On 22 September 2016 at 23:15, Joseph Myers <jos...@codesourcery.com> wrote:
> On Thu, 22 Sep 2016, Prathamesh Kulkarni wrote:
>
>> Would that be acceptable ? I am not sure how to make %Z check if the
>> argument has type vec<int> *
>> since vec<int> is not really a builtin C type.
>> Could you suggest me a better solution so that the format checker will check
>> if arg has type vec<int> * instead of checking if it's just a pointer ?
>> Also for testing, should I create a testcase in g++.dg since
>> gcc.dg/format/ tests are C-only ?
>
> If it's C++-only then it would need to be in g++.dg.
>
> The way we handle GCC-specific types in checking these formats is that the
> code using these formats has to define typedefs which the format-checking
> code then looks up. In most cases it can just look up names like
> location_t or tree, but for HOST_WIDE_INT it looks up
> __gcc_host_wide_int__ which the user must have defined as a typedef.
> Probably that's the way to go in this case: the user must do "typedef
> vec<int> __gcc_vec_int__;" or similar, and the code looks up
> __gcc_vec_int__.
Thanks for the suggestions. To keep it simple, instead of vec<int>,
I made %Z take two args: int *v, unsigned len, and prints elements in
v having length == len.
Is that OK ?
Bootstrapped+tested on x86_64-unknown-linux-gnu.
As pointed out earlier in the thread, the patch can give false positives because
it only checks whether parameters are qualified with restrict, not how
parameters
are used inside the function. For instance it warned for example 10
mentioned in n1570
under section 6.7.3.1 - "Formal definition of restrict".
Should we keep the warning in Wall or keep it in Wextra ?
The attached patch enables it with Wall.
Thanks,
Prathamesh
>
> --
> Joseph S. Myers
> jos...@codesourcery.com
diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 491c637..751af90 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -48,6 +48,7 @@ along with GCC; see the file COPYING3. If not see
#include "gimplify.h"
#include "substring-locations.h"
#include "spellcheck.h"
+#include "gcc-rich-location.h"
cpp_reader *parse_in; /* Declared in c-pragma.h. */
@@ -13156,4 +13157,59 @@ diagnose_mismatched_attributes (tree olddecl, tree
newdecl)
return warned;
}
+/* Warn if an argument at position param_pos is passed to a
+ restrict-qualified param, and it aliases with another argument. */
+
+void
+warn_for_restrict (unsigned param_pos, vec<tree, va_gc> *args)
+{
+ tree arg = (*args)[param_pos];
+ if (TREE_VISITED (arg) || operand_equal_p (arg, null_pointer_node, 0))
+ return;
+
+ location_t loc = EXPR_LOC_OR_LOC (arg, input_location);
+ gcc_rich_location richloc (loc);
+
+ unsigned i;
+ tree current_arg;
+ int *arg_positions = XNEWVEC (int, args->length ());
+ unsigned arg_positions_len = 0;
+
+ FOR_EACH_VEC_ELT (*args, i, current_arg)
+ {
+ if (i == param_pos)
+ continue;
+
+ tree current_arg = (*args)[i];
+ if (operand_equal_p (arg, current_arg, 0))
+ {
+ TREE_VISITED (current_arg) = 1;
+ arg_positions[arg_positions_len++] = (i + 1);
+ }
+ }
+
+ if (arg_positions_len == 0)
+ {
+ free (arg_positions);
+ return;
+ }
+
+ for (unsigned i = 0; i < arg_positions_len; i++)
+ {
+ unsigned pos = arg_positions[i];
+ tree arg = (*args)[pos - 1];
+ if (EXPR_HAS_LOCATION (arg))
+ richloc.add_range (EXPR_LOCATION (arg), false);
+ }
+
+ warning_at_rich_loc_n (&richloc, OPT_Wrestrict, arg_positions_len,
+ "passing argument %i to restrict-qualified parameter"
+ " aliases with argument %Z",
+ "passing argument %i to restrict-qualified parameter"
+ " aliases with arguments %Z",
+ param_pos + 1, arg_positions, arg_positions_len);
+
+ free (arg_positions);
+}
+
