diagnostics: Add function call parens matching to c_parser.

The C++ parser already tracks function call parens matching, but the C
parser doesn't. This adds the same functionality to the C parser and adds
a testcase showing the C++ and C parser matching function call parens
in an error message.

gcc/c/ChangeLog:

	* c-parser.c (c_parser_postfix_expression_after_primary): Add
	scope with matching_parens after CPP_OPEN_PAREN.

gcc/testsuite/ChangeLog:

	* c-c++-common/missing-close-func-paren.c: New test.
---
 gcc/c/c-parser.c                              | 32 ++++++++-------
 .../c-c++-common/missing-close-func-paren.c   | 40 +++++++++++++++++++
 2 files changed, 57 insertions(+), 15 deletions(-)
 create mode 100644 gcc/testsuite/c-c++-common/missing-close-func-paren.c

On Sun, May 24, 2020 at 11:46:34PM +0200, Mark Wielaard wrote:
> The C++ parser already tracks function call parens matching, but the C
> parser doesn't. This adds the same functionality to the C parser and adds
> a testcase showing the C++ and C parser matching function call parens
> in an error message.
> 
> gcc/c/ChangeLog:
> 
> 	* c-parser.c (c_parser_postfix_expression_after_primary): Add
> 	scope with matching_parens after CPP_OPEN_PAREN.
> 
> gcc/testsuite/ChangeLog:
> 
> 	* c-c++-common/missing-close-func-paren.c: New test.

Ping.

> ---
>  gcc/c/c-parser.c                              | 32 ++++++++-------
>  .../c-c++-common/missing-close-func-paren.c   | 40 +++++++++++++++++++
>  2 files changed, 57 insertions(+), 15 deletions(-)
>  create mode 100644 gcc/testsuite/c-c++-common/missing-close-func-paren.c
> 
> diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
> index 5d11e7e73c16..23d6fa22b685 100644
> --- a/gcc/c/c-parser.c
> +++ b/gcc/c/c-parser.c
> @@ -10458,21 +10458,23 @@ c_parser_postfix_expression_after_primary (c_parser *parser,
>  	  break;
>  	case CPP_OPEN_PAREN:
>  	  /* Function call.  */
> -	  c_parser_consume_token (parser);
> -	  for (i = 0; i < 3; i++)
> -	    {
> -	      sizeof_arg[i] = NULL_TREE;
> -	      sizeof_arg_loc[i] = UNKNOWN_LOCATION;
> -	    }
> -	  literal_zero_mask = 0;
> -	  if (c_parser_next_token_is (parser, CPP_CLOSE_PAREN))
> -	    exprlist = NULL;
> -	  else
> -	    exprlist = c_parser_expr_list (parser, true, false, &origtypes,
> -					   sizeof_arg_loc, sizeof_arg,
> -					   &arg_loc, &literal_zero_mask);
> -	  c_parser_skip_until_found (parser, CPP_CLOSE_PAREN,
> -				     "expected %<)%>");
> +	  {
> +	    matching_parens parens;
> +	    parens.consume_open (parser);
> +	    for (i = 0; i < 3; i++)
> +	      {
> +		sizeof_arg[i] = NULL_TREE;
> +		sizeof_arg_loc[i] = UNKNOWN_LOCATION;
> +	      }
> +	    literal_zero_mask = 0;
> +	    if (c_parser_next_token_is (parser, CPP_CLOSE_PAREN))
> +	      exprlist = NULL;
> +	    else
> +	      exprlist = c_parser_expr_list (parser, true, false, &origtypes,
> +					     sizeof_arg_loc, sizeof_arg,
> +					     &arg_loc, &literal_zero_mask);
> +	    parens.skip_until_found_close (parser);
> +	  }
>  	  orig_expr = expr;
>  	  mark_exp_read (expr.value);
>  	  if (warn_sizeof_pointer_memaccess)
> diff --git a/gcc/testsuite/c-c++-common/missing-close-func-paren.c b/gcc/testsuite/c-c++-common/missing-close-func-paren.c
> new file mode 100644
> index 000000000000..3177e250e1c3
> --- /dev/null
> +++ b/gcc/testsuite/c-c++-common/missing-close-func-paren.c
> @@ -0,0 +1,40 @@
> +/* { dg-options "-fdiagnostics-show-caret" } */
> +
> +/* Verify that the C/C++ frontends show the pertinent opening symbol when
> +   a closing symbol is missing for a function call.  */
> +
> +/* Verify that, when they are on the same line, that the opening symbol is
> +   shown as a secondary range within the main diagnostic.  */
> +
> +extern int __attribute__((const)) foo (int a, int b, int c);
> +
> +void single_func ()
> +{
> +  int single =
> +    foo (1, (1 + 2), (1 + 2 + 3):); /* { dg-error "expected '\\)' before ':' token" } */
> +  /* { dg-begin-multiline-output "" }
> +     foo (1, (1 + 2), (1 + 2 + 3):);
> +         ~                       ^
> +                                 )
> +     { dg-end-multiline-output "" } */
> +}
> +
> +/* Verify that, when they are on different lines, that the opening symbol is
> +   shown via a secondary diagnostic.  */
> +
> +void multi_func ()
> +{
> +  int multi =
> +    foo (1, /* { dg-message "to match this '\\('" } */
> +         (1 + 2),
> +         (1 + 2 + 3):); /* { dg-error "expected '\\)' before ':' token" } */
> +  /* { dg-begin-multiline-output "" }
> +          (1 + 2 + 3):);
> +                     ^
> +                     )
> +     { dg-end-multiline-output "" } */
> +  /* { dg-begin-multiline-output "" }
> +     foo (1,
> +         ^
> +     { dg-end-multiline-output "" } */
> +}
> -- 
> 2.20.1
>

On Sun, 31 May 2020, Mark Wielaard wrote:

> On Sun, May 24, 2020 at 11:46:34PM +0200, Mark Wielaard wrote:
> > The C++ parser already tracks function call parens matching, but the C
> > parser doesn't. This adds the same functionality to the C parser and adds
> > a testcase showing the C++ and C parser matching function call parens
> > in an error message.
> > 
> > gcc/c/ChangeLog:
> > 
> > 	* c-parser.c (c_parser_postfix_expression_after_primary): Add
> > 	scope with matching_parens after CPP_OPEN_PAREN.
> > 
> > gcc/testsuite/ChangeLog:
> > 
> > 	* c-c++-common/missing-close-func-paren.c: New test.
> 
> Ping.

OK.