c++: Reject UDLs in certain contexts [PR105300]

Message ID 20221112165331.349041-1-polacek@redhat.com
State Accepted
Headers
Series c++: Reject UDLs in certain contexts [PR105300] |

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Context Check Description
snail/gcc-patch-check success Github commit url

Commit Message

Marek Polacek Nov. 12, 2022, 4:53 p.m. UTC
  In this PR, we are crashing because we've encountered a UDL where a
string-literal is expected.  This patch makes the parser reject string
and character UDLs in all places where the grammar requires a
string-literal and not a user-defined-string-literal.

Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?

	PR c++/105300

gcc/c-family/ChangeLog:

	* c-pragma.cc (handle_pragma_message): Warn for CPP_STRING_USERDEF.

gcc/cp/ChangeLog:

	* parser.cc (cp_parser_string_literal): Add a bool parameter.
	Give an error when UDLs are not permitted.
	(cp_parser_primary_expression): Adjust the call to
	cp_parser_string_literal.
	(cp_parser_linkage_specification): Likewise.
	(cp_parser_static_assert): Likewise.
	(cp_parser_operator): Likewise.
	(cp_parser_asm_definition): Likewise.
	(cp_parser_asm_specification_opt): Likewise.
	(cp_parser_asm_operand_list): Likewise.
	(cp_parser_asm_clobber_list): Likewise.
	(cp_parser_omp_context_selector): Likewise.
	(pragma_lex): Likewise.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp0x/udlit-error1.C: New test.
---
 gcc/c-family/c-pragma.cc                  |  3 +
 gcc/cp/parser.cc                          | 69 ++++++++++++++---------
 gcc/testsuite/g++.dg/cpp0x/udlit-error1.C | 21 +++++++
 3 files changed, 65 insertions(+), 28 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/udlit-error1.C


base-commit: f232715d15618e91c90eb210e23de10909590944
  

Comments

Jason Merrill Nov. 15, 2022, 11:58 p.m. UTC | #1
On 11/12/22 06:53, Marek Polacek wrote:
> In this PR, we are crashing because we've encountered a UDL where a
> string-literal is expected.  This patch makes the parser reject string
> and character UDLs in all places where the grammar requires a
> string-literal and not a user-defined-string-literal.
> 
> Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?

Since the grammar has

user-defined-string-literal :
	string-literal ud-suffix

maybe we want to move the UDL handling out to a 
cp_parser_udl_string_literal that calls cp_parser_string_literal?

