implement a bare-bones cparser --help

[r27643]

diff --git a/main.c b/main.c
index 5ad031d..d9be646 100644 (file)
--- a/main.c
+++ b/main.c
@@ -540,7 +540,7 @@ typedef enum compile_mode_t {
 
 static void usage(const char *argv0)
 {
-       fprintf(stderr, "Usage %s input [-o output] [-c]\n", argv0);
+       fprintf(stderr, "Usage %s [options] input [-o output]\n", argv0);
 }
 
 static void print_cparser_version(void)
@@ -565,6 +565,15 @@ static void print_cparser_version(void)
             "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n");
 }
 
+static void print_help(const char *argv0)
+{
+       usage(argv0);
+       puts("");
+       puts("\t-fhelp     Display help about firm optimisation options");
+       puts("\t-bhelp     Display help about firm backend options");
+       puts("A big number of gcc flags is also supported");
+}
+
 static void set_be_option(const char *arg)
 {
        int res = be_parse_arg(arg);
@@ -1082,6 +1091,9 @@ int main(int argc, char **argv)
                                } else if (streq(option, "version")) {
                                        print_cparser_version();
                                        exit(EXIT_SUCCESS);
+                               } else if (streq(option, "help")) {
+                                       print_help(argv[0]);
+                                       help_displayed = true;
                                } else if (streq(option, "dump-function")) {
                                        ++i;
                                        if (i >= argc) {
@@ -1150,19 +1162,19 @@ int main(int argc, char **argv)
                }
        }
 
+       if (help_displayed) {
+               return !argument_errors;
+       }
+
        if (print_file_name_file != NULL) {
                print_file_name(print_file_name_file);
                return 0;
        }
-
        if (files == NULL) {
                fprintf(stderr, "error: no input files specified\n");
                argument_errors = true;
        }
 
-       if (help_displayed) {
-               return !argument_errors;
-       }
        if (argument_errors) {
                usage(argv[0]);
                return 1;