From 808694e8a330e32741b7781467610d8cec99ae6e Mon Sep 17 00:00:00 2001
From: Mike Frysinger <vapier@gentoo.org>
Date: Fri, 8 Dec 2006 22:53:40 +0000
Subject: Richard Sandiford writes: add support for init/fini arrays in shared
flat libraries
---
libc/misc/internals/Makefile.in | 4 +-
libc/misc/internals/__uClibc_main.c | 16 ++++++--
libc/misc/internals/shared_flat_add_library.c | 46 +++++++++++++++++++++++
libc/misc/internals/shared_flat_initfini.c | 53 +++++++++++++++++++++++++++
libc/misc/internals/shared_flat_lib.h | 35 ++++++++++++++++++
5 files changed, 149 insertions(+), 5 deletions(-)
create mode 100644 libc/misc/internals/shared_flat_add_library.c
create mode 100644 libc/misc/internals/shared_flat_initfini.c
create mode 100644 libc/misc/internals/shared_flat_lib.h
(limited to 'libc/misc')
diff --git a/libc/misc/internals/Makefile.in b/libc/misc/internals/Makefile.in
index a9638125d..af97b39af 100644
--- a/libc/misc/internals/Makefile.in
+++ b/libc/misc/internals/Makefile.in
@@ -18,7 +18,9 @@ MISC_INTERNALS_OBJ := $(patsubst %.c,$(MISC_INTERNALS_OUT)/%.o,$(CSRC))
libc-y += $(MISC_INTERNALS_OBJ)
libc-shared-y += $(MISC_INTERNALS_OUT)/__uClibc_main.oS
libc-static-y += $(MISC_INTERNALS_OUT)/__uClibc_main.o
-
+libc-static-$(HAVE_SHARED_FLAT) += \
+ $(MISC_INTERNALS_OUT)/shared_flat_initfini.o \
+ $(MISC_INTERNALS_OUT)/shared_flat_add_library.o
libc-nomulti-y += $(MISC_INTERNALS_OUT)/__uClibc_main.o
objclean-y += misc_internals_objclean
diff --git a/libc/misc/internals/__uClibc_main.c b/libc/misc/internals/__uClibc_main.c
index 7578a97fb..a2fbf6c89 100644
--- a/libc/misc/internals/__uClibc_main.c
+++ b/libc/misc/internals/__uClibc_main.c
@@ -88,7 +88,9 @@ extern void weak_function _locale_init(void) attribute_hidden;
extern void weak_function __pthread_initialize_minimal(void);
#endif
-#ifdef __UCLIBC_CTOR_DTOR__
+/* If __HAVE_SHARED_FLAT__, all array initialisation and finalisation
+ * is handled by the routines passed to __uClibc_main(). */
+#if defined (__UCLIBC_CTOR_DTOR__) && !defined (__HAVE_SHARED_FLAT__)
extern void _dl_app_init_array(void);
extern void _dl_app_fini_array(void);
# ifndef SHARED
@@ -247,9 +249,11 @@ libc_hidden_proto(__uClibc_fini)
void __uClibc_fini(void)
{
#ifdef __UCLIBC_CTOR_DTOR__
+ /* If __HAVE_SHARED_FLAT__, all array finalisation is handled
+ * by __app_fini. */
# ifdef SHARED
_dl_app_fini_array();
-# else
+# elif !defined (__HAVE_SHARED_FLAT__)
size_t i = __fini_array_end - __fini_array_start;
while (i-- > 0)
(*__fini_array_start [i]) ();
@@ -348,7 +352,9 @@ void __uClibc_main(int (*main)(int, char **, char **), int argc,
/* Arrange for the application's dtors to run before we exit. */
__app_fini = app_fini;
-# ifndef SHARED
+ /* If __HAVE_SHARED_FLAT__, all array initialisation is handled
+ * by __app_init. */
+# if !defined (SHARED) && !defined (__HAVE_SHARED_FLAT__)
/* For dynamically linked executables the preinit array is executed by
the dynamic linker (before initializing any shared object).
For static executables, preinit happens rights before init. */
@@ -363,9 +369,11 @@ void __uClibc_main(int (*main)(int, char **, char **), int argc,
if (app_init!=NULL) {
app_init();
}
+ /* If __HAVE_SHARED_FLAT__, all array initialisation is handled
+ * by __app_init. */
# ifdef SHARED
_dl_app_init_array();
-# else
+# elif !defined (__HAVE_SHARED_FLAT__)
{
const size_t size = __init_array_end - __init_array_start;
size_t i;
diff --git a/libc/misc/internals/shared_flat_add_library.c b/libc/misc/internals/shared_flat_add_library.c
new file mode 100644
index 000000000..f03480f56
--- /dev/null
+++ b/libc/misc/internals/shared_flat_add_library.c
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2006 CodeSourcery Inc
+ *
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ *
+ * This file defines __shared_flat_add_library. If a library has
+ * initialistion and finalisation code, it should use this routine
+ * to register itself.
