Ticket #241: 0001-cleanup-mhl_str_concat-reduced-stack-usage-remo.patch

mhl/string.h

@@ -51 +51 @@
             *str = toupper(*str);
 }
 
-#define __STR_CONCAT_MAX        32
+/* note: we use ((char*)(1)) as terminator - NULL is a valid argument ! */
+static const char * mhl_s_c_sep__ = (const char *)1;
 /* _NEVER_ call this function directly ! */
-static inline char* __mhl_str_concat_hlp(const char* base, ...)
+static inline char* mhl_str_concat_hlp__(const char* va_start_dummy, ...)
 {
-    static const char* arg_ptr[__STR_CONCAT_MAX];
-    static size_t      arg_sz[__STR_CONCAT_MAX];
-    int         count = 0;
-    size_t      totalsize = 0;
-
-    if (base)
-    {
-        arg_ptr[0] = base;
-        arg_sz[0]  = totalsize = strlen(base);
-        count = 1;
-    }
+    char * result;
+    size_t result_len = 0;
+    char * p;
+    const char * chunk;
 
     va_list args;
-    va_start(args,base);
-    char* a;
-    /* note: we use ((char*)(1)) as terminator - NULL is a valid argument ! */
-    while ((a = va_arg(args, char*))!=(char*)1 && count < __STR_CONCAT_MAX )
+    va_start(args,va_start_dummy);
+    while ((chunk = va_arg(args, const char*)) != mhl_s_c_sep__)
     {
-        if (a)
+        if (chunk)
         {
-            arg_ptr[count] = a;
-            arg_sz[count]  = strlen(a);
-            totalsize += arg_sz[count];
-            count++;
+            result_len += strlen (chunk);
         }
     }
     va_end(args);
 
-    if (!count)
+    if (result_len == 0)
         return mhl_str_dup("");
 
-    /* now as we know how much to copy, allocate the buffer */
-    char* buffer = (char*)mhl_mem_alloc_u(totalsize+2);
-    char* current = buffer;
-    int x=0;
-    for (x=0; x<count; x++)
+    /* now as we know how much to copy, allocate the buffer + '\0'*/
+    result = (char*)mhl_mem_alloc_u (result_len + 1);
+
+    p = result;
+
+    va_start(args,va_start_dummy);
+    while ((chunk = va_arg(args, const char*)) != mhl_s_c_sep__)
     {
-        memcpy(current, arg_ptr[x], arg_sz[x]);
-        current += arg_sz[x];
+        if (chunk)
+        {
+            size_t chunk_len = strlen (chunk);
+            memcpy (p, chunk, chunk_len);
+            p += chunk_len;
+        }
     }
+    va_end(args);
 
-    *current = 0;
-    return buffer;
+    *p = '\0';
+    return result;
 }
 
-#define mhl_str_concat(...)     (__mhl_str_concat_hlp(__VA_ARGS__, (char*)(1)))
+#define mhl_str_concat(...)     (mhl_str_concat_hlp__(mhl_s_c_sep__, __VA_ARGS__, mhl_s_c_sep__))
 
 static inline char* mhl_str_reverse(char* ptr)
 {