ccanlint: with -vv, give details on attempts to compile examples.
[ccan] / tools / ccanlint / tests / examples_compile.c
index 7e1f14f3088ab55ab605e1a1262d8d7d8f58875d..82b479620c614ba6c1e7d995003b60bdd96a0864 100644 (file)
@@ -1,6 +1,7 @@
 #include <tools/ccanlint/ccanlint.h>
 #include <tools/tools.h>
 #include <ccan/talloc/talloc.h>
+#include <ccan/str/str.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
@@ -8,6 +9,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <ctype.h>
+#include <assert.h>
 
 static const char *can_run(struct manifest *m)
 {
@@ -16,10 +18,58 @@ static const char *can_run(struct manifest *m)
        return NULL;
 }
 
-static char *obj_list(const struct manifest *m)
+/* FIXME: We should build if it doesn't exist... */
+static bool expect_obj_file(const char *dir)
 {
-       char *list;
+       struct manifest *dep_man;
+       bool has_c_files;
+
+       dep_man = get_manifest(dir, dir);
+
+       /* If it has C files, we expect an object file built from them. */
+       has_c_files = !list_empty(&dep_man->c_files);
+       talloc_free(dep_man);
+       return has_c_files;
+}
+
+static char *add_dep(const struct manifest *m, char *list, const char *mod)
+{
+       char **deps, *obj;
+       unsigned int i;
+
+       /* Not ourselves. */
+       if (streq(m->basename, mod))
+               return list;
+
+       /* Not if there's no object file for that module */
+       if (!expect_obj_file(talloc_asprintf(list, "%s/ccan/%s", ccan_dir,mod)))
+               return list;
+
+       obj = talloc_asprintf(list, "%s/ccan/%s.o", ccan_dir, mod);
+
+       /* Not anyone we've already included. */
+       if (strstr(list, obj))
+               return list;
+
+       list = talloc_asprintf_append(list, " %s", obj);
+
+       /* Get that modules depends as well... */
+       assert(!safe_mode);
+       deps = get_deps(m, talloc_asprintf(list, "%s/ccan/%s", ccan_dir, mod),
+                       false, NULL);
+
+       for (i = 0; deps[i]; i++) {
+               if (strstarts(deps[i], "ccan/"))
+                       list = add_dep(m, list, deps[i] + strlen("ccan/"));
+       }
+       return list;
+}
+
+static char *obj_list(const struct manifest *m, struct ccan_file *f)
+{
+       char *list = talloc_strdup(m, "");
        struct ccan_file *i;
+       char **lines;
 
        /* Object files for this module. */
        list_for_each(&m->c_files, i, list)
@@ -31,6 +81,20 @@ static char *obj_list(const struct manifest *m)
                        list = talloc_asprintf_append(list, " %s", i->compiled);
        }
 
+       /* Other modules implied by includes. */
+       for (lines = get_ccan_file_lines(f); *lines; lines++) {
+               unsigned preflen = strspn(*lines, " \t");
+               if (strstarts(*lines + preflen, "#include <ccan/")) {
+                       const char *mod;
+                       unsigned modlen;
+
+                       mod = *lines + preflen + strlen("#include <ccan/");
+                       modlen = strcspn(mod, "/");
+                       mod = talloc_strndup(f, mod, modlen);
+                       list = add_dep(m, list, mod);
+               }
+       }
+
        return list;
 }
 
@@ -54,7 +118,8 @@ static char *compile(const void *ctx,
 
        file->compiled = maybe_temp_file(ctx, "", keep, file->fullname);
        errmsg = compile_and_link(ctx, file->fullname, ccan_dir,
-                                 obj_list(m), "", lib_list(m), file->compiled);
+                                 obj_list(m, file),
+                                 "", lib_list(m), file->compiled);
        if (errmsg) {
                talloc_free(file->compiled);
                return errmsg;
@@ -67,25 +132,180 @@ struct score {
        char *errors;
 };
 
