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Re: [C/C++] PR 13358 long long and C++ do not mix well
- From: "Manuel López-Ibáñez" <lopezibanez at gmail dot com>
- To: "Joseph S. Myers" <joseph at codesourcery dot com>
- Cc: "Gcc Patch List" <gcc-patches at gcc dot gnu dot org>
- Date: Thu, 23 Oct 2008 02:05:27 +0200
- Subject: Re: [C/C++] PR 13358 long long and C++ do not mix well
- References: <6c33472e0808281543w5d464fe6r1fa5e584797ac46c@mail.gmail.com> <Pine.LNX.4.64.0808282321560.4350@digraph.polyomino.org.uk> <6c33472e0808281700m457e1f2euf6a0da108dd5b84a@mail.gmail.com>
I think the following patch addresses all requirements and in the
process it fixes some small deficiencies of the current status, such
as talking about C99 when invoked from C++.
Bootstrapped and regression tested on x86_64-unknown-linux-gnu with
--enable-languages=all,obj-c++ --enable-decimal-float and
--target_board=\{-m32,-m64\}
OK for trunk?
2008-10-23 Manuel Lopez-Ibanez <manu@gcc.gnu.org>
PR 13358
* doc/invoke.texi (-Wlong-long): Update description.
* c-lex (interpret_integer): Only warn if there was no previous
overflow and -Wlong-long is enabled.
* c-decl.c (declspecs_add_type): Drop redundant flags.
* c.opt (Wlong-long): Init to -1.
* c-opts.c (sanitize_cpp_opts): Synchronize cpp's warn_long_long
and front-end warn_long_long. Wlong-long only depends on other
flags if it is uninitialized.
* c-parser.c (disable_extension_diagnostics): warn_long_long is
the same for CPP and FE.
(restore_extension_diagnostics): Likewise.
libcpp/
* init.c (cpp_create_reader): Wlong_long is disabled by default.
* expr.c (cpp_classify_number): Give different messages for C and
C++ front-ends.
cp/
* parser.c (cp_parser_check_decl_spec): Drop redundant flags.
* error.c (pedwarn_cxx98): New.
* cp-tree.h (pedwarn_cxx98): Declare.
testsuite/
* gcc.dg/wtr-int-type-1.c: Use two dg-warning to match two
messages. Test for "long long" in system headers.
* gcc.dg/c99-longlong-2.c: New.
* g++.dg/warn/pr13358.C: New.
* g++.dg/warn/pr13358-2.C: New.
* g++.dg/warn/pr13358-3.C: New.
* g++.dg/warn/pr13358-4.C: New.
2008/8/29 Manuel López-Ibáñez <lopezibanez@gmail.com>:
> 2008/8/29 Joseph S. Myers <joseph@codesourcery.com>:
>> On Fri, 29 Aug 2008, Manuel López-Ibáñez wrote:
>>
>>> CPP and the FE were using different semantics. invoke.texi said that
>>> Wlong-long was the default. This was not correct. It was the default
>>> for CPP but -Wno-long-long was the default for the FE. Now there is
>>> only one semantic: the one from the FE.
>>>
>>> However, we were inhibiting warning even if the user requested it
>>> through Wlong-long. Now explicit Wlong-long (or Wno-long-long)
>>> overrides everything else, except in system headers.
>>
>> If you allow -Wlong-long to have an effect in C99 mode, -std=c99
>> -pedantic-errors -Wlong-long should give the diagnostics as warnings not
>> errors. Does it?
>
> No but I can make it do that just using pedwarn_c90 instead of pedwarn
> and add a testcase. I'll do the same for c++98. I''ll need to add an
> equivalent of pedwarn_c90 to C++ and CPP. In C++ is probably easy.
>
> Is there a way to tell in CPP if we are being called from the C++ FE?
> and which standard? I cannot find anything in the sources apart from
> CPP_OPTION (pfile, c99).