> 	PR c++/105300
> 
> gcc/c-family/ChangeLog:
> 
> 	* c-pragma.cc (handle_pragma_message): Warn for CPP_STRING_USERDEF.
> 
> gcc/cp/ChangeLog:
> 
> 	* parser.cc (cp_parser_string_literal): Add a bool parameter.
> 	Give an error when UDLs are not permitted.
> 	(cp_parser_primary_expression): Adjust the call to
> 	cp_parser_string_literal.
> 	(cp_parser_linkage_specification): Likewise.
> 	(cp_parser_static_assert): Likewise.
> 	(cp_parser_operator): Likewise.
> 	(cp_parser_asm_definition): Likewise.
> 	(cp_parser_asm_specification_opt): Likewise.
> 	(cp_parser_asm_operand_list): Likewise.
> 	(cp_parser_asm_clobber_list): Likewise.
> 	(cp_parser_omp_context_selector): Likewise.
> 	(pragma_lex): Likewise.
> 
> gcc/testsuite/ChangeLog:
> 
> 	* g++.dg/cpp0x/udlit-error1.C: New test.
> ---
>   gcc/c-family/c-pragma.cc                  |  3 +
>   gcc/cp/parser.cc                          | 69 ++++++++++++++---------
>   gcc/testsuite/g++.dg/cpp0x/udlit-error1.C | 21 +++++++
>   3 files changed, 65 insertions(+), 28 deletions(-)
>   create mode 100644 gcc/testsuite/g++.dg/cpp0x/udlit-error1.C
> 
> diff --git a/gcc/c-family/c-pragma.cc b/gcc/c-family/c-pragma.cc
> index 142a46441ac..49f405b605b 100644
> --- a/gcc/c-family/c-pragma.cc
> +++ b/gcc/c-family/c-pragma.cc
> @@ -1390,6 +1390,9 @@ handle_pragma_message (cpp_reader *)
>       }
>     else if (token == CPP_STRING)
>       message = x;
> +  else if (token == CPP_STRING_USERDEF)
> +    GCC_BAD ("string literal with user-defined suffix is invalid in this "
> +	     "context");
>     else
>       GCC_BAD ("expected a string after %<#pragma message%>");
>   
> diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
> index e4021835ed5..ae2798e2a33 100644
> --- a/gcc/cp/parser.cc
> +++ b/gcc/cp/parser.cc
> @@ -2226,7 +2226,7 @@ pop_unparsed_function_queues (cp_parser *parser)
>   static cp_expr cp_parser_identifier
>     (cp_parser *);
>   static cp_expr cp_parser_string_literal
> -  (cp_parser *, bool, bool, bool);
> +  (cp_parser *, bool, bool, bool, bool);
>   static cp_expr cp_parser_userdef_char_literal
>     (cp_parser *);
>   static tree cp_parser_userdef_string_literal
> @@ -4402,7 +4402,8 @@ cp_parser_identifier (cp_parser* parser)
>      TREE_STRING representing the combined, nul-terminated string
>      constant.  If TRANSLATE is true, translate the string to the
>      execution character set.  If WIDE_OK is true, a wide string is
> -   invalid here.
> +   valid here.  If UDL_OK is true, a string literal with user-defined
> +   suffix can be used in this context.
>   
>      C++98 [lex.string] says that if a narrow string literal token is
>      adjacent to a wide string literal token, the behavior is undefined.
> @@ -4414,7 +4415,7 @@ cp_parser_identifier (cp_parser* parser)
>      FUTURE: ObjC++ will need to handle @-strings here.  */
>   static cp_expr
>   cp_parser_string_literal (cp_parser *parser, bool translate, bool wide_ok,
> -			  bool lookup_udlit = true)
> +			  bool udl_ok, bool lookup_udlit = true)
>   {
>     tree value;
>     size_t count;
> @@ -4439,6 +4440,12 @@ cp_parser_string_literal (cp_parser *parser, bool translate, bool wide_ok,
>   
>     if (cpp_userdef_string_p (tok->type))
>       {
> +      if (!udl_ok)
> +	{
> +	  error_at (loc, "string literal with user-defined suffix "
> +		    "is invalid in this context");
> +	  return error_mark_node;
> +	}
>         string_tree = USERDEF_LITERAL_VALUE (tok->u.value);
>         curr_type = cpp_userdef_string_remove_type (tok->type);
>         curr_tok_is_userdef_p = true;
> @@ -5655,7 +5662,7 @@ cp_parser_primary_expression (cp_parser *parser,
>   	 argument to cp_parser_string_literal.  */
>         return (cp_parser_string_literal (parser,
>   					parser->translate_strings_p,
> -					true)
> +					/*wide_ok=*/true, /*udl_ok=*/true)