+ */
+#include "shared_flat_lib.h"
+
+/* The initialisation and finalisation symbols for this library. */
+extern void _init(void) attribute_hidden weak_function;
+extern void _fini(void) attribute_hidden weak_function;
+extern void (*__preinit_array_start[])(void) attribute_hidden;
+extern void (*__preinit_array_end[])(void) attribute_hidden;
+extern void (*__init_array_start[])(void) attribute_hidden;
+extern void (*__init_array_end[])(void) attribute_hidden;
+extern void (*__fini_array_start[])(void) attribute_hidden;
+extern void (*__fini_array_end[])(void) attribute_hidden;
+
+/* The shared_flat_lib structure that describes this library. */
+static struct shared_flat_lib this_lib = {
+ 0,
+ 0,
+ __preinit_array_start,
+ __preinit_array_end,
+ __init_array_start,
+ __init_array_end,
+ __fini_array_start,
+ __fini_array_end,
+ _init,
+ _fini
+};
+
+/* Add this_lib to the end of the global list. */
+void __shared_flat_add_library(void) attribute_hidden;
+void __shared_flat_add_library(void)
+{
+ this_lib.prev = __last_shared_lib;
+ if (this_lib.prev)
+ this_lib.prev->next = &this_lib;
+ else
+ __first_shared_lib = &this_lib;
+ __last_shared_lib = &this_lib;
+}
diff --git a/libc/misc/internals/shared_flat_initfini.c b/libc/misc/internals/shared_flat_initfini.c
new file mode 100644
index 000000000..81e53834e
--- /dev/null
+++ b/libc/misc/internals/shared_flat_initfini.c
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2006 CodeSourcery Inc
+ *
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ *
+ * This file defines the main initialisation and finalisation code for
+ * shared flat libraries. It in turn calls the initialisation and
+ * finalisation code for each registered library.
+ */
+#include "shared_flat_lib.h"
+
+/* A doubly-linked list of shared libraries. Those nearer the head
+ * of the list should be initialised first and finalised last. */
+struct shared_flat_lib *__first_shared_lib;
+struct shared_flat_lib *__last_shared_lib;
+
+void __shared_flat_init(void)
+{
+ struct shared_flat_lib *lib;
+ void (**start)(void);
+ void (**end)(void);
+
+ for (lib = __first_shared_lib; lib; lib = lib->next) {
+ end = lib->preinit_array_end;
+ for (start = lib->preinit_array_start; start < end; start++)
+ (*start)();
+ }
+
+ for (lib = __first_shared_lib; lib; lib = lib->next) {
+ if (lib->init)
+ lib->init();
+
+ end = lib->init_array_end;
+ for (start = lib->init_array_start; start < end; start++)
+ (*start)();
+ }
+}
+
+void __shared_flat_fini(void)
+{
+ struct shared_flat_lib *lib;
+ void (**start)(void);
+ void (**end)(void);
+
+ for (lib = __last_shared_lib; lib; lib = lib->prev) {
+ start = lib->fini_array_start;
+ for (end = lib->fini_array_end; end > start;)
+ (*--end)();
+
+ if (lib->fini)
+ lib->fini();
+ }
+}
diff --git a/libc/misc/internals/shared_flat_lib.h b/libc/misc/internals/shared_flat_lib.h
new file mode 100644
index 000000000..e01213564
--- /dev/null
+++ b/libc/misc/internals/shared_flat_lib.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2006 CodeSourcery Inc
+ *
+ * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
+ *
+ * This file defines the shared_flat_lib structure and the global library
+ * list. The structure is used to provide something close to ELF-like
+ * initialisation and finalisation when using shared flat libraries.
+ */
+#ifndef __SHARED_FLAT_LIB__
+#define __SHARED_FLAT_LIB__
+
+struct shared_flat_lib {
+ struct shared_flat_lib *prev;
+ struct shared_flat_lib *next;
+ /* .preinit_array is usually only supported for executables.
+ * However, the distinction between the executable and its
+ * shared libraries isn't as pronounced for flat files; a shared
+ * library is really just a part of an executable that can be
+ * shared with other executables. We therefore allow
+ * .preinit_array to be used in libraries too. */
+ void (**preinit_array_start)(void);
+ void (**preinit_array_end)(void);
+ void (**init_array_start)(void);
+ void (**init_array_end)(void);
+ void (**fini_array_start)(void);
+ void (**fini_array_end)(void);
+ void (*init)(void);
+ void (*fini)(void);
+};
+
+extern struct shared_flat_lib *__first_shared_lib;
+extern struct shared_flat_lib *__last_shared_lib;
+
+#endif
--
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