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PR preprocessor/53463 - Fix system header detection for built-in macro tokens

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The location for a built-in macro token is BUILTIN_LOCATION.  When we
see that location value, we cannot know if that token was used in a
system header or not.  And that can trigger some unwanted warnings on
e.g, the use of __LONG_LONG_MAX__ built-in macro in system headers
when we compile with -pedantic, like in the test case accompanying
this patch.

In that case, I think we ought to step-up to see where the built-in
macro has been expanded, until we see a location that is not for a
built-in macro.  Then we can check if the resulting location is in a
system header or not.

Now that we step up to the location of first non-built-in-macro token,
it appeared that for
testsuite/c-c++-common/dfp/convert-int-saturate.c, G++ then fails to
emit the warning in:

    volatile unsigned int usi;
    int
    main ()
    {
      usi = DEC32_MAX;  /* { dg-warning "overflow in implicit constant conversion" } */
     ...
    }

Because DEC32_MAX is defined in the system header float.h as a
built-in macro:

    #define DEC32_MAX	__DEC32_MAX__

And during the parsing of the assignment expression that should have
led to the warning above, input_location is set to the location for
the DEC32_MAX, which is actually the location for the built-in
__DECL32_MAX_EXP.

A possible fix is to use the location of the "=" operator as the
default location for assignment expressions.  This is what the patch
does.

I had to adjust a couple of tests to arrange for this.

Bootstrapped and tested on x86_64-unknown-linux-gnu against trunk.

libcpp/

	PR preprocessor/53463
	* line-map.c (linemap_location_in_system_header_p): For built-in
	macro tokens, check the first expansion point location for that is
	not for a token coming from a built-in macro.

gcc/cp/

	PR preprocessor/53463
	* parser.c (cp_parser_assignment_expression): Use the location
	for the LHS as the default location for the expression.

gcc/testsuite/

	PR preprocessor/53463
	* g++.dg/cpp/limits.C: New test.
	* g++.dg/parse/error19.C: Adjust.
	* g++.dg/warn/Wconversion-real-integer2.C: Likewise.
	* g++.dg/warn/pr35635.C: Likewise.
	* g++.old-deja/g++.pt/assign1.C: Likewise.

From-SVN: r188203
This commit is contained in:
Dodji Seketeli 2012-06-04 19:19:58 +00:00 • committed by Dodji Seketeli
parent aadd9700d5
commit 7ca643e17e
10 changed files with 81 additions and 11 deletions
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6
gcc/ChangeLog
View file

@ -1,3 +1,9 @@
2012-06-04 Dodji Seketeli <dodji@redhat.com>
PR preprocessor/53463
* parser.c (cp_parser_assignment_expression): Use the location
for the '=' as the default location for the expression.
2012-06-04 Edmar Wienskoski <edmar@freescale.com>
PR target/53559

7
gcc/cp/parser.c
View file

@ -7481,6 +7481,7 @@ cp_parser_assignment_expression (cp_parser* parser, bool cast_p,
if (assignment_operator != ERROR_MARK)
{
bool non_constant_p;
location_t saved_input_location;
/* Parse the right-hand side of the assignment. */
tree rhs = cp_parser_initializer_clause (parser, &non_constant_p);
@ -7493,11 +7494,15 @@ cp_parser_assignment_expression (cp_parser* parser, bool cast_p,
if (cp_parser_non_integral_constant_expression (parser,
NIC_ASSIGNMENT))
return error_mark_node;
/* Build the assignment expression. */
/* Build the assignment expression. Its default
location is the location of the '=' token. */
saved_input_location = input_location;
input_location = loc;
expr = build_x_modify_expr (loc, expr,
assignment_operator,
rhs,
tf_warning_or_error);
input_location = saved_input_location;
}
}
}

9
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,12 @@
2012-06-04 Dodji Seketeli <dodji@redhat.com>
PR preprocessor/53463
* g++.dg/cpp/limits.C: New test.
* g++.dg/parse/error19.C: Adjust.
* g++.dg/warn/Wconversion-real-integer2.C: Likewise.
* g++.dg/warn/pr35635.C: Likewise.
* g++.old-deja/g++.pt/assign1.C: Likewise.
2012-06-04 Edmar Wienskoski <edmar@freescale.com>
PR target/53559

