* [C PATCH] Implement -Wc90-c99-compat (PR c/51849)
@ 2014-07-31 7:47 Marek Polacek
2014-08-07 6:43 ` Marek Polacek
2014-08-07 17:10 ` Joseph S. Myers
0 siblings, 2 replies; 4+ messages in thread
From: Marek Polacek @ 2014-07-31 7:47 UTC (permalink / raw)
To: GCC Patches, Joseph S. Myers
One of the prerequisites to moving the default from gnu89 to gnu11
is that we need both -Wc90-c99-compat and -Wc99-c11-compat options.
This patch implements the former. Its purpose is similar to
-Wtraditional - that people who build code in C99/C11 mode can easily
check whether the code uses something outside C90. Since
__extension__ disables this warning, features that are properly
conditioned are fine and not warned about.
As I said privately, it turned out to be convenient to reuse
pedwarn_c90 - the patch now mostly removes code. Earlier I defined
a special function, but that rendered pedwarn_c90 unused. Another
benefit I see is that if we ever add pedwarn_c90, we have
-Wc90-c99-compat handled for free. And obviously, defining yet
another warn/pedwarn function would be confusing.
A few issues: currently we don't warn (in -std=c90 -pedantic mode)
about the usage of __func__ and _Pragma (possible others - va_copy?).
I'm hoping this is not that important though. For restrict/inline,
in GNU90 mode we just don't compile the code at all (unless we use
__restrict and similar), and -Wc90-c99-compat does not warn about those.
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2014-07-31 Marek Polacek <polacek@redhat.com>
PR c/51849
gcc/
* gcc/doc/invoke.texi: Document -Wc90-c99-compat.
gcc/c-family/
* c-opts.c (sanitize_cpp_opts): Pass warn_c90_c99_compat to libcpp.
* c.opt (Wc90-c99-compat): Add option.
gcc/c/
* c-decl.c (build_array_declarator): Remove check for !flag_isoc99.
Call pedwarn_c90 instead of pedwarn.
(check_bitfield_type_and_width): Likewise.
(declspecs_add_qual): Likewise.
(declspecs_add_type): Likewise.
(warn_variable_length_array): Unify function for -pedantic and -Wvla.
Adjust to only call pedwarn_c90.
(grokdeclarator): Remove pedantic && !flag_isoc99 check. Call
pedwarn_c90 instead of pedwarn.
* c-errors.c (pedwarn_c90): Handle -Wc90-c99-compat.
* c-parser.c (disable_extension_diagnostics): Handle
warn_c90_c99_compat.
(restore_extension_diagnostics): Likewise.
(c_parser_enum_specifier): Remove check for !flag_isoc99. Call
pedwarn_c90 instead of pedwarn.
(c_parser_initelt): Likewise.
(c_parser_postfix_expression): Likewise.
(c_parser_postfix_expression_after_paren_type): Likewise.
(c_parser_compound_statement_nostart): Remove check for !flag_isoc99.
* c-tree.h: Fix formatting.
* c-typeck.c (build_array_ref): Remove check for !flag_isoc99. Call
pedwarn_c90 instead of pedwarn.
gcc/testsuite/
* gcc.dg/Wc90-c99-compat-1.c: New test.
* gcc.dg/Wc90-c99-compat-2.c: New test.
* gcc.dg/Wc90-c99-compat-3.c: New test.
* gcc.dg/Wc90-c99-compat-4.c: New test.
* gcc.dg/Wc90-c99-compat-5.c: New test.
* gcc.dg/Wc90-c99-compat-6.c: New test.
* gcc.dg/wvla-1.c: Adjust dg-warning.
* gcc.dg/wvla-2.c: Adjust dg-warning.
* gcc.dg/wvla-4.c: Adjust dg-warning.
* gcc.dg/wvla-6.c: Adjust dg-warning.
libcpp/
* lex.c (_cpp_lex_direct): Warn when -Wc90-c99-compat is in effect.
* charset.c (_cpp_valid_ucn): Likewise.
* include/cpplib.h (cpp_options): Add cpp_warn_c90_c99_compat.
* macro.c (replace_args): Warn when -Wc90-c99-compat is in effect.
(parse_params): Likewise.
diff --git gcc/gcc/c-family/c-opts.c gcc/gcc/c-family/c-opts.c
index 3f8e6e6..43a8b9d 100644
--- gcc/gcc/c-family/c-opts.c
+++ gcc/gcc/c-family/c-opts.c
@@ -1295,6 +1295,7 @@ sanitize_cpp_opts (void)
cpp_opts->unsigned_char = !flag_signed_char;
cpp_opts->stdc_0_in_system_headers = STDC_0_IN_SYSTEM_HEADERS;
cpp_opts->warn_date_time = cpp_warn_date_time;
+ cpp_opts->cpp_warn_c90_c99_compat = warn_c90_c99_compat;
/* Wlong-long is disabled by default. It is enabled by:
[-Wpedantic | -Wtraditional] -std=[gnu|c]++98 ; or
diff --git gcc/gcc/c-family/c.opt gcc/gcc/c-family/c.opt
index f427da1..b62bac1 100644
--- gcc/gcc/c-family/c.opt
+++ gcc/gcc/c-family/c.opt
@@ -291,6 +291,10 @@ Wbuiltin-macro-redefined
C ObjC C++ ObjC++ Warning
Warn when a built-in preprocessor macro is undefined or redefined
+Wc90-c99-compat
+C ObjC Var(warn_c90_c99_compat) Warning
+Warn about features not present in ISO C90, but present in ISO C99
+
Wc++-compat
C ObjC Var(warn_cxx_compat) Warning
Warn about C constructs that are not in the common subset of C and C++
diff --git gcc/gcc/c/c-decl.c gcc/gcc/c/c-decl.c
index 2a4b439..b1c5862 100644
--- gcc/gcc/c/c-decl.c
+++ gcc/gcc/c/c-decl.c
@@ -3968,16 +3968,13 @@ build_array_declarator (location_t loc,
}
declarator->u.array.static_p = static_p;
declarator->u.array.vla_unspec_p = vla_unspec_p;
- if (!flag_isoc99)
- {
- if (static_p || quals != NULL)
- pedwarn (loc, OPT_Wpedantic,
+ if (static_p || quals != NULL)
+ pedwarn_c90 (loc, OPT_Wpedantic,
"ISO C90 does not support %<static%> or type "
"qualifiers in parameter array declarators");
- if (vla_unspec_p)
- pedwarn (loc, OPT_Wpedantic,
+ if (vla_unspec_p)
+ pedwarn_c90 (loc, OPT_Wpedantic,
"ISO C90 does not support %<[*]%> array declarators");
- }
if (vla_unspec_p)
{
if (!current_scope->parm_flag)
@@ -4891,10 +4888,9 @@ check_bitfield_type_and_width (tree *type, tree *width, tree orig_name)
if (!in_system_header_at (input_location)
&& type_mv != integer_type_node
&& type_mv != unsigned_type_node
- && type_mv != boolean_type_node
- && !flag_isoc99)
- pedwarn (input_location, OPT_Wpedantic,
- "type of bit-field %qs is a GCC extension", name);
+ && type_mv != boolean_type_node)
+ pedwarn_c90 (input_location, OPT_Wpedantic,
+ "type of bit-field %qs is a GCC extension", name);
max_width = TYPE_PRECISION (*type);
@@ -4925,52 +4921,27 @@ static void
warn_variable_length_array (tree name, tree size)
{
int const_size = TREE_CONSTANT (size);
+ enum opt_code opt = (warn_vla == -1 && !warn_c90_c99_compat)
+ ? OPT_Wpedantic : OPT_Wvla;
- if (!flag_isoc99 && pedantic && warn_vla != 0)
+ if (const_size)
{
- if (const_size)
- {
- if (name)
- pedwarn (input_location, OPT_Wvla,
+ if (name)
+ pedwarn_c90 (input_location, opt,
"ISO C90 forbids array %qE whose size "
- "can%'t be evaluated",
- name);
- else
- pedwarn (input_location, OPT_Wvla, "ISO C90 forbids array whose size "
- "can%'t be evaluated");
- }
+ "can%'t be evaluated", name);
else
- {
- if (name)
- pedwarn (input_location, OPT_Wvla,
- "ISO C90 forbids variable length array %qE",
- name);
- else
- pedwarn (input_location, OPT_Wvla, "ISO C90 forbids variable length array");
- }
+ pedwarn_c90 (input_location, opt, "ISO C90 forbids array "
+ "whose size can%'t be evaluated");
}
- else if (warn_vla > 0)
+ else
{
- if (const_size)
- {
- if (name)
- warning (OPT_Wvla,
- "the size of array %qE can"
- "%'t be evaluated", name);
- else
- warning (OPT_Wvla,
- "the size of array can %'t be evaluated");
- }
+ if (name)
+ pedwarn_c90 (input_location, opt,
+ "ISO C90 forbids variable length array %qE", name);
else
- {
- if (name)
- warning (OPT_Wvla,
- "variable length array %qE is used",
- name);
- else
- warning (OPT_Wvla,
- "variable length array is used");
- }
+ pedwarn_c90 (input_location, opt, "ISO C90 forbids variable "
+ "length array");
}
}
@@ -5186,18 +5157,14 @@ grokdeclarator (const struct c_declarator *declarator,
as2 = TYPE_ADDR_SPACE (element_type);
address_space = ADDR_SPACE_GENERIC_P (as1)? as2 : as1;
- if (pedantic && !flag_isoc99)
- {
- if (constp > 1)
- pedwarn (loc, OPT_Wpedantic, "duplicate %<const%>");
- if (restrictp > 1)
- pedwarn (loc, OPT_Wpedantic, "duplicate %<restrict%>");
- if (volatilep > 1)
- pedwarn (loc, OPT_Wpedantic, "duplicate %<volatile%>");
- if (atomicp > 1)
- pedwarn (loc, OPT_Wpedantic, "duplicate %<_Atomic%>");
-
- }
+ if (constp > 1)
+ pedwarn_c90 (loc, OPT_Wpedantic, "duplicate %<const%>");
+ if (restrictp > 1)
+ pedwarn_c90 (loc, OPT_Wpedantic, "duplicate %<restrict%>");
+ if (volatilep > 1)
+ pedwarn_c90 (loc, OPT_Wpedantic, "duplicate %<volatile%>");
+ if (atomicp > 1)
+ pedwarn_c90 (loc, OPT_Wpedantic, "duplicate %<_Atomic%>");
if (!ADDR_SPACE_GENERIC_P (as1) && !ADDR_SPACE_GENERIC_P (as2) && as1 != as2)
error_at (loc, "conflicting named address spaces (%s vs %s)",
@@ -5602,10 +5569,9 @@ grokdeclarator (const struct c_declarator *declarator,
flexible_array_member = (t->kind == cdk_id);
}
if (flexible_array_member
- && pedantic && !flag_isoc99
&& !in_system_header_at (input_location))
- pedwarn (loc, OPT_Wpedantic,
- "ISO C90 does not support flexible array members");
+ pedwarn_c90 (loc, OPT_Wpedantic, "ISO C90 does not "
+ "support flexible array members");
/* ISO C99 Flexible array members are effectively
identical to GCC's zero-length array extension. */
@@ -9140,8 +9106,8 @@ declspecs_add_qual (source_location loc,
default:
gcc_unreachable ();
}
- if (dupe && !flag_isoc99)
- pedwarn (loc, OPT_Wpedantic, "duplicate %qE", qual);
+ if (dupe)
+ pedwarn_c90 (loc, OPT_Wpedantic, "duplicate %qE", qual);
return specs;
}
@@ -9385,9 +9351,9 @@ declspecs_add_type (location_t loc, struct c_declspecs *specs,
break;
case RID_COMPLEX:
dupe = specs->complex_p;
- if (!flag_isoc99 && !in_system_header_at (loc))
- pedwarn (loc, OPT_Wpedantic,
- "ISO C90 does not support complex types");
+ if (!in_system_header_at (loc))
+ pedwarn_c90 (loc, OPT_Wpedantic,
+ "ISO C90 does not support complex types");
if (specs->typespec_word == cts_auto_type)
error_at (loc,
("both %<complex%> and %<__auto_type%> in "
@@ -9603,9 +9569,9 @@ declspecs_add_type (location_t loc, struct c_declspecs *specs,
}
return specs;
case RID_BOOL:
- if (!flag_isoc99 && !in_system_header_at (loc))
- pedwarn (loc, OPT_Wpedantic,
- "ISO C90 does not support boolean types");
+ if (!in_system_header_at (loc))
+ pedwarn_c90 (loc, OPT_Wpedantic,
+ "ISO C90 does not support boolean types");
if (specs->long_p)
error_at (loc,
("both %<long%> and %<_Bool%> in "
diff --git gcc/gcc/c/c-errors.c gcc/gcc/c/c-errors.c
index 92136e7..1cc1dbf 100644
--- gcc/gcc/c/c-errors.c
+++ gcc/gcc/c/c-errors.c
@@ -44,21 +44,38 @@ pedwarn_c99 (location_t location, int opt, const char *gmsgid, ...)
va_end (ap);
}
-/* Issue an ISO C90 pedantic warning MSGID. This function is supposed to
- be used for matters that are allowed in ISO C99 but not supported in
- ISO C90, thus we explicitly don't pedwarn when C99 is specified.
