PR c/22476

	* c-common.c (check_function_arguments): Call
	'check_function_format' if either -Wformat or
	-Wmissing-format-attribute are specified.
	* c-format.c (check_function_format): Check -Wformat before
	calling 'check_format_info'.
	* c-opts.c (c_common_post_options): Don't warn for
	-Wmissing-format-attribute without -Wformat.
	* c-typeck.c (convert_for_assignment): Detect additional cases for
	-Wmissing-format-attribute.
	* doc/invoke.texi (-Wmissing-format-attribute): Document new
	behavior.

testsuite:
	* gcc.dg/format/miss-1.c, gcc.dg/format/miss-2.c: Don't
	specify -Wformat for these tests.
	* 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.
	* gcc.dg/format/opt-6.c: Delete.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@102155 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6bf8c3f..f87dac1 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,18 @@
+2005-07-19  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
+
+       PR c/22476
+       * c-common.c (check_function_arguments): Call
+       'check_function_format' if either -Wformat or
+       -Wmissing-format-attribute are specified.
+       * c-format.c (check_function_format): Check -Wformat before
+       calling 'check_format_info'.
+       * c-opts.c (c_common_post_options): Don't warn for
+       -Wmissing-format-attribute without -Wformat.
+       * c-typeck.c (convert_for_assignment): Detect additional cases for
+       -Wmissing-format-attribute.
+       * doc/invoke.texi (-Wmissing-format-attribute): Document new
+       behavior.
+
 2005-07-19  Richard Guenther  <rguenther@suse.de>
 
        * config/i386/i386.md (lrint<mode>2): Use temporary

diff --git a/gcc/c-common.c b/gcc/c-common.c
index f7463e1..90a373c 100644 (file)
--- a/gcc/c-common.c
+++ b/gcc/c-common.c
@@ -5505,11 +5505,11 @@ check_function_arguments (tree attrs, tree params, tree typelist)
 
   /* Check for errors in format strings.  */
 
-  if (warn_format)
-    {
+  if (warn_format || warn_missing_format_attribute)
       check_function_format (attrs, params);
-      check_function_sentinel (attrs, params, typelist);
-    }
+
+  if (warn_format)
+    check_function_sentinel (attrs, params, typelist);
 }
 
 /* Generic argument checking recursion routine.  PARAM is the argument to

diff --git a/gcc/c-format.c b/gcc/c-format.c
index 10a5f21..587f15e 100644 (file)
--- a/gcc/c-format.c
+++ b/gcc/c-format.c
@@ -864,7 +864,8 @@ check_function_format (tree attrs, tree params)
          /* Yup; check it.  */
          function_format_info info;
          decode_format_attr (TREE_VALUE (a), &info, 1);
-         check_format_info (&info, params);
+         if (warn_format)
+           check_format_info (&info, params);
          if (warn_missing_format_attribute && info.first_arg_num == 0
              && (format_types[info.format_type].flags
                  & (int) FMT_FLAG_ARG_CONVERT))

diff --git a/gcc/c-opts.c b/gcc/c-opts.c
index b1dcc04..e353119 100644 (file)
--- a/gcc/c-opts.c
+++ b/gcc/c-opts.c
@@ -991,8 +991,6 @@ c_common_post_options (const char **pfilename)
               "-Wformat-nonliteral ignored without -Wformat");
       warning (OPT_Wformat_security,
               "-Wformat-security ignored without -Wformat");
-      warning (OPT_Wmissing_format_attribute,
-              "-Wmissing-format-attribute ignored without -Wformat");
     }
 
   /* C99 requires special handling of complex multiplication and division;

diff --git a/gcc/c-typeck.c b/gcc/c-typeck.c
index 907a4fc..928084f 100644 (file)
--- a/gcc/c-typeck.c
+++ b/gcc/c-typeck.c
@@ -3793,6 +3793,55 @@ convert_for_assignment (tree type, tree rhs, enum impl_conv errtype,
         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 (OPT_Wmissing_format_attribute,
+                            "argument %d of %qE might be "
+                            "a candidate for a format attribute",
+                            parmnum, rname);
+                   break;
+                 case ic_assign:
+                   warning (OPT_Wmissing_format_attribute,
+                            "assignment left-hand side might be "
+                            "a candidate for a format attribute");
+                   break;
+                 case ic_init:
+                   warning (OPT_Wmissing_format_attribute,
+                            "initialization left-hand side might be "
+                            "a candidate for a format attribute");
+                   break;
+                 case ic_return:
+                   warning (OPT_Wmissing_format_attribute,
+                            "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.  */

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index ba355c0..d4a504b 100644 (file)
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -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
+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.
+
+GCC will 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.  This option has no effect unless
-@option{-Wformat} is enabled (possibly by @option{-Wall}).
+appropriate may not be detected.
 
