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Re: [testcase] Simplified testcases why current gcc trunk cannot compile glibc


On Oct 15, 2001, Jakub Jelinek <jakub@redhat.com> wrote:

> I prefer something like __attribute__((used)) and __attribute__((noinline)),

How about this?  Ok to install?  Tested on athlon-pc-linux-gnu.

Index: gcc/ChangeLog
from  Alexandre Oliva  <aoliva@redhat.com>

	* attribs.c (handle_noinline_attribute): New function.
	(handle_used_attribute): Likewise.
	(c_common_attribute_table): Added noinline and used.
	* doc/extend.texi (Function Attributes): Document them.
	* c-decl.c (duplicate_decls): Propagate DECL_UNINLINABLE.

Index: gcc/cp/ChangeLog
from  Alexandre Oliva  <aoliva@redhat.com>

	* decl.c (duplicate_decls): Propagate DECL_UNINLINABLE.

Index: gcc/testsuite/ChangeLog
from  Alexandre Oliva  <aoliva@redhat.com>

	* gcc.dg/attr-noinline.c, gcc.dg/attr-used.c: New tests.

Index: gcc/attribs.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/attribs.c,v
retrieving revision 1.2
diff -u -p -r1.2 attribs.c
--- gcc/attribs.c 2001/10/02 07:12:20 1.2
+++ gcc/attribs.c 2001/10/17 18:56:10
@@ -49,6 +49,10 @@ static tree handle_common_attribute	PARA
 						 bool *));
 static tree handle_noreturn_attribute	PARAMS ((tree *, tree, tree, int,
 						 bool *));
+static tree handle_noinline_attribute	PARAMS ((tree *, tree, tree, int,
+						 bool *));
+static tree handle_used_attribute	PARAMS ((tree *, tree, tree, int,
+						 bool *));
 static tree handle_unused_attribute	PARAMS ((tree *, tree, tree, int,
 						 bool *));
 static tree handle_const_attribute	PARAMS ((tree *, tree, tree, int,
@@ -100,6 +104,10 @@ static const struct attribute_spec c_com
 			      handle_noreturn_attribute },
   { "volatile",               0, 0, true,  false, false,
 			      handle_noreturn_attribute },
+  { "noinline",               0, 0, true,  false, false,
+			      handle_noinline_attribute },
+  { "used",                   0, 0, true,  false, false,
+			      handle_used_attribute },
   { "unused",                 0, 0, false, false, false,
 			      handle_unused_attribute },
   /* The same comments as for noreturn attributes apply to const ones.  */
@@ -500,6 +508,53 @@ handle_noreturn_attribute (node, name, a
       = build_pointer_type
 	(build_type_variant (TREE_TYPE (type),
 			     TREE_READONLY (TREE_TYPE (type)), 1));
+  else
+    {
+      warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
+      *no_add_attrs = true;
+    }
+
+  return NULL_TREE;
+}
+
+/* Handle a "noinline" attribute; arguments as in
+   struct attribute_spec.handler.  */
+
+static tree
+handle_noinline_attribute (node, name, args, flags, no_add_attrs)
+     tree *node;
+     tree name;
+     tree args ATTRIBUTE_UNUSED;
+     int flags ATTRIBUTE_UNUSED;
+     bool *no_add_attrs;
+{
+  tree type = TREE_TYPE (*node);
+
+  if (TREE_CODE (*node) == FUNCTION_DECL)
+    DECL_UNINLINABLE (*node) = 1;
+  else
+    {
+      warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
+      *no_add_attrs = true;
+    }
+
+  return NULL_TREE;
+}
+
+/* Handle a "used" attribute; arguments as in
+   struct attribute_spec.handler.  */
+
+static tree
+handle_used_attribute (node, name, args, flags, no_add_attrs)
+     tree *node;
+     tree name;
+     tree args ATTRIBUTE_UNUSED;
+     int flags ATTRIBUTE_UNUSED;
+     bool *no_add_attrs;
+{
+  if (TREE_CODE (*node) == FUNCTION_DECL)
+    TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (*node))
+      = TREE_USED (*node) = 1;
   else
     {
       warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name));
Index: gcc/c-decl.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/c-decl.c,v
retrieving revision 1.254
diff -u -p -r1.254 c-decl.c
--- gcc/c-decl.c 2001/10/11 03:15:18 1.254
+++ gcc/c-decl.c 2001/10/17 18:56:11
@@ -1983,6 +1983,11 @@ duplicate_decls (newdecl, olddecl, diffe
 	    DECL_DECLARED_INLINE_P (olddecl) = 1;
 
 	  DECL_DECLARED_INLINE_P (newdecl) = DECL_DECLARED_INLINE_P (olddecl);
+
+	  /* If either decl has attribute `noinline', make both
+             uninlinable.  */
+	  DECL_UNINLINABLE (newdecl) = DECL_UNINLINABLE (olddecl)
+	    = (DECL_UNINLINABLE (newdecl) || DECL_UNINLINABLE (olddecl));
 	}
 
       if (DECL_BUILT_IN (olddecl))
Index: gcc/cp/decl.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/cp/decl.c,v
retrieving revision 1.820
diff -u -p -r1.820 decl.c
--- gcc/cp/decl.c 2001/10/16 13:01:44 1.820
+++ gcc/cp/decl.c 2001/10/17 18:56:12
@@ -3640,6 +3640,11 @@ duplicate_decls (newdecl, olddecl)
 	DECL_INLINE (olddecl) = 1;
       DECL_INLINE (newdecl) = DECL_INLINE (olddecl);
 
