From: Steven Bosscher <stevenb.gcc@gmail.com>
To: GCC Patches <gcc-patches@gcc.gnu.org>,
java-patches@gcc.gnu.org,
Richard Guenther <richard.guenther@gmail.com>
Subject: [patch] Do not call output_constant from the front end
Date: Tue, 27 Mar 2012 20:36:00 -0000 [thread overview]
Message-ID: <CABu31nPAkz+xn4OVa-N+zee0b44TYd-rqQgSVg=m7+NxOMyTqg@mail.gmail.com> (raw)
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Hello,
The Java front end emits assembly from class.c:emit_register_classes()
to fill the .jcr section. This is not something a front end ought to
be doing. Things to write out to the assembler output file should go
through the varpool/varasm mechanism. The attached patch makes
emit_register_classes build a constructor for the .jcr section, and
stops it calling output_constant.
The patch passes build+testing on powerpc64-unknown-linux-gnu.
With this patch a variable named "_Jv_CLS" is written out. The
assembly before and after the patch is the same, except for the
variable name. I want to write out a nameless variable but I don't
know how. Help welcome.
Ciao!
Steven
java/
PR java/52730
* class.c (emit_register_classes_in_jcr_section): New function.
(emit_Jv_RegisterClass_calls): New function, split out from ...
(emit_register_classes): ... here. Reorganize. Do not call
output_constant.
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java/
* class.c (emit_register_classes_in_jcr_section): New function.
(emit_Jv_RegisterClass_calls): New function, split out from ...
(emit_register_classes): ... here. Reorganize. Do not call
output_constant.
Index: class.c
===================================================================
--- class.c (revision 185813)
+++ class.c (working copy)
@@ -2786,10 +2786,75 @@ emit_indirect_register_classes (tree *list_p)
append_to_statement_list (t, list_p);
}
+/* Emit a list of pointers to all classes we have emitted to JCR_SECTION. */
+static void
+emit_register_classes_in_jcr_section (void)
+{
+ tree klass, cdecl, class_array_type;
+ int i;
+ int size = VEC_length (tree, registered_class);
+ VEC(constructor_elt,gc) *init = VEC_alloc (constructor_elt, gc, size);
+
+#ifndef JCR_SECTION_NAME
+ /* A target has defined TARGET_USE_JCR_SECTION,
+ but doesn't have a JCR_SECTION_NAME. */
+ gcc_unreachable ();
+#endif
+
+ FOR_EACH_VEC_ELT (tree, registered_class, i, klass)
+ CONSTRUCTOR_APPEND_ELT (init, NULL_TREE, build_fold_addr_expr (klass));
+
+ class_array_type = build_prim_array_type (ptr_type_node, size);
+ cdecl = build_decl (UNKNOWN_LOCATION,
+ VAR_DECL, get_identifier ("_Jv_CLS"),
+ class_array_type);
+ DECL_SECTION_NAME (cdecl) = build_string (strlen (JCR_SECTION_NAME),
+ JCR_SECTION_NAME);
+ DECL_ALIGN (cdecl) = POINTER_SIZE;
+ DECL_INITIAL (cdecl) = build_constructor (class_array_type, init);
+ TREE_CONSTANT (DECL_INITIAL (cdecl)) = 1;
+ TREE_STATIC (cdecl) = 1;
+ DECL_ARTIFICIAL (cdecl) = 1;
+ DECL_IGNORED_P (cdecl) = 1;
+ TREE_READONLY (cdecl) = 1;
+ TREE_CONSTANT (cdecl) = 1;
+ pushdecl_top_level (cdecl);
+ relayout_decl (cdecl);
+ rest_of_decl_compilation (cdecl, 1, 0);
+ mark_decl_referenced (cdecl);
+}
+
+
+/* Emit a series of calls to _Jv_RegisterClass for every class we emitted.
+ A series of calls is added to LIST_P. */
+
+static void
+emit_Jv_RegisterClass_calls (tree *list_p)
+{
+ tree klass, t, register_class_fn;
+ int i;
+
+ t = build_function_type_list (void_type_node, class_ptr_type, NULL);
+ t = build_decl (input_location,
+ FUNCTION_DECL, get_identifier ("_Jv_RegisterClass"), t);
+ TREE_PUBLIC (t) = 1;
+ DECL_EXTERNAL (t) = 1;
+ register_class_fn = t;
+
+ FOR_EACH_VEC_ELT (tree, registered_class, i, klass)
+ {
+ t = build_fold_addr_expr (klass);
+ t = build_call_expr (register_class_fn, 1, t);
+ append_to_statement_list (t, list_p);
+ }
+}
+
/* Emit something to register classes at start-up time.
- The preferred mechanism is through the .jcr section, which contain
+ The default mechanism is to generate instances at run-time.
+
+ An alternative mechanism is through the .jcr section, which contain
a list of pointers to classes which get registered during constructor
invocation time.
@@ -2803,55 +2868,18 @@ emit_register_classes (tree *list_p)
if (registered_class == NULL)
return;
+ /* By default, generate instances of Class at runtime. */
if (flag_indirect_classes)
- {
- emit_indirect_register_classes (list_p);
- return;
- }
-
+ emit_indirect_register_classes (list_p);
/* TARGET_USE_JCR_SECTION defaults to 1 if SUPPORTS_WEAK and
TARGET_ASM_NAMED_SECTION, else 0. Some targets meet those conditions
but lack suitable crtbegin/end objects or linker support. These
targets can override the default in tm.h to use the fallback mechanism. */
- if (TARGET_USE_JCR_SECTION)
- {
- tree klass, t;
- int i;
-
-#ifdef JCR_SECTION_NAME
- switch_to_section (get_section (JCR_SECTION_NAME, SECTION_WRITE, NULL));
-#else
- /* A target has defined TARGET_USE_JCR_SECTION,
- but doesn't have a JCR_SECTION_NAME. */
- gcc_unreachable ();
-#endif
- assemble_align (POINTER_SIZE);
-
- FOR_EACH_VEC_ELT (tree, registered_class, i, klass)
- {
- t = build_fold_addr_expr (klass);
- output_constant (t, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE);
- }
- }
+ else if (TARGET_USE_JCR_SECTION)
+ emit_register_classes_in_jcr_section ();
+ /* Use the fallback mechanism. */
else
- {
- tree klass, t, register_class_fn;
- int i;
-
- t = build_function_type_list (void_type_node, class_ptr_type, NULL);
- t = build_decl (input_location,
- FUNCTION_DECL, get_identifier ("_Jv_RegisterClass"), t);
- TREE_PUBLIC (t) = 1;
- DECL_EXTERNAL (t) = 1;
- register_class_fn = t;
-
- FOR_EACH_VEC_ELT (tree, registered_class, i, klass)
- {
- t = build_fold_addr_expr (klass);
- t = build_call_expr (register_class_fn, 1, t);
- append_to_statement_list (t, list_p);
- }
- }
+ emit_Jv_RegisterClass_calls (list_p);
}
/* Build a constructor for an entry in the symbol table. */
next reply other threads:[~2012-03-27 20:36 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-27 20:36 Steven Bosscher [this message]
2012-03-27 21:07 ` Eric Botcazou
2012-03-27 21:52 ` Steven Bosscher
2012-03-27 22:23 ` [patch][rfa] " Steven Bosscher
2012-03-28 7:46 ` Andrew Haley
2012-03-28 10:02 ` Richard Guenther
2012-03-29 21:04 ` Steven Bosscher
2012-04-02 12:24 ` Rainer Orth
2012-04-02 12:29 ` Richard Guenther
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