diff mbox

[C++] report better diagnostic for static following '[' in parameter declaration

Message ID CAAgBjMkRurZGqT6QgcnBX8CSimYUsyP2xb4oQFioreSvJcOOug@mail.gmail.com
State New
Headers show

Commit Message

Prathamesh Kulkarni Jan. 29, 2016, 5:01 p.m. UTC 
On 29 January 2016 at 05:03, Marek Polacek <polacek@redhat.com> wrote:
> On Fri, Jan 29, 2016 at 04:46:56AM +0530, Prathamesh Kulkarni wrote:

>> @@ -19016,10 +19017,22 @@ cp_parser_direct_declarator (cp_parser* parser,

>>         cp_lexer_consume_token (parser->lexer);

>>         /* Peek at the next token.  */

>>         token = cp_lexer_peek_token (parser->lexer);

>> +

>> +       /* If static keyword immediately follows [, report error.  */

>> +       if (cp_lexer_next_token_is_keyword (parser->lexer, RID_STATIC)

>> +           && current_binding_level->kind == sk_function_parms)

>> +         {

>> +           error_at (token->location,

>> +                     "static array size is a C99 feature,"

>> +                     "not permitted in C++");

>> +           bounds = error_mark_node;

>> +         }

>> +

>

> I think this isn't sufficient as-is; if we're changing the diagnostics here,

> we should also handle e.g. void f(int a[const 10]); where clang++ says

> g.C:1:13: error: qualifier in array size is a C99 feature, not permitted in C++

>

> And also e.g.

> void f(int a[const static 10]);

> void f(int a[static const 10]);

> and similar.

Thanks for the review. AFAIK the type-qualifiers would be const,
restrict, volatile and _Atomic (n1570 p 6.7.3) ?
I added a check for those and for variable length array.
I am having issues with writing the test-case,
some cases pass with -std=c++11 but fail with -std=c++98.
Could you please have a look ?

Thanks,
Prathamesh
>

>         Marek
diff mbox

Patch

diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 33f1df3..04137b3 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -982,6 +982,24 @@  cp_lexer_next_token_is_decl_specifier_keyword (cp_lexer *lexer)
     }
 }
 
+static bool
+cp_lexer_next_token_is_c_type_qual (cp_lexer *lexer)
+{
+  if (cp_lexer_next_token_is_keyword (lexer, RID_CONST) 
+      || cp_lexer_next_token_is_keyword (lexer, RID_VOLATILE))
+    return true;
+
+  cp_token *token = cp_lexer_peek_token (lexer);
+  if (token->type == CPP_NAME)
+    {
+      tree name = token->u.value;
+      const char *p = IDENTIFIER_POINTER (name);
+      return !strcmp (p, "restrict") || !strcmp (p, "_Atomic");
+    }
+
+  return false;
+}
+
 /* Returns TRUE iff the token T begins a decltype type.  */
 
 static bool
@@ -18998,10 +19016,40 @@  cp_parser_direct_declarator (cp_parser* parser,
 	  cp_lexer_consume_token (parser->lexer);
 	  /* Peek at the next token.  */
 	  token = cp_lexer_peek_token (parser->lexer);
+
+	  /* If static or type-qualifier or * immediately follows [,
+	     report error.  */
+	  if (current_binding_level->kind == sk_function_parms)
+	    {
+	      if (cp_lexer_next_token_is_keyword (parser->lexer, RID_STATIC))
+	        {
+		    error_at (token->location,
+			      "static array size is a C99 feature, "
+			      "not permitted in C++");
+		    bounds = error_mark_node;
+		}
+	      else if (cp_lexer_next_token_is_c_type_qual (parser->lexer))
+		{
+		    error_at (token->location,
+			      "qualifier in array size is a C99 feature, "
+			      "not permitted in C++");
+		    bounds = error_mark_node;
+		}
+	      
+	      else if (token->type == CPP_MULT)
+		{
+		    error_at (token->location,
+			      "variable-length array size is a C99 feature, "
+			      "not permitted in C++");
+		    bounds = error_mark_node;
+		}
+	    }
+
 	  /* If the next token is `]', then there is no
 	     constant-expression.  */
-	  if (token->type != CPP_CLOSE_SQUARE)
+	  if (token->type != CPP_CLOSE_SQUARE && bounds != error_mark_node)
 	    {
+
 	      bool non_constant_p;
 	      bounds
 		= cp_parser_constant_expression (parser,
diff --git a/gcc/testsuite/g++.dg/parse/static-array-error.C b/gcc/testsuite/g++.dg/parse/static-array-error.C
new file mode 100644
index 0000000..028320d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/parse/static-array-error.C
@@ -0,0 +1,33 @@ 
+// { dg-do compile }
+
+void f1(int a[static 10]);  /* { dg-error "static array size is a C99 feature" } */
+/* { dg-error "expected '\\]' before 'static'" "" { target *-*-* } 3 } */
+/* { dg-error "expected '\\)' before 'static'" "" { target *-*-* } 3 } */
+/* { dg-error "expected initializer before 'static'" "" { target *-*-* } 3 } */
+
+void f2(int a[const 10]); /* { dg-error "qualifier in array size is a C99 feature" } */
+/* { dg-error "expected '\\]' before 'const'" "" { target *-*-* } 8 } */
+/* { dg-error "expected '\\)' before 'const'" "" { target *-*-* } 8 } */
+/* { dg-error "expected initializer before numeric constant" "" { target *-*-* } 8 } */
+
+void f3(int a[restrict 10]); /* { dg-error "qualifier in array size is a C99 feature" } */
+/* { dg-error "expected '\\]' before 'restrict'" "" { target *-*-* } 13 } */
+/* { dg-error "expected '\\)' before 'restrict'" "" { target *-*-* } 13 } */
+/* { dg-error "expected initializer before 'restrict'" "" { target *-*-* } 13 } */
+
+void f4(int a[volatile 10]); /* { dg-error "qualifier in array size is a C99 feature" } */
+/* { dg-error "expected '\\]' before 'volatile'" "" { target *-*-* } 18 } */
+/* { dg-error "expected '\\)' before 'volatile'" "" { target *-*-* } 18 } */
+/* { dg-error "expected initializer before numeric constant" "" { target *-*-* } 18 } */
+
+
+void f4(int a[_Atomic 10]); /* { dg-error "qualifier in array size is a C99 feature" } */
+/* { dg-error "expected '\\]' before '_Atomic'" "" { target *-*-* } 24 } */
+/* { dg-error "expected '\\)' before '_Atomic'" "" { target *-*-* } 24 } */
+/* { dg-error "expected initializer before '_Atomic'" "" { target *-*-* } 24 } */
+
+
+void f5(int a[*]); /* { dg-error "variable-length array size is a C99 feature" } */
+/* { dg-error "expected ']' before '*' token" "" { target *-*-* } 24 } */
+/* { dg-error "expected '\\)' before '*' token" "" { target *-*-* } 24 } */
+/* { dg-error "expected initializer before '*' token" "" { target *-*-* } 24 } */