-static char *start_main(char *ret)
+static char *start_main(char *ret, const char *why)
 {
        return talloc_asprintf_append(ret,
-                                     "/* Fake function wrapper inserted */\n"
-                                     "int main(int argc, char *argv[])\n"
-                                     "{\n");
+             "/* The example %s, so fake function wrapper inserted */\n"
+             "int main(int argc, char *argv[])\n"
+             "{\n", why);
+}
+
+/* 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",
+                                     (unsigned)(end - p + 1), p);
+}
+
+static void strip_leading_whitespace(char **lines)
+{
+       unsigned int i, min_span = -1U;
+
+       for (i = 0; lines[i]; i++) {
+               unsigned int span = strspn(lines[i], " \t");
+               /* All whitespace?  Ignore */
+               if (!lines[i][span])
+                       continue;
+               if (span < min_span)
+                       min_span = span;
+       }
+
+       for (i = 0; lines[i]; i++)
+               if (strlen(lines[i]) >= min_span)
+                       lines[i] += min_span;
+}
+
+static bool looks_internal(char **lines, char **why)
+{
+       unsigned int i;
+       bool last_ended = true; /* Did last line finish a statement? */
+
+       for (i = 0; lines[i]; i++) {
+               /* Skip leading whitespace. */
+               const char *line = lines[i] + strspn(lines[i], " \t");
+               unsigned len = strspn(line, IDENT_CHARS);
+
+               if (!line[0] || isblank(line[0]) || strstarts(line, "//"))
+                       continue;
+
+               /* The winners. */
+               if (strstarts(line, "if") && len == 2) {
+                       *why = "starts with if";
+                       return true;
+               }
+               if (strstarts(line, "for") && len == 3) {
+                       *why = "starts with for";
+                       return true;
+               }
+               if (strstarts(line, "while") && len == 5) {
+                       *why = "starts with while";
+                       return true;
+               }
+               if (strstarts(line, "do") && len == 2) {
+                       *why = "starts with do";
+                       return true;
+               }
+
+               /* The losers. */
+               if (strstarts(line, "#include")) {
+                       *why = "starts with #include";
+                       return false;
+               }
+
+               if (last_ended && strchr(line, '(')) {
+                       if (strstarts(line, "static")) {
+                               *why = "starts with static and contains (";
+                               return false;
+                       }
+                       if (strends(line, ")")) {
+                               *why = "contains ( and ends with )";
+                               return false;
+                       }
+               }
+
+               /* Single identifier then operator == inside function. */
+               if (last_ended && len
+                   && ispunct(line[len+strspn(line+len, " ")])) {
+                       *why = "starts with identifier then punctuation";
+                       return true;
+               }
+
+               last_ended = (strends(line, "}")
+                             || strends(line, ";")
+                             || streq(line, "..."));
+       }
+
+       /* No idea... Say yes? */
+       *why = "gave no clues";
+       return true;
+}
+
+/* Examples will often build on prior ones.  Try combining them. */
+static char **combine(const void *ctx, char **lines, char **prev)
+{
+       unsigned int i, lines_total, prev_total, count;
+       char **ret;
+       const char *reasoning;
+       char *why = NULL;
+
+       if (!prev)
+               return NULL;
+
+       /* If it looks internal, put prev at start. */
+       if (looks_internal(lines, &why)) {
+               count = 0;
+               reasoning = "seemed to belong inside a function";
+       } else {
+               /* Try inserting in first elided position */
+               for (count = 0; lines[count]; count++) {
+                       if (strcmp(lines[count], "...") == 0)
+                               break;
+               }
+               if (!lines[count]) {
+                       /* Try at start anyway? */
+                       count = 0;
+                       reasoning = "didn't seem to belong inside"
+                               " a function, so we prepended the previous"
+                               " example";
+               } else {
+                       reasoning = "didn't seem to belong inside"
+                               " a function, so we put the previous example"
+                               " at the first ...";
+
+                       count++;
+               }
+       }
+
+       for (i = 0; lines[i]; i++);
+       lines_total = i;
+
+       for (i = 0; prev[i]; i++);
+       prev_total = i;
+
+       ret = talloc_array(ctx, char *, 1 +lines_total + prev_total + 1);
+       ret[0] = talloc_asprintf(ret, "/* The example %s, thus %s */\n",
+                                why, reasoning);
+       memcpy(ret+1, lines, count * sizeof(ret[0]));
+       memcpy(ret+1 + count, prev, prev_total * sizeof(ret[0]));
+       memcpy(ret+1 + count + prev_total, lines + count,
+              (lines_total - count + 1) * sizeof(ret[0]));
+       return ret;
 }
 
-static char *mangle(struct manifest *m, struct ccan_file *example)
+static char *mangle(struct manifest *m, char **lines)
 {
-       char **lines = get_ccan_file_lines(example);
-       char *ret;
-       bool in_function = false, fake_function = false;
+       char *ret, *use_funcs = NULL, *why;
+       bool in_function = false, fake_function = false, has_main = false;
        unsigned int i;
 
        ret = talloc_strdup(m, "/* Prepend a heap of headers. */\n"
                            "#include <assert.h>\n"
                            "#include <err.h>\n"
+                           "#include <errno.h>\n"
                            "#include <fcntl.h>\n"
+                           "#include <limits.h>\n"
                            "#include <stdbool.h>\n"
                            "#include <stdint.h>\n"
                            "#include <stdio.h>\n"
@@ -98,16 +318,22 @@ 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"
-                                    "int somefunc(void);\n"
-                                    "int somefunc(void) { return 0; }\n");
+       ret = talloc_asprintf_append(ret, "/* Useful dummy functions. */\n"
+                                    "extern int somefunc(void);\n"
+                                    "int somefunc(void) { return 0; }\n"
+                                    "extern char somestring[];\n"
+                                    "char somestring[] = \"hello world\";\n");
 
-       /* Starts indented?  Wrap it in a main() function. */
-       if (lines[0] && isblank(lines[0][0])) {
-               ret = start_main(ret);
+       if (looks_internal(lines, &why)) {
+               /* Wrap it all in main(). */
+               ret = start_main(ret, why);
                fake_function = true;
                in_function = true;
-       }
+               has_main = true;
+       } else
+               ret = talloc_asprintf_append(ret,
+                            "/* The example %s, so didn't wrap in main() */\n",
+                                    why);
 