>   	      .maybe_add_location_wrapper ());
>   
>       case CPP_OPEN_PAREN:
> @@ -16161,15 +16168,14 @@ cp_parser_function_specifier_opt (cp_parser* parser,
>   static void
>   cp_parser_linkage_specification (cp_parser* parser, tree prefix_attr)
>   {
> -  tree linkage;
> -
>     /* Look for the `extern' keyword.  */
>     cp_token *extern_token
>       = cp_parser_require_keyword (parser, RID_EXTERN, RT_EXTERN);
>   
>     /* Look for the string-literal.  */
>     cp_token *string_token = cp_lexer_peek_token (parser->lexer);
> -  linkage = cp_parser_string_literal (parser, false, false);
> +  tree linkage = cp_parser_string_literal (parser, /*translate=*/false,
> +					   /*wide_ok=*/false, /*udl_ok=*/false);
>   
>     /* Transform the literal into an identifier.  If the literal is a
>        wide-character string, or contains embedded NULs, then we can't
> @@ -16300,8 +16306,8 @@ cp_parser_static_assert(cp_parser *parser, bool member_p)
>   
>         /* Parse the string-literal message.  */
>         message = cp_parser_string_literal (parser,
> -                                	  /*translate=*/false,
> -                                	  /*wide_ok=*/true);
> +					  /*translate=*/false, /*wide_ok=*/true,
> +					  /*udl_ok=*/false);
>   
>         /* A `)' completes the static assertion.  */
>         if (!parens.require_close (parser))
> @@ -17349,7 +17355,6 @@ cp_parser_operator (cp_parser* parser, location_t start_loc)
>       case CPP_STRING16_USERDEF:
>       case CPP_STRING32_USERDEF:
>         {
> -	cp_expr str;
>   	tree string_tree;
>   	int sz, len;
>   
> @@ -17357,8 +17362,10 @@ cp_parser_operator (cp_parser* parser, location_t start_loc)
>   	  maybe_warn_cpp0x (CPP0X_USER_DEFINED_LITERALS);
>   
>   	/* Consume the string.  */
> -	str = cp_parser_string_literal (parser, /*translate=*/true,
> -				      /*wide_ok=*/true, /*lookup_udlit=*/false);
> +	cp_expr str = cp_parser_string_literal (parser, /*translate=*/true,
> +						/*wide_ok=*/true,
> +						/*udl_ok=*/true,
> +						/*lookup_udlit=*/false);
>   	if (str == error_mark_node)
>   	  return error_mark_node;
>   	else if (TREE_CODE (str) == USERDEF_LITERAL)
> @@ -21975,7 +21982,6 @@ cp_parser_using_directive (cp_parser* parser)
>   static void
>   cp_parser_asm_definition (cp_parser* parser)
>   {
> -  tree string;
>     tree outputs = NULL_TREE;
>     tree inputs = NULL_TREE;
>     tree clobbers = NULL_TREE;
> @@ -22083,7 +22089,8 @@ cp_parser_asm_definition (cp_parser* parser)
>     if (!cp_parser_require (parser, CPP_OPEN_PAREN, RT_OPEN_PAREN))
>       return;
>     /* Look for the string.  */
> -  string = cp_parser_string_literal (parser, false, false);
> +  tree string = cp_parser_string_literal (parser, /*translate=*/false,
> +					  /*wide_ok=*/false, /*udl_ok=*/false);
>     if (string == error_mark_node)
>       {
>         cp_parser_skip_to_closing_parenthesis (parser, true, false,
> @@ -28485,11 +28492,8 @@ cp_parser_yield_expression (cp_parser* parser)
>   static tree
>   cp_parser_asm_specification_opt (cp_parser* parser)
>   {
> -  cp_token *token;
> -  tree asm_specification;
> -
>     /* Peek at the next token.  */
> -  token = cp_lexer_peek_token (parser->lexer);
> +  cp_token *token = cp_lexer_peek_token (parser->lexer);
>     /* If the next token isn't the `asm' keyword, then there's no
>        asm-specification.  */
>     if (!cp_parser_is_keyword (token, RID_ASM))
> @@ -28502,7 +28506,10 @@ cp_parser_asm_specification_opt (cp_parser* parser)
>     parens.require_open (parser);
>   
>     /* Look for the string-literal.  */
> -  asm_specification = cp_parser_string_literal (parser, false, false);
> +  tree asm_specification = cp_parser_string_literal (parser,
> +						     /*translate=*/false,
> +						     /*wide_ok=*/false,