+      /* If either decl has attribute `noinline', make both
+	 uninlinable.  */
+      DECL_UNINLINABLE (newdecl) = DECL_UNINLINABLE (olddecl)
+	= (DECL_UNINLINABLE (newdecl) || DECL_UNINLINABLE (olddecl));
+
       /* Preserve abstractness on cloned [cd]tors.  */
       DECL_ABSTRACT (newdecl) = DECL_ABSTRACT (olddecl);
 
Index: gcc/doc/extend.texi
===================================================================
RCS file: /cvs/gcc/egcs/gcc/doc/extend.texi,v
retrieving revision 1.31
diff -u -p -r1.31 extend.texi
--- gcc/doc/extend.texi 2001/10/11 07:07:30 1.31
+++ gcc/doc/extend.texi 2001/10/17 18:56:13
@@ -1925,13 +1925,14 @@ carefully.
 
 The keyword @code{__attribute__} allows you to specify special
 attributes when making a declaration.  This keyword is followed by an
-attribute specification inside double parentheses.  Fourteen attributes,
-@code{noreturn}, @code{pure}, @code{const}, @code{format},
-@code{format_arg}, @code{no_instrument_function}, @code{section},
-@code{constructor}, @code{destructor}, @code{unused}, @code{weak},
-@code{malloc}, @code{alias} and @code{no_check_memory_usage} are
-currently defined for functions.  Several other attributes are defined
-for functions on particular target systems.  Other attributes, including
+attribute specification inside double parentheses.  The following
+attributs are currently defined for functions on all targets:
+@code{noreturn}, @code{noinline}, @code{pure}, @code{const},
+@code{format}, @code{format_arg}, @code{no_instrument_function},
+@code{section}, @code{constructor}, @code{destructor}, @code{used},
+@code{unused}, @code{weak}, @code{malloc}, @code{alias} and
+@code{no_check_memory_usage}.  Several other attributes are defined for
+functions on particular target systems.  Other attributes, including
 @code{section} are supported for variables declarations (@pxref{Variable
 Attributes}) and for types (@pxref{Type Attributes}).
 
@@ -1987,6 +1988,11 @@ typedef void voidfn ();
 volatile voidfn fatal;
 @end smallexample
 
+@cindex @code{noinline} function attribute
+@item noinline
+This function attribute prevents a function from being considered for
+inlining.
+
 @cindex @code{pure} function attribute
 @item pure
 Many functions have no effects except the return value and their
@@ -2174,11 +2180,19 @@ the program.
 
 These attributes are not currently implemented for Objective-C@.
 
+@cindex @code{unused} attribute.
 @item unused
 This attribute, attached to a function, means that the function is meant
 to be possibly unused.  GCC will not produce a warning for this
 function.  GNU C++ does not currently support this attribute as
 definitions without parameters are valid in C++.
+
+@cindex @code{used} attribute.
+@item used
+This attribute, attached to a function, means that code must be emitted
+for the function even if it appears that the function is not referenced.
+This is useful, for example, when the function is referenced only in
+inline assembly.
 
 @item weak
 @cindex @code{weak} attribute
Index: gcc/testsuite/gcc.dg/attr-noinline.c
===================================================================
RCS file: attr-noinline.c
diff -N attr-noinline.c
--- /dev/null	Tue May  5 13:32:27 1998
+++ gcc/testsuite/gcc.dg/attr-noinline.c Wed Oct 17 12:03:08 2001
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+extern inline void function_declaration_before(void) __attribute__((__noinline__));
+
+extern inline void function_declaration_before(void) {}
+
+extern inline void function_declaration_after(void) {}
+
+extern inline void function_declaration_after(void) __attribute__((__noinline__));
+
+int f () {
+  function_declaration_before ();
+  function_declaration_after ();
+}
+
+/* { dg-final { scan-assembler "function_declaration_before" } } */
+/* { dg-final { scan-assembler "function_declaration_after" } } */
Index: gcc/testsuite/gcc.dg/attr-used.c
===================================================================
RCS file: attr-used.c
diff -N attr-used.c
--- /dev/null	Tue May  5 13:32:27 1998
+++ gcc/testsuite/gcc.dg/attr-used.c Wed Oct 17 12:03:08 2001
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O3" } */
+
+static void function_declaration_before(void) __attribute__((__used__));
+
+static void function_declaration_before(void) {}
+
+static void function_declaration_after(void) {}
+
+static void function_declaration_after(void) __attribute__((__used__));
+
+/* { dg-final { scan-assembler "function_declaration_before" } } */
+/* { dg-final { scan-assembler "function_declaration_after" } } */

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer                  aoliva@{cygnus.com, redhat.com}
CS PhD student at IC-Unicamp        oliva@{lsd.ic.unicamp.br, gnu.org}
Free Software Evangelist    *Please* write to mailing lists, not to me

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