>
> Cheers,
>
> Manuel.
>
Index: gcc/doc/invoke.texi
===================================================================
--- gcc/doc/invoke.texi (revision 141265)
+++ gcc/doc/invoke.texi (working copy)
@@ -4059,14 +4059,13 @@ Warn if a precompiled header (@pxref{Pre
the search path but can't be used.
@item -Wlong-long
@opindex Wlong-long
@opindex Wno-long-long
-Warn if @samp{long long} type is used. This is default. To inhibit
-the warning messages, use @option{-Wno-long-long}. Flags
-@option{-Wlong-long} and @option{-Wno-long-long} are taken into account
-only when @option{-pedantic} flag is used.
+Warn if @samp{long long} type is used. This is enabled by either
+@option{-pedantic} or @option{-Wtraditional} in ISO C90 and C++98
+modes. To inhibit the warning messages, use @option{-Wno-long-long}.
@item -Wvariadic-macros
@opindex Wvariadic-macros
@opindex Wno-variadic-macros
Warn if variadic macros are used in pedantic ISO C90 mode, or the GNU
Index: gcc/c-lex.c
===================================================================
--- gcc/c-lex.c (revision 141265)
+++ gcc/c-lex.c (working copy)
@@ -580,17 +580,22 @@ interpret_integer (const cpp_token *toke
/* cpplib has already issued a warning for overflow. */
type = ((flags & CPP_N_UNSIGNED)
? widest_unsigned_literal_type_node
: widest_integer_literal_type_node);
else
- type = integer_types[itk];
-
- if (itk > itk_unsigned_long
- && (flags & CPP_N_WIDTH) != CPP_N_LARGE
- && !in_system_header && !flag_isoc99)
- pedwarn (input_location, 0, "integer constant is too large for %qs type",
- (flags & CPP_N_UNSIGNED) ? "unsigned long" : "long");
+ {
+ type = integer_types[itk];
+ if (itk > itk_unsigned_long
+ && (flags & CPP_N_WIDTH) != CPP_N_LARGE)
+ emit_diagnostic
+ ((c_dialect_cxx () ? cxx_dialect == cxx98 : !flag_isoc99)
+ ? DK_PEDWARN : DK_WARNING,
+ input_location, OPT_Wlong_long,
+ (flags & CPP_N_UNSIGNED)
+ ? "integer constant is too large for %<unsigned long%> type"
+ : "integer constant is too large for %<long%> type");
+ }
value = build_int_cst_wide (type, integer.low, integer.high);
/* Convert imaginary to a complex type. */
if (flags & CPP_N_IMAGINARY)
Index: gcc/testsuite/gcc.dg/wtr-int-type-1.c
===================================================================
--- gcc/testsuite/gcc.dg/wtr-int-type-1.c (revision 141265)
+++ gcc/testsuite/gcc.dg/wtr-int-type-1.c (working copy)
@@ -23,13 +23,21 @@ testfunc ()
we can pretend it worked the way it does in C99.] */
i = 9223372036854775807;
/* But this one should, since it doesn't fit in long (long), but
does fit in unsigned long (long). */
- i = 18446744073709551615; /* { dg-warning "decimal constant|unsigned" "decimal constant" } */
-
+ i = 18446744073709551615; /* { dg-warning "integer constant is so large that it is unsigned" "decimal constant" } */
+ /* { dg-warning "this decimal constant would be unsigned in ISO C90" "decimal constant" { target *-*-* } 28 } */
+
# 29 "sys-header.h" 3
+}
+
+void
+testfunc2( )
+{
+ long long i;
+
/* We are in system headers now, no -Wtraditional warnings should issue. */
i = 0x80000000;
i = 0xFFFFFFFF;
i = 037777777777;
@@ -39,5 +47,6 @@ testfunc ()
i = 01777777777777777777777;
i = 9223372036854775807;
i = 18446744073709551615;
}
+
Index: gcc/testsuite/gcc.dg/c99-longlong-2.c
===================================================================
--- gcc/testsuite/gcc.dg/c99-longlong-2.c (revision 0)
+++ gcc/testsuite/gcc.dg/c99-longlong-2.c (revision 0)
@@ -0,0 +1,6 @@
+/* Test for long long: if explicit Wlong-long, in C99 only warn, not
+ pedwarn. */
+/* { dg-do compile } */
+/* { dg-options "-std=iso9899:1999 -pedantic-errors -Wlong-long" } */
+
+long long foo; /* { dg-warning "long long" } */
Index: gcc/testsuite/g++.dg/warn/pr13358-2.C
===================================================================
--- gcc/testsuite/g++.dg/warn/pr13358-2.C (revision 0)
+++ gcc/testsuite/g++.dg/warn/pr13358-2.C (revision 0)
@@ -0,0 +1,24 @@
+// PR c++/13358: g++ should accept a long long constant sans LL suffix
+// if -Wno-long-long is in use.
