[PATCH]: PR c/22476 -Wmissing-format-attribute [take 2]
Kaveh R. Ghazi
ghazi@caipclassic.rutgers.edu
Sat Jul 16 12:23:00 GMT 2005
This version incorporates the previous feedback, includes a ChangeLog
and has been bootstrapped/regtested on x86_64-unknown-linux-gnu with
no regressions plus all the new testcases pass.
Okay for mainline?
Thanks,
--Kaveh
2005-07-15 Kaveh R. Ghazi <ghazi@caip.rutgers.edu>
PR c/22476
* c-typeck.c (convert_for_assignment): Detect additional cases for
-Wmissing-format-attribute.
(digest_init): Call 'convert_for_assignment' before returning.
* doc/invoke.texi (-Wmissing-format-attribute): Document new
behavior.
cp:
* call.c (diagnostic_fn_t): New.
(build_temp, convert_like_real): Use diagnostic_fn_t.
testsuite:
* gcc.dg/format/miss-3.c, gcc.dg/format/miss-4.c,
gcc.dg/format/miss-5.c, gcc.dg/format/miss-6.c: New.
diff -rup orig/egcc-CVS20050714/gcc/c-typeck.c egcc-CVS20050714/gcc/c-typeck.c
--- orig/egcc-CVS20050714/gcc/c-typeck.c 2005-07-05 20:01:52.000000000 -0400
+++ egcc-CVS20050714/gcc/c-typeck.c 2005-07-15 10:49:31.708181415 -0400
@@ -3793,6 +3793,51 @@ convert_for_assignment (tree type, tree
warning (OPT_Wc___compat, "request for implicit conversion from "
"%qT to %qT not permitted in C++", rhstype, type);
+ /* Check if the right-hand side has a format attribute but the
+ left-hand side doesn't. */
+ if (warn_missing_format_attribute)
+ {
+ tree rattrs = TYPE_ATTRIBUTES (ttr), ra;
+ for (ra = rattrs; ra; ra = TREE_CHAIN (ra))
+ {
+ if (is_attribute_p ("format", TREE_PURPOSE (ra)))
+ break;
+ }
+ if (ra)
+ {
+ tree lattrs = TYPE_ATTRIBUTES (ttl), la;
+ for (la = lattrs; la; la = TREE_CHAIN (la))
+ {
+ if (is_attribute_p ("format", TREE_PURPOSE (la)))
+ break;
+ }
+ if (!la)
+ switch (errtype)
+ {
+ case ic_argpass:
+ case ic_argpass_nonproto:
+ warning (0, "argument %d of %qE might be "
+ "a candidate for a format attribute",
+ parmnum, rname);
+ break;
+ case ic_assign:
+ warning (0, "assignment left-hand side might be "
+ "a candidate for a format attribute");
+ break;
+ case ic_init:
+ warning (0, "initialization left-hand side might be "
+ "a candidate for a format attribute");
+ break;
+ case ic_return:
+ warning (0, "return type might be "
+ "a candidate for a format attribute");
+ break;
+ default:
+ gcc_unreachable ();
+ }
+ }
+ }
+
/* Any non-function converts to a [const][volatile] void *
and vice versa; otherwise, targets must be the same.
Meanwhile, the lhs target must have all the qualifiers of the rhs. */
@@ -4442,6 +4487,10 @@ digest_init (tree type, tree init, bool
inside_init = error_mark_node;
}
+ /* Added to enable additional -Wmissing-format-attribute warnings. */
+ if (TREE_CODE (TREE_TYPE (inside_init)) == POINTER_TYPE)
+ inside_init = convert_for_assignment (type, inside_init, ic_init, NULL_TREE,
+ NULL_TREE, 0);
return inside_init;
}
diff -rup orig/egcc-CVS20050714/gcc/cp/call.c egcc-CVS20050714/gcc/cp/call.c
--- orig/egcc-CVS20050714/gcc/cp/call.c 2005-07-02 20:01:21.000000000 -0400
+++ egcc-CVS20050714/gcc/cp/call.c 2005-07-15 09:50:56.355491111 -0400
@@ -194,7 +194,8 @@ static void add_candidates (tree, tree,
int, struct z_candidate **);
static conversion *merge_conversion_sequences (conversion *, conversion *);
static bool magic_varargs_p (tree);
-static tree build_temp (tree, tree, int, void (**)(const char *, ...));
+typedef void (*diagnostic_fn_t) (const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
+static tree build_temp (tree, tree, int, diagnostic_fn_t *);
static void check_constructor_callable (tree, tree);
/* Returns nonzero iff the destructor name specified in NAME
@@ -4087,7 +4088,7 @@ check_constructor_callable (tree type, t
static tree
build_temp (tree expr, tree type, int flags,
- void (**diagnostic_fn)(const char *, ...))