- (There is no flag_c90.) */
+/* Issue an ISO C90 pedantic warning MSGID if -pedantic outside C99 mode,
+ otherwise issue warning MSGID if -Wc90-c99-compat is specified, or if
+ specific option such as -Wlong-long is specified.
+ This function is supposed to be used for matters that are allowed in
+ ISO C99 but not supported in ISO C90, thus we explicitly don't pedwarn
+ when C99 is specified. (There is no flag_c90.) */
void
pedwarn_c90 (location_t location, int opt, const char *gmsgid, ...)
{
diagnostic_info diagnostic;
va_list ap;
+ bool warned = false;
va_start (ap, gmsgid);
- diagnostic_set_info (&diagnostic, gmsgid, &ap, location,
- flag_isoc99 ? DK_WARNING : DK_PEDWARN);
- diagnostic.option_index = opt;
- report_diagnostic (&diagnostic);
+ if (pedantic && !flag_isoc99)
+ {
+ diagnostic_set_info (&diagnostic, gmsgid, &ap, location, DK_PEDWARN);
+ diagnostic.option_index = opt;
+ warned = report_diagnostic (&diagnostic);
+ }
+ else if (opt != OPT_Wpedantic)
+ {
+ diagnostic_set_info (&diagnostic, gmsgid, &ap, location, DK_WARNING);
+ diagnostic.option_index = opt;
+ warned = report_diagnostic (&diagnostic);
+ }
+ if (warn_c90_c99_compat && !warned)
+ {
+ diagnostic_set_info (&diagnostic, gmsgid, &ap, location, DK_WARNING);
+ diagnostic.option_index = OPT_Wc90_c99_compat;
+ report_diagnostic (&diagnostic);
+ }
va_end (ap);
}
diff --git gcc/gcc/c/c-parser.c gcc/gcc/c/c-parser.c
index e32bf04..ca8577c 100644
--- gcc/gcc/c/c-parser.c
+++ gcc/gcc/c/c-parser.c
@@ -1072,7 +1072,8 @@ disable_extension_diagnostics (void)
| (flag_iso << 3)
| (warn_long_long << 4)
| (warn_cxx_compat << 5)
- | (warn_overlength_strings << 6));
+ | (warn_overlength_strings << 6)
+ | (warn_c90_c99_compat << 7));
cpp_opts->cpp_pedantic = pedantic = 0;
warn_pointer_arith = 0;
cpp_opts->cpp_warn_traditional = warn_traditional = 0;
@@ -1080,6 +1081,7 @@ disable_extension_diagnostics (void)
cpp_opts->cpp_warn_long_long = warn_long_long = 0;
warn_cxx_compat = 0;
warn_overlength_strings = 0;
+ warn_c90_c99_compat = 0;
return ret;
}
@@ -1096,6 +1098,7 @@ restore_extension_diagnostics (int flags)
cpp_opts->cpp_warn_long_long = warn_long_long = (flags >> 4) & 1;
warn_cxx_compat = (flags >> 5) & 1;
warn_overlength_strings = (flags >> 6) & 1;
+ warn_c90_c99_compat = (flags >> 7) & 1;
}
/* Possibly kinds of declarator to parse. */
@@ -2545,8 +2548,9 @@ c_parser_enum_specifier (c_parser *parser)
}
if (c_parser_next_token_is (parser, CPP_CLOSE_BRACE))
{
- if (seen_comma && !flag_isoc99)
- pedwarn (comma_loc, OPT_Wpedantic, "comma at end of enumerator list");
+ if (seen_comma)
+ pedwarn_c90 (comma_loc, OPT_Wpedantic,
+ "comma at end of enumerator list");
c_parser_consume_token (parser);
break;
}
@@ -4348,9 +4352,9 @@ c_parser_initelt (c_parser *parser, struct obstack * braced_init_obstack)
{
if (c_parser_next_token_is (parser, CPP_EQ))
{
- if (!flag_isoc99)
- pedwarn (des_loc, OPT_Wpedantic,
- "ISO C90 forbids specifying subobject to initialize");
+ pedwarn_c90 (des_loc, OPT_Wpedantic,
+ "ISO C90 forbids specifying subobject "
+ "to initialize");
c_parser_consume_token (parser);
}
else
@@ -4566,10 +4570,9 @@ c_parser_compound_statement_nostart (c_parser *parser)
c_parser_declaration_or_fndef (parser, true, true, true, true,
true, NULL, vNULL);
if (last_stmt)
- pedwarn_c90 (loc,
- (pedantic && !flag_isoc99)
- ? OPT_Wpedantic
- : OPT_Wdeclaration_after_statement,
+ pedwarn_c90 (loc, (pedantic && !flag_isoc99)
+ ? OPT_Wpedantic
+ : OPT_Wdeclaration_after_statement,
"ISO C90 forbids mixed declarations and code");
last_stmt = false;
}
@@ -4598,8 +4601,8 @@ c_parser_compound_statement_nostart (c_parser *parser)
restore_extension_diagnostics (ext);
if (last_stmt)
pedwarn_c90 (loc, (pedantic && !flag_isoc99)
- ? OPT_Wpedantic
- : OPT_Wdeclaration_after_statement,
+ ? OPT_Wpedantic
+ : OPT_Wdeclaration_after_statement,
"ISO C90 forbids mixed declarations and code");
last_stmt = false;
}
@@ -7401,9 +7404,8 @@ c_parser_postfix_expression (c_parser *parser)
expr.value = error_mark_node;
break;
}
- if (!flag_isoc99)
- pedwarn (loc, OPT_Wpedantic,
- "ISO C90 does not support complex types");
+ pedwarn_c90 (loc, OPT_Wpedantic,
+ "ISO C90 does not support complex types");
expr.value = build2 (COMPLEX_EXPR,
build_complex_type
(TYPE_MAIN_VARIANT
@@ -7607,8 +7609,7 @@ c_parser_postfix_expression_after_paren_type (c_parser *parser,
type = error_mark_node;
}
- if (!flag_isoc99)
- pedwarn (start_loc, OPT_Wpedantic, "ISO C90 forbids compound literals");
+ pedwarn_c90 (start_loc, OPT_Wpedantic, "ISO C90 forbids compound literals");
non_const = ((init.value && TREE_CODE (init.value) == CONSTRUCTOR)
? CONSTRUCTOR_NON_CONST (init.value)
: init.original_code == C_MAYBE_CONST_EXPR);
diff --git gcc/gcc/c/c-tree.h gcc/gcc/c/c-tree.h
index f97d0d5..55e71dc 100644
--- gcc/gcc/c/c-tree.h
+++ gcc/gcc/c/c-tree.h
@@ -676,7 +676,9 @@ extern tree c_omp_reduction_lookup (tree, tree);
extern tree c_check_omp_declare_reduction_r (tree *, int *, void *);
/* In c-errors.c */
-extern void pedwarn_c90 (location_t, int opt, const char *, ...) ATTRIBUTE_GCC_DIAG(3,4);
-extern void pedwarn_c99 (location_t, int opt, const char *, ...) ATTRIBUTE_GCC_DIAG(3,4);
+extern void pedwarn_c90 (location_t, int opt, const char *, ...)
+ ATTRIBUTE_GCC_DIAG(3,4);
+extern void pedwarn_c99 (location_t, int opt, const char *, ...)
+ ATTRIBUTE_GCC_DIAG(3,4);
#endif /* ! GCC_C_TREE_H */
diff --git gcc/gcc/c/c-typeck.c gcc/gcc/c/c-typeck.c
index a938933..64c7a74 100644
--- gcc/gcc/c/c-typeck.c
+++ gcc/gcc/c/c-typeck.c
@@ -2511,7 +2511,7 @@ build_array_ref (location_t loc, tree array, tree index)
return error_mark_node;
}
- if (pedantic)
+ if (pedantic || warn_c90_c99_compat)
{
tree foo = array;
while (TREE_CODE (foo) == COMPONENT_REF)
@@ -2519,9 +2519,10 @@ build_array_ref (location_t loc, tree array, tree index)
if (TREE_CODE (foo) == VAR_DECL && C_DECL_REGISTER (foo))
pedwarn (loc, OPT_Wpedantic,
"ISO C forbids subscripting %<register%> array");
- else if (!flag_isoc99 && !lvalue_p (foo))
- pedwarn (loc, OPT_Wpedantic,
- "ISO C90 forbids subscripting non-lvalue array");
+ else if (!lvalue_p (foo))
+ pedwarn_c90 (loc, OPT_Wpedantic,
+ "ISO C90 forbids subscripting non-lvalue "
+ "array");
}
type = TREE_TYPE (TREE_TYPE (array));
diff --git gcc/gcc/doc/invoke.texi gcc/gcc/doc/invoke.texi
index 51757f0..f48552b 100644
--- gcc/gcc/doc/invoke.texi
+++ gcc/gcc/doc/invoke.texi
@@ -241,6 +241,7 @@ Objective-C and Objective-C++ Dialects}.
-w -Wextra -Wall -Waddress -Waggregate-return @gol
-Waggressive-loop-optimizations -Warray-bounds @gol
-Wno-attributes -Wno-builtin-macro-redefined @gol
+-Wc90-c99-compat @gol
-Wc++-compat -Wc++11-compat -Wcast-align -Wcast-qual @gol
-Wchar-subscripts -Wclobbered -Wcomment -Wconditionally-supported @gol
-Wconversion -Wcoverage-mismatch -Wdate-time -Wdelete-incomplete -Wno-cpp @gol
@@ -4497,6 +4498,15 @@ example, warn if an unsigned variable is compared against zero with
Warn whenever a function call is cast to a non-matching type.
For example, warn if @code{int malloc()} is cast to @code{anything *}.
+@item -Wc90-c99-compat @r{(C and Objective-C only)}
+@opindex Wc90-c99-compat
+@opindex Wno-c90-c99-compat
+Warn about features not present in ISO C90, but present in ISO C99.
+For instance, warn about use of variable length arrays, @code{long long}
+type, @code{bool} type, compound literals, designated initializers, and so
+on. This option is independent of the standards mode. Warnings are disabled
+in the expression that follows @code{__extension__}.
+
@item -Wc++-compat @r{(C and Objective-C only)}
Warn about ISO C constructs that are outside of the common subset of
ISO C and ISO C++, e.g.@: request for implicit conversion from
diff --git gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-1.c gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-1.c
index e69de29..15e71e8 100644
--- gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-1.c
+++ gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-1.c
@@ -0,0 +1,56 @@
+/* { dg-do compile } */
+/* { dg-options "-std=gnu90 -Wpedantic -Wc90-c99-compat" } */
+
+_Bool b; /* { dg-warning "ISO C90 does not support boolean types" } */
+_Complex double c = __builtin_complex (0.0, 0.0); /* { dg-warning "ISO C90 does not support complex types" } */
+long long l; /* { dg-warning "ISO C90 does not support .long long." } */
+struct A { int i; char a[]; }; /* { dg-warning "ISO C90 does not support flexible array members" } */
+struct { long int b: 2; } s; /* { dg-warning "type of bit-field .b. is a GCC extension" } */
+const const int i; /* { dg-warning "duplicate .const." } */
+volatile volatile v; /* { dg-warning "duplicate .volatile." } */
+
+struct S { int a[2]; };
+extern struct S foo (void);
+
+#define V(v, ...) (v, __VA_ARGS) /* { dg-warning "anonymous variadic macros were introduced in C99" } */
+
+enum { E, }; /* { dg-warning "comma at end of enumerator list" } */
+
+void fn1 (char [*]); /* { dg-warning "ISO C90 does not support .\\\[\\\*\\\]. array declarators" } */
+
+void
+fn2 (char x[static 4]) /* { dg-warning "ISO C90 does not support .static. or type qualifiers" } */
+{
+ int i = (int) { 1 }; /* { dg-warning "ISO C90 forbids compound literals" } */
+ struct A a = { .i = 3 }; /* { dg-warning "ISO C90 forbids specifying subobject to initialize" } */
+}
+
+void
+fn3 (int n)
+{
+ n = 3;
+ int i; /* { dg-warning "ISO C90 forbids mixed declarations and code" } */
+}
+
+void
+fn4 (int n)
+{
+ n = 3;
+ __extension__ int i; /* { dg-warning "ISO C90 forbids mixed declarations and code" } */
+}
+
+void
+fn5 (void)
+{
+ (foo ()).a[0]; /* { dg-warning "ISO C90 forbids subscripting non-lvalue array" } */
+}
+
+#define F(a) a
+
+void
+fn6 (void)
+{
+ F(); /* { dg-warning "invoking macro F argument" } */
+}
+
+void fn7 (int n, int a[n]); /* { dg-warning "ISO C90 forbids variable length array .a." } */
diff --git gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-2.c gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-2.c
index e69de29..d00f0df 100644
--- gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-2.c
+++ gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-2.c
@@ -0,0 +1,56 @@
+/* { dg-do compile } */
+/* { dg-options "-std=gnu99 -Wc90-c99-compat -pedantic-errors" } */
+
+_Bool b; /* { dg-warning "ISO C90 does not support boolean types" } */
+_Complex double c = __builtin_complex (0.0, 0.0); /* { dg-warning "ISO C90 does not support complex types" } */
+long long l; /* { dg-warning "ISO C90 does not support .long long." } */
+struct A { int i; char a[]; }; /* { dg-warning "ISO C90 does not support flexible array members" } */
+struct { long int b: 2; } s; /* { dg-warning "type of bit-field .b. is a GCC extension" } */
+const const int i; /* { dg-warning "duplicate .const." } */
+volatile volatile int v; /* { dg-warning "duplicate .volatile." } */
+
+struct S { int a[2]; };
+extern struct S foo (void);
+
+#define V(v, ...) (v, __VA_ARGS) /* { dg-warning "anonymous variadic macros were introduced in C99" } */
+
+enum { E, }; /* { dg-warning "comma at end of enumerator list" } */
+
+void fn1 (char [*]); /* { dg-warning "ISO C90 does not support .\\\[\\\*\\\]. array declarators" } */
+
+void
+fn2 (char x[static 4]) /* { dg-warning "ISO C90 does not support .static. or type qualifiers" } */
+{
+ int i = (int) { 1 }; /* { dg-warning "ISO C90 forbids compound literals" } */
+ struct A a = { .i = 3 }; /* { dg-warning "ISO C90 forbids specifying subobject to initialize" } */
+}
+
+void
+fn3 (int n)
+{
+ n = 3;
+ int i; /* { dg-warning "ISO C90 forbids mixed declarations and code" } */
+}
+
+void
+fn4 (int n)
+{
+ n = 3;
+ __extension__ int i; /* { dg-warning "ISO C90 forbids mixed declarations and code" } */
+}
+
+void
+fn5 (void)
+{
+ (foo ()).a[0]; /* { dg-warning "ISO C90 forbids subscripting non-lvalue array" } */
+}
+
+#define F(a) a
+
+void
+fn6 (void)
+{
+ F(); /* { dg-warning "invoking macro F argument" } */
+}
+
+void fn7 (int n, int a[n]); /* { dg-warning "ISO C90 forbids variable length array .a." } */
diff --git gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-3.c gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-3.c
index e69de29..78f012c 100644
--- gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-3.c
+++ gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-3.c
@@ -0,0 +1,56 @@
+/* { dg-do compile } */
+/* { dg-options "-std=gnu11 -Wc90-c99-compat -pedantic-errors" } */
+
+_Bool b; /* { dg-warning "ISO C90 does not support boolean types" } */
+_Complex double c = __builtin_complex (0.0, 0.0); /* { dg-warning "ISO C90 does not support complex types" } */
+long long l; /* { dg-warning "ISO C90 does not support .long long." } */
+struct A { int i; char a[]; }; /* { dg-warning "ISO C90 does not support flexible array members" } */
+struct { long int b: 2; } s; /* { dg-warning "type of bit-field .b. is a GCC extension" } */
+const const int i; /* { dg-warning "duplicate .const." } */
+volatile volatile int v; /* { dg-warning "duplicate .volatile." } */
+
+struct S { int a[2]; };
+extern struct S foo (void);
+
+#define V(v, ...) (v, __VA_ARGS) /* { dg-warning "anonymous variadic macros were introduced in C99" } */
+
+enum { E, }; /* { dg-warning "comma at end of enumerator list" } */
+
+void fn1 (char [*]); /* { dg-warning "ISO C90 does not support .\\\[\\\*\\\]. array declarators" } */
+
+void
+fn2 (char x[static 4]) /* { dg-warning "ISO C90 does not support .static. or type qualifiers" } */
+{
+ int i = (int) { 1 }; /* { dg-warning "ISO C90 forbids compound literals" } */
+ struct A a = { .i = 3 }; /* { dg-warning "ISO C90 forbids specifying subobject to initialize" } */
+}
+
+void
+fn3 (int n)
+{
+ n = 3;
+ int i; /* { dg-warning "ISO C90 forbids mixed declarations and code" } */
+}
+
+void
+fn4 (int n)
+{
+ n = 3;
+ __extension__ int i; /* { dg-warning "ISO C90 forbids mixed declarations and code" } */
+}
+
+void
+fn5 (void)
+{
+ (foo ()).a[0]; /* { dg-warning "ISO C90 forbids subscripting non-lvalue array" } */
+}
+
+#define F(a) a
+
+void
+fn6 (void)
+{
+ F(); /* { dg-warning "invoking macro F argument" } */
+}
+
+void fn7 (int n, int a[n]); /* { dg-warning "ISO C90 forbids variable length array .a." } */
diff --git gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-4.c gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-4.c
index e69de29..e8d2f03 100644
--- gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-4.c
+++ gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-4.c
@@ -0,0 +1,56 @@
+/* { dg-do compile } */
+/* { dg-options "-std=gnu90 -Wpedantic -Wno-c90-c99-compat" } */
+
+_Bool b; /* { dg-warning "ISO C90 does not support boolean types" } */
+_Complex double c = __builtin_complex (0.0, 0.0); /* { dg-warning "ISO C90 does not support complex types" } */
+long long l; /* { dg-warning "ISO C90 does not support .long long." } */
+struct A { int i; char a[]; }; /* { dg-warning "ISO C90 does not support flexible array members" } */
+struct { long int b: 2; } s; /* { dg-warning "type of bit-field .b. is a GCC extension" } */
+const const int i; /* { dg-warning "duplicate .const." } */
+volatile volatile int v; /* { dg-warning "duplicate .volatile." } */
+
+struct S { int a[2]; };
+extern struct S foo (void);
+
+#define V(v, ...) (v, __VA_ARGS) /* { dg-warning "anonymous variadic macros were introduced in C99" } */
+
+enum { E, }; /* { dg-warning "comma at end of enumerator list" } */
+
+void fn1 (char [*]); /* { dg-warning "ISO C90 does not support .\\\[\\\*\\\]. array declarators" } */
+
+void
+fn2 (char x[static 4]) /* { dg-warning "ISO C90 does not support .static. or type qualifiers" } */
+{
+ int i = (int) { 1 }; /* { dg-warning "ISO C90 forbids compound literals" } */
+ struct A a = { .i = 3 }; /* { dg-warning "ISO C90 forbids specifying subobject to initialize" } */
+}
+
+void
+fn3 (int n)
+{
+ n = 3;
+ int i; /* { dg-warning "ISO C90 forbids mixed declarations and code" } */
+}
+
+void
+fn4 (int n)
+{
+ n = 3;
+ __extension__ int i; /* { dg-warning "ISO C90 forbids mixed declarations and code" } */
+}
+
+void
+fn5 (void)
+{
+ (foo ()).a[0]; /* { dg-warning "ISO C90 forbids subscripting non-lvalue array" } */
+}
+
+#define F(a) a
+
+void
+fn6 (void)
+{
+ F(); /* { dg-warning "invoking macro F argument" } */
+}
+
+void fn7 (int n, int a[n]); /* { dg-warning "ISO C90 forbids variable length array .a." } */
diff --git gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-5.c gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-5.c
index e69de29..1344ae8 100644
--- gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-5.c
+++ gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-5.c
@@ -0,0 +1,56 @@
+/* { dg-do compile } */
+/* { dg-options "-std=gnu90 -pedantic-errors -Wno-c90-c99-compat" } */
+
+_Bool b; /* { dg-error "ISO C90 does not support boolean types" } */
+_Complex double c = __builtin_complex (0.0, 0.0); /* { dg-error "ISO C90 does not support complex types" } */
+long long l; /* { dg-error "ISO C90 does not support .long long." } */
+struct A { int i; char a[]; }; /* { dg-error "ISO C90 does not support flexible array members" } */
+struct { long int b: 2; } s; /* { dg-error "type of bit-field .b. is a GCC extension" } */
+const const int i; /* { dg-error "duplicate .const." } */
+volatile volatile int v; /* { dg-error "duplicate .volatile." } */
+
+struct S { int a[2]; };
+extern struct S foo (void);
+
+#define V(v, ...) (v, __VA_ARGS) /* { dg-error "anonymous variadic macros were introduced in C99" } */
+
+enum { E, }; /* { dg-error "comma at end of enumerator list" } */
+
+void fn1 (char [*]); /* { dg-error "ISO C90 does not support .\\\[\\\*\\\]. array declarators" } */
+
+void
+fn2 (char x[static 4]) /* { dg-error "ISO C90 does not support .static. or type qualifiers" } */
+{
+ int i = (int) { 1 }; /* { dg-error "ISO C90 forbids compound literals" } */
+ struct A a = { .i = 3 }; /* { dg-error "ISO C90 forbids specifying subobject to initialize" } */
+}
+
+void
+fn3 (int n)
+{
+ n = 3;
+ int i; /* { dg-error "ISO C90 forbids mixed declarations and code" } */
+}
+
+void
+fn4 (int n)
+{
+ n = 3;
+ __extension__ int i; /* { dg-error "ISO C90 forbids mixed declarations and code" } */
+}
+
+void
+fn5 (void)
+{
+ (foo ()).a[0]; /* { dg-error "ISO C90 forbids subscripting non-lvalue array" } */
+}
+
+#define F(a) a
+
+void
+fn6 (void)
+{
+ F(); /* { dg-error "invoking macro F argument" } */
+}
+
+void fn7 (int n, int a[n]); /* { dg-error "ISO C90 forbids variable length array .a." } */
diff --git gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-6.c gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-6.c
index e69de29..8728cd9 100644
--- gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-6.c
+++ gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-6.c
@@ -0,0 +1,29 @@
+/* { dg-do compile } */
+/* { dg-options "-std=gnu90 -Wc90-c99-compat" } */
+
+__extension__ _Bool b;
+__extension__ _Complex double c = __builtin_complex (0.0, 0.0);
+__extension__ long long l;
+__extension__ struct A { int i; char a[]; };
+__extension__ struct { long int b: 2; } s;
+__extension__ const const int i;
+__extension__ volatile volatile int v;
+__extension__ struct S { int a[2]; };
+extern struct S foo (void);
+__extension__ enum { E, };
+__extension__ void fn1 (char [*]);
+
+__extension__ void
+fn2 (char x[static 4])
+{
+ int i = (int) { 1 };
+ struct A a = { .i = 3 };
+}
+
+__extension__ void
+fn5 (void)
+{
+ (foo ()).a[0];
+}
+
+__extension__ void fn7 (int n, int a[n]);
diff --git gcc/gcc/testsuite/gcc.dg/wvla-1.c gcc/gcc/testsuite/gcc.dg/wvla-1.c
index c8f2107..d2e3cb5 100644
--- gcc/gcc/testsuite/gcc.dg/wvla-1.c
+++ gcc/gcc/testsuite/gcc.dg/wvla-1.c
@@ -2,4 +2,4 @@
/* { dg-options "-std=c89 -Wvla" } */
extern void
-func (int i, int array[i]); /* { dg-warning "variable length array 'array' is used" } */
+func (int i, int array[i]); /* { dg-warning "ISO C90 forbids variable length array 'array'" } */
diff --git gcc/gcc/testsuite/gcc.dg/wvla-2.c gcc/gcc/testsuite/gcc.dg/wvla-2.c
index d811a11..92c67ed 100644
--- gcc/gcc/testsuite/gcc.dg/wvla-2.c
+++ gcc/gcc/testsuite/gcc.dg/wvla-2.c
@@ -2,4 +2,4 @@
/* { dg-options "-std=c99 -Wvla" } */
extern void
-func (int i, int array[i]); /* { dg-warning "variable length array 'array' is used" } */
+func (int i, int array[i]); /* { dg-warning "ISO C90 forbids variable length array 'array'" } */
diff --git gcc/gcc/testsuite/gcc.dg/wvla-4.c gcc/gcc/testsuite/gcc.dg/wvla-4.c
index 8c15292..ae2e0b0 100644
--- gcc/gcc/testsuite/gcc.dg/wvla-4.c
+++ gcc/gcc/testsuite/gcc.dg/wvla-4.c
@@ -2,4 +2,4 @@
/* { dg-options "-pedantic-errors -std=c99 -Wvla" } */
extern void
-func (int i, int array[i]); /* { dg-warning "variable length array 'array' is used" } */
+func (int i, int array[i]); /* { dg-warning "ISO C90 forbids variable length array 'array'" } */
diff --git gcc/gcc/testsuite/gcc.dg/wvla-6.c gcc/gcc/testsuite/gcc.dg/wvla-6.c
index f21435b..694a4cc 100644
--- gcc/gcc/testsuite/gcc.dg/wvla-6.c
+++ gcc/gcc/testsuite/gcc.dg/wvla-6.c
@@ -2,4 +2,4 @@
/* { dg-options "-std=c89 -Wvla" } */
extern void
-func (int i, int [i]); /* { dg-warning "variable length array is used" } */
+func (int i, int [i]); /* { dg-warning "ISO C90 forbids variable length array" } */
diff --git gcc/libcpp/charset.c gcc/libcpp/charset.c
index a3c24d6..fa46f92 100644
--- gcc/libcpp/charset.c
+++ gcc/libcpp/charset.c
@@ -995,6 +995,10 @@ _cpp_valid_ucn (cpp_reader *pfile, const uchar **pstr,
if (!CPP_OPTION (pfile, cplusplus) && !CPP_OPTION (pfile, c99))
cpp_error (pfile, CPP_DL_WARNING,
"universal character names are only valid in C++ and C99");
+ else if (CPP_OPTION (pfile, cpp_warn_c90_c99_compat)
+ && !CPP_OPTION (pfile, cplusplus))
+ cpp_error (pfile, CPP_DL_WARNING,
+ "C99's universal character names are incompatible with C90");
else if (CPP_WTRADITIONAL (pfile) && identifier_pos == 0)
cpp_warning (pfile, CPP_W_TRADITIONAL,
"the meaning of '\\%c' is different in traditional C",
diff --git gcc/libcpp/include/cpplib.h gcc/libcpp/include/cpplib.h
index a83452b..4cd66cd 100644
--- gcc/libcpp/include/cpplib.h
+++ gcc/libcpp/include/cpplib.h
@@ -466,6 +466,9 @@ struct cpp_options
/* True if dependencies should be restored from a precompiled header. */
bool restore_pch_deps;
+ /* True if warn about differences between C90 and C99. */
+ bool cpp_warn_c90_c99_compat;
+
/* Dependency generation. */
struct
{
diff --git gcc/libcpp/lex.c gcc/libcpp/lex.c
index 7e2db64..5cc2224 100644
--- gcc/libcpp/lex.c
+++ gcc/libcpp/lex.c
@@ -2325,7 +2325,7 @@ _cpp_lex_direct (cpp_reader *pfile)
else if (c == '/' && (CPP_OPTION (pfile, cplusplus_comments)
|| cpp_in_system_header (pfile)))
{
- /* Warn about comments only if pedantically GNUC89, and not
+ /* Warn about comments if pedantically GNUC89, and not
in system headers. */
if (CPP_OPTION (pfile, lang) == CLK_GNUC89 && CPP_PEDANTIC (pfile)
&& ! buffer->warned_cplusplus_comments)
@@ -2336,6 +2336,16 @@ _cpp_lex_direct (cpp_reader *pfile)
"(this will be reported only once per input file)");
buffer->warned_cplusplus_comments = 1;
}
+ /* Or if specifically desired via -Wc90-c99-compat. */
+ else if (CPP_OPTION (pfile, cpp_warn_c90_c99_compat)
+ && ! buffer->warned_cplusplus_comments)
+ {
+ cpp_error (pfile, CPP_DL_WARNING,
+ "C++ style comments are are incompatible with C90");
+ cpp_error (pfile, CPP_DL_WARNING,
+ "(this will be reported only once per input file)");
+ buffer->warned_cplusplus_comments = 1;
+ }
if (skip_line_comment (pfile) && CPP_OPTION (pfile, warn_comments))
cpp_warning (pfile, CPP_W_COMMENTS, "multi-line comment");
diff --git gcc/libcpp/macro.c gcc/libcpp/macro.c
index 556628b..ff6685c 100644
--- gcc/libcpp/macro.c
+++ gcc/libcpp/macro.c
@@ -1795,6 +1795,16 @@ replace_args (cpp_reader *pfile, cpp_hashnode *node, cpp_macro *macro,
NODE_NAME (node),
src->val.macro_arg.arg_no);
}
+ else if (CPP_OPTION (pfile, cpp_warn_c90_c99_compat)
+ && ! macro->syshdr
+ && ! cpp_in_system_header (pfile)
+ && ! CPP_OPTION (pfile, cplusplus))
+ cpp_error (pfile, CPP_DL_WARNING,
+ "invoking macro %s argument %d: "
+ "empty macro arguments are undefined"
+ " in ISO C90",
+ NODE_NAME (node),
+ src->val.macro_arg.arg_no);
/* Avoid paste on RHS (even case count == 0). */
if (!pfile->state.in_directive && !(src->flags & PASTE_LEFT))
@@ -2848,6 +2858,10 @@ parse_params (cpp_reader *pfile, cpp_macro *macro)
(pfile, CPP_W_VARIADIC_MACROS,
"anonymous variadic macros were introduced in C99");
}
+ else if (CPP_OPTION (pfile, cpp_warn_c90_c99_compat)
+ && ! CPP_OPTION (pfile, cplusplus))
+ cpp_error (pfile, CPP_DL_WARNING,
+ "anonymous variadic macros were introduced in C99");
}
else if (CPP_OPTION (pfile, cpp_pedantic)
&& CPP_OPTION (pfile, warn_variadic_macros))
Marek
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [C PATCH] Implement -Wc90-c99-compat (PR c/51849)
2014-07-31 7:47 [C PATCH] Implement -Wc90-c99-compat (PR c/51849) Marek Polacek
@ 2014-08-07 6:43 ` Marek Polacek
2014-08-07 17:10 ` Joseph S. Myers
1 sibling, 0 replies; 4+ messages in thread
From: Marek Polacek @ 2014-08-07 6:43 UTC (permalink / raw)
To: GCC Patches, Joseph S. Myers
Ping.
On Thu, Jul 31, 2014 at 09:39:21AM +0200, Marek Polacek wrote:
> One of the prerequisites to moving the default from gnu89 to gnu11
> is that we need both -Wc90-c99-compat and -Wc99-c11-compat options.
> This patch implements the former. Its purpose is similar to
> -Wtraditional - that people who build code in C99/C11 mode can easily
> check whether the code uses something outside C90. Since
> __extension__ disables this warning, features that are properly
> conditioned are fine and not warned about.
>
> As I said privately, it turned out to be convenient to reuse
> pedwarn_c90 - the patch now mostly removes code. Earlier I defined
> a special function, but that rendered pedwarn_c90 unused. Another
> benefit I see is that if we ever add pedwarn_c90, we have
> -Wc90-c99-compat handled for free. And obviously, defining yet
> another warn/pedwarn function would be confusing.
>
> A few issues: currently we don't warn (in -std=c90 -pedantic mode)
> about the usage of __func__ and _Pragma (possible others - va_copy?).
> I'm hoping this is not that important though. For restrict/inline,
> in GNU90 mode we just don't compile the code at all (unless we use
> __restrict and similar), and -Wc90-c99-compat does not warn about those.
>
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
>
> 2014-07-31 Marek Polacek <polacek@redhat.com>
>
> PR c/51849
> gcc/
> * gcc/doc/invoke.texi: Document -Wc90-c99-compat.
> gcc/c-family/
> * c-opts.c (sanitize_cpp_opts): Pass warn_c90_c99_compat to libcpp.
> * c.opt (Wc90-c99-compat): Add option.
> gcc/c/
> * c-decl.c (build_array_declarator): Remove check for !flag_isoc99.
> Call pedwarn_c90 instead of pedwarn.
> (check_bitfield_type_and_width): Likewise.
> (declspecs_add_qual): Likewise.
> (declspecs_add_type): Likewise.
> (warn_variable_length_array): Unify function for -pedantic and -Wvla.
> Adjust to only call pedwarn_c90.
> (grokdeclarator): Remove pedantic && !flag_isoc99 check. Call
> pedwarn_c90 instead of pedwarn.
> * c-errors.c (pedwarn_c90): Handle -Wc90-c99-compat.
> * c-parser.c (disable_extension_diagnostics): Handle
> warn_c90_c99_compat.
> (restore_extension_diagnostics): Likewise.
> (c_parser_enum_specifier): Remove check for !flag_isoc99. Call
> pedwarn_c90 instead of pedwarn.
> (c_parser_initelt): Likewise.
> (c_parser_postfix_expression): Likewise.
> (c_parser_postfix_expression_after_paren_type): Likewise.
> (c_parser_compound_statement_nostart): Remove check for !flag_isoc99.
> * c-tree.h: Fix formatting.
> * c-typeck.c (build_array_ref): Remove check for !flag_isoc99. Call
> pedwarn_c90 instead of pedwarn.
> gcc/testsuite/
> * gcc.dg/Wc90-c99-compat-1.c: New test.
> * gcc.dg/Wc90-c99-compat-2.c: New test.
> * gcc.dg/Wc90-c99-compat-3.c: New test.
> * gcc.dg/Wc90-c99-compat-4.c: New test.
> * gcc.dg/Wc90-c99-compat-5.c: New test.
> * gcc.dg/Wc90-c99-compat-6.c: New test.
> * gcc.dg/wvla-1.c: Adjust dg-warning.
> * gcc.dg/wvla-2.c: Adjust dg-warning.
> * gcc.dg/wvla-4.c: Adjust dg-warning.
> * gcc.dg/wvla-6.c: Adjust dg-warning.
> libcpp/
> * lex.c (_cpp_lex_direct): Warn when -Wc90-c99-compat is in effect.
> * charset.c (_cpp_valid_ucn): Likewise.
> * include/cpplib.h (cpp_options): Add cpp_warn_c90_c99_compat.
> * macro.c (replace_args): Warn when -Wc90-c99-compat is in effect.
> (parse_params): Likewise.
>
> diff --git gcc/gcc/c-family/c-opts.c gcc/gcc/c-family/c-opts.c
> index 3f8e6e6..43a8b9d 100644
> --- gcc/gcc/c-family/c-opts.c
> +++ gcc/gcc/c-family/c-opts.c
> @@ -1295,6 +1295,7 @@ sanitize_cpp_opts (void)
> cpp_opts->unsigned_char = !flag_signed_char;
> cpp_opts->stdc_0_in_system_headers = STDC_0_IN_SYSTEM_HEADERS;
> cpp_opts->warn_date_time = cpp_warn_date_time;
> + cpp_opts->cpp_warn_c90_c99_compat = warn_c90_c99_compat;
>
> /* Wlong-long is disabled by default. It is enabled by:
> [-Wpedantic | -Wtraditional] -std=[gnu|c]++98 ; or
> diff --git gcc/gcc/c-family/c.opt gcc/gcc/c-family/c.opt
> index f427da1..b62bac1 100644
> --- gcc/gcc/c-family/c.opt
> +++ gcc/gcc/c-family/c.opt
> @@ -291,6 +291,10 @@ Wbuiltin-macro-redefined
> C ObjC C++ ObjC++ Warning
> Warn when a built-in preprocessor macro is undefined or redefined
>
> +Wc90-c99-compat
> +C ObjC Var(warn_c90_c99_compat) Warning
> +Warn about features not present in ISO C90, but present in ISO C99
> +
> Wc++-compat
> C ObjC Var(warn_cxx_compat) Warning
> Warn about C constructs that are not in the common subset of C and C++
> diff --git gcc/gcc/c/c-decl.c gcc/gcc/c/c-decl.c
> index 2a4b439..b1c5862 100644
> --- gcc/gcc/c/c-decl.c
> +++ gcc/gcc/c/c-decl.c
> @@ -3968,16 +3968,13 @@ build_array_declarator (location_t loc,
> }
> declarator->u.array.static_p = static_p;
> declarator->u.array.vla_unspec_p = vla_unspec_p;
> - if (!flag_isoc99)
> - {
> - if (static_p || quals != NULL)
> - pedwarn (loc, OPT_Wpedantic,
> + if (static_p || quals != NULL)
> + pedwarn_c90 (loc, OPT_Wpedantic,
> "ISO C90 does not support %<static%> or type "
> "qualifiers in parameter array declarators");
> - if (vla_unspec_p)
> - pedwarn (loc, OPT_Wpedantic,
> + if (vla_unspec_p)
> + pedwarn_c90 (loc, OPT_Wpedantic,
> "ISO C90 does not support %<[*]%> array declarators");
> - }
> if (vla_unspec_p)
> {
> if (!current_scope->parm_flag)
> @@ -4891,10 +4888,9 @@ check_bitfield_type_and_width (tree *type, tree *width, tree orig_name)
> if (!in_system_header_at (input_location)
> && type_mv != integer_type_node
> && type_mv != unsigned_type_node
> - && type_mv != boolean_type_node
> - && !flag_isoc99)
> - pedwarn (input_location, OPT_Wpedantic,
> - "type of bit-field %qs is a GCC extension", name);
> + && type_mv != boolean_type_node)
> + pedwarn_c90 (input_location, OPT_Wpedantic,
> + "type of bit-field %qs is a GCC extension", name);
>
> max_width = TYPE_PRECISION (*type);
>
> @@ -4925,52 +4921,27 @@ static void
> warn_variable_length_array (tree name, tree size)
> {
> int const_size = TREE_CONSTANT (size);
> + enum opt_code opt = (warn_vla == -1 && !warn_c90_c99_compat)
> + ? OPT_Wpedantic : OPT_Wvla;
>
> - if (!flag_isoc99 && pedantic && warn_vla != 0)
> + if (const_size)
> {
> - if (const_size)
> - {
> - if (name)
> - pedwarn (input_location, OPT_Wvla,
> + if (name)
> + pedwarn_c90 (input_location, opt,
> "ISO C90 forbids array %qE whose size "
> - "can%'t be evaluated",
> - name);
> - else
> - pedwarn (input_location, OPT_Wvla, "ISO C90 forbids array whose size "
> - "can%'t be evaluated");
> - }
> + "can%'t be evaluated", name);
> else
> - {
> - if (name)
> - pedwarn (input_location, OPT_Wvla,
> - "ISO C90 forbids variable length array %qE",
> - name);
> - else
> - pedwarn (input_location, OPT_Wvla, "ISO C90 forbids variable length array");
> - }
> + pedwarn_c90 (input_location, opt, "ISO C90 forbids array "
> + "whose size can%'t be evaluated");
> }
> - else if (warn_vla > 0)
> + else
> {
> - if (const_size)
> - {
> - if (name)
> - warning (OPT_Wvla,
> - "the size of array %qE can"
> - "%'t be evaluated", name);
> - else
> - warning (OPT_Wvla,
> - "the size of array can %'t be evaluated");
> - }
> + if (name)
> + pedwarn_c90 (input_location, opt,
> + "ISO C90 forbids variable length array %qE", name);
> else
> - {
> - if (name)
> - warning (OPT_Wvla,
> - "variable length array %qE is used",
> - name);
> - else
> - warning (OPT_Wvla,
> - "variable length array is used");
> - }
> + pedwarn_c90 (input_location, opt, "ISO C90 forbids variable "
> + "length array");
> }
> }
>
> @@ -5186,18 +5157,14 @@ grokdeclarator (const struct c_declarator *declarator,
> as2 = TYPE_ADDR_SPACE (element_type);
> address_space = ADDR_SPACE_GENERIC_P (as1)? as2 : as1;
>
> - if (pedantic && !flag_isoc99)
> - {
> - if (constp > 1)
> - pedwarn (loc, OPT_Wpedantic, "duplicate %<const%>");
> - if (restrictp > 1)
> - pedwarn (loc, OPT_Wpedantic, "duplicate %<restrict%>");
> - if (volatilep > 1)
> - pedwarn (loc, OPT_Wpedantic, "duplicate %<volatile%>");
> - if (atomicp > 1)
> - pedwarn (loc, OPT_Wpedantic, "duplicate %<_Atomic%>");
> -
> - }
> + if (constp > 1)
> + pedwarn_c90 (loc, OPT_Wpedantic, "duplicate %<const%>");
> + if (restrictp > 1)
> + pedwarn_c90 (loc, OPT_Wpedantic, "duplicate %<restrict%>");
> + if (volatilep > 1)
> + pedwarn_c90 (loc, OPT_Wpedantic, "duplicate %<volatile%>");
> + if (atomicp > 1)
> + pedwarn_c90 (loc, OPT_Wpedantic, "duplicate %<_Atomic%>");
>
> if (!ADDR_SPACE_GENERIC_P (as1) && !ADDR_SPACE_GENERIC_P (as2) && as1 != as2)
> error_at (loc, "conflicting named address spaces (%s vs %s)",
> @@ -5602,10 +5569,9 @@ grokdeclarator (const struct c_declarator *declarator,
> flexible_array_member = (t->kind == cdk_id);
> }
> if (flexible_array_member
> - && pedantic && !flag_isoc99
> && !in_system_header_at (input_location))
> - pedwarn (loc, OPT_Wpedantic,
> - "ISO C90 does not support flexible array members");
> + pedwarn_c90 (loc, OPT_Wpedantic, "ISO C90 does not "
> + "support flexible array members");
>
> /* ISO C99 Flexible array members are effectively
> identical to GCC's zero-length array extension. */
> @@ -9140,8 +9106,8 @@ declspecs_add_qual (source_location loc,
> default:
> gcc_unreachable ();
> }
> - if (dupe && !flag_isoc99)
> - pedwarn (loc, OPT_Wpedantic, "duplicate %qE", qual);
> + if (dupe)
> + pedwarn_c90 (loc, OPT_Wpedantic, "duplicate %qE", qual);
> return specs;
> }
>
> @@ -9385,9 +9351,9 @@ declspecs_add_type (location_t loc, struct c_declspecs *specs,
> break;
> case RID_COMPLEX:
> dupe = specs->complex_p;
> - if (!flag_isoc99 && !in_system_header_at (loc))
> - pedwarn (loc, OPT_Wpedantic,
> - "ISO C90 does not support complex types");
> + if (!in_system_header_at (loc))
> + pedwarn_c90 (loc, OPT_Wpedantic,
> + "ISO C90 does not support complex types");
> if (specs->typespec_word == cts_auto_type)
> error_at (loc,
> ("both %<complex%> and %<__auto_type%> in "
> @@ -9603,9 +9569,9 @@ declspecs_add_type (location_t loc, struct c_declspecs *specs,
> }
> return specs;
> case RID_BOOL:
> - if (!flag_isoc99 && !in_system_header_at (loc))
> - pedwarn (loc, OPT_Wpedantic,
> - "ISO C90 does not support boolean types");
> + if (!in_system_header_at (loc))
> + pedwarn_c90 (loc, OPT_Wpedantic,
> + "ISO C90 does not support boolean types");
> if (specs->long_p)
> error_at (loc,
> ("both %<long%> and %<_Bool%> in "
> diff --git gcc/gcc/c/c-errors.c gcc/gcc/c/c-errors.c
> index 92136e7..1cc1dbf 100644
> --- gcc/gcc/c/c-errors.c
> +++ gcc/gcc/c/c-errors.c
> @@ -44,21 +44,38 @@ pedwarn_c99 (location_t location, int opt, const char *gmsgid, ...)
> va_end (ap);
> }
>
> -/* Issue an ISO C90 pedantic warning MSGID. This function is supposed to
> - be used for matters that are allowed in ISO C99 but not supported in
> - ISO C90, thus we explicitly don't pedwarn when C99 is specified.
> - (There is no flag_c90.) */
> +/* Issue an ISO C90 pedantic warning MSGID if -pedantic outside C99 mode,
> + otherwise issue warning MSGID if -Wc90-c99-compat is specified, or if
> + specific option such as -Wlong-long is specified.
> + This function is supposed to be used for matters that are allowed in
> + ISO C99 but not supported in ISO C90, thus we explicitly don't pedwarn
> + when C99 is specified. (There is no flag_c90.) */
>
> void
> pedwarn_c90 (location_t location, int opt, const char *gmsgid, ...)
> {
> diagnostic_info diagnostic;
> va_list ap;
> + bool warned = false;
>
> va_start (ap, gmsgid);
> - diagnostic_set_info (&diagnostic, gmsgid, &ap, location,
> - flag_isoc99 ? DK_WARNING : DK_PEDWARN);
> - diagnostic.option_index = opt;
> - report_diagnostic (&diagnostic);
> + if (pedantic && !flag_isoc99)
> + {
> + diagnostic_set_info (&diagnostic, gmsgid, &ap, location, DK_PEDWARN);
> + diagnostic.option_index = opt;
> + warned = report_diagnostic (&diagnostic);
> + }
> + else if (opt != OPT_Wpedantic)
> + {
> + diagnostic_set_info (&diagnostic, gmsgid, &ap, location, DK_WARNING);
> + diagnostic.option_index = opt;
> + warned = report_diagnostic (&diagnostic);
> + }
> + if (warn_c90_c99_compat && !warned)
> + {
> + diagnostic_set_info (&diagnostic, gmsgid, &ap, location, DK_WARNING);
> + diagnostic.option_index = OPT_Wc90_c99_compat;
> + report_diagnostic (&diagnostic);
> + }
> va_end (ap);
> }
> diff --git gcc/gcc/c/c-parser.c gcc/gcc/c/c-parser.c
> index e32bf04..ca8577c 100644
> --- gcc/gcc/c/c-parser.c
> +++ gcc/gcc/c/c-parser.c
> @@ -1072,7 +1072,8 @@ disable_extension_diagnostics (void)
> | (flag_iso << 3)
> | (warn_long_long << 4)
> | (warn_cxx_compat << 5)
> - | (warn_overlength_strings << 6));
> + | (warn_overlength_strings << 6)
> + | (warn_c90_c99_compat << 7));
> cpp_opts->cpp_pedantic = pedantic = 0;
> warn_pointer_arith = 0;
> cpp_opts->cpp_warn_traditional = warn_traditional = 0;
> @@ -1080,6 +1081,7 @@ disable_extension_diagnostics (void)
> cpp_opts->cpp_warn_long_long = warn_long_long = 0;
> warn_cxx_compat = 0;
> warn_overlength_strings = 0;
> + warn_c90_c99_compat = 0;
> return ret;
> }
>
> @@ -1096,6 +1098,7 @@ restore_extension_diagnostics (int flags)
> cpp_opts->cpp_warn_long_long = warn_long_long = (flags >> 4) & 1;
> warn_cxx_compat = (flags >> 5) & 1;
> warn_overlength_strings = (flags >> 6) & 1;
> + warn_c90_c99_compat = (flags >> 7) & 1;
> }
>
> /* Possibly kinds of declarator to parse. */
> @@ -2545,8 +2548,9 @@ c_parser_enum_specifier (c_parser *parser)
> }
> if (c_parser_next_token_is (parser, CPP_CLOSE_BRACE))
> {
> - if (seen_comma && !flag_isoc99)
> - pedwarn (comma_loc, OPT_Wpedantic, "comma at end of enumerator list");
> + if (seen_comma)
> + pedwarn_c90 (comma_loc, OPT_Wpedantic,
> + "comma at end of enumerator list");
> c_parser_consume_token (parser);
> break;
> }
> @@ -4348,9 +4352,9 @@ c_parser_initelt (c_parser *parser, struct obstack * braced_init_obstack)
> {
> if (c_parser_next_token_is (parser, CPP_EQ))
> {
> - if (!flag_isoc99)
> - pedwarn (des_loc, OPT_Wpedantic,
> - "ISO C90 forbids specifying subobject to initialize");
> + pedwarn_c90 (des_loc, OPT_Wpedantic,
> + "ISO C90 forbids specifying subobject "
> + "to initialize");
> c_parser_consume_token (parser);
> }
> else
> @@ -4566,10 +4570,9 @@ c_parser_compound_statement_nostart (c_parser *parser)
> c_parser_declaration_or_fndef (parser, true, true, true, true,
> true, NULL, vNULL);
> if (last_stmt)
> - pedwarn_c90 (loc,
> - (pedantic && !flag_isoc99)
> - ? OPT_Wpedantic
> - : OPT_Wdeclaration_after_statement,
> + pedwarn_c90 (loc, (pedantic && !flag_isoc99)
> + ? OPT_Wpedantic
> + : OPT_Wdeclaration_after_statement,
> "ISO C90 forbids mixed declarations and code");
> last_stmt = false;
> }
> @@ -4598,8 +4601,8 @@ c_parser_compound_statement_nostart (c_parser *parser)
> restore_extension_diagnostics (ext);
> if (last_stmt)
> pedwarn_c90 (loc, (pedantic && !flag_isoc99)
> - ? OPT_Wpedantic
> - : OPT_Wdeclaration_after_statement,
> + ? OPT_Wpedantic
> + : OPT_Wdeclaration_after_statement,
> "ISO C90 forbids mixed declarations and code");
> last_stmt = false;
> }
> @@ -7401,9 +7404,8 @@ c_parser_postfix_expression (c_parser *parser)
> expr.value = error_mark_node;
> break;
> }
> - if (!flag_isoc99)
> - pedwarn (loc, OPT_Wpedantic,
> - "ISO C90 does not support complex types");
> + pedwarn_c90 (loc, OPT_Wpedantic,
> + "ISO C90 does not support complex types");
> expr.value = build2 (COMPLEX_EXPR,
> build_complex_type
> (TYPE_MAIN_VARIANT
> @@ -7607,8 +7609,7 @@ c_parser_postfix_expression_after_paren_type (c_parser *parser,
> type = error_mark_node;
> }
>
> - if (!flag_isoc99)
> - pedwarn (start_loc, OPT_Wpedantic, "ISO C90 forbids compound literals");
> + pedwarn_c90 (start_loc, OPT_Wpedantic, "ISO C90 forbids compound literals");
> non_const = ((init.value && TREE_CODE (init.value) == CONSTRUCTOR)
> ? CONSTRUCTOR_NON_CONST (init.value)
> : init.original_code == C_MAYBE_CONST_EXPR);
> diff --git gcc/gcc/c/c-tree.h gcc/gcc/c/c-tree.h
> index f97d0d5..55e71dc 100644
> --- gcc/gcc/c/c-tree.h
> +++ gcc/gcc/c/c-tree.h
> @@ -676,7 +676,9 @@ extern tree c_omp_reduction_lookup (tree, tree);
> extern tree c_check_omp_declare_reduction_r (tree *, int *, void *);
>
> /* In c-errors.c */
> -extern void pedwarn_c90 (location_t, int opt, const char *, ...) ATTRIBUTE_GCC_DIAG(3,4);
> -extern void pedwarn_c99 (location_t, int opt, const char *, ...) ATTRIBUTE_GCC_DIAG(3,4);
> +extern void pedwarn_c90 (location_t, int opt, const char *, ...)
> + ATTRIBUTE_GCC_DIAG(3,4);
> +extern void pedwarn_c99 (location_t, int opt, const char *, ...)
> + ATTRIBUTE_GCC_DIAG(3,4);
>
> #endif /* ! GCC_C_TREE_H */
> diff --git gcc/gcc/c/c-typeck.c gcc/gcc/c/c-typeck.c
> index a938933..64c7a74 100644
> --- gcc/gcc/c/c-typeck.c
> +++ gcc/gcc/c/c-typeck.c
> @@ -2511,7 +2511,7 @@ build_array_ref (location_t loc, tree array, tree index)
> return error_mark_node;
> }
>
> - if (pedantic)
> + if (pedantic || warn_c90_c99_compat)
> {
> tree foo = array;
> while (TREE_CODE (foo) == COMPONENT_REF)
> @@ -2519,9 +2519,10 @@ build_array_ref (location_t loc, tree array, tree index)
> if (TREE_CODE (foo) == VAR_DECL && C_DECL_REGISTER (foo))
> pedwarn (loc, OPT_Wpedantic,
> "ISO C forbids subscripting %<register%> array");
> - else if (!flag_isoc99 && !lvalue_p (foo))
> - pedwarn (loc, OPT_Wpedantic,
> - "ISO C90 forbids subscripting non-lvalue array");
> + else if (!lvalue_p (foo))
> + pedwarn_c90 (loc, OPT_Wpedantic,
> + "ISO C90 forbids subscripting non-lvalue "
> + "array");
> }
>
> type = TREE_TYPE (TREE_TYPE (array));
> diff --git gcc/gcc/doc/invoke.texi gcc/gcc/doc/invoke.texi
> index 51757f0..f48552b 100644
> --- gcc/gcc/doc/invoke.texi
> +++ gcc/gcc/doc/invoke.texi
> @@ -241,6 +241,7 @@ Objective-C and Objective-C++ Dialects}.
> -w -Wextra -Wall -Waddress -Waggregate-return @gol
> -Waggressive-loop-optimizations -Warray-bounds @gol
> -Wno-attributes -Wno-builtin-macro-redefined @gol
> +-Wc90-c99-compat @gol
> -Wc++-compat -Wc++11-compat -Wcast-align -Wcast-qual @gol
> -Wchar-subscripts -Wclobbered -Wcomment -Wconditionally-supported @gol
> -Wconversion -Wcoverage-mismatch -Wdate-time -Wdelete-incomplete -Wno-cpp @gol
> @@ -4497,6 +4498,15 @@ example, warn if an unsigned variable is compared against zero with
> Warn whenever a function call is cast to a non-matching type.
> For example, warn if @code{int malloc()} is cast to @code{anything *}.
>
> +@item -Wc90-c99-compat @r{(C and Objective-C only)}
> +@opindex Wc90-c99-compat
> +@opindex Wno-c90-c99-compat
> +Warn about features not present in ISO C90, but present in ISO C99.
> +For instance, warn about use of variable length arrays, @code{long long}
> +type, @code{bool} type, compound literals, designated initializers, and so
> +on. This option is independent of the standards mode. Warnings are disabled
> +in the expression that follows @code{__extension__}.
> +
> @item -Wc++-compat @r{(C and Objective-C only)}
> Warn about ISO C constructs that are outside of the common subset of
> ISO C and ISO C++, e.g.@: request for implicit conversion from
> diff --git gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-1.c gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-1.c
> index e69de29..15e71e8 100644
> --- gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-1.c
> +++ gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-1.c
> @@ -0,0 +1,56 @@
> +/* { dg-do compile } */
> +/* { dg-options "-std=gnu90 -Wpedantic -Wc90-c99-compat" } */
> +
> +_Bool b; /* { dg-warning "ISO C90 does not support boolean types" } */
> +_Complex double c = __builtin_complex (0.0, 0.0); /* { dg-warning "ISO C90 does not support complex types" } */
> +long long l; /* { dg-warning "ISO C90 does not support .long long." } */
> +struct A { int i; char a[]; }; /* { dg-warning "ISO C90 does not support flexible array members" } */
> +struct { long int b: 2; } s; /* { dg-warning "type of bit-field .b. is a GCC extension" } */
> +const const int i; /* { dg-warning "duplicate .const." } */
> +volatile volatile v; /* { dg-warning "duplicate .volatile." } */
> +
> +struct S { int a[2]; };
> +extern struct S foo (void);
> +
> +#define V(v, ...) (v, __VA_ARGS) /* { dg-warning "anonymous variadic macros were introduced in C99" } */
> +
> +enum { E, }; /* { dg-warning "comma at end of enumerator list" } */
> +
> +void fn1 (char [*]); /* { dg-warning "ISO C90 does not support .\\\[\\\*\\\]. array declarators" } */
> +
> +void
> +fn2 (char x[static 4]) /* { dg-warning "ISO C90 does not support .static. or type qualifiers" } */
> +{
> + int i = (int) { 1 }; /* { dg-warning "ISO C90 forbids compound literals" } */
> + struct A a = { .i = 3 }; /* { dg-warning "ISO C90 forbids specifying subobject to initialize" } */
> +}
> +
> +void
> +fn3 (int n)
> +{
> + n = 3;
> + int i; /* { dg-warning "ISO C90 forbids mixed declarations and code" } */
> +}
> +
> +void
> +fn4 (int n)
> +{
> + n = 3;
> + __extension__ int i; /* { dg-warning "ISO C90 forbids mixed declarations and code" } */
> +}
> +
> +void
> +fn5 (void)
> +{
> + (foo ()).a[0]; /* { dg-warning "ISO C90 forbids subscripting non-lvalue array" } */
> +}
> +
> +#define F(a) a
> +
> +void
> +fn6 (void)
> +{
> + F(); /* { dg-warning "invoking macro F argument" } */
> +}
> +
> +void fn7 (int n, int a[n]); /* { dg-warning "ISO C90 forbids variable length array .a." } */
> diff --git gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-2.c gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-2.c
> index e69de29..d00f0df 100644
> --- gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-2.c
> +++ gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-2.c
> @@ -0,0 +1,56 @@
> +/* { dg-do compile } */
> +/* { dg-options "-std=gnu99 -Wc90-c99-compat -pedantic-errors" } */
> +
> +_Bool b; /* { dg-warning "ISO C90 does not support boolean types" } */
> +_Complex double c = __builtin_complex (0.0, 0.0); /* { dg-warning "ISO C90 does not support complex types" } */
> +long long l; /* { dg-warning "ISO C90 does not support .long long." } */
> +struct A { int i; char a[]; }; /* { dg-warning "ISO C90 does not support flexible array members" } */
> +struct { long int b: 2; } s; /* { dg-warning "type of bit-field .b. is a GCC extension" } */
> +const const int i; /* { dg-warning "duplicate .const." } */
> +volatile volatile int v; /* { dg-warning "duplicate .volatile." } */
> +
> +struct S { int a[2]; };
> +extern struct S foo (void);
> +
> +#define V(v, ...) (v, __VA_ARGS) /* { dg-warning "anonymous variadic macros were introduced in C99" } */
> +
> +enum { E, }; /* { dg-warning "comma at end of enumerator list" } */
> +
> +void fn1 (char [*]); /* { dg-warning "ISO C90 does not support .\\\[\\\*\\\]. array declarators" } */
> +
> +void
> +fn2 (char x[static 4]) /* { dg-warning "ISO C90 does not support .static. or type qualifiers" } */
> +{
> + int i = (int) { 1 }; /* { dg-warning "ISO C90 forbids compound literals" } */
> + struct A a = { .i = 3 }; /* { dg-warning "ISO C90 forbids specifying subobject to initialize" } */
> +}
> +
> +void
> +fn3 (int n)
> +{
> + n = 3;
> + int i; /* { dg-warning "ISO C90 forbids mixed declarations and code" } */
> +}
> +
> +void
> +fn4 (int n)
> +{
> + n = 3;
> + __extension__ int i; /* { dg-warning "ISO C90 forbids mixed declarations and code" } */
> +}
> +
> +void
> +fn5 (void)
> +{
> + (foo ()).a[0]; /* { dg-warning "ISO C90 forbids subscripting non-lvalue array" } */
> +}
> +
> +#define F(a) a
> +
> +void
> +fn6 (void)
> +{
> + F(); /* { dg-warning "invoking macro F argument" } */
> +}
> +
> +void fn7 (int n, int a[n]); /* { dg-warning "ISO C90 forbids variable length array .a." } */
> diff --git gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-3.c gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-3.c
> index e69de29..78f012c 100644
> --- gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-3.c
> +++ gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-3.c
> @@ -0,0 +1,56 @@
> +/* { dg-do compile } */
> +/* { dg-options "-std=gnu11 -Wc90-c99-compat -pedantic-errors" } */
> +
> +_Bool b; /* { dg-warning "ISO C90 does not support boolean types" } */
> +_Complex double c = __builtin_complex (0.0, 0.0); /* { dg-warning "ISO C90 does not support complex types" } */
> +long long l; /* { dg-warning "ISO C90 does not support .long long." } */
> +struct A { int i; char a[]; }; /* { dg-warning "ISO C90 does not support flexible array members" } */
> +struct { long int b: 2; } s; /* { dg-warning "type of bit-field .b. is a GCC extension" } */
> +const const int i; /* { dg-warning "duplicate .const." } */
> +volatile volatile int v; /* { dg-warning "duplicate .volatile." } */
> +
> +struct S { int a[2]; };
> +extern struct S foo (void);
> +
> +#define V(v, ...) (v, __VA_ARGS) /* { dg-warning "anonymous variadic macros were introduced in C99" } */
> +
> +enum { E, }; /* { dg-warning "comma at end of enumerator list" } */
> +
> +void fn1 (char [*]); /* { dg-warning "ISO C90 does not support .\\\[\\\*\\\]. array declarators" } */
> +
> +void
> +fn2 (char x[static 4]) /* { dg-warning "ISO C90 does not support .static. or type qualifiers" } */
> +{
> + int i = (int) { 1 }; /* { dg-warning "ISO C90 forbids compound literals" } */
> + struct A a = { .i = 3 }; /* { dg-warning "ISO C90 forbids specifying subobject to initialize" } */
> +}
> +
> +void
> +fn3 (int n)
> +{
> + n = 3;
> + int i; /* { dg-warning "ISO C90 forbids mixed declarations and code" } */
> +}
> +
> +void
> +fn4 (int n)
> +{
> + n = 3;
> + __extension__ int i; /* { dg-warning "ISO C90 forbids mixed declarations and code" } */
> +}
> +
> +void
> +fn5 (void)
> +{
> + (foo ()).a[0]; /* { dg-warning "ISO C90 forbids subscripting non-lvalue array" } */
> +}
> +
> +#define F(a) a
> +
> +void
> +fn6 (void)
> +{
> + F(); /* { dg-warning "invoking macro F argument" } */
> +}
> +
> +void fn7 (int n, int a[n]); /* { dg-warning "ISO C90 forbids variable length array .a." } */
> diff --git gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-4.c gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-4.c
> index e69de29..e8d2f03 100644
> --- gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-4.c
> +++ gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-4.c
> @@ -0,0 +1,56 @@
> +/* { dg-do compile } */
> +/* { dg-options "-std=gnu90 -Wpedantic -Wno-c90-c99-compat" } */
> +
> +_Bool b; /* { dg-warning "ISO C90 does not support boolean types" } */
> +_Complex double c = __builtin_complex (0.0, 0.0); /* { dg-warning "ISO C90 does not support complex types" } */
> +long long l; /* { dg-warning "ISO C90 does not support .long long." } */
> +struct A { int i; char a[]; }; /* { dg-warning "ISO C90 does not support flexible array members" } */
> +struct { long int b: 2; } s; /* { dg-warning "type of bit-field .b. is a GCC extension" } */
> +const const int i; /* { dg-warning "duplicate .const." } */
> +volatile volatile int v; /* { dg-warning "duplicate .volatile." } */
> +
> +struct S { int a[2]; };
> +extern struct S foo (void);
> +
> +#define V(v, ...) (v, __VA_ARGS) /* { dg-warning "anonymous variadic macros were introduced in C99" } */
> +
> +enum { E, }; /* { dg-warning "comma at end of enumerator list" } */
> +
> +void fn1 (char [*]); /* { dg-warning "ISO C90 does not support .\\\[\\\*\\\]. array declarators" } */
> +
> +void
> +fn2 (char x[static 4]) /* { dg-warning "ISO C90 does not support .static. or type qualifiers" } */
> +{
> + int i = (int) { 1 }; /* { dg-warning "ISO C90 forbids compound literals" } */
> + struct A a = { .i = 3 }; /* { dg-warning "ISO C90 forbids specifying subobject to initialize" } */
> +}
> +
> +void
> +fn3 (int n)
> +{
> + n = 3;
> + int i; /* { dg-warning "ISO C90 forbids mixed declarations and code" } */
> +}
> +
> +void
> +fn4 (int n)
> +{
> + n = 3;
> + __extension__ int i; /* { dg-warning "ISO C90 forbids mixed declarations and code" } */
> +}
> +
> +void
> +fn5 (void)
> +{
> + (foo ()).a[0]; /* { dg-warning "ISO C90 forbids subscripting non-lvalue array" } */
> +}
> +
> +#define F(a) a
> +
> +void
> +fn6 (void)
> +{
> + F(); /* { dg-warning "invoking macro F argument" } */
> +}
> +
> +void fn7 (int n, int a[n]); /* { dg-warning "ISO C90 forbids variable length array .a." } */
> diff --git gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-5.c gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-5.c
> index e69de29..1344ae8 100644
> --- gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-5.c
> +++ gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-5.c
> @@ -0,0 +1,56 @@
> +/* { dg-do compile } */
> +/* { dg-options "-std=gnu90 -pedantic-errors -Wno-c90-c99-compat" } */
> +
> +_Bool b; /* { dg-error "ISO C90 does not support boolean types" } */
> +_Complex double c = __builtin_complex (0.0, 0.0); /* { dg-error "ISO C90 does not support complex types" } */
> +long long l; /* { dg-error "ISO C90 does not support .long long." } */
> +struct A { int i; char a[]; }; /* { dg-error "ISO C90 does not support flexible array members" } */
> +struct { long int b: 2; } s; /* { dg-error "type of bit-field .b. is a GCC extension" } */
> +const const int i; /* { dg-error "duplicate .const." } */
> +volatile volatile int v; /* { dg-error "duplicate .volatile." } */
> +
> +struct S { int a[2]; };
> +extern struct S foo (void);
> +
> +#define V(v, ...) (v, __VA_ARGS) /* { dg-error "anonymous variadic macros were introduced in C99" } */
> +
> +enum { E, }; /* { dg-error "comma at end of enumerator list" } */
> +
> +void fn1 (char [*]); /* { dg-error "ISO C90 does not support .\\\[\\\*\\\]. array declarators" } */
> +
> +void
> +fn2 (char x[static 4]) /* { dg-error "ISO C90 does not support .static. or type qualifiers" } */
> +{
> + int i = (int) { 1 }; /* { dg-error "ISO C90 forbids compound literals" } */
> + struct A a = { .i = 3 }; /* { dg-error "ISO C90 forbids specifying subobject to initialize" } */
> +}
> +
> +void
> +fn3 (int n)
> +{
> + n = 3;
> + int i; /* { dg-error "ISO C90 forbids mixed declarations and code" } */
> +}
> +
> +void
> +fn4 (int n)
> +{
> + n = 3;
> + __extension__ int i; /* { dg-error "ISO C90 forbids mixed declarations and code" } */
> +}
> +
> +void
> +fn5 (void)
> +{
> + (foo ()).a[0]; /* { dg-error "ISO C90 forbids subscripting non-lvalue array" } */
> +}
> +
> +#define F(a) a
> +
> +void
> +fn6 (void)
> +{
> + F(); /* { dg-error "invoking macro F argument" } */
> +}
> +
