ccanlint: more heuristics for compiling examples.
authorRusty Russell <rusty@rustcorp.com.au>
Wed, 6 Oct 2010 03:31:24 +0000 (14:01 +1030)
committerRusty Russell <rusty@rustcorp.com.au>
Wed, 6 Oct 2010 03:31:24 +0000 (14:01 +1030)
These are from hash: the entire example is indented, there is no main(), and
there are unused static functions.

tools/ccanlint/tests/examples_compile.c

index 7e1f14f3088ab55ab605e1a1262d8d7d8f58875d..d72ad1db8973b25deef327bc986fea73babe5f73 100644 (file)
@@ -75,11 +75,46 @@ static char *start_main(char *ret)
                                      "{\n");
 }
 
+/* We only handle simple function definitions here. */
+static char *add_func(char *others, const char *line)
+{
+       const char *p, *end = strchr(line, '(') - 1;
+       while (isblank(*end)) {
+               end--;
+               if (end == line)
+                       return others;
+       }
+
+       for (p = end; isalnum(*p) || *p == '_'; p--) {
+               if (p == line)
+                       return others;
+       }
+
+       return talloc_asprintf_append(others, "printf(\"%%p\", %.*s);\n",
+                                     end - p + 1, p);
+}
+
+static bool looks_internal(const char *p)
+{
+       return (strncmp(p, "#", 1) != 0
+               && strncmp(p, "static", 6) != 0
+               && strncmp(p, "struct", 6) != 0
+               && strncmp(p, "union", 5) != 0);
+}
+
+static void strip_leading_whitespace(char **lines, unsigned prefix_len)
+{
+       unsigned int i;
+
+       for (i = 0; lines[i]; i++)
+               lines[i] += prefix_len;
+}
+
 static char *mangle(struct manifest *m, struct ccan_file *example)
 {
        char **lines = get_ccan_file_lines(example);
-       char *ret;
-       bool in_function = false, fake_function = false;
+       char *ret, *use_funcs = NULL;
+       bool in_function = false, fake_function = false, has_main = false;
        unsigned int i;
 
        ret = talloc_strdup(m, "/* Prepend a heap of headers. */\n"
@@ -102,11 +137,17 @@ static char *mangle(struct manifest *m, struct ccan_file *example)
                                     "int somefunc(void);\n"
                                     "int somefunc(void) { return 0; }\n");
 
-       /* Starts indented?  Wrap it in a main() function. */
+       /* Starts indented? */
        if (lines[0] && isblank(lines[0][0])) {
-               ret = start_main(ret);
-               fake_function = true;
-               in_function = true;
+               unsigned prefix = strspn(lines[0], " \t");
+               if (looks_internal(lines[0] + prefix)) {
+                       /* Wrap it all in main(). */
+                       ret = start_main(ret);
+                       fake_function = true;
+                       in_function = true;
+                       has_main = true;
+               } else
+                       strip_leading_whitespace(lines, prefix);
        }
 
        /* Primitive, very primitive. */
@@ -120,8 +161,15 @@ static char *mangle(struct manifest *m, struct ccan_file *example)
                         * == function start. */
                        if (!isblank(lines[i][0])
                            && strchr(lines[i], '(')
-                           && !strchr(lines[i], ';'))
+                           && !strchr(lines[i], ';')) {
                                in_function = true;
+                               if (strncmp(lines[i], "int main", 8) == 0)
+                                       has_main = true;
+                               if (strncmp(lines[i], "static", 6) == 0) {
+                                       use_funcs = add_func(use_funcs,
+                                                            lines[i]);
+                               }
+                       }
                }
                /* ... means elided code.  If followed by spaced line, means
                 * next part is supposed to be inside a function. */
@@ -141,6 +189,23 @@ static char *mangle(struct manifest *m, struct ccan_file *example)
                ret = talloc_asprintf_append(ret, "%s\n", lines[i]);
        }
 
+       /* Need a main to link successfully. */
+       if (!has_main) {
+               ret = talloc_asprintf_append(ret, "int main(void)\n{\n");
+               fake_function = true;
+       }
+
+       /* Get rid of unused warnings by printing addresses of static funcs. */
+       if (use_funcs) {
+               if (!fake_function) {
+                       ret = talloc_asprintf_append(ret,
+                                                    "int use_funcs(void);\n"
+                                                    "int use_funcs(void) {\n");
+                       fake_function = true;
+               }
+               ret = talloc_asprintf_append(ret, "     %s\n", use_funcs);
+       }
+
        if (fake_function)
                ret = talloc_asprintf_append(ret, "return 0;\n"
                                             "}\n");