+// { dg-do compile }
+// { dg-require-effective-target int32plus }
+// { dg-options "-std=c++98 -pedantic-errors" }
+
+
+void use_longlong ()
+{
+ unsigned long long x1, x2, x3; // { dg-error "ISO C\\+\\+ 1998 does not support 'long long'" }
+ // make sure we error with hex, decimal and octal
+ x1 = 0x1b27da572ef3cd86; // { dg-error "integer constant is too large for 'long' type" "long long" { target ilp32 } }
+ x2 = 1956772631100509574; // { dg-error "integer constant is too large for 'long' type" "long long" { target ilp32 } }
+ x3 = 0154476645345674746606; // { dg-error "integer constant is too large for 'long' type" "long long" { target ilp32 } }
+}
+
+void use_longlong2 ()
+{
+ unsigned long long x1, x2, x3; // { dg-error "ISO C\\+\\+ 1998 does not support 'long long'" }
+ // make sure we error with hex, decimal and octal
+ x1 = 0x1b27da572ef3cd86LL; // { dg-error "long long" }
+ x2 = 1956772631100509574LL; // { dg-error "long long" }
+ x3 = 0154476645345674746606LL; // { dg-error "long long" }
+}
Index: gcc/testsuite/g++.dg/warn/pr13358-3.C
===================================================================
--- gcc/testsuite/g++.dg/warn/pr13358-3.C (revision 0)
+++ gcc/testsuite/g++.dg/warn/pr13358-3.C (revision 0)
@@ -0,0 +1,24 @@
+// PR c++/13358: g++ should accept a long long constant sans LL suffix
+// if -Wno-long-long is in use
+// { dg-do compile }
+// { dg-require-effective-target int32plus }
+// { dg-options "-std=c++0x -pedantic-errors" }
+
+
+void use_longlong ()
+{
+ unsigned long long x1, x2, x3;
+ // make sure it's ok with hex, decimal and octal
+ x1 = 0x1b27da572ef3cd86;
+ x2 = 1956772631100509574;
+ x3 = 0154476645345674746606;
+}
+
+void use_longlong2 ()
+{
+ unsigned long long x1, x2, x3;
+ // make sure it's ok with hex, decimal and octal
+ x1 = 0x1b27da572ef3cd86LL;
+ x2 = 1956772631100509574LL;
+ x3 = 0154476645345674746606LL;
+}
Index: gcc/testsuite/g++.dg/warn/pr13358-4.C
===================================================================
--- gcc/testsuite/g++.dg/warn/pr13358-4.C (revision 0)
+++ gcc/testsuite/g++.dg/warn/pr13358-4.C (revision 0)
@@ -0,0 +1,24 @@
+// PR c++/13358: g++ should accept a long long constant sans LL suffix
+// if -Wno-long-long is in use.