        /* Primitive, very primitive. */
        for (i = 0; lines[i]; i++) {
@@ -117,20 +343,27 @@ static char *mangle(struct manifest *m, struct ccan_file *example)
                                in_function = false;
                } else {
                        /* Character at start of line, with ( and no ;
-                        * == function start. */
+                        * == function start.  Ignore comments. */
                        if (!isblank(lines[i][0])
                            && strchr(lines[i], '(')
-                           && !strchr(lines[i], ';'))
+                           && !strchr(lines[i], ';')
+                           && !strstr(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. */
+               /* ... means elided code. */
                if (strcmp(lines[i], "...") == 0) {
-                       if (!in_function
-                           && lines[i+1]
-                           && isblank(lines[i+1][0])) {
+                       if (!in_function && !has_main
+                           && looks_internal(lines + i + 1, &why)) {
                                /* This implies we start a function here. */
-                               ret = start_main(ret);
+                               ret = start_main(ret, why);
+                               has_main = true;
                                fake_function = true;
                                in_function = true;
                        }
@@ -141,6 +374,27 @@ static char *mangle(struct manifest *m, struct ccan_file *example)
                ret = talloc_asprintf_append(ret, "%s\n", lines[i]);
        }
 
+       if (!has_main) {
+               ret = talloc_asprintf_append(ret,
+                            "/* Need a main to link successfully. */\n"
+                            "int main(void)\n{\n");
+               fake_function = true;
+       }
+
+       if (use_funcs) {
+               ret = talloc_asprintf_append(ret,
+                                            "/* Get rid of unused warnings"
+                                            " by printing addresses of"
+                                            " static 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 +402,9 @@ 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;
@@ -166,12 +422,13 @@ 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;
        }
        close(fd);
+       f->contents = talloc_steal(f, contents);
        return f;
 }
 
@@ -180,35 +437,74 @@ static void *build_examples(struct manifest *m, bool keep,
 {
        struct ccan_file *i;
        struct score *score = talloc(m, struct score);
+       char **prev = NULL;
 
        score->score = 0;
-       score->errors = NULL;
+       score->errors = talloc_strdup(score, "");
 
+       examples_compile.total_score = 0;
        list_for_each(&m->examples, i, list) {
-               char *ret;
+               char *ret, *ret1 = NULL, *ret2;
+               struct ccan_file *mangle1 = NULL, *mangle2;
 
                examples_compile.total_score++;
+               /* Simplify our dumb parsing. */
+               strip_leading_whitespace(get_ccan_file_lines(i));
                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;
+               }
+
+               /* Try combining with previous (successful) example... */
+               if (prev) {
+                       char **new = combine(i, get_ccan_file_lines(i), prev);
 
-                       talloc_free(ret);
-                       ret = compile(score, m, mangle, keep);
-                       if (!ret)
+                       mangle1 = mangle_example(m, i, new, keep);
+                       ret1 = compile(score, m, mangle1, keep);
+                       if (!ret1) {
+                               prev = new;
                                score->score++;
-                       else {
-                               if (!score->errors)
-                                       score->errors = ret;
-                               else {
-                                       score->errors
-                                       = talloc_append_string(score->errors,
-                                                              ret);
-                                       talloc_free(ret);
-                               }
+                               continue;
                        }
                }
+
+               /* Try standalone. */
+               mangle2 = mangle_example(m, i, get_ccan_file_lines(i), keep);
+               ret2 = compile(score, m, mangle2, keep);
+               if (!ret2) {
+                       prev = get_ccan_file_lines(i);
+                       score->score++;
+                       continue;
+               }
+
+               score->errors = talloc_asprintf_append(score->errors,
+                                      "%s: tried standalone example:\n"
+                                      "%s\n"
+                                      "Errors: %s\n\n",
+                                      i->name,
+                                      get_ccan_file_contents(i),
+                                      ret);
+               if (mangle1) {
+                       score->errors = talloc_asprintf_append(score->errors,
+                                              "%s: tried combining with"
+                                              " previous example:\n"
+                                              "%s\n"
+                                              "Errors: %s\n\n",
+                                              i->name,
+                                              get_ccan_file_contents(mangle1),
+                                              ret1);
+               }
+               score->errors = talloc_asprintf_append(score->errors,
+                                      "%s: tried adding headers, wrappers:\n"
+                                      "%s\n"
+                                      "Errors: %s\n\n",
+                                      i->name,
+                                      get_ccan_file_contents(mangle2),
+                                      ret2);
+               /* This didn't work, so not a candidate for combining. */
+               prev = NULL;
        }
        return score;
 }
@@ -232,6 +528,7 @@ struct ccanlint examples_compile = {
        .key = "examples-compile",
        .name = "Module examples compile",
        .score = score_examples,
+       .total_score = 3, /* This gets changed to # examples, if they exist */
        .check = build_examples,
        .describe = describe,
        .can_run = can_run,