]> git.ozlabs.org Git - ccan/blobdiff - tools/ccanlint/tests/examples_compile.c
ccanlint: more heuristics for compiling examples.
[ccan] / tools / ccanlint / tests / examples_compile.c
index 7e1f14f3088ab55ab605e1a1262d8d7d8f58875d..529c526f09f1152b12a28e61977d07c559a3cfe8 100644 (file)
@@ -18,7 +18,7 @@ static const char *can_run(struct manifest *m)
 
 static char *obj_list(const struct manifest *m)
 {
-       char *list;
+       char *list = talloc_strdup(m, "");
        struct ccan_file *i;
 
        /* Object files for this module. */
@@ -75,11 +75,85 @@ static char *start_main(char *ret)
                                      "{\n");
 }
 
-static char *mangle(struct manifest *m, struct ccan_file *example)
+/* 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)
 {
-       char **lines = get_ccan_file_lines(example);
-       char *ret;
-       bool in_function = false, fake_function = false;
+       unsigned int i;
+
+       for (i = 0; lines[i]; i++)
+               if (strlen(lines[i]) >= prefix_len)
+                       lines[i] += prefix_len;
+}
+
+/* Examples will often build on prior ones.  Try combining them. */
+static char **combine(char **lines, char **prev)
+{
+       unsigned int i, lines_total, prev_total, count;
+       char **ret;
+
+       if (!prev)
+               return NULL;
+
+       /* If it looks internal, put prev at start. */
+       if (lines[0]
+           && isblank(lines[0][0])
+           && looks_internal(lines[0] + strspn(lines[0], " \t"))) {
+               count = 0;
+       } else {
+               /* Try inserting in first elided position */
+               for (count = 0; lines[count]; count++) {
+                       if (strcmp(lines[count], "...") == 0)
+                               break;
+               }
+               if (!lines[count])
+                       return NULL;
+               count++;
+       }
+
+       for (i = 0; lines[i]; i++);
+       lines_total = i;
+
+       for (i = 0; prev[i]; i++);
+       prev_total = i;
+
+       ret = talloc_array(lines, char *, lines_total + prev_total + 1);
+       memcpy(ret, lines, count * sizeof(ret[0]));
+       memcpy(ret + count, prev, prev_total * sizeof(ret[0]));
+       memcpy(ret + count + prev_total, lines + count,
+              (lines_total - count + 1) * sizeof(ret[0]));
+       return ret;
+}
+
+static char *mangle(struct manifest *m, char **lines)
+{
+       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"
@@ -98,15 +172,21 @@ static char *mangle(struct manifest *m, struct ccan_file *example)
                                     "#include <ccan/%s/%s.h>\n",
                                     m->basename, m->basename);
 
-       ret = talloc_asprintf_append(ret, "/* Useful dummmy functions. */\n"
+       ret = talloc_asprintf_append(ret, "/* Useful dummy functions. */\n"
                                     "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 +200,15 @@ 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. */
@@ -131,6 +218,7 @@ static char *mangle(struct manifest *m, struct ccan_file *example)
                            && isblank(lines[i+1][0])) {
                                /* This implies we start a function here. */
                                ret = start_main(ret);
+                               has_main = true;
                                fake_function = true;
                                in_function = true;
                        }
@@ -141,6 +229,23 @@ 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");
@@ -148,7 +253,9 @@ static char *mangle(struct manifest *m, struct ccan_file *example)
 }
 
 static struct ccan_file *mangle_example(struct manifest *m,
-                                       struct ccan_file *example, bool keep)
+                                       struct ccan_file *example,
+                                       char **lines,
+                                       bool keep)
 {
        char *name, *contents;
        int fd;
@@ -166,7 +273,7 @@ static struct ccan_file *mangle_example(struct manifest *m,
        if (fd < 0)
                return NULL;
 
-       contents = mangle(m, example);
+       contents = mangle(m, lines);
        if (write(fd, contents, strlen(contents)) != strlen(contents)) {
                close(fd);
                return NULL;
@@ -180,6 +287,8 @@ static void *build_examples(struct manifest *m, bool keep,
 {
        struct ccan_file *i;
        struct score *score = talloc(m, struct score);
+       struct ccan_file *mangle;
+       char **prev = NULL;
 
        score->score = 0;
        score->errors = NULL;
@@ -189,26 +298,49 @@ static void *build_examples(struct manifest *m, bool keep,
 
                examples_compile.total_score++;
                ret = compile(score, m, i, keep);
-               if (!ret)
+               if (!ret) {
+                       prev = get_ccan_file_lines(i);
                        score->score++;
-               else {
-                       struct ccan_file *mangle = mangle_example(m, i, keep);
+                       continue;
+               }
+
+               talloc_free(ret);
+               mangle = mangle_example(m, i, get_ccan_file_lines(i), keep);
+               ret = compile(score, m, mangle, keep);
+               if (!ret) {
+                       prev = get_ccan_file_lines(i);
+                       score->score++;
+                       continue;
+               }
 
+               /* Try combining with previous (successful) example... */
+               prev = combine(get_ccan_file_lines(i), prev);
+               if (prev) {
                        talloc_free(ret);
+
+                       /* We're going to replace this failure. */
+                       if (keep)
+                               unlink(mangle->fullname);
+                       talloc_free(mangle);
+
+                       mangle = mangle_example(m, i, prev, keep);
                        ret = compile(score, m, mangle, keep);
-                       if (!ret)
+                       if (!ret) {
                                score->score++;
-                       else {
-                               if (!score->errors)
-                                       score->errors = ret;
-                               else {
-                                       score->errors
-                                       = talloc_append_string(score->errors,
-                                                              ret);
-                                       talloc_free(ret);
-                               }
+                               continue;
                        }
                }
+
+               if (!score->errors)
+                       score->errors = ret;
+               else {
+                       score->errors = talloc_append_string(score->errors,
+                                                            ret);
+                       talloc_free(ret);
+               }
+               /* This didn't work, so not a candidate for combining. */
+               talloc_free(prev);
+               prev = NULL;
        }
        return score;
 }