+// { dg-do compile }
+// { dg-require-effective-target int32plus }
+// { dg-options "-std=c++0x -pedantic-errors -Wlong-long" }
+
+
+void use_longlong ()
+{
+ unsigned long long x1, x2, x3; // { dg-warning "ISO C\\+\\+ 1998 does not support 'long long'" }
+ // make sure we warn with hex, decimal and octal
+ x1 = 0x1b27da572ef3cd86; // { dg-warning "integer constant is too large for 'long' type" "long long" { target ilp32 } }
+ x2 = 1956772631100509574; // { dg-warning "integer constant is too large for 'long' type" "long long" { target ilp32 } }
+ x3 = 0154476645345674746606; // { dg-warning "integer constant is too large for 'long' type" "long long" { target ilp32 } }
+}
+
+void use_longlong2 ()
+{
+ unsigned long long x1, x2, x3; // { dg-warning "ISO C\\+\\+ 1998 does not support 'long long'" }
+ // make sure we warn with hex, decimal and octal
+ x1 = 0x1b27da572ef3cd86LL; // { dg-warning "long long" }
+ x2 = 1956772631100509574LL; // { dg-warning "long long" }
+ x3 = 0154476645345674746606LL; // { dg-warning "long long" }
+}
Index: gcc/testsuite/g++.dg/warn/pr13358.C
===================================================================
--- gcc/testsuite/g++.dg/warn/pr13358.C (revision 0)
+++ gcc/testsuite/g++.dg/warn/pr13358.C (revision 0)
@@ -0,0 +1,24 @@
+// PR c++/13358: g++ should accept a long long constant sans LL suffix
+// if -Wno-long-long is in use.
+// { dg-do compile }
+// { dg-require-effective-target int32plus }
+// { dg-options "-std=c++98 -Wno-long-long -pedantic-errors" }
+
+
+void use_longlong ()
+{
+ unsigned long long x1, x2, x3;
+ // make sure it's ok with hex, decimal and octal
+ x1 = 0x1b27da572ef3cd86;
+ x2 = 1956772631100509574;
+ x3 = 0154476645345674746606;
+}
+
+void use_longlong2 ()
+{
+ unsigned long long x1, x2, x3;
+ // make sure it's ok with hex, decimal and octal
+ x1 = 0x1b27da572ef3cd86LL;
+ x2 = 1956772631100509574LL;
+ x3 = 0154476645345674746606LL;
+}
Index: gcc/cp/error.c
===================================================================
--- gcc/cp/error.c (revision 141265)
+++ gcc/cp/error.c (working copy)
@@ -2704,5 +2704,24 @@ maybe_warn_cpp0x (const char* str)
void
maybe_warn_variadic_templates (void)
{
maybe_warn_cpp0x ("variadic templates");
}
+
+
+/* Issue an ISO C++98 pedantic warning MSGID. This function is supposed to
+ be used for matters that are allowed in ISO C++0x but not supported in
+ ISO C++98, thus we explicitly don't pedwarn when ISO c++0x is specified. */
+
+bool
+pedwarn_cxx98 (location_t location, int opt, const char *gmsgid, ...)