> +						     /*udl_ok=*/false);
>   
>     /* Look for the `)'.  */
>     parens.require_close (parser);
> @@ -28535,8 +28542,6 @@ cp_parser_asm_operand_list (cp_parser* parser)
>   
>     while (true)
>       {
> -      tree string_literal;
> -      tree expression;
>         tree name;
>   
>         if (cp_lexer_next_token_is (parser->lexer, CPP_OPEN_SQUARE))
> @@ -28554,13 +28559,16 @@ cp_parser_asm_operand_list (cp_parser* parser)
>         else
>   	name = NULL_TREE;
>         /* Look for the string-literal.  */
> -      string_literal = cp_parser_string_literal (parser, false, false);
> +      tree string_literal = cp_parser_string_literal (parser,
> +						      /*translate=*/false,
> +						      /*wide_ok=*/false,
> +						      /*udl_ok=*/false);
>   
>         /* Look for the `('.  */
>         matching_parens parens;
>         parens.require_open (parser);
>         /* Parse the expression.  */
> -      expression = cp_parser_expression (parser);
> +      tree expression = cp_parser_expression (parser);
>         /* Look for the `)'.  */
>         parens.require_close (parser);
>   
> @@ -28600,10 +28608,11 @@ cp_parser_asm_clobber_list (cp_parser* parser)
>   
>     while (true)
>       {
> -      tree string_literal;
> -
>         /* Look for the string literal.  */
> -      string_literal = cp_parser_string_literal (parser, false, false);
> +      tree string_literal = cp_parser_string_literal (parser,
> +						      /*translate=*/false,
> +						      /*wide_ok=*/false,
> +						      /*udl_ok=*/false);
>         /* Add it to the list.  */
>         clobbers = tree_cons (NULL_TREE, string_literal, clobbers);
>         /* If the next token is not a `,', then the list is
> @@ -45761,7 +45770,10 @@ cp_parser_omp_context_selector (cp_parser *parser, tree set, bool has_parms_p)
>   		      cp_lexer_consume_token (parser->lexer);
>   		    }
>   		  else if (cp_lexer_next_token_is (parser->lexer, CPP_STRING))
> -		    value = cp_parser_string_literal (parser, false, false);
> +		    value = cp_parser_string_literal (parser,
> +						      /*translate=*/false,
> +						      /*wide_ok=*/false,
> +						      /*udl_ok=*/false);
>   		  else
>   		    {
>   		      cp_parser_error (parser, "expected identifier or "
> @@ -48783,7 +48795,8 @@ pragma_lex (tree *value, location_t *loc)
>     if (ret == CPP_PRAGMA_EOL)
>       ret = CPP_EOF;
>     else if (ret == CPP_STRING)
> -    *value = cp_parser_string_literal (the_parser, false, false);
> +    *value = cp_parser_string_literal (the_parser, /*translate=*/false,
> +				       /*wide_ok=*/false, /*udl_ok=*/false);
>     else
>       {
>         if (ret == CPP_KEYWORD)
> diff --git a/gcc/testsuite/g++.dg/cpp0x/udlit-error1.C b/gcc/testsuite/g++.dg/cpp0x/udlit-error1.C
> new file mode 100644
> index 00000000000..66e300e350f
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/cpp0x/udlit-error1.C
> @@ -0,0 +1,21 @@
> +// PR c++/105300
> +// { dg-do compile { target c++11 } }
> +
> +void operator""_x(const char *, decltype(sizeof(0)));
> +
> +#include ""_x		  // { dg-error "include expects" }
> +#line ""_x		  // { dg-error "not a positive integer" }
> +#if __has_include(""_x)	  // { dg-error "requires a header-name" }
> +#endif
> +
> +#pragma message "hi"_x	  // { dg-warning "string literal with user-defined suffix is invalid in this context" }
> +
> +extern "C"_x { void g(); } // { dg-error "before user-defined string literal" }
> +static_assert(true, "foo"_x); // { dg-error "string literal with user-defined suffix is invalid in this context|expected" }
> +
> +[[deprecated("oof"_x)]]
> +void
> +lol () // { dg-error "not a string" }
> +{
> +  asm (""_x); // { dg-error "string literal with user-defined suffix is invalid in this context" }
> +}
> 
> base-commit: f232715d15618e91c90eb210e23de10909590944
  