#include "gt-c-family-c-common.h"
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index c88619b..45b7439 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -923,6 +923,7 @@ extern void c_parse_final_cleanups (void);
extern void warn_for_omitted_condop (location_t, tree);
extern void warn_for_memset (location_t, tree, tree, int);
+extern void warn_for_restrict (unsigned, vec<tree, va_gc> *);
/* These macros provide convenient access to the various _STMT nodes. */
diff --git a/gcc/c-family/c-format.c b/gcc/c-family/c-format.c
index bf39ee0..8a4bf6f 100644
--- a/gcc/c-family/c-format.c
+++ b/gcc/c-family/c-format.c
@@ -713,6 +713,7 @@ static const format_char_info gcc_tdiag_char_table[] =
{ "r", 1, STD_C89, { T89_C, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN,
BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "", "cR", NULL },
{ "<>'R",0, STD_C89, NOARGUMENTS, "", "", NULL },
{ "m", 0, STD_C89, NOARGUMENTS, "q", "", NULL },
+ { "Z", 1, STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN,
BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "", "",
&gcc_tdiag_char_table[0] },
{ NULL, 0, STD_C89, NOLENGTHS, NULL, NULL, NULL }
};
@@ -736,6 +737,7 @@ static const format_char_info gcc_cdiag_char_table[] =
{ "r", 1, STD_C89, { T89_C, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN,
BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "", "cR", NULL },
{ "<>'R",0, STD_C89, NOARGUMENTS, "", "", NULL },
{ "m", 0, STD_C89, NOARGUMENTS, "q", "", NULL },
+ { "Z", 1, STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN,
BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "", "",
&gcc_tdiag_char_table[0] },
{ NULL, 0, STD_C89, NOLENGTHS, NULL, NULL, NULL }
};
@@ -762,6 +764,7 @@ static const format_char_info gcc_cxxdiag_char_table[] =
{ "r", 1, STD_C89, { T89_C, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN,
BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "", "cR", NULL },
{ "<>'R",0, STD_C89, NOARGUMENTS, "", "", NULL },
{ "m", 0, STD_C89, NOARGUMENTS, "q", "", NULL },
+ { "Z", 1, STD_C89, { T89_I, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN,
BADLEN, BADLEN, BADLEN, BADLEN, BADLEN, BADLEN }, "", "",
&gcc_tdiag_char_table[0] },
{ NULL, 0, STD_C89, NOLENGTHS, NULL, NULL, NULL }
};
diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index e146781..da89e9f 100644
--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -1054,6 +1054,11 @@ Wduplicate-decl-specifier
C ObjC Var(warn_duplicate_decl_specifier) Warning LangEnabledBy(C ObjC,Wall)
Warn when a declaration has duplicate const, volatile, restrict or _Atomic
specifier.
+Wrestrict
+C ObjC C++ ObjC++ Var(warn_restrict) Warning LangEnabledBy(C ObjC C++
ObjC++,Wall)
+Warn when an argument passed to a restrict-qualified parameter aliases with
+another argument.
+
ansi
C ObjC C++ ObjC++
A synonym for -std=c89 (for C) or -std=c++98 (for C++).
diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
index 6bc42da..52a5edd 100644
--- a/gcc/c/c-parser.c
+++ b/gcc/c/c-parser.c
@@ -8451,6 +8451,28 @@ c_parser_postfix_expression_after_primary (c_parser
*parser,
warn_for_memset (expr_loc, arg0, arg2, literal_zero_mask);
}
+ if (TREE_CODE (expr.value) == FUNCTION_DECL && warn_restrict)
+ {
+ unsigned i;
+ tree arg;
+ FOR_EACH_VEC_SAFE_ELT (exprlist, i, arg)
+ TREE_VISITED (arg) = 0;
+
+ unsigned param_pos = 0;
+ function_args_iterator iter;
+ tree t;
+ FOREACH_FUNCTION_ARGS (TREE_TYPE (expr.value), t, iter)
+ {
+ if (POINTER_TYPE_P (t) && TYPE_RESTRICT (t)
+ && !TYPE_READONLY (TREE_TYPE (t)))
+ warn_for_restrict (param_pos, exprlist);
+ param_pos++;
+ }
+
+ FOR_EACH_VEC_SAFE_ELT (exprlist, i, arg)
+ TREE_VISITED (arg) = 0;
+ }
+
