Libc-262.tar.gz

[apple/libc.git] / sys / crt_externs.c

diff --git a/sys/crt_externs.c b/sys/crt_externs.c
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+/*
+ * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ * 
+ * The contents of this file constitute Original Code as defined in and
+ * are subject to the Apple Public Source License Version 1.1 (the
+ * "License").  You may not use this file except in compliance with the
+ * License.  Please obtain a copy of the License at
+ * http://www.apple.com/publicsource and read it before using this file.
+ * 
+ * This Original Code and all software distributed under the License are
+ * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
+ * License for the specific language governing rights and limitations
+ * under the License.
+ * 
+ * @APPLE_LICENSE_HEADER_END@
+ */
+/*
+** This file contains interfaces to the symbols defined int the crt modules.
+** 3 April 1995
+** Matt Watson (mwatson@next.com)
+**
+*/
+
+#if defined(__DYNAMIC__)
+#include "mach-o/dyld.h" /* defines _dyld_lookup_and_bind() */
+#define STRINGIFY(a) # a
+#define DECLARE_VAR(var, type) \
+        static type * var ## _pointer = 0
+#define SETUP_VAR(var)                                         \
+    if ( var ## _pointer == 0) {                               \
+        _dyld_lookup_and_bind( STRINGIFY(_ ## var),            \
+                (unsigned long *) & var ## _pointer, 0);       \
+    }
+#define USE_VAR(var) (var ## _pointer)
+#else
+#define DECLARE_VAR(var, type) extern type var
+#define SETUP_VAR(var)
+#define USE_VAR(var) (& var)
+#endif
+
+char ***_NSGetArgv(void) {
+    DECLARE_VAR(NXArgv, char **);
+    SETUP_VAR(NXArgv);
+    return(USE_VAR(NXArgv));
+}
+
+int *_NSGetArgc(void) {
+    DECLARE_VAR(NXArgc, int);
+    SETUP_VAR(NXArgc);
+    return(USE_VAR(NXArgc));
+}
+
+char ***_NSGetEnviron(void) {
+    DECLARE_VAR(environ, char **);
+    SETUP_VAR(environ);
+    return(USE_VAR(environ));
+}
+
+char **_NSGetProgname(void) {
+    DECLARE_VAR(__progname, char *);
+    SETUP_VAR(__progname);
+    return(USE_VAR(__progname));
+}
+
+struct mach_header *_NSGetMachExecuteHeader(void) {
+    DECLARE_VAR(_mh_execute_header, struct mach_header);
+    SETUP_VAR(_mh_execute_header);
+    return(USE_VAR(_mh_execute_header));
+}
+
+/*
+ * Fix for Radar bug 2200596 --
+ * EH symbol definitions for gcc 2.7.2.x implementation of
+ * C++ exception handling.  The problem:  the EH implementation
+ * has "throw" store stuff into these pointers, and then as the
+ * stack is unwound, the code generated into each function (for
+ * checking whether this function contains a relevant "catch"
+ * clause and for calling destructors for local variables) looks
+ * at these globals to find the type and value thrown.
+ *
+ * The problem was that the compiler generated the symbols as
+ * "common" symbols, and common symbols cannot be placed in
+ * dynamic shared libraries.  So we must put these guys as
+ * "data" symbols into crt0.o or the System Framework (library),
+ * and the compiler must generate code that defines the symbols
+ * as external references instead of common.
+ *
+ * I changed the symbol names (added the "_272") to be utterly
+ * paranoid about any possible future use of similar names by
+ * any future versions of gcc.
+ *                      -- D. Landauer, Jan. 1998
+ */
+
+void *__eh_pc_gcc_272 = (void *)0;
+void *__eh_type_gcc_272 = (void *)0;
+void *__eh_value_gcc_272 = (void *)0;
+
+/* This is what egcs uses for its global data pointer */
+void *__eh_global_dataptr = (void *)0;
+
+void *__keymgr_global[3] = { (void *)0 };