Implement -Wmain.

[cparser] / parser.c

diff --git a/parser.c b/parser.c
index 845f491..d1182b1 100644 (file)
--- a/parser.c
+++ b/parser.c
@@ -2249,6 +2249,33 @@ static declaration_t *append_declaration(declaration_t* const declaration)
        return declaration;
 }
 
+static void check_type_of_main(const declaration_t *const decl, const function_type_t *const func_type)
+{
+       if (skip_typeref(func_type->return_type) != type_int) {
+               warningf(decl->source_position, "return type of 'main' should be 'int', but is '%T'", func_type->return_type);
+       }
+       const function_parameter_t *parm = func_type->parameters;
+       if (parm != NULL) {
+               type_t *const first_type = parm->type;
+               if (!types_compatible(skip_typeref(first_type), type_int)) {
+                       warningf(decl->source_position, "first argument of 'main' should be 'int', but is '%T'", first_type);
+               }
+               parm = parm->next;
+               if (parm != NULL) {
+                       type_t *const second_type = parm->type;
+                       if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
+                               warningf(decl->source_position, "second argument of 'main' should be 'char**', but is '%T'", second_type);
+                       }
+                       parm = parm->next;
+                       if (parm != NULL) {
+                               warningf(decl->source_position, "'main' takes only zero or two arguments");
+                       }
+               } else {
+                       warningf(decl->source_position, "'main' takes only zero or two arguments");
+               }
+       }
+}
+
 static bool is_sym_main(const symbol_t *const sym)
 {
        return strcmp(sym->string, "main") == 0;
@@ -2271,6 +2298,10 @@ static declaration_t *internal_record_declaration(
                         orig_type, declaration->symbol);
        }
 
+       if (is_function_definition && warning.main && is_sym_main(symbol)) {
+               check_type_of_main(declaration, &type->function);
+       }
+
        declaration_t *const previous_declaration = get_declaration(symbol, namespc);
        assert(declaration != previous_declaration);
        if (previous_declaration != NULL) {