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

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.

I've introduced two new wrappers; the existing cp_parser_string_literal
was renamed to cp_parser_string_literal_common and should not be called
directly.  finish_userdef_string_literal is renamed from
cp_parser_userdef_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: Remove unnecessary forward declarations.
	(cp_parser_string_literal): New wrapper.
	(cp_parser_string_literal_common): Renamed from
	cp_parser_string_literal.  Add a bool parameter.  Give an error when
	UDLs are not permitted.
	(cp_parser_userdef_string_literal): New wrapper.
	(finish_userdef_string_literal): Renamed from
	cp_parser_userdef_string_literal.
	(cp_parser_primary_expression): Call cp_parser_userdef_string_literal
	instead of cp_parser_string_literal.
	(cp_parser_linkage_specification): Move a variable declaration closer
	to its first use.
	(cp_parser_static_assert): Likewise.
	(cp_parser_operator): Call cp_parser_userdef_string_literal instead of
	cp_parser_string_literal.
	(cp_parser_asm_definition): Move a variable declaration closer to its
	first use.
	(cp_parser_asm_specification_opt): Move variable declarations closer to
	their first use.
	(cp_parser_asm_operand_list): Likewise.
	(cp_parser_asm_clobber_list): Likewise.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp0x/udlit-error1.C: New test.

diff --git a/gcc/c-family/c-pragma.cc b/gcc/c-family/c-pragma.cc
index 68d1c8b..0d2b333 100644 (file)
--- 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 e0c46d2..4cdc1cd 100644 (file)
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -2227,16 +2227,8 @@ pop_unparsed_function_queues (cp_parser *parser)
 
 /* Lexical conventions [gram.lex]  */
 
-static cp_expr cp_parser_identifier
-  (cp_parser *);
-static cp_expr cp_parser_string_literal
-  (cp_parser *, bool, bool, bool);
-static cp_expr cp_parser_userdef_char_literal
-  (cp_parser *);
-static tree cp_parser_userdef_string_literal
+static tree finish_userdef_string_literal
   (tree);
-static cp_expr cp_parser_userdef_numeric_literal
-  (cp_parser *);
 
 /* Basic concepts [gram.basic]  */
 
@@ -4408,11 +4400,15 @@ cp_parser_identifier (cp_parser* parser)
     return error_mark_node;
 }
 
-/* Parse a sequence of adjacent string constants.  Returns a
+/* Worker for cp_parser_string_literal and cp_parser_userdef_string_literal.
+   Do not call this directly; use either of the above.
+
+   Parse a sequence of adjacent string constants.  Return a
    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.
@@ -4422,9 +4418,11 @@ cp_parser_identifier (cp_parser* parser)
    This code is largely lifted from lex_string() in c-lex.cc.
 
    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)
+cp_parser_string_literal_common (cp_parser *parser, bool translate,
+                                bool wide_ok, bool udl_ok,
+                                bool lookup_udlit)
 {
   tree value;
   size_t count;
@@ -4449,6 +4447,12 @@ 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;
@@ -4539,6 +4543,12 @@ cp_parser_string_literal (cp_parser *parser, bool translate, bool wide_ok,
          tok = cp_lexer_peek_token (parser->lexer);
          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;
@@ -4608,7 +4618,7 @@ cp_parser_string_literal (cp_parser *parser, bool translate, bool wide_ok,
          tree literal = build_userdef_literal (suffix_id, value,
                                                OT_NONE, NULL_TREE);
          if (lookup_udlit)
-           value = cp_parser_userdef_string_literal (literal);
+           value = finish_userdef_string_literal (literal);
          else
            value = literal;
        }
@@ -4626,6 +4636,37 @@ cp_parser_string_literal (cp_parser *parser, bool translate, bool wide_ok,
   return cp_expr (value, loc);
 }
 