start = expr.get_start ();
finish = parser->tokens_buf[0].get_finish ();
expr.value
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 16b895c..444132f3 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -6878,6 +6878,29 @@ cp_parser_postfix_expression (cp_parser *parser, bool
address_p, bool cast_p,
warn_for_memset (input_location, arg0, arg2, literal_mask);
}
+ if (TREE_CODE (postfix_expression) == FUNCTION_DECL
+ && warn_restrict)
+ {
+ unsigned i;
+ tree arg;
+ FOR_EACH_VEC_SAFE_ELT (args, i, arg)
+ TREE_VISITED (arg) = 0;
+
+ unsigned param_pos = 0;
+ for (tree decl = DECL_ARGUMENTS (postfix_expression);
+ decl != NULL_TREE;
+ decl = DECL_CHAIN (decl), param_pos++)
+ {
+ tree type = TREE_TYPE (decl);
+ if (POINTER_TYPE_P (type) && TYPE_RESTRICT (type)
+ && !TYPE_READONLY (TREE_TYPE (type)))
+ warn_for_restrict (param_pos, args);
+ }
+
+ FOR_EACH_VEC_SAFE_ELT (args, i, arg)
+ TREE_VISITED (arg) = 0;
+ }
+
if (TREE_CODE (postfix_expression) == COMPONENT_REF)
{
tree instance = TREE_OPERAND (postfix_expression, 0);
diff --git a/gcc/diagnostic-core.h b/gcc/diagnostic-core.h
index 51df150..4a1766c 100644
--- a/gcc/diagnostic-core.h
+++ b/gcc/diagnostic-core.h
@@ -65,6 +65,9 @@ extern bool warning_at (location_t, int, const char *, ...)
ATTRIBUTE_GCC_DIAG(3,4);
extern bool warning_at_rich_loc (rich_location *, int, const char *, ...)
ATTRIBUTE_GCC_DIAG(3,4);
+extern bool warning_at_rich_loc_n (rich_location *, int, int, const char *,
+ const char *, ...)
+ ATTRIBUTE_GCC_DIAG(4, 6) ATTRIBUTE_GCC_DIAG(5, 6);
extern void error (const char *, ...) ATTRIBUTE_GCC_DIAG(1,2);
extern void error_n (location_t, int, const char *, const char *, ...)
ATTRIBUTE_GCC_DIAG(3,5) ATTRIBUTE_GCC_DIAG(4,5);
diff --git a/gcc/diagnostic.c b/gcc/diagnostic.c
index 585028e..167a1b5 100644
--- a/gcc/diagnostic.c
+++ b/gcc/diagnostic.c
@@ -53,6 +53,10 @@ static bool diagnostic_impl (rich_location *, int, const
char *,
static bool diagnostic_n_impl (location_t, int, int, const char *,
const char *, va_list *,
diagnostic_t) ATTRIBUTE_GCC_DIAG(5,0);
+static bool diagnostic_n_impl_richloc (rich_location *, int, int, const char *,
+ const char *, va_list *,
+ diagnostic_t) ATTRIBUTE_GCC_DIAG(5,0);
+
static void error_recursion (diagnostic_context *) ATTRIBUTE_NORETURN;
static void real_abort (void) ATTRIBUTE_NORETURN;
@@ -1064,6 +1068,22 @@ diagnostic_impl (rich_location *richloc, int opt,
return report_diagnostic (&diagnostic);
}
+/* Same as diagonostic_n_impl taking rich_location instead of location_t. */
+static bool
+diagnostic_n_impl_richloc (rich_location *richloc, int opt, int n,
+ const char *singular_gmsgid,
+ const char *plural_gmsgid,
+ va_list *ap, diagnostic_t kind)
+{
+ diagnostic_info diagnostic;
+ diagnostic_set_info_translated (&diagnostic,
+ ngettext (singular_gmsgid, plural_gmsgid, n),
+ ap, richloc, kind);
+ if (kind == DK_WARNING)
+ diagnostic.option_index = opt;
+ return report_diagnostic (&diagnostic);
+}
+
/* Implement inform_n, warning_n, and error_n, as documented and
defined below. */
static bool
@@ -1072,14 +1092,9 @@ diagnostic_n_impl (location_t location, int opt, int n,
const char *plural_gmsgid,
va_list *ap, diagnostic_t kind)
{
- diagnostic_info diagnostic;
rich_location richloc (line_table, location);
- diagnostic_set_info_translated (&diagnostic,
- ngettext (singular_gmsgid, plural_gmsgid, n),
- ap, &richloc, kind);
- if (kind == DK_WARNING)
- diagnostic.option_index = opt;
- return report_diagnostic (&diagnostic);
+ return diagnostic_n_impl_richloc (&richloc, opt, n,
+ singular_gmsgid, plural_gmsgid, ap, kind);
}
bool
@@ -1170,6 +1185,21 @@ warning_at_rich_loc (rich_location *richloc, int opt,
const char *gmsgid, ...)