Marek Polacek Nov. 16, 2022, 12:35 a.m. UTC | #2
On Tue, Nov 15, 2022 at 06:58:39PM -0500, Jason Merrill wrote:
> On 11/12/22 06:53, Marek Polacek wrote:
> > In this PR, we are crashing because we've encountered a UDL where a
> > string-literal is expected.  This patch makes the parser reject string
> > and character UDLs in all places where the grammar requires a
> > string-literal and not a user-defined-string-literal.
> > 
> > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
> 
> Since the grammar has
> 
> user-defined-string-literal :
> 	string-literal ud-suffix
> 
> maybe we want to move the UDL handling out to a cp_parser_udl_string_literal
> that calls cp_parser_string_literal?

Umm, maybe, but the UDL handling code seems to be too entrenched in
cp_parser_string_literal and I don't think it's going to be easy to extract
it :/.

Marek
  
Jason Merrill Nov. 16, 2022, 1:22 p.m. UTC | #3
On 11/15/22 19:35, Marek Polacek wrote:
> On Tue, Nov 15, 2022 at 06:58:39PM -0500, Jason Merrill wrote:
>> On 11/12/22 06:53, Marek Polacek wrote:
>>> In this PR, we are crashing because we've encountered a UDL where a
>>> string-literal is expected.  This patch makes the parser reject string
>>> and character UDLs in all places where the grammar requires a
>>> string-literal and not a user-defined-string-literal.
>>>
>>> Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
>>
>> Since the grammar has
>>
>> user-defined-string-literal :
>> 	string-literal ud-suffix
>>
>> maybe we want to move the UDL handling out to a cp_parser_udl_string_literal
>> that calls cp_parser_string_literal?
> 
> Umm, maybe, but the UDL handling code seems to be too entrenched in
> cp_parser_string_literal and I don't think it's going to be easy to extract
> it :/.

Fair enough; maybe a wrapper, then?

Jason
  
Marek Polacek Nov. 17, 2022, 1:12 a.m. UTC | #4
On Wed, Nov 16, 2022 at 08:22:39AM -0500, Jason Merrill wrote:
> On 11/15/22 19:35, Marek Polacek wrote:
> > On Tue, Nov 15, 2022 at 06:58:39PM -0500, Jason Merrill wrote:
> > > On 11/12/22 06:53, Marek Polacek wrote:
> > > > In this PR, we are crashing because we've encountered a UDL where a
> > > > string-literal is expected.  This patch makes the parser reject string
> > > > and character UDLs in all places where the grammar requires a
> > > > string-literal and not a user-defined-string-literal.
> > > > 
> > > > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
> > > 
> > > Since the grammar has
> > > 
> > > user-defined-string-literal :
> > > 	string-literal ud-suffix
> > > 
> > > maybe we want to move the UDL handling out to a cp_parser_udl_string_literal
> > > that calls cp_parser_string_literal?
> > 
> > Umm, maybe, but the UDL handling code seems to be too entrenched in
> > cp_parser_string_literal and I don't think it's going to be easy to extract
> > it :/.
> 
> Fair enough; maybe a wrapper, then?

As in, have a cp_parser_udl_string_literal wrapper that calls
cp_parser_string_literal with udl_ok=true, rename cp_parser_string_literal,
introduce a new cp_parser_string_literal wrapper that passes udl_ok=false?

One problem with cp_parser_udl_string_literal is that it's too similar to
cp_parser_userdef_string_literal, which would be confusing, I think.

Marek
  
Jason Merrill Nov. 18, 2022, 12:06 a.m. UTC | #5
On 11/16/22 20:12, Marek Polacek wrote:
> On Wed, Nov 16, 2022 at 08:22:39AM -0500, Jason Merrill wrote:
>> On 11/15/22 19:35, Marek Polacek wrote:
>>> On Tue, Nov 15, 2022 at 06:58:39PM -0500, Jason Merrill wrote:
>>>> On 11/12/22 06:53, Marek Polacek wrote:
>>>>> In this PR, we are crashing because we've encountered a UDL where a
>>>>> string-literal is expected.  This patch makes the parser reject string
>>>>> and character UDLs in all places where the grammar requires a
>>>>> string-literal and not a user-defined-string-literal.
>>>>>
>>>>> Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
>>>>
>>>> Since the grammar has
>>>>
>>>> user-defined-string-literal :
>>>> 	string-literal ud-suffix
>>>>
>>>> maybe we want to move the UDL handling out to a cp_parser_udl_string_literal
>>>> that calls cp_parser_string_literal?
>>>
>>> Umm, maybe, but the UDL handling code seems to be too entrenched in
>>> cp_parser_string_literal and I don't think it's going to be easy to extract
>>> it :/.
>>
>> Fair enough; maybe a wrapper, then?
> 
> As in, have a cp_parser_udl_string_literal wrapper that calls
> cp_parser_string_literal with udl_ok=true, rename cp_parser_string_literal,
> introduce a new cp_parser_string_literal wrapper that passes udl_ok=false?