+/* Parse a sequence of adjacent string constants.  Return a 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 valid here.
+
+   This function issues an error if a user defined string literal is
+   encountered; use cp_parser_userdef_string_literal if UDLs are allowed.  */
+
+static inline cp_expr
+cp_parser_string_literal (cp_parser *parser, bool translate, bool wide_ok)
+{
+  return cp_parser_string_literal_common (parser, translate, wide_ok,
+                                         /*udl_ok=*/false,
+                                         /*lookup_udlit=*/false);
+}
+
+/* Parse a string literal or user defined string literal.
+
+   user-defined-string-literal :
+     string-literal ud-suffix
+
+   If LOOKUP_UDLIT, perform a lookup for a suitable template function.  */
+
+static inline cp_expr
+cp_parser_userdef_string_literal (cp_parser *parser, bool lookup_udlit)
+{
+  return cp_parser_string_literal_common (parser, /*translate=*/true,
+                                         /*wide_ok=*/true, /*udl_ok=*/true,
+                                         lookup_udlit);
+}
+
 /* Look up a literal operator with the name and the exact arguments.  */
 
 static tree
@@ -4923,7 +4964,7 @@ cp_parser_userdef_numeric_literal (cp_parser *parser)
    as arguments.  */
 
 static tree
-cp_parser_userdef_string_literal (tree literal)
+finish_userdef_string_literal (tree literal)
 {
   tree suffix_id = USERDEF_LITERAL_SUFFIX_ID (literal);
   tree name = cp_literal_operator_id (IDENTIFIER_POINTER (suffix_id));
@@ -5663,10 +5704,15 @@ cp_parser_primary_expression (cp_parser *parser,
       /* ??? Should wide strings be allowed when parser->translate_strings_p
         is false (i.e. in attributes)?  If not, we can kill the third
         argument to cp_parser_string_literal.  */
-      return (cp_parser_string_literal (parser,
-                                       parser->translate_strings_p,
-                                       true)
-             .maybe_add_location_wrapper ());
+      if (parser->translate_strings_p)
+       return (cp_parser_userdef_string_literal (parser,
+                                                 /*lookup_udlit=*/true)
+               .maybe_add_location_wrapper ());
+      else
+       return (cp_parser_string_literal (parser,
+                                         /*translate=*/false,
+                                         /*wide_ok=*/true)
+               .maybe_add_location_wrapper ());
 
     case CPP_OPEN_PAREN:
       /* If we see `( { ' then we are looking at the beginning of
@@ -16222,15 +16268,14 @@ 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);
 
   /* Transform the literal into an identifier.  If the literal is a
      wide-character string, or contains embedded NULs, then we can't
@@ -16360,9 +16405,8 @@ cp_parser_static_assert(cp_parser *parser, bool member_p)
       cp_parser_require (parser, CPP_COMMA, RT_COMMA);
 
       /* Parse the string-literal message.  */
-      message = cp_parser_string_literal (parser,
-                                         /*translate=*/false,
-                                         /*wide_ok=*/true);
+      message = cp_parser_string_literal (parser, /*translate=*/false,
+                                         /*wide_ok=*/true);
 
       /* A `)' completes the static assertion.  */
       if (!parens.require_close (parser))
@@ -17410,7 +17454,6 @@ 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;
 
@@ -17418,8 +17461,8 @@ 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_userdef_string_literal (parser,
+                                                       /*lookup_udlit=*/false);
        if (str == error_mark_node)
          return error_mark_node;
        else if (TREE_CODE (str) == USERDEF_LITERAL)
@@ -22072,7 +22115,6 @@ 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;
@@ -22180,7 +22222,8 @@ 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);
   if (string == error_mark_node)
     {
       cp_parser_skip_to_closing_parenthesis (parser, true, false,
@@ -28655,11 +28698,8 @@ 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))
@@ -28672,7 +28712,9 @@ 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);
 
   /* Look for the `)'.  */
   parens.require_close (parser);
@@ -28705,8 +28747,6 @@ 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))
@@ -28724,13 +28764,15 @@ 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);
 
       /* 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);
 
@@ -28770,10 +28812,10 @@ 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);
       /* Add it to the list.  */
       clobbers = tree_cons (NULL_TREE, string_literal, clobbers);
       /* If the next token is not a `,', then the list is
@@ -46372,7 +46414,9 @@ 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);
                  else
                    {
                      cp_parser_error (parser, "expected identifier or "
@@ -49394,7 +49438,8 @@ 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);
   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 (file)
index 0000000..66e300e
--- /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" }
+}