21
gcc/testsuite/g++.dg/cpp/limits.C Normal file
View file

@ -0,0 +1,21 @@
// { dg-options "-pedantic" }
// { dg-do compile }
#include <limits>
// Compiling this with -pedantic was wrongly triggering this error:
// libstdc++-v3/include/limits:1269:45: warning : use of C++0x long long integer constant [-Wlong-long]
// min() _GLIBCXX_USE_NOEXCEPT { return -__LONG_LONG_MAX__ - 1; }
// ^
// libstdc++-v3/include/limits:1272:44: warning : use of C++0x long long integer constant [-Wlong-long]
// max() _GLIBCXX_USE_NOEXCEPT { return __LONG_LONG_MAX__; }
// ^
// libstdc++-v3/include/limits:1342:44: warning : use of C++0x long long integer constant [-Wlong-long]
// max() _GLIBCXX_USE_NOEXCEPT { return __LONG_LONG_MAX__ * 2ULL + 1
// ^
int
main ()
{
return 0;
}

2
gcc/testsuite/g++.dg/parse/error19.C
View file

@ -10,6 +10,6 @@ const A& foo();
void bar()
{
foo()=A(0); // { dg-error "12:no match for 'operator='" }
foo()=A(0); // { dg-error "8:no match for 'operator='" }
// { dg-message "candidate" "candidate note" { target *-*-* } 13 }
}

4
gcc/testsuite/g++.dg/warn/Wconversion-real-integer2.C
View file

@ -23,11 +23,11 @@
//
// That is more useful.
#define INT_MAX __INT_MAX__ // { dg-warning "conversion to .float. alters .int. constant value" }
#define INT_MAX __INT_MAX__
float vfloat;
void h (void)
{
vfloat = INT_MAX; // { dg-message "in expansion of macro 'INT_MAX'" }
vfloat = INT_MAX; // { dg-warning "conversion to .float. alters .int. constant value" }
}

4
gcc/testsuite/g++.dg/warn/pr35635.C
View file

@ -62,9 +62,9 @@ void func3()
/* At least one branch of ? does not fit in the destination, thus
warn. */
uchar_x = bar != 0 ? 2.1 : 10; /* { dg-warning "conversion" } */
uchar_x = bar != 0
uchar_x = bar != 0 /* { dg-warning "negative integer implicitly converted to unsigned type" } */
? (unsigned char) 1024
: -1; /* { dg-warning "negative integer implicitly converted to unsigned type" } */
: -1;
}
void func4()

2
gcc/testsuite/g++.old-deja/g++.pt/assign1.C
View file

@ -2,7 +2,7 @@
// Origin: Mark Mitchell <mark@codesourcery.com>
template <class T>
struct S { // { dg-error "const|operator=" }
struct S { // { dg-error "const member\[^\n\r\]*can't use default assignment operator" }
S();
T t;
};

7
libcpp/ChangeLog
View file

@ -1,3 +1,10 @@
2012-06-04 Dodji Seketeli <dodji@redhat.com>
PR preprocessor/53463
* line-map.c (linemap_location_in_system_header_p): For built-in
macro tokens, check the first expansion point location that is not
for a token coming from a built-in macro.
2012-05-29 Joseph Myers <joseph@codesourcery.com>
* directives.c: Fix typos.

30
libcpp/line-map.c
View file

@ -755,13 +755,35 @@ linemap_location_in_system_header_p (struct line_maps *set,
{
const struct line_map *map = NULL;
location =
linemap_resolve_location (set, location, LRK_SPELLING_LOCATION, &map);
if (location < RESERVED_LOCATION_COUNT)
return false;
return LINEMAP_SYSP (map);
/* Let's look at where the token for LOCATION comes from. */
while (true)
{
map = linemap_lookup (set, location);
if (map != NULL)
{
if (!linemap_macro_expansion_map_p (map))
/* It's a normal token. */
return LINEMAP_SYSP (map);
else
{
/* It's a token resulting from a macro expansion. */
source_location loc =
linemap_macro_map_loc_unwind_toward_spelling (map, location);
if (loc < RESERVED_LOCATION_COUNT)
/* This token might come from a built-in macro. Let's
look at where that macro got expanded. */
location = linemap_macro_map_loc_to_exp_point (map, location);
else
location = loc;
}
}
else
break;
}
return false;
}
/* Return TRUE if LOCATION is a source code location of a token coming