That's what I was thinking.  And the new cp_parser_string_literal could 
also omit the lookup_udlit parm.

> One problem with cp_parser_udl_string_literal is that it's too similar to
> cp_parser_userdef_string_literal, which would be confusing, I think.

True, probably better to use that name instead, and rename the current 
one to something like finish_userdef_string_literal

Jason
  

Patch

diff --git a/gcc/c-family/c-pragma.cc b/gcc/c-family/c-pragma.cc
index 142a46441ac..49f405b605b 100644
--- a/gcc/c-family/c-pragma.cc
+++ b/gcc/c-family/c-pragma.cc
@@ -1390,6 +1390,9 @@  handle_pragma_message (cpp_reader *)
     }
   else if (token == CPP_STRING)
     message = x;
+  else if (token == CPP_STRING_USERDEF)
+    GCC_BAD ("string literal with user-defined suffix is invalid in this "
+	     "context");
   else
     GCC_BAD ("expected a string after %<#pragma message%>");
 
diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index e4021835ed5..ae2798e2a33 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -2226,7 +2226,7 @@  pop_unparsed_function_queues (cp_parser *parser)
 static cp_expr cp_parser_identifier
   (cp_parser *);
 static cp_expr cp_parser_string_literal
-  (cp_parser *, bool, bool, bool);
+  (cp_parser *, bool, bool, bool, bool);
 static cp_expr cp_parser_userdef_char_literal
   (cp_parser *);
 static tree cp_parser_userdef_string_literal
@@ -4402,7 +4402,8 @@  cp_parser_identifier (cp_parser* parser)
    TREE_STRING representing the combined, nul-terminated string
    constant.  If TRANSLATE is true, translate the string to the
    execution character set.  If WIDE_OK is true, a wide string is
-   invalid here.
+   valid here.  If UDL_OK is true, a string literal with user-defined
+   suffix can be used in this context.
 
    C++98 [lex.string] says that if a narrow string literal token is
    adjacent to a wide string literal token, the behavior is undefined.
@@ -4414,7 +4415,7 @@  cp_parser_identifier (cp_parser* parser)
    FUTURE: ObjC++ will need to handle @-strings here.  */
 static cp_expr
 cp_parser_string_literal (cp_parser *parser, bool translate, bool wide_ok,
-			  bool lookup_udlit = true)
+			  bool udl_ok, bool lookup_udlit = true)
 {
   tree value;
   size_t count;
@@ -4439,6 +4440,12 @@  cp_parser_string_literal (cp_parser *parser, bool translate, bool wide_ok,
 
   if (cpp_userdef_string_p (tok->type))
     {
+      if (!udl_ok)
+	{
+	  error_at (loc, "string literal with user-defined suffix "
+		    "is invalid in this context");
+	  return error_mark_node;
+	}
       string_tree = USERDEF_LITERAL_VALUE (tok->u.value);
       curr_type = cpp_userdef_string_remove_type (tok->type);
       curr_tok_is_userdef_p = true;
@@ -5655,7 +5662,7 @@  cp_parser_primary_expression (cp_parser *parser,
 	 argument to cp_parser_string_literal.  */
       return (cp_parser_string_literal (parser,
 					parser->translate_strings_p,
-					true)
+					/*wide_ok=*/true, /*udl_ok=*/true)
 	      .maybe_add_location_wrapper ());
 
     case CPP_OPEN_PAREN:
@@ -16161,15 +16168,14 @@  cp_parser_function_specifier_opt (cp_parser* parser,
 static void
 cp_parser_linkage_specification (cp_parser* parser, tree prefix_attr)
 {
-  tree linkage;
-
   /* Look for the `extern' keyword.  */
   cp_token *extern_token
     = cp_parser_require_keyword (parser, RID_EXTERN, RT_EXTERN);
 
