[PATCH] Accept %DATADIR% anywhere in data load path

[Tim Rühsen]

2020-04-09  Tim Rühsen  <address@hidden>

        * lib/pk-utils.h: Add declaration of pk_str_replace.
        * lib/pk-utils.c: Add implementation of pk_str_replace.
        * lib/pkl.c (pkl_resolve_module): Make use of pk_str_replace.
---
 ChangeLog      |  6 ++++++
 lib/pk-utils.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 lib/pk-utils.h |  3 +++
 lib/pkl.c      | 20 +++++++++++---------
 4 files changed, 62 insertions(+), 9 deletions(-)

diff --git a/lib/pk-utils.c b/lib/pk-utils.c
index 74dc5447..676435fb 100644
--- a/lib/pk-utils.c
+++ b/lib/pk-utils.c
@@ -157,3 +157,45 @@ pk_str_concat(const char *s0, ...)

   return res;
 }
+
+/* Replace all occurrences of 'search' in 'in' by 'replace'.
+ * Return 'in' in case 'search' was not found, else
+ * return a new allocated string with the replaced sequences.
+ * Return NULL on allocation failure.
+ */
+char *
+pk_str_replace (const char *in, const char *search, const char *replace)
+{
+  const char *s, *e;
+  char *out, *d;
+  int num = 0;
+
+  /* count number of occurrences of 'search' in 'in' */
+  for (s = in; (s = strstr (s, search)); s++, num++)
+    ;
+
+  if (!num)
+    return (char *) in;
+
+  size_t search_len = strlen (search);
+  size_t replace_len = strlen (replace);
+  size_t in_len = strlen (in);
+
+  d = out = malloc (in_len + (replace_len - search_len) * num + 1);
+  if (!out)
+    return NULL;
+
+  for (s = in; (e = strstr (s, search)); s = e + search_len)
+    {
+      memcpy (d, s, e - s);
+      d += e - s;
+
+      memcpy (d, replace, replace_len);
+      d += replace_len;
+    }
+
+  /* copy rest of 'in' + trailing zero */
+  strcpy (d, s);
+
+  return out;
+}
diff --git a/lib/pk-utils.h b/lib/pk-utils.h
index 46286ca3..256aa877 100644
--- a/lib/pk-utils.h
+++ b/lib/pk-utils.h
@@ -53,4 +53,7 @@ void pk_print_binary (uint64_t val, int size, int sign);
 /* Concatenate string arguments into an malloc'ed string. */
 char *pk_str_concat(const char *s0, ...);

+/* Replace all occurrences of 'search' in 'in' by 'replace'. */
+char *pk_str_replace (const char *in, const char *search, const char *replace);
+
 #endif /* ! PK_UTILS_H */
diff --git a/lib/pkl.c b/lib/pkl.c
index 3547255e..75db7b35 100644
--- a/lib/pkl.c
+++ b/lib/pkl.c
@@ -478,6 +478,7 @@ pkl_resolve_module (pkl_compiler compiler,
                     int filename_p)
 {
   const char *load_path;
+  char *full_filename = NULL;

   /* Get the load path from the run-time environment.  */
   {
@@ -503,30 +504,31 @@ pkl_resolve_module (pkl_compiler compiler,
   /* Traverse the directories in the load path and try to load the
      requested module.  */
   {
-    char *full_filename;
     const char *ext = filename_p ? "" : ".pk";
     const char *s, *e;

-    for (s = load_path, e = s; *e; s = e + 1)
+    char *fixed_load_path = pk_str_replace (load_path, "%DATADIR%", 
PKGDATADIR);
+
+    for (s = fixed_load_path, e = s; *e; s = e + 1)
       {
         /* Ignore empty entries. */
         if ((e = strchrnul (s, ':')) == s)
           continue;

-        if (!strncmp (s, "%DATADIR%", e - s))
-          full_filename = pk_str_concat (PKGDATADIR, s + sizeof ("%DATADIR%") 
- 1,
-                                         "/", module, ext, NULL);
-        else
-          asprintf (&full_filename, "%.*s/%s%s", (int) (e - s), s, module, 
ext);
+        asprintf (&full_filename, "%.*s/%s%s", (int) (e - s), s, module, ext);

         if (pk_file_readable (full_filename) == NULL)
-          return full_filename;
+          break;

         free (full_filename);
+        full_filename = NULL;
       }
+
+    if (fixed_load_path != load_path)
+      free (fixed_load_path);
   }

-  return NULL;
+  return full_filename;
 }

 int
--
2.26.0