From: Jakub Jelinek <jakub@redhat.com>
Date: Wed, 27 Jan 2016 19:32:49 +0000 (+0100)
Subject: re PR debug/66869 (-Wunused-function no longer warns for static declarations without... 
X-Git-Tag: basepoints/gcc-7~1272
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cbdd8ae08c2cec98ed063a0ef2c237e80539e597;p=thirdparty%2Fgcc.git

re PR debug/66869 (-Wunused-function no longer warns for static declarations without definition)

	PR debug/66869
	* c-decl.c (c_write_global_declarations_1): Warn with
	warn_unused_function if static prototype without definition
	is not C_DECL_USED.

	* gcc.dg/pr66869.c: New test.

From-SVN: r232899
---

diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog
index 7999d2a987a8..5341f044d284 100644
--- a/gcc/c/ChangeLog
+++ b/gcc/c/ChangeLog
@@ -1,3 +1,10 @@
+2016-01-27  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/66869
+	* c-decl.c (c_write_global_declarations_1): Warn with
+	warn_unused_function if static prototype without definition
+	is not C_DECL_USED.
+
 2016-01-27  Marek Polacek  <polacek@redhat.com>
 
 	PR c/68062
diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
index 1ec60420db9c..502fa5c70569 100644
--- a/gcc/c/c-decl.c
+++ b/gcc/c/c-decl.c
@@ -10741,11 +10741,22 @@ c_write_global_declarations_1 (tree globals)
       if (TREE_CODE (decl) == FUNCTION_DECL
 	  && DECL_INITIAL (decl) == 0
 	  && DECL_EXTERNAL (decl)
-	  && !TREE_PUBLIC (decl)
-	  && C_DECL_USED (decl))
+	  && !TREE_PUBLIC (decl))
 	{
-	  pedwarn (input_location, 0, "%q+F used but never defined", decl);
-	  TREE_NO_WARNING (decl) = 1;
+	  if (C_DECL_USED (decl))
+	    {
+	      pedwarn (input_location, 0, "%q+F used but never defined", decl);
+	      TREE_NO_WARNING (decl) = 1;
+	    }
+	  /* For -Wunused-function warn about unused static prototypes.  */
+	  else if (warn_unused_function
+		   && ! DECL_ARTIFICIAL (decl)
+		   && ! TREE_NO_WARNING (decl))
+	    {
+	      warning (OPT_Wunused_function,
+		       "%q+F declared %<static%> but never defined", decl);
+	      TREE_NO_WARNING (decl) = 1;
+	    }
 	}
 
       wrapup_global_declaration_1 (decl);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 22a124a1ab39..1ee941396ce5 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-01-27  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/66869
+	* gcc.dg/pr66869.c: New test.
+
 2016-01-25  Jeff Law  <law@redhat.com>
 
 	PR tree-optimization/68398
diff --git a/gcc/testsuite/gcc.dg/pr66869.c b/gcc/testsuite/gcc.dg/pr66869.c
new file mode 100644
index 000000000000..916d1419982c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr66869.c
@@ -0,0 +1,6 @@
+/* PR debug/66869 */
+/* { dg-do compile } */
+/* { dg-options "-Wunused-function" } */
+
+static void test (void); /* { dg-warning "'test' declared 'static' but never defined" } */
+int i;