   /* Look for the string-literal.  */
   cp_token *string_token = cp_lexer_peek_token (parser->lexer);
-  linkage = cp_parser_string_literal (parser, false, false);
+  tree linkage = cp_parser_string_literal (parser, /*translate=*/false,
+					   /*wide_ok=*/false, /*udl_ok=*/false);
 
   /* Transform the literal into an identifier.  If the literal is a
      wide-character string, or contains embedded NULs, then we can't
@@ -16300,8 +16306,8 @@  cp_parser_static_assert(cp_parser *parser, bool member_p)
 
       /* Parse the string-literal message.  */
       message = cp_parser_string_literal (parser,
-                                	  /*translate=*/false,
-                                	  /*wide_ok=*/true);
+					  /*translate=*/false, /*wide_ok=*/true,
+					  /*udl_ok=*/false);
 
       /* A `)' completes the static assertion.  */
       if (!parens.require_close (parser))
@@ -17349,7 +17355,6 @@  cp_parser_operator (cp_parser* parser, location_t start_loc)
     case CPP_STRING16_USERDEF:
     case CPP_STRING32_USERDEF:
       {
-	cp_expr str;
 	tree string_tree;
 	int sz, len;
 
@@ -17357,8 +17362,10 @@  cp_parser_operator (cp_parser* parser, location_t start_loc)
 	  maybe_warn_cpp0x (CPP0X_USER_DEFINED_LITERALS);
 
 	/* Consume the string.  */
-	str = cp_parser_string_literal (parser, /*translate=*/true,
-				      /*wide_ok=*/true, /*lookup_udlit=*/false);
+	cp_expr str = cp_parser_string_literal (parser, /*translate=*/true,
+						/*wide_ok=*/true,
+						/*udl_ok=*/true,
+						/*lookup_udlit=*/false);
 	if (str == error_mark_node)
 	  return error_mark_node;
 	else if (TREE_CODE (str) == USERDEF_LITERAL)
@@ -21975,7 +21982,6 @@  cp_parser_using_directive (cp_parser* parser)
 static void
 cp_parser_asm_definition (cp_parser* parser)
 {
-  tree string;
   tree outputs = NULL_TREE;
   tree inputs = NULL_TREE;
   tree clobbers = NULL_TREE;
@@ -22083,7 +22089,8 @@  cp_parser_asm_definition (cp_parser* parser)
   if (!cp_parser_require (parser, CPP_OPEN_PAREN, RT_OPEN_PAREN))
     return;
   /* Look for the string.  */
-  string = cp_parser_string_literal (parser, false, false);
+  tree string = cp_parser_string_literal (parser, /*translate=*/false,
+					  /*wide_ok=*/false, /*udl_ok=*/false);
   if (string == error_mark_node)
     {
       cp_parser_skip_to_closing_parenthesis (parser, true, false,
@@ -28485,11 +28492,8 @@  cp_parser_yield_expression (cp_parser* parser)
 static tree
 cp_parser_asm_specification_opt (cp_parser* parser)
 {
-  cp_token *token;
-  tree asm_specification;
-
   /* Peek at the next token.  */
-  token = cp_lexer_peek_token (parser->lexer);
+  cp_token *token = cp_lexer_peek_token (parser->lexer);
   /* If the next token isn't the `asm' keyword, then there's no
      asm-specification.  */
   if (!cp_parser_is_keyword (token, RID_ASM))
@@ -28502,7 +28506,10 @@  cp_parser_asm_specification_opt (cp_parser* parser)
   parens.require_open (parser);
 
   /* Look for the string-literal.  */
-  asm_specification = cp_parser_string_literal (parser, false, false);
+  tree asm_specification = cp_parser_string_literal (parser,
+						     /*translate=*/false,
+						     /*wide_ok=*/false,
+						     /*udl_ok=*/false);
 