 @item -Wno-multichar
 @opindex Wno-multichar

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 41039c9..3032a0a 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2005-07-19  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
+
+       * gcc.dg/format/miss-1.c, gcc.dg/format/miss-2.c: Don't
+       specify -Wformat for these tests.
+       * 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.
+       * gcc.dg/format/opt-6.c: Delete.
+
 2005-07-18  Andrew Pinski  <pinskia@physics.uc.edu>
 
        * gcc.dg/tree-ssa/sra-2.c: Pass --param sra-max-structure-size.

diff --git a/gcc/testsuite/gcc.dg/format/miss-1.c b/gcc/testsuite/gcc.dg/format/miss-1.c
index 2345785..839f296 100644 (file)
--- a/gcc/testsuite/gcc.dg/format/miss-1.c
+++ b/gcc/testsuite/gcc.dg/format/miss-1.c
@@ -1,7 +1,7 @@
 /* Test for warnings for missing format attributes.  */
 /* Origin: Joseph Myers <jsm28@cam.ac.uk> */
 /* { dg-do compile } */
-/* { dg-options "-std=gnu99 -Wformat -Wmissing-format-attribute" } */
+/* { dg-options "-std=gnu99 -Wmissing-format-attribute" } */
 
 #include "format.h"
 

diff --git a/gcc/testsuite/gcc.dg/format/miss-2.c b/gcc/testsuite/gcc.dg/format/miss-2.c
index f3afe24..241b22d 100644 (file)
--- a/gcc/testsuite/gcc.dg/format/miss-2.c
+++ b/gcc/testsuite/gcc.dg/format/miss-2.c
@@ -2,7 +2,7 @@
    relevant parameters for a format attribute; see c/1017.  */
 /* Origin: Joseph Myers <jsm28@cam.ac.uk> */
 /* { dg-do compile } */
-/* { dg-options "-std=gnu99 -Wformat -Wmissing-format-attribute" } */
+/* { dg-options "-std=gnu99 -Wmissing-format-attribute" } */
 
 #include "format.h"
 

diff --git a/gcc/testsuite/gcc.dg/format/miss-3.c b/gcc/testsuite/gcc.dg/format/miss-3.c
new file mode 100644 (file)
index 0000000..c588bed
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/format/miss-3.c
@@ -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 -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 --git a/gcc/testsuite/gcc.dg/format/miss-4.c b/gcc/testsuite/gcc.dg/format/miss-4.c
new file mode 100644 (file)
index 0000000..9be5e4d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/format/miss-4.c
@@ -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 -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 --git a/gcc/testsuite/gcc.dg/format/miss-5.c b/gcc/testsuite/gcc.dg/format/miss-5.c
new file mode 100644 (file)
index 0000000..eaf1473
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/format/miss-5.c
@@ -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 -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 --git a/gcc/testsuite/gcc.dg/format/miss-6.c b/gcc/testsuite/gcc.dg/format/miss-6.c
new file mode 100644 (file)
index 0000000..abe221f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/format/miss-6.c
@@ -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 -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);
+}

diff --git a/gcc/testsuite/gcc.dg/format/opt-6.c b/gcc/testsuite/gcc.dg/format/opt-6.c
deleted file mode 100644 (file)
index 140da30..0000000
--- a/gcc/testsuite/gcc.dg/format/opt-6.c
+++ /dev/null
@@ -1,7 +0,0 @@
-/* Test diagnostics for options used on their own without
-   -Wformat.  -Wmissing-format-attribute.  */
-/* Origin: Joseph Myers <joseph@codesourcery.com> */
-/* { dg-do compile } */
-/* { dg-options "-Wmissing-format-attribute" } */
-
-/* { dg-warning "warning: -Wmissing-format-attribute ignored without -Wformat" "ignored" { target *-*-* } 0 } */