+ diagnostic_fn_t *diagnostic_fn)
{
int savew, savee;
@@ -4122,7 +4123,7 @@ convert_like_real (conversion *convs, tr
bool c_cast_p)
{
tree totype = convs->type;
- void (*diagnostic_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
+ diagnostic_fn_t diagnostic_fn;
if (convs->bad_p
&& convs->kind != ck_user
diff -rup orig/egcc-CVS20050714/gcc/doc/invoke.texi egcc-CVS20050714/gcc/doc/invoke.texi
--- orig/egcc-CVS20050714/gcc/doc/invoke.texi 2005-07-13 20:01:58.000000000 -0400
+++ egcc-CVS20050714/gcc/doc/invoke.texi 2005-07-15 11:01:27.511412880 -0400
@@ -3126,14 +3126,23 @@ hosted C environments.
@item -Wmissing-format-attribute
@opindex Wmissing-format-attribute
@opindex Wformat
-If @option{-Wformat} is enabled, also warn about functions which might be
-candidates for @code{format} attributes. Note these are only possible
-candidates, not absolute ones. GCC will guess that @code{format}
-attributes might be appropriate for any function that calls a function
-like @code{vprintf} or @code{vscanf}, but this might not always be the
-case, and some functions for which @code{format} attributes are
-appropriate may not be detected. This option has no effect unless
-@option{-Wformat} is enabled (possibly by @option{-Wall}).
+Warn about function pointers which might be candidates for @code{format}
+attributes. Note these are only possible candidates, not absolute ones.
+GCC will guess that function pointers with @code{format} attributes that
+are used in assignment, initialization, parameter passing or return
+statements should have a corresponding @code{format} attribute in the
+resulting type. I.e.@: the left-hand side of the assignment or
+initialization, the type of the parameter variable, or the return type
+of the containing function respectively should also have a @code{format}
+attribute to avoid the warning.
+
+If @option{-Wformat} is enabled (possibly by @option{-Wall}), also warn
+about function definitions which might be candidates for @code{format}
+attributes. Again, these are only possible candidates. GCC will guess
+that @code{format} attributes might be appropriate for any function that
+calls a function like @code{vprintf} or @code{vscanf}, but this might
+not always be the case, and some functions for which @code{format}
+attributes are appropriate may not be detected.
@item -Wno-multichar
@opindex Wno-multichar
diff -rup orig/egcc-CVS20050714/gcc/testsuite/gcc.dg/format/miss-3.c egcc-CVS20050714/gcc/testsuite/gcc.dg/format/miss-3.c
--- orig/egcc-CVS20050714/gcc/testsuite/gcc.dg/format/miss-3.c 2005-07-15 11:04:30.284341598 -0400
+++ egcc-CVS20050714/gcc/testsuite/gcc.dg/format/miss-3.c 2005-07-15 09:50:56.355491111 -0400
@@ -0,0 +1,26 @@
+/* Test warnings for missing format attributes on function pointers. */
+/* Origin: Kaveh Ghazi <ghazi@caip.rutgers.edu> */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu99 -Wformat -Wmissing-format-attribute" } */
+
+#include "format.h"
+
+typedef void (*noattr_t) (const char *, ...);
+typedef noattr_t __attribute__ ((__format__(__printf__, 1, 2))) attr_t;
+
+typedef void (*vnoattr_t) (const char *, va_list);
+typedef vnoattr_t __attribute__ ((__format__(__printf__, 1, 0))) vattr_t;
+
+void
+foo1 (noattr_t na, attr_t a, vnoattr_t vna, vattr_t va)
+{
+ noattr_t na1 = na;
+ noattr_t na2 = a; /* { dg-warning "candidate" "initialization warning" } */
+ attr_t a1 = na;
+ attr_t a2 = a;
+
+ vnoattr_t vna1 = vna;
+ vnoattr_t vna2 = va; /* { dg-warning "candidate" "initialization warning" } */
+ vattr_t va1 = vna;
+ vattr_t va2 = va;
+}
diff -rup orig/egcc-CVS20050714/gcc/testsuite/gcc.dg/format/miss-4.c egcc-CVS20050714/gcc/testsuite/gcc.dg/format/miss-4.c
