if the variable _could_ be
  63                                    exported.  */
  64     unsigned int expanding:1;   /* Nonzero if currently being expanded.  */
  65     unsigned int private_var:1; /* Nonzero avoids inheritance of this
  66                                    target-specific variable.  */
  67     unsigned int exp_count:EXP_COUNT_BITS;
  68                                 /* If >1, allow this many self-referential
  69                                    expansions.  */
  70     enum variable_flavor
  71       flavor ENUM_BITFIELD (3); /* Variable flavor.  */
  72     enum variable_origin
  73       origin ENUM_BITFIELD (3); /* Variable origin.  */
  74     enum variable_export
  75       {
  76         v_export,               /* Export this variable.  */
  77         v_noexport,             /* Don't export this variable.  */
  78         v_ifset,                /* Export it if it has a non-default value.  */
  79         v_default               /* Decide in target_environment.  */
  80       } export ENUM_BITFIELD (2);
  81   };
  82
  83 /* Structure that represents a variable set.  */
  84
  85 struct variable_set
  86   {
  87     struct hash_table table;    /* Hash table of variables.  */
  88   };
  89
  90 /* Structure that represents a list of variable sets.  */
  91
  92 struct variable_set_list
  93   {
  94     struct variable_set_list *next;     /* Link in the chain.  */
  95     struct variable_set *set;           /* Variable set.  */
  96     int next_is_parent;                 /* True if next is a parent target.  */
  97   };
  98
  99 /* Structure used for pattern-specific variables.  */
 100
 101 struct pattern_var
 102   {
 103     struct pattern_var *next;
 104     const char *suffix;
 105     const char *target;
 106     unsigned int len;
 107     struct variable variable;
 108   };
 109
 110 extern char *variable_buffer;
 111 extern struct variable_set_list *current_variable_set_list;
 112 extern struct variable *default_goal_var;
 113
 114 /* expand.c */
 115 char *variable_buffer_output (char *ptr, const char *string, unsigned int length);
 116 char *variable_expand (const char *line);
 117 char *variable_expand_for_file (const char *line, struct file *file);
 118 char *allocated_variable_expand_for_file (const char *line, struct file *file);
 119 #define allocated_variable_expand(line) \
 120   allocated_variable_expand_for_file (line, (struct file *) 0)
 121 char *expand_argument (const char *str, const char *end);
 122 char *variable_expand_string (char *line, const char *string, long length);
 123 void install_variable_buffer (char **bufp, unsigned int *lenp);
 124 void restore_variable_buffer (char *buf, unsigned int len);
 125
 126 /* function.c */
 127 int handle_function (char **op, const char **stringp);
 128 int pattern_matches (const char *pattern, const char *percent, const char *str);
 129 char *subst_expand (char *o, const char *text, const char *subst,
 130                     const char *replace, unsigned int slen, unsigned int rlen,
 131                     int by_word);
 132 char *patsubst_expand_pat (char *o, const char *text, const char *pattern,
 133                            const char *replace, const char *pattern_percent,
 134                            const char *replace_percent);
 135 char *patsubst_expand (char *o, const char *text, char *pattern, char *replace);
 136 char *func_shell_base (char *o, char **argv, int trim_newlines);
 137
 138
 139 /* expand.c */
 140 char *recursively_expand_for_file (struct variable *v, struct file *file);
 141 #define recursively_expand(v)   recursively_expand_for_file (v, NULL)
 142
 143 /* variable.c */
 144 struct variable_set_list *create_new_variable_set (void);
 145 void free_variable_set (struct variable_set_list *);
 146 struct variable_set_list *push_new_variable_scope (void);
 147 void pop_variable_scope (void);
 148 void define_automatic_variables (void);
 149 void initialize_file_variables (struct file *file, int reading);
 150 void print_file_variables (const struct file *file);
 151 void print_file_variables (const struct file *file);
 152 void print_target_variables (const struct file *file);
 153 void merge_variable_set_lists (struct variable_set_list **to_list,
 154                                struct variable_set_list *from_list);
 155 struct variable *do_variable_definition (const struct floc *flocp,
 156                                          const char *name, const char *value,
 157                                          enum variable_origin origin,
 158                                          enum variable_flavor flavor,
 159                                          int target_var);
 160 char *parse_variable_definition (const char *line,
 161                                  struct variable *v);
 162 struct variable *assign_variable_definition (struct variable *v, char *line);
 163 struct variable *try_variable_definition (const struct floc *flocp, char *line,
 164                                           enum variable_origin origin,
 165                                           int target_var);
 166 void init_hash_global_variable_set (void);
 167 void hash_init_function_table (void);
 168 void define_new_function(const struct floc *flocp,
 169                          const char *name, int min, int max, int expand,
 170                          char *(*func)(char *, char **, const char *));
 171 struct variable *lookup_variable (const char *name, unsigned int length);
 172 struct variable *lookup_variable_in_set (const char *name, unsigned int length,
 173                                          const struct variable_set *set);
 174
 175 struct variable *define_variable_in_set (const char *name, unsigned int length,
 176                                          const char *value,
 177                                          enum variable_origin origin,
 178                                          int recursive,
 179                                          struct variable_set *set,
 180                                          const struct floc *flocp);
 181
 182 /* Define a variable in the current variable set.  */
 183
 184 #define define_variable(n,l,v,o,r) \
 185           define_variable_in_set((n),(l),(v),(o),(r),\
 186                                  current_variable_set_list->set,NILF)
 187
 188 /* Define a variable with a constant name in the current variable set.  */
 189
 190 #define define_variable_cname(n,v,o,r) \
 191           define_variable_in_set((n),(sizeof (n) - 1),(v),(o),(r),\
 192                                  current_variable_set_list->set,NILF)
 193
 194 /* Define a variable with a location in the current variable set.  */
 195
 196 #define define_variable_loc(n,l,v,o,r,f) \
 197           define_variable_in_set((n),(l),(v),(o),(r),\
 198                                  current_variable_set_list->set,(f))
 199
 200 /* Define a variable with a location in the global variable set.  */
 201
 202 #define define_variable_global(n,l,v,o,r,f) \
 203           define_variable_in_set((n),(l),(v),(o),(r),NULL,(f))
 204
 205 /* Define a variable in FILE's variable set.  */
 206
 207 #define define_variable_for_file(n,l,v,o,r,f) \
 208           define_variable_in_set((n),(l),(v),(o),(r),(f)->variables->set,NILF)
 209
 210 void undefine_variable_in_set (const char *name, unsigned int length,
 211                                enum variable_origin origin,
 212                                struct variable_set *set);
 213
 214 /* Remove variable from the current variable set. */
 215
 216 #define undefine_variable_global(n,l,o) \
 217           undefine_variable_in_set((n),(l),(o),NULL)
 218
 219 /* Warn that NAME is an undefined variable.  */
 220
 221 #define warn_undefined(n,l) do{\
 222                               if (warn_undefined_variables_flag) \
 223                                 error (reading_file, \
 224                                        _("warning: undefined variable '%.*s'"), \
 225                                 (int)(l), (n)); \
 226                               }while(0)
 227
 228 char **target_environment (struct file *file);
 229
 230 struct pattern_var *create_pattern_var (const char *target,
 231                                         const char *suffix);
 232
 233 extern int export_all_variables;
 234
 235 #define MAKELEVEL_NAME "MAKELEVEL"
 236 #define MAKELEVEL_LENGTH (CSTRLEN (MAKELEVEL_NAME))