+{
+ diagnostic_info diagnostic;
+ va_list ap;
+
+ va_start (ap, gmsgid);
+ diagnostic_set_info (&diagnostic, gmsgid, &ap, location,
+ (cxx_dialect == cxx98) ? DK_PEDWARN : DK_WARNING);
+ diagnostic.option_index = opt;
+ va_end (ap);
+ return report_diagnostic (&diagnostic);
+}
Index: gcc/cp/cp-tree.h
===================================================================
--- gcc/cp/cp-tree.h (revision 141265)
+++ gcc/cp/cp-tree.h (working copy)
@@ -4432,10 +4432,11 @@ extern const char *lang_decl_name (tree
extern const char *language_to_string (enum languages);
extern const char *class_key_or_enum_as_string (tree);
extern void print_instantiation_context (void);
extern void maybe_warn_variadic_templates (void);
extern void maybe_warn_cpp0x (const char *);
+extern bool pedwarn_cxx98 (location_t, int, const char *, ...) ATTRIBUTE_GCC_CXXDIAG(3,4);
/* in except.c */
extern void init_exception_processing (void);
extern tree expand_start_catch_block (tree);
extern void expand_end_catch_block (void);
Index: gcc/cp/parser.c
===================================================================
--- gcc/cp/parser.c (revision 141265)
+++ gcc/cp/parser.c (working copy)
@@ -2162,14 +2162,13 @@ cp_parser_check_decl_spec (cp_decl_speci
/* The "long" specifier is a special case because of "long long". */
if (ds == ds_long)
{
if (count > 2)
error ("%H%<long long long%> is too long for GCC", &location);
- else if (pedantic && !in_system_header && warn_long_long
- && cxx_dialect == cxx98)
- pedwarn (location, OPT_Wlong_long,
- "ISO C++ 1998 does not support %<long long%>");
+ else
+ pedwarn_cxx98 (location, OPT_Wlong_long,
+ "ISO C++ 1998 does not support %<long long%>");
}
else if (count > 1)
{
static const char *const decl_spec_names[] = {
"signed",
Index: gcc/c-decl.c
===================================================================
--- gcc/c-decl.c (revision 141265)
+++ gcc/c-decl.c (working copy)
@@ -7214,12 +7214,12 @@ declspecs_add_type (struct c_declspecs *
{
error ("both %<long long%> and %<double%> in "
"declaration specifiers");
break;
}
- if (pedantic && !flag_isoc99 && !in_system_header)
- pedwarn (input_location, OPT_Wlong_long, "ISO C90 does not support %<long long%>");
+ pedwarn_c90 (input_location, OPT_Wlong_long,
+ "ISO C90 does not support %<long long%>");
specs->long_long_p = 1;
break;
}
if (specs->short_p)
error ("both %<long%> and %<short%> in "
Index: gcc/c.opt
===================================================================
--- gcc/c.opt (revision 141265)
+++ gcc/c.opt (working copy)
@@ -279,11 +279,11 @@ Warn about invalid uses of the \"offseto
Winvalid-pch
C ObjC C++ ObjC++ Warning
Warn about PCH files that are found but not used
Wlong-long
-C ObjC C++ ObjC++ Var(warn_long_long) Init(1) Warning
+C ObjC C++ ObjC++ Var(warn_long_long) Init(-1) Warning
Do not warn about using \"long long\" when -pedantic
Wmain
C ObjC C++ ObjC++ Var(warn_main) Init(-1) Warning
Warn about suspicious declarations of \"main\"
Index: gcc/c-opts.c
===================================================================
--- gcc/c-opts.c (revision 141265)
+++ gcc/c-opts.c (working copy)
@@ -1394,18 +1394,19 @@ sanitize_cpp_opts (void)
error ("-MG may only be used with -M or -MM");
cpp_opts->unsigned_char = !flag_signed_char;
cpp_opts->stdc_0_in_system_headers = STDC_0_IN_SYSTEM_HEADERS;
- /* We want -Wno-long-long to override -pedantic -std=non-c99
- and/or -Wtraditional, whatever the ordering. */
- cpp_opts->warn_long_long
- = warn_long_long && ((pedantic
- && (c_dialect_cxx ()
- ? cxx_dialect == cxx98
- : !flag_isoc99))
- || warn_traditional);
+ /* Wlong-long is disabled by default. It is enabled by:
+ [-pedantic | -Wtraditional] -std=[gnu|c]++98 ; or
+ [-pedantic | -Wtraditional] -std=non-c99 .