return ret;
}
+/* Same as warning_at_rich_loc but for plural variant. */
+
+bool
+warning_at_rich_loc_n (rich_location *richloc, int opt, int n,
+ const char *singular_gmsgid, const char *plural_gmsgid,
...)
+{
+ va_list ap;
+ va_start (ap, plural_gmsgid);
+ bool ret = diagnostic_n_impl_richloc (richloc, opt, n,
+ singular_gmsgid, plural_gmsgid,
+ &ap, DK_WARNING);
+ va_end (ap);
+ return ret;
+}
+
/* A warning at LOCATION. Use this for code which is correct according to the
relevant language specification but is likely to be buggy anyway.
Returns true if the warning was printed, false if it was inhibited. */
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index d9667e7..9fcc742 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -290,7 +290,7 @@ Objective-C and Objective-C++ Dialects}.
-Wparentheses -Wno-pedantic-ms-format @gol
-Wplacement-new -Wplacement-new=@var{n} @gol
-Wpointer-arith -Wno-pointer-to-int-cast @gol
--Wno-pragmas -Wredundant-decls -Wno-return-local-addr @gol
+-Wno-pragmas -Wredundant-decls -Wrestrict -Wno-return-local-addr @gol
-Wreturn-type -Wsequence-point -Wshadow -Wno-shadow-ivar @gol
-Wshift-overflow -Wshift-overflow=@var{n} @gol
-Wshift-count-negative -Wshift-count-overflow -Wshift-negative-value @gol
@@ -5544,6 +5544,12 @@ compilations.
Warn when deleting a pointer to incomplete type, which may cause
undefined behavior at runtime. This warning is enabled by default.
+@item -Wrestrict
+@opindex Wrestrict
+@opindex Wno-restrict
+Warn when an argument passed to a restrict-qualified parameter
+aliases with another argument
+
@item -Wuseless-cast @r{(C++ and Objective-C++ only)}
@opindex Wuseless-cast
@opindex Wno-useless-cast
diff --git a/gcc/pretty-print.c b/gcc/pretty-print.c
index a39815e..e58619d 100644
--- a/gcc/pretty-print.c
+++ b/gcc/pretty-print.c
@@ -294,6 +294,8 @@ pp_indent (pretty_printer *pp)
integer.
%Ns: likewise, but length specified as constant in the format string.
Flag 'q': quote formatted text (must come immediately after '%').
+ %Z: Requires two arguments - array of int, and len. Prints elements
+ of the array.