--- orig/egcc-CVS20050714/gcc/testsuite/gcc.dg/format/miss-4.c 2005-07-15 11:04:31.704249631 -0400
+++ egcc-CVS20050714/gcc/testsuite/gcc.dg/format/miss-4.c 2005-07-15 09:50:56.355491111 -0400
@@ -0,0 +1,32 @@
+/* Test warnings for missing format attributes on function pointers. */
+/* Origin: Kaveh Ghazi <ghazi@caip.rutgers.edu> */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu99 -Wformat -Wmissing-format-attribute" } */
+
+#include "format.h"
+
+typedef void (*noattr_t) (const char *, ...);
+typedef noattr_t __attribute__ ((__format__(__printf__, 1, 2))) attr_t;
+
+typedef void (*vnoattr_t) (const char *, va_list);
+typedef vnoattr_t __attribute__ ((__format__(__printf__, 1, 0))) vattr_t;
+
+void
+foo1 (noattr_t na, attr_t a, vnoattr_t vna, vattr_t va)
+{
+ noattr_t na1, na2;
+ attr_t a1, a2;
+
+ vnoattr_t vna1, vna2;
+ vattr_t va1, va2;
+
+ na1 = na;
+ na2 = a; /* { dg-warning "candidate" "assignment warning" } */
+ a1 = na;
+ a2 = a;
+
+ vna1 = vna;
+ vna2 = va; /* { dg-warning "candidate" "assignment warning" } */
+ va1 = vna;
+ va1 = va;
+}
diff -rup orig/egcc-CVS20050714/gcc/testsuite/gcc.dg/format/miss-5.c egcc-CVS20050714/gcc/testsuite/gcc.dg/format/miss-5.c
--- orig/egcc-CVS20050714/gcc/testsuite/gcc.dg/format/miss-5.c 2005-07-15 11:04:33.184061609 -0400
+++ egcc-CVS20050714/gcc/testsuite/gcc.dg/format/miss-5.c 2005-07-15 09:50:56.355491111 -0400
@@ -0,0 +1,48 @@
+/* Test warnings for missing format attributes on function pointers. */
+/* Origin: Kaveh Ghazi <ghazi@caip.rutgers.edu> */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu99 -Wformat -Wmissing-format-attribute" } */
+
+#include "format.h"
+
+typedef void (*noattr_t) (const char *, ...);
+typedef noattr_t __attribute__ ((__format__(__printf__, 1, 2))) attr_t;
+
+typedef void (*vnoattr_t) (const char *, va_list);
+typedef vnoattr_t __attribute__ ((__format__(__printf__, 1, 0))) vattr_t;
+
+noattr_t
+foo1 (noattr_t na, attr_t a, int i)
+{
+ if (i)
+ return na;
+ else
+ return a; /* { dg-warning "candidate" "return type warning" } */
+}
+
+attr_t
+foo2 (noattr_t na, attr_t a, int i)
+{
+ if (i)
+ return na;
+ else
+ return a;
+}
+
+vnoattr_t
+foo3 (vnoattr_t vna, vattr_t va, int i)
+{
+ if (i)
+ return vna;
+ else
+ return va; /* { dg-warning "candidate" "return type warning" } */
+}
+
+vattr_t
+foo4 (vnoattr_t vna, vattr_t va, int i)
+{
+ if (i)
+ return vna;
+ else
+ return va;
+}
diff -rup orig/egcc-CVS20050714/gcc/testsuite/gcc.dg/format/miss-6.c egcc-CVS20050714/gcc/testsuite/gcc.dg/format/miss-6.c
--- orig/egcc-CVS20050714/gcc/testsuite/gcc.dg/format/miss-6.c 2005-07-15 11:04:34.923874680 -0400
+++ egcc-CVS20050714/gcc/testsuite/gcc.dg/format/miss-6.c 2005-07-15 09:50:56.365491133 -0400
@@ -0,0 +1,31 @@
+/* Test warnings for missing format attributes on function pointers. */
+/* Origin: Kaveh Ghazi <ghazi@caip.rutgers.edu> */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu99 -Wformat -Wmissing-format-attribute" } */
+
+#include "format.h"
+
+typedef void (*noattr_t) (const char *, ...);
+typedef noattr_t __attribute__ ((__format__(__printf__, 1, 2))) attr_t;
+
+typedef void (*vnoattr_t) (const char *, va_list);
+typedef vnoattr_t __attribute__ ((__format__(__printf__, 1, 0))) vattr_t;
+
+extern void foo1 (noattr_t);
+extern void foo2 (attr_t);
+extern void foo3 (vnoattr_t);
+extern void foo4 (vattr_t);
+
+void
+foo (noattr_t na, attr_t a, vnoattr_t vna, vattr_t va)
+{
+ foo1 (na);
+ foo1 (a); /* { dg-warning "candidate" "parameter passing warning" } */
+ foo2 (na);
+ foo2 (a);
+
+ foo3 (vna);
+ foo3 (va); /* { dg-warning "candidate" "parameter passing warning" } */
+ foo4 (vna);
+ foo4 (va);
+}
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