   /* Look for the `)'.  */
   parens.require_close (parser);
@@ -28535,8 +28542,6 @@  cp_parser_asm_operand_list (cp_parser* parser)
 
   while (true)
     {
-      tree string_literal;
-      tree expression;
       tree name;
 
       if (cp_lexer_next_token_is (parser->lexer, CPP_OPEN_SQUARE))
@@ -28554,13 +28559,16 @@  cp_parser_asm_operand_list (cp_parser* parser)
       else
 	name = NULL_TREE;
       /* Look for the string-literal.  */
-      string_literal = cp_parser_string_literal (parser, false, false);
+      tree string_literal = cp_parser_string_literal (parser,
+						      /*translate=*/false,
+						      /*wide_ok=*/false,
+						      /*udl_ok=*/false);
 
       /* Look for the `('.  */
       matching_parens parens;
       parens.require_open (parser);
       /* Parse the expression.  */
-      expression = cp_parser_expression (parser);
+      tree expression = cp_parser_expression (parser);
       /* Look for the `)'.  */
       parens.require_close (parser);
 
@@ -28600,10 +28608,11 @@  cp_parser_asm_clobber_list (cp_parser* parser)
 
   while (true)
     {
-      tree string_literal;
-
       /* Look for the string literal.  */
-      string_literal = cp_parser_string_literal (parser, false, false);
+      tree string_literal = cp_parser_string_literal (parser,
+						      /*translate=*/false,
+						      /*wide_ok=*/false,
+						      /*udl_ok=*/false);
       /* Add it to the list.  */
       clobbers = tree_cons (NULL_TREE, string_literal, clobbers);
       /* If the next token is not a `,', then the list is
@@ -45761,7 +45770,10 @@  cp_parser_omp_context_selector (cp_parser *parser, tree set, bool has_parms_p)
 		      cp_lexer_consume_token (parser->lexer);
 		    }
 		  else if (cp_lexer_next_token_is (parser->lexer, CPP_STRING))
-		    value = cp_parser_string_literal (parser, false, false);
+		    value = cp_parser_string_literal (parser,
+						      /*translate=*/false,
+						      /*wide_ok=*/false,
+						      /*udl_ok=*/false);
 		  else
 		    {
 		      cp_parser_error (parser, "expected identifier or "
@@ -48783,7 +48795,8 @@  pragma_lex (tree *value, location_t *loc)
   if (ret == CPP_PRAGMA_EOL)
     ret = CPP_EOF;
   else if (ret == CPP_STRING)
-    *value = cp_parser_string_literal (the_parser, false, false);
+    *value = cp_parser_string_literal (the_parser, /*translate=*/false,
+				       /*wide_ok=*/false, /*udl_ok=*/false);
   else
     {
       if (ret == CPP_KEYWORD)
diff --git a/gcc/testsuite/g++.dg/cpp0x/udlit-error1.C b/gcc/testsuite/g++.dg/cpp0x/udlit-error1.C
new file mode 100644
index 00000000000..66e300e350f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/udlit-error1.C
@@ -0,0 +1,21 @@ 
+// PR c++/105300
+// { dg-do compile { target c++11 } }
+
+void operator""_x(const char *, decltype(sizeof(0)));
+
+#include ""_x		  // { dg-error "include expects" }
+#line ""_x		  // { dg-error "not a positive integer" }
+#if __has_include(""_x)	  // { dg-error "requires a header-name" }
+#endif
+
+#pragma message "hi"_x	  // { dg-warning "string literal with user-defined suffix is invalid in this context" }
+
+extern "C"_x { void g(); } // { dg-error "before user-defined string literal" }
+static_assert(true, "foo"_x); // { dg-error "string literal with user-defined suffix is invalid in this context|expected" }
+
+[[deprecated("oof"_x)]]
+void
+lol () // { dg-error "not a string" }
+{
+  asm (""_x); // { dg-error "string literal with user-defined suffix is invalid in this context" }
+}