Arguments can be used sequentially, or through %N$ resp. *N$
notation Nth argument after the format string. If %N$ / *N$
@@ -610,6 +612,23 @@ pp_format (pretty_printer *pp, text_info *text)
(pp, *text->args_ptr, precision, unsigned, "u");
break;
+ case 'Z':
+ {
+ int *v = va_arg (*text->args_ptr, int *);
+ unsigned len = va_arg (*text->args_ptr, unsigned);
+
+ for (unsigned i = 0; i < len; ++i)
+ {
+ pp_scalar (pp, "%i", v[i]);
+ if (i < len - 1)
+ {
+ pp_comma (pp);
+ pp_space (pp);
+ }
+ }
+ break;
+ }
+
case 'x':
if (wide)
pp_scalar (pp, HOST_WIDE_INT_PRINT_HEX,
@@ -1424,6 +1443,13 @@ test_pp_format ()
"`\33[01m\33[Kfoo\33[m\33[K' 12345678", "%qs %x",
"foo", 0x12345678);
+ /* Verify %Z. */
+ int v[] = { 1, 2, 3 };
+ ASSERT_PP_FORMAT_3 ("1, 2, 3 12345678", "%Z %x", v, 3, 0x12345678);
+
+ int v2[] = { 0 };
+ ASSERT_PP_FORMAT_3 ("0 12345678", "%Z %x", v2, 1, 0x12345678);
+
/* Verify that combinations work, along with unformatted text. */
assert_pp_format (SELFTEST_LOCATION,
"the quick brown fox jumps over the lazy dog",
diff --git a/gcc/testsuite/c-c++-common/pr35503-1.c
b/gcc/testsuite/c-c++-common/pr35503-1.c
new file mode 100644
index 0000000..25e3721
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr35503-1.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-Wrestrict" } */
+
+int foo (char *__restrict buf, const char *__restrict fmt, ...);
+
+void f(void)
+{
+ char buf[100] = "hello";
+ foo (buf, "%s-%s", buf, "world"); /* { dg-warning "passing argument 1 to
restrict-qualified parameter aliases with argument 3" } */
+}
diff --git a/gcc/testsuite/c-c++-common/pr35503-2.c
b/gcc/testsuite/c-c++-common/pr35503-2.c
new file mode 100644
index 0000000..bfcd944
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr35503-2.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-fdiagnostics-show-caret -Wrestrict" } */
+
+void f(int *__restrict x, int *y, int *__restrict z, int *w);
+
+void foo(int alpha, int beta)
+{
+ f (&alpha, &beta, &alpha, &alpha); /* { dg-warning "passing argument 1 to
restrict-qualified parameter aliases with arguments 3, 4" } */
+
+/* { dg-begin-multiline-output "" }
+ f (&alpha, &beta, &alpha, &alpha);
+ ^~~~~~ ~~~~~~ ~~~~~~
+ { dg-end-multiline-output "" } */
+}
diff --git a/gcc/testsuite/c-c++-common/pr35503-3.c
b/gcc/testsuite/c-c++-common/pr35503-3.c
new file mode 100644
index 0000000..8cbacab
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr35503-3.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-Wrestrict" } */
+
+void f(int *x, int *__restrict y);
+
+void foo(int a)
+{
+ f (&a, &a); /* { dg-warning "passing argument 2 to restrict-qualified
parameter aliases with argument 1" } */
+}
diff --git a/gcc/testsuite/gcc.dg/format/gcc_diag-1.c
b/gcc/testsuite/gcc.dg/format/gcc_diag-1.c
index 953c944..f4922cd 100644
--- a/gcc/testsuite/gcc.dg/format/gcc_diag-1.c
+++ b/gcc/testsuite/gcc.dg/format/gcc_diag-1.c
@@ -32,7 +32,7 @@ foo (int i, int i1, int i2, unsigned int u, double d, char
*s, void *p,
ullong ull, unsigned int *un, const int *cn, signed char *ss,
unsigned char *us, const signed char *css, unsigned int u1,
unsigned int u2, location_t *loc, tree t1, union tree_node *t2,
- tree *t3, tree t4[])
+ tree *t3, tree t4[], int *v, unsigned v_len)
{
/* Acceptable C90 specifiers, flags and modifiers. */
diag ("%%");
@@ -90,6 +90,10 @@ foo (int i, int i1, int i2, unsigned int u, double d, char
*s, void *p,
cdiag ("%v%qv%#v", i, i, i);
cxxdiag ("%v%qv%#v", i, i, i);
+ tdiag ("%Z", v, v_len);
+ cdiag ("%Z", v, v_len);
+ cxxdiag ("%Z", v, v_len);
+
/* Bad stuff with extensions. */
diag ("%m", i); /* { dg-warning "format" "extra arg" } */
tdiag ("%m", i); /* { dg-warning "format" "extra arg" } */
@@ -133,6 +137,9 @@ foo (int i, int i1, int i2, unsigned int u, double d, char
*s, void *p,
cdiag ("%v", t1); /* { dg-warning "format" "wrong arg" } */
cxxdiag ("%v", t1); /* { dg-warning "format" "wrong arg" } */
+ tdiag ("%Z"); /* { dg-warning "format" "missing arg" } */
+ tdiag ("%Z", t1); /* { dg-warning "format" "wrong arg" } */
+
/* Standard specifiers not accepted in the diagnostic framework. */
diag ("%X\n", u); /* { dg-warning "format" "HEX" } */
diag ("%f\n", d); /* { dg-warning "format" "float" } */
