This is a major update, which switches virtually every allocated-but-not-freed

string into the strcache.  As a side-effect, many more structure members and
function arguments can/should be declared const.

As mentioned in the changelog, unfortunately measurement shows that this
change does not yet reduce memory.  The problem is with secondary expansion:
because of this we store all the prerequisites in the string cache twice.
First we store the prerequisite string after initial expansion but before
secondary expansion, then we store each individual file after secondary
expansion and expand_deps().  I plan to change expand_deps() to be callable
in either context (eval or snap_deps) then have non-second-expansion
targets call expand_deps() during eval, so that we only need to store that
dependency list once.

1 files changed, 13 insertions, 9 deletions

diff --git a/variable.h b/variable.h
index 937a88e..61ee6be 100644
--- a/variable.h
+++ b/variable.h
@@ -99,9 +99,9 @@ struct variable_set_list
 struct pattern_var
   {
     struct pattern_var *next;
-    char *target;
+    const char *suffix;
+    const char *target;
     unsigned int len;
-    char *suffix;
     struct variable variable;
   };
 
@@ -123,10 +123,13 @@ void restore_variable_buffer (char *buf, unsigned int len);
 /* function.c */
 int handle_function (char **op, const char **stringp);
 int pattern_matches (const char *pattern, const char *percent, const char *str);
-char *subst_expand (char *o, char *text, char *subst, char *replace,
-                    unsigned int slen, unsigned int rlen, int by_word);
-char *patsubst_expand (char *o, char *text, char *pattern, char *replace,
-                       char *pattern_percent, char *replace_percent);
+char *subst_expand (char *o, const char *text, const char *subst,
+                    const char *replace, unsigned int slen, unsigned int rlen,
+                    int by_word);
+char *patsubst_expand_pat (char *o, const char *text, const char *pattern,
+                           const char *replace, const char *pattern_percent,
+                           const char *replace_percent);
+char *patsubst_expand (char *o, const char *text, char *pattern, char *replace);
 
 /* expand.c */
 char *recursively_expand_for_file (struct variable *v, struct file *file);
@@ -139,12 +142,12 @@ struct variable_set_list *push_new_variable_scope (void);
 void pop_variable_scope (void);
 void define_automatic_variables (void);
 void initialize_file_variables (struct file *file, int reading);
-void print_file_variables (struct file *file);
+void print_file_variables (const struct file *file);
 void print_variable_set (struct variable_set *set, char *prefix);
 void merge_variable_set_lists (struct variable_set_list **to_list,
                                struct variable_set_list *from_list);
 struct variable *do_variable_definition (const struct floc *flocp,
-                                         const char *name, char *value,
+                                         const char *name, const char *value,
                                          enum variable_origin origin,
                                          enum variable_flavor flavor,
                                          int target_var);
@@ -198,7 +201,8 @@ struct variable *define_variable_in_set (const char *name, unsigned int length,
 
 char **target_environment (struct file *file);
 
-struct pattern_var *create_pattern_var (char *target, char *suffix);
+struct pattern_var *create_pattern_var (const char *target,
+                                        const char *suffix);
 
 extern int export_all_variables;