Add some error recovery points

grammar.coffee

@@ -62,18 +62,21 @@ module.exports = grammar
     preproc_define: -> seq(
       "#define",
       @identifier,
-      token(seq(/.+/, repeat(seq("\\\n", /.+/)))))
+      optional(@_preproc_arg))
 
-    preproc_call: -> choice(
-      seq(@preproc_directive, /.*/))
+    preproc_call: -> seq(
+      @preproc_directive,
+      @_preproc_arg)
+
+    _preproc_arg: -> token(prec(-1, repeat(choice(/./, "\\\n"))))
 
     preproc_ifdef: -> seq(
       choice("#ifdef", "#ifndef"),
       @identifier,
-      repeat(choice(
+      err(repeat(choice(
         @_preproc_statement,
         @function_definition,
-        @declaration)),
+        @declaration))),
       optional(@preproc_else),
       "#endif")
 
@@ -84,7 +87,7 @@ module.exports = grammar
         @function_definition,
         @declaration)))
 
-    preproc_directive: -> /#\a\w+/
+    preproc_directive: -> /#\a\w*/
 
     # Section - Main Grammar
 
@@ -162,7 +165,7 @@ module.exports = grammar
 
     compound_statement: -> seq(
       "{",
-      repeat(choice(@declaration, @_statement)),
+      err(repeat(choice(@declaration, @_statement))),
       "}")
 
     storage_class_specifier: -> choice(
@@ -345,7 +348,7 @@ module.exports = grammar
       @number_literal,
       @string_literal,
       @char_literal,
-      seq("(", @_expression, ")"))
+      seq("(", err(@_expression), ")"))
 
     conditional_expression: -> prec.right(PREC.conditional, seq(
       @_expression,

grammar_test/errors.txt

@@ -0,0 +1,81 @@
+========================================
+Errors inside ifdefs
+========================================
+
+#ifdef something
+int x // no semicolon
+#endif
+
+int a;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int b;
+
+#ifdef __cplusplus
+}
+#endif
+
+int c;
+
+---
+
+(translation_unit
+  (preproc_ifdef
+    (identifier)
+    (ERROR (identifier) (identifier) (comment) (UNEXPECTED '#')))
+
+  (declaration (identifier) (identifier))
+
+  (preproc_ifdef
+    (identifier)
+    (ERROR (UNEXPECTED '"') (string_literal)))
+
+  (declaration (identifier) (identifier))
+
+  (preproc_ifdef
+    (identifier)
+    (ERROR (UNEXPECTED '}')))
+
+  (declaration (identifier) (identifier)))
+
+========================================
+Errors inside blocks
+========================================
+
+int main() {
+  int x;
+  int %$#@
+}
+
+---
+
+(translation_unit
+  (function_definition
+    (identifier)
+    (function_declarator (identifier))
+    (compound_statement
+      (ERROR
+        (declaration (identifier) (identifier))
+        (identifier) (UNEXPECTED '$')))))
+
+========================================
+Errors inside expressions
+========================================
+
+int main() {
+  int x = (123 123);
+}
+
+---
+
+(translation_unit
+  (function_definition
+    (identifier)
+    (function_declarator (identifier))
+    (compound_statement
+      (declaration (identifier) (init_declarator
+        (identifier)
+        (ERROR (number_literal) (UNEXPECTED '1') (number_literal)))))))

grammar_test/preprocessor.txt

@@ -40,7 +40,7 @@ ssize_t b;
 #define c 32
 #else
 int b;
-#define c 16;
+#define c 16
 #endif
 
 #ifdef DEFINE2