Checking in C runtime.

[repair.git] / Repair / RepairCompiler / MCC / CRuntime / stack.c

diff --git a/Repair/RepairCompiler/MCC/CRuntime/stack.c b/Repair/RepairCompiler/MCC/CRuntime/stack.c
new file mode 100755 (executable)
index 0000000..c9586dc
--- /dev/null
+++ b/Repair/RepairCompiler/MCC/CRuntime/stack.c
@@ -0,0 +1,80 @@
+/*
+Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
+Copyright (c) 1991-1995 by Xerox Corporation.  All rights reserved.
+Copyright (c) 1996-1999 by Silicon Graphics.  All rights reserved.
+Copyright (c) 1999-2001 by Hewlett-Packard. All rights reserved.
+
+THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
+OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
+
+Permission is hereby granted to use or copy this program
+for any purpose,  provided the above notices are retained on all copies.
+Permission to modify the code and to distribute modified code is granted,
+provided the above notices are retained, and a notice that the code was
+modified is included with the above copyright notice.
+ */
+
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <ctype.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#define ptr_t void *
+#pragma weak __libc_stack_end
+extern ptr_t __libc_stack_end;
+#define word unsigned int
+# define STAT_SKIP 27   /* Number of fields preceding startstack       */
+                       /* field in /proc/self/stat                     */
+#define ABORT printf
+
+  ptr_t GC_linux_stack_base(void)
+  {
+    /* We read the stack base value from /proc/self/stat.  We do this  */
+    /* using direct I/O system calls in order to avoid calling malloc   */
+    /* in case REDIRECT_MALLOC is defined.                             */
+#   define STAT_BUF_SIZE 4096
+#   define STAT_READ read
+         /* Should probably call the real read, if read is wrapped.    */
+    char stat_buf[STAT_BUF_SIZE];
+    int f;
+    char c;
+    word result = 0;
+    size_t i, buf_offset = 0;
+
+    /* First try the easy way.  This should work for glibc 2.2 */
+      if (0 != &__libc_stack_end) {
+#       ifdef IA64
+         /* Some versions of glibc set the address 16 bytes too        */
+         /* low while the initialization code is running.              */
+         if (((word)__libc_stack_end & 0xfff) + 0x10 < 0x1000) {
+           return __libc_stack_end + 0x10;
+         } /* Otherwise it's not safe to add 16 bytes and we fall      */
+           /* back to using /proc.                                     */
+#      else
+         return __libc_stack_end;
+#      endif
+      }
+    f = open("/proc/self/stat", O_RDONLY);
+    if (f < 0 || STAT_READ(f, stat_buf, STAT_BUF_SIZE) < 2 * STAT_SKIP) {
+       ABORT("Couldn't read /proc/self/stat");
+    }
+    c = stat_buf[buf_offset++];
+    /* Skip the required number of fields.  This number is hopefully   */
+    /* constant across all Linux implementations.                      */
+      for (i = 0; i < STAT_SKIP; ++i) {
+       while (isspace(c)) c = stat_buf[buf_offset++];
+       while (!isspace(c)) c = stat_buf[buf_offset++];
+      }
+    while (isspace(c)) c = stat_buf[buf_offset++];
+    while (isdigit(c)) {
+      result *= 10;
+      result += c - '0';
+      c = stat_buf[buf_offset++];
+    }
+    close(f);
+    if (result < 0x10000000) ABORT("Absurd stack bottom value");
+    return (ptr_t)result;
+  }