+
+ Either -Wlong-long or -Wno-long-long override any other settings. */
+ if (warn_long_long == -1)
+ warn_long_long = ((pedantic || warn_traditional)
+ && (c_dialect_cxx () ? cxx_dialect == cxx98 : !flag_isoc99));
+ cpp_opts->warn_long_long = warn_long_long;
/* Similarly with -Wno-variadic-macros. No check for c99 here, since
this also turns off warnings about GCCs extension. */
cpp_opts->warn_variadic_macros
= warn_variadic_macros && (pedantic || warn_traditional);
Index: gcc/c-parser.c
===================================================================
--- gcc/c-parser.c (revision 141265)
+++ gcc/c-parser.c (working copy)
@@ -815,18 +815,16 @@ disable_extension_diagnostics (void)
{
int ret = (pedantic
| (warn_pointer_arith << 1)
| (warn_traditional << 2)
| (flag_iso << 3)
- | (warn_long_long << 4)
- | (cpp_opts->warn_long_long << 5));
+ | (warn_long_long << 4));
cpp_opts->pedantic = pedantic = 0;
warn_pointer_arith = 0;
cpp_opts->warn_traditional = warn_traditional = 0;
flag_iso = 0;
- warn_long_long = 0;
- cpp_opts->warn_long_long = 0;
+ cpp_opts->warn_long_long = warn_long_long = 0;
return ret;
}
/* Restore the warning flags which are controlled by __extension__.
FLAGS is the return value from disable_extension_diagnostics. */
@@ -836,12 +834,11 @@ restore_extension_diagnostics (int flags
{
cpp_opts->pedantic = pedantic = flags & 1;
warn_pointer_arith = (flags >> 1) & 1;
cpp_opts->warn_traditional = warn_traditional = (flags >> 2) & 1;
flag_iso = (flags >> 3) & 1;
- warn_long_long = (flags >> 4) & 1;
- cpp_opts->warn_long_long = (flags >> 5) & 1;
+ cpp_opts->warn_long_long = warn_long_long = (flags >> 4) & 1;
}
/* Possibly kinds of declarator to parse. */
typedef enum c_dtr_syn {
/* A normal declarator with an identifier. */
Index: libcpp/init.c
===================================================================
--- libcpp/init.c (revision 141265)
+++ libcpp/init.c (working copy)
@@ -157,11 +157,11 @@ cpp_create_reader (enum c_lang lang, has
CPP_OPTION (pfile, tabstop) = 8;
CPP_OPTION (pfile, operator_names) = 1;
CPP_OPTION (pfile, warn_trigraphs) = 2;
CPP_OPTION (pfile, warn_endif_labels) = 1;
CPP_OPTION (pfile, warn_deprecated) = 1;
- CPP_OPTION (pfile, warn_long_long) = !CPP_OPTION (pfile, c99);
+ CPP_OPTION (pfile, warn_long_long) = 0;
CPP_OPTION (pfile, dollars_in_ident) = 1;
CPP_OPTION (pfile, warn_dollars) = 1;
CPP_OPTION (pfile, warn_variadic_macros) = 1;
CPP_OPTION (pfile, warn_builtin_macro_redefined) = 1;
CPP_OPTION (pfile, warn_normalize) = normalized_C;
Index: libcpp/expr.c
===================================================================
--- libcpp/expr.c (revision 141265)
+++ libcpp/expr.c (working copy)
@@ -393,14 +393,16 @@ cpp_classify_number (cpp_reader *pfile,
"traditional C rejects the \"%.*s\" suffix",
(int) (limit - str), str);
}
if ((result & CPP_N_WIDTH) == CPP_N_LARGE
- && ! CPP_OPTION (pfile, c99)
&& CPP_OPTION (pfile, warn_long_long))
- cpp_error (pfile, CPP_DL_PEDWARN,
- "use of C99 long long integer constant");
+ cpp_error (pfile,
+ CPP_OPTION (pfile, c99) ? CPP_DL_WARNING : CPP_DL_PEDWARN,
+ CPP_OPTION (pfile, cplusplus)
+ ? "use of C++0x long long integer constant"
+ : "use of C99 long long integer constant");
result |= CPP_N_INTEGER;
}
syntax_ok: