+2008-09-18 Simon Baldwin <simonb@google.com>
+
+ * c-opts.c (c_common_handle_option): Add handling for
+ -Wbuiltin-macro-redefined command line option.
+ * c.opt: Added builtin-macro-redefined option.
+ * doc/invoke.texi (Warning Options): Add -Wbuiltin-macro-redefined
+ documentation.
+
2008-09-18 Richard Guenther <rguenther@suse.de>
PR tree-optimization/37258
warn_pointer_sign = 1;
break;
+ case OPT_Wbuiltin_macro_redefined:
+ cpp_opts->warn_builtin_macro_redefined = value;
+ break;
+
case OPT_Wcomment:
case OPT_Wcomments:
cpp_opts->warn_comments = value;
C ObjC Var(warn_bad_function_cast) Warning
Warn about casting functions to incompatible types
+Wbuiltin-macro-redefined
+C ObjC C++ ObjC++ Warning
+Warn when a built-in preprocessor macro is undefined or redefined
+
Wc++-compat
C ObjC Var(warn_cxx_compat) Warning
Warn about C constructs that are not in the common subset of C and C++
@xref{Warning Options,,Options to Request or Suppress Warnings}.
@gccoptlist{-fsyntax-only -pedantic -pedantic-errors @gol
-w -Wextra -Wall -Waddress -Waggregate-return -Warray-bounds @gol
--Wno-attributes -Wc++-compat -Wc++0x-compat -Wcast-align -Wcast-qual @gol
+-Wno-attributes -Wno-builtin-macro-redefined @gol
+-Wc++-compat -Wc++0x-compat -Wcast-align -Wcast-qual @gol
-Wchar-subscripts -Wclobbered -Wcomment @gol
-Wconversion -Wcoverage-mismatch -Wno-deprecated @gol
-Wno-deprecated-declarations -Wdisabled-optimization @gol
etc. This will not stop errors for incorrect use of supported
attributes.
+@item -Wno-builtin-macro-redefined
+@opindex Wno-builtin-macro-redefined
+@opindex Wbuiltin-macro-redefined
+Do not warn if certain built-in macros are redefined. This suppresses
+warnings for redefinition of @code{__TIMESTAMP__}, @code{__TIME__},
+@code{__DATE__}, @code{__FILE__}, and @code{__BASE_FILE__}.
+
@item -Wstrict-prototypes @r{(C and Objective-C only)}
@opindex Wstrict-prototypes
@opindex Wno-strict-prototypes
+2008-09-18 Simon Baldwin <simonb@google.com>
+
+ * gcc.dg/builtin-redefine.c: New.
+
2008-09-18 Richard Guenther <rguenther@suse.de>
PR tree-optimization/37258
--- /dev/null
+/* Test -Wno-builtin-macro-redefined warnings. */
+
+/* { dg-do compile } */
+/* { dg-options "-Wno-builtin-macro-redefined -U__DATE__ -D__TIME__=X" } */
+
+/* Check date, time, and datestamp built-ins warnings may be suppressed. */
+
+#if defined(__DATE__)
+#error "__DATE__ is defined, but should not be (-U command line error)"
+/* { dg-bogus "__DATE__ is defined" "" { target *-*-* } 9 } */
+#endif
+
+#if __TIME__ != X
+#error "__TIME__ is not defined as expected (-D command line error)"
+/* { dg-bogus "__TIME__ is not defined" "" { target *-*-* } 14 } */
+#endif
+
+#if !defined(__TIMESTAMP__)
+#error "__TIMESTAMP__ is not defined (built-in macro expectation error)"
+/* { dg-bogus "__TIMESTAMP__ is not defined" "" { target *-*-* } 19 } */
+#endif
+
+
+#undef __TIME__ /* Undefine while defined. */
+#undef __TIME__ /* Undefine while already undefined. */
+
+#define __TIME__ "X" /* Define while undefined. */
+#define __TIME__ "X" /* Re-define while defined. */
+
+#define __TIME__ "Y" /* { dg-warning "\"__TIME__\" redefined" } */
+/* { dg-warning "previous definition" "" { target *-*-* } 28 } */
+
+#undef __TIME__ /* Undefine while defined. */
+
+
+#undef __DATE__ /* Undefine while already undefined. */
+
+#define __DATE__ "X" /* Define while undefined. */
+#define __DATE__ "X" /* Re-define while defined. */
+
+#define __DATE__ "Y" /* { dg-warning "\"__DATE__\" redefined" } */
+/* { dg-warning "previous definition" "" { target *-*-* } 39 } */
+
+#undef __DATE__ /* Undefine while defined. */
+
+
+#define __TIMESTAMP__ "X" /* Define while already defined. */
+#define __TIMESTAMP__ "X" /* Re-define while defined. */
+
+#define __TIMESTAMP__ "Y" /* { dg-warning "\"__TIMESTAMP__\" redefined" } */
+/* { dg-warning "previous definition" "" { target *-*-* } 48 } */
+
+#undef __TIMESTAMP__ /* Undefine while defined. */
+
+
+/* Check other built-ins with warnings that may be suppressed. */
+
+#if !defined(__FILE__) || !defined(__BASE_FILE__)
+#error "Expected built-in is not defined (built-in macro expectation error)"
+/* { dg-bogus "Expected built-in is not defined" "" { target *-*-* } 59 } */
+#endif
+
+#define __FILE__ "X" /* Define while already defined. */
+#define __BASE_FILE__ "X" /* Define while already defined. */
+
+
+/* Check selected built-ins not affected by warning suppression. */
+
+#if !defined(__LINE__) || !defined(__INCLUDE_LEVEL__) || !defined(__COUNTER__)
+#error "Expected built-in is not defined (built-in macro expectation error)"
+/* { dg-bogus "Expected built-in is not defined" "" { target *-*-* } 70 } */
+#endif
+
+#define __LINE__ 0 /* { dg-warning "\"__LINE__\" redef" } */
+#define __INCLUDE_LEVEL__ 0 /* { dg-warning "\"__INCLUDE_LEVEL__\" redef" } */
+#define __COUNTER__ 0 /* { dg-warning "\"__COUNTER__\" redef" } */
+
+
+int unused; /* Silence `ISO C forbids an empty translation unit' warning. */
+2008-09-18 Simon Baldwin <simonb@google.com>
+
+ * include/cpplib.h (struct cpp_options): Add new boolean flag
+ warn_builtin_macro_redefined.