> +void fn7 (int n, int a[n]); /* { dg-error "ISO C90 forbids variable length array .a." } */
> diff --git gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-6.c gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-6.c
> index e69de29..8728cd9 100644
> --- gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-6.c
> +++ gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-6.c
> @@ -0,0 +1,29 @@
> +/* { dg-do compile } */
> +/* { dg-options "-std=gnu90 -Wc90-c99-compat" } */
> +
> +__extension__ _Bool b;
> +__extension__ _Complex double c = __builtin_complex (0.0, 0.0);
> +__extension__ long long l;
> +__extension__ struct A { int i; char a[]; };
> +__extension__ struct { long int b: 2; } s;
> +__extension__ const const int i;
> +__extension__ volatile volatile int v;
> +__extension__ struct S { int a[2]; };
> +extern struct S foo (void);
> +__extension__ enum { E, };
> +__extension__ void fn1 (char [*]);
> +
> +__extension__ void
> +fn2 (char x[static 4])
> +{
> + int i = (int) { 1 };
> + struct A a = { .i = 3 };
> +}
> +
> +__extension__ void
> +fn5 (void)
> +{
> + (foo ()).a[0];
> +}
> +
> +__extension__ void fn7 (int n, int a[n]);
> diff --git gcc/gcc/testsuite/gcc.dg/wvla-1.c gcc/gcc/testsuite/gcc.dg/wvla-1.c
> index c8f2107..d2e3cb5 100644
> --- gcc/gcc/testsuite/gcc.dg/wvla-1.c
> +++ gcc/gcc/testsuite/gcc.dg/wvla-1.c
> @@ -2,4 +2,4 @@
> /* { dg-options "-std=c89 -Wvla" } */
>
> extern void
> -func (int i, int array[i]); /* { dg-warning "variable length array 'array' is used" } */
> +func (int i, int array[i]); /* { dg-warning "ISO C90 forbids variable length array 'array'" } */
> diff --git gcc/gcc/testsuite/gcc.dg/wvla-2.c gcc/gcc/testsuite/gcc.dg/wvla-2.c
> index d811a11..92c67ed 100644
> --- gcc/gcc/testsuite/gcc.dg/wvla-2.c
> +++ gcc/gcc/testsuite/gcc.dg/wvla-2.c
> @@ -2,4 +2,4 @@
> /* { dg-options "-std=c99 -Wvla" } */
>
> extern void
> -func (int i, int array[i]); /* { dg-warning "variable length array 'array' is used" } */
> +func (int i, int array[i]); /* { dg-warning "ISO C90 forbids variable length array 'array'" } */
> diff --git gcc/gcc/testsuite/gcc.dg/wvla-4.c gcc/gcc/testsuite/gcc.dg/wvla-4.c
> index 8c15292..ae2e0b0 100644
> --- gcc/gcc/testsuite/gcc.dg/wvla-4.c
> +++ gcc/gcc/testsuite/gcc.dg/wvla-4.c
> @@ -2,4 +2,4 @@
> /* { dg-options "-pedantic-errors -std=c99 -Wvla" } */
>
> extern void
> -func (int i, int array[i]); /* { dg-warning "variable length array 'array' is used" } */
> +func (int i, int array[i]); /* { dg-warning "ISO C90 forbids variable length array 'array'" } */
> diff --git gcc/gcc/testsuite/gcc.dg/wvla-6.c gcc/gcc/testsuite/gcc.dg/wvla-6.c
> index f21435b..694a4cc 100644
> --- gcc/gcc/testsuite/gcc.dg/wvla-6.c
> +++ gcc/gcc/testsuite/gcc.dg/wvla-6.c
> @@ -2,4 +2,4 @@
> /* { dg-options "-std=c89 -Wvla" } */
>
> extern void
> -func (int i, int [i]); /* { dg-warning "variable length array is used" } */
> +func (int i, int [i]); /* { dg-warning "ISO C90 forbids variable length array" } */
> diff --git gcc/libcpp/charset.c gcc/libcpp/charset.c
> index a3c24d6..fa46f92 100644
> --- gcc/libcpp/charset.c
> +++ gcc/libcpp/charset.c
> @@ -995,6 +995,10 @@ _cpp_valid_ucn (cpp_reader *pfile, const uchar **pstr,
> if (!CPP_OPTION (pfile, cplusplus) && !CPP_OPTION (pfile, c99))
> cpp_error (pfile, CPP_DL_WARNING,
> "universal character names are only valid in C++ and C99");
> + else if (CPP_OPTION (pfile, cpp_warn_c90_c99_compat)
> + && !CPP_OPTION (pfile, cplusplus))
> + cpp_error (pfile, CPP_DL_WARNING,
> + "C99's universal character names are incompatible with C90");
> else if (CPP_WTRADITIONAL (pfile) && identifier_pos == 0)
> cpp_warning (pfile, CPP_W_TRADITIONAL,
> "the meaning of '\\%c' is different in traditional C",
> diff --git gcc/libcpp/include/cpplib.h gcc/libcpp/include/cpplib.h
> index a83452b..4cd66cd 100644
> --- gcc/libcpp/include/cpplib.h
> +++ gcc/libcpp/include/cpplib.h
> @@ -466,6 +466,9 @@ struct cpp_options
> /* True if dependencies should be restored from a precompiled header. */
> bool restore_pch_deps;
>
> + /* True if warn about differences between C90 and C99. */
> + bool cpp_warn_c90_c99_compat;
> +
> /* Dependency generation. */
> struct
> {
> diff --git gcc/libcpp/lex.c gcc/libcpp/lex.c
> index 7e2db64..5cc2224 100644
> --- gcc/libcpp/lex.c
> +++ gcc/libcpp/lex.c
> @@ -2325,7 +2325,7 @@ _cpp_lex_direct (cpp_reader *pfile)
> else if (c == '/' && (CPP_OPTION (pfile, cplusplus_comments)
> || cpp_in_system_header (pfile)))
> {
> - /* Warn about comments only if pedantically GNUC89, and not
> + /* Warn about comments if pedantically GNUC89, and not
> in system headers. */
> if (CPP_OPTION (pfile, lang) == CLK_GNUC89 && CPP_PEDANTIC (pfile)
> && ! buffer->warned_cplusplus_comments)
> @@ -2336,6 +2336,16 @@ _cpp_lex_direct (cpp_reader *pfile)
> "(this will be reported only once per input file)");
> buffer->warned_cplusplus_comments = 1;
> }
> + /* Or if specifically desired via -Wc90-c99-compat. */
> + else if (CPP_OPTION (pfile, cpp_warn_c90_c99_compat)
> + && ! buffer->warned_cplusplus_comments)
> + {
> + cpp_error (pfile, CPP_DL_WARNING,
> + "C++ style comments are are incompatible with C90");
> + cpp_error (pfile, CPP_DL_WARNING,
> + "(this will be reported only once per input file)");
> + buffer->warned_cplusplus_comments = 1;
> + }
>
> if (skip_line_comment (pfile) && CPP_OPTION (pfile, warn_comments))
> cpp_warning (pfile, CPP_W_COMMENTS, "multi-line comment");
> diff --git gcc/libcpp/macro.c gcc/libcpp/macro.c
> index 556628b..ff6685c 100644
> --- gcc/libcpp/macro.c
> +++ gcc/libcpp/macro.c
> @@ -1795,6 +1795,16 @@ replace_args (cpp_reader *pfile, cpp_hashnode *node, cpp_macro *macro,
> NODE_NAME (node),
> src->val.macro_arg.arg_no);
> }
> + else if (CPP_OPTION (pfile, cpp_warn_c90_c99_compat)
> + && ! macro->syshdr
> + && ! cpp_in_system_header (pfile)
> + && ! CPP_OPTION (pfile, cplusplus))
> + cpp_error (pfile, CPP_DL_WARNING,
> + "invoking macro %s argument %d: "
> + "empty macro arguments are undefined"
> + " in ISO C90",
> + NODE_NAME (node),
> + src->val.macro_arg.arg_no);
>
> /* Avoid paste on RHS (even case count == 0). */
> if (!pfile->state.in_directive && !(src->flags & PASTE_LEFT))
> @@ -2848,6 +2858,10 @@ parse_params (cpp_reader *pfile, cpp_macro *macro)
> (pfile, CPP_W_VARIADIC_MACROS,
> "anonymous variadic macros were introduced in C99");
> }
> + else if (CPP_OPTION (pfile, cpp_warn_c90_c99_compat)
> + && ! CPP_OPTION (pfile, cplusplus))
> + cpp_error (pfile, CPP_DL_WARNING,
> + "anonymous variadic macros were introduced in C99");
> }
> else if (CPP_OPTION (pfile, cpp_pedantic)
> && CPP_OPTION (pfile, warn_variadic_macros))
>
> Marek
Marek
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [C PATCH] Implement -Wc90-c99-compat (PR c/51849)
2014-07-31 7:47 [C PATCH] Implement -Wc90-c99-compat (PR c/51849) Marek Polacek
2014-08-07 6:43 ` Marek Polacek
@ 2014-08-07 17:10 ` Joseph S. Myers
2014-08-09 18:30 ` Marek Polacek
1 sibling, 1 reply; 4+ messages in thread
From: Joseph S. Myers @ 2014-08-07 17:10 UTC (permalink / raw)
To: Marek Polacek; +Cc: GCC Patches
On Thu, 31 Jul 2014, Marek Polacek wrote:
> A few issues: currently we don't warn (in -std=c90 -pedantic mode)
> about the usage of __func__ and _Pragma (possible others - va_copy?).
> I'm hoping this is not that important though. For restrict/inline,
> in GNU90 mode we just don't compile the code at all (unless we use
> __restrict and similar), and -Wc90-c99-compat does not warn about those.
And, -pedantic -Wno-c90-c99-compat - outside C99 mode - doesn't disable
the relevant warnings (I'd think of it as logically like -pedantic
-Wno-long-long, so it should disable them, while leaving all the -pedantic
diagnostics for features that aren't in C99). Though I think implementing
that could reasonably be a followup fix.
E.g., in C90 mode, -Wlong-long is more specific than -Wc90-c99-compat,
which is more specific than -pedantic. So the "long long" warnings should
be determined by any explicit -W(no-)long-long if given, otherwise by any
-W(no-)c90-c99-compat if given, otherwise by -pedantic, following the
general rule of the most specific option taking precedence (and
command-line order only being relevant when multiple variants of the same
option are used, e.g. -Wlong-long -Wno-long-long). Outside C90 mode,
-pedantic is irrelevant to such warnings; -W(no-)long-long should take
precedence over -W(no-)c90-c99-compat if both are used. For warnings
without a more specific option such as -Wlong-long, of course it's a bit
simpler.
> @@ -44,21 +44,38 @@ pedwarn_c99 (location_t location, int opt, const char *gmsgid, ...)
> va_end (ap);
> }
>
> -/* Issue an ISO C90 pedantic warning MSGID. This function is supposed to
> - be used for matters that are allowed in ISO C99 but not supported in
> - ISO C90, thus we explicitly don't pedwarn when C99 is specified.
> - (There is no flag_c90.) */
> +/* Issue an ISO C90 pedantic warning MSGID if -pedantic outside C99 mode,
> + otherwise issue warning MSGID if -Wc90-c99-compat is specified, or if
> + specific option such as -Wlong-long is specified.
"a specific option".
OK with that change.
--
Joseph S. Myers
joseph@codesourcery.com
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [C PATCH] Implement -Wc90-c99-compat (PR c/51849)
2014-08-07 17:10 ` Joseph S. Myers
@ 2014-08-09 18:30 ` Marek Polacek
0 siblings, 0 replies; 4+ messages in thread
From: Marek Polacek @ 2014-08-09 18:30 UTC (permalink / raw)
To: Joseph S. Myers; +Cc: GCC Patches
On Thu, Aug 07, 2014 at 05:10:43PM +0000, Joseph S. Myers wrote:
> On Thu, 31 Jul 2014, Marek Polacek wrote:
>
> > A few issues: currently we don't warn (in -std=c90 -pedantic mode)
> > about the usage of __func__ and _Pragma (possible others - va_copy?).
> > I'm hoping this is not that important though. For restrict/inline,
> > in GNU90 mode we just don't compile the code at all (unless we use
> > __restrict and similar), and -Wc90-c99-compat does not warn about those.
>
> And, -pedantic -Wno-c90-c99-compat - outside C99 mode - doesn't disable
> the relevant warnings (I'd think of it as logically like -pedantic
> -Wno-long-long, so it should disable them, while leaving all the -pedantic
> diagnostics for features that aren't in C99). Though I think implementing
> that could reasonably be a followup fix.
>
> E.g., in C90 mode, -Wlong-long is more specific than -Wc90-c99-compat,
> which is more specific than -pedantic. So the "long long" warnings should
> be determined by any explicit -W(no-)long-long if given, otherwise by any
> -W(no-)c90-c99-compat if given, otherwise by -pedantic, following the
> general rule of the most specific option taking precedence (and
> command-line order only being relevant when multiple variants of the same
> option are used, e.g. -Wlong-long -Wno-long-long). Outside C90 mode,
> -pedantic is irrelevant to such warnings; -W(no-)long-long should take
> precedence over -W(no-)c90-c99-compat if both are used. For warnings
> without a more specific option such as -Wlong-long, of course it's a bit
> simpler.
Yeah, makes sense. I just finished testing a patch that implements
the above; will post it momentarily.
> "a specific option".
>
> OK with that change.
Fixed, thanks for reviewing this.
Marek
^ permalink raw reply [flat|nested] 4+ messages in thread
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2014-07-31 7:47 [C PATCH] Implement -Wc90-c99-compat (PR c/51849) Marek Polacek
2014-08-07 6:43 ` Marek Polacek
2014-08-07 17:10 ` Joseph S. Myers
2014-08-09 18:30 ` Marek Polacek
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