+ * init.c (cpp_create_reader): Initialize warn_builtin_macro_redefined.
+ * (struct builtin_operator): Split out from previous struct builtin,
+ enhance extra const correctness.
+ * (struct builtin_macro): Split out from previous struct builtin, add
+ new always_warn_if_redefined flag, enhance const correctness.
+ * (mark_named_operators): Use struct builtin_operator.
+ * (cpp_init_special_builtins): Use struct builtin_macro, add NODE_WARN
+ to builtins selectively.
+ * macro.c (warn_of_redefinition): Return false if a builtin macro
+ is not flagged with NODE_WARN.
+
2008-07-31 Jakub Jelinek <jakub@redhat.com>
PR preprocessor/36649
Presumably the usage is protected by the appropriate #ifdef. */
unsigned char warn_variadic_macros;
+ /* Nonzero means warn about builtin macros that are redefined or
+ explicitly undefined. */
+ unsigned char warn_builtin_macro_redefined;
+
/* Nonzero means turn warnings into errors. */
unsigned char warnings_are_errors;
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;
/* Default CPP arithmetic to something sensible for the host for the
altered through #define, and #if recognizes them as operators. In
C, these are not entered into the hash table at all (but see
<iso646.h>). The value is a token-type enumerator. */
-struct builtin
+struct builtin_macro
{
- const uchar *name;
- unsigned short len;
- unsigned short value;
+ const uchar *const name;
+ const unsigned short len;
+ const unsigned short value;
+ const bool always_warn_if_redefined;
};
-#define B(n, t) { DSC(n), t }
-static const struct builtin builtin_array[] =
+#define B(n, t, f) { DSC(n), t, f }
+static const struct builtin_macro builtin_array[] =
{
- B("__TIMESTAMP__", BT_TIMESTAMP),
- B("__TIME__", BT_TIME),
- B("__DATE__", BT_DATE),
- B("__FILE__", BT_FILE),
- B("__BASE_FILE__", BT_BASE_FILE),
- B("__LINE__", BT_SPECLINE),
- B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL),
- B("__COUNTER__", BT_COUNTER),
+ B("__TIMESTAMP__", BT_TIMESTAMP, false),
+ B("__TIME__", BT_TIME, false),
+ B("__DATE__", BT_DATE, false),
+ B("__FILE__", BT_FILE, false),
+ B("__BASE_FILE__", BT_BASE_FILE, false),
+ B("__LINE__", BT_SPECLINE, true),
+ B("__INCLUDE_LEVEL__", BT_INCLUDE_LEVEL, true),
+ B("__COUNTER__", BT_COUNTER, true),
/* Keep builtins not used for -traditional-cpp at the end, and
update init_builtins() if any more are added. */
- B("_Pragma", BT_PRAGMA),
- B("__STDC__", BT_STDC),
+ B("_Pragma", BT_PRAGMA, true),
+ B("__STDC__", BT_STDC, true),
+};
+#undef B
+
+struct builtin_operator
+{
+ const uchar *const name;
+ const unsigned short len;
+ const unsigned short value;
};
-static const struct builtin operator_array[] =
+#define B(n, t) { DSC(n), t }
+static const struct builtin_operator operator_array[] =
{
B("and", CPP_AND_AND),
B("and_eq", CPP_AND_EQ),
static void
mark_named_operators (cpp_reader *pfile)
{
- const struct builtin *b;
+ const struct builtin_operator *b;
for (b = operator_array;
b < (operator_array + ARRAY_SIZE (operator_array));
void
cpp_init_special_builtins (cpp_reader *pfile)
{
- const struct builtin *b;
+ const struct builtin_macro *b;
size_t n = ARRAY_SIZE (builtin_array);
if (CPP_OPTION (pfile, traditional))
{
cpp_hashnode *hp = cpp_lookup (pfile, b->name, b->len);
hp->type = NT_MACRO;
- hp->flags |= NODE_BUILTIN | NODE_WARN;
+ hp->flags |= NODE_BUILTIN;
+ if (b->always_warn_if_redefined
+ || CPP_OPTION (pfile, warn_builtin_macro_redefined))
+ hp->flags |= NODE_WARN;
hp->value.builtin = (enum builtin_type) b->value;
}
}
if (node->flags & NODE_WARN)
return true;
+ /* Suppress warnings for builtins that lack the NODE_WARN flag. */
+ if (node->flags & NODE_BUILTIN)
+ return false;
+
/* Redefinitions of conditional (context-sensitive) macros, on
the other hand, must be allowed silently. */
if (node->flags & NODE_CONDITIONAL)
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