Adding upstream version 5.1.upstream/5.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 382 insertions, 0 deletions

diff --git a/unwind_prot.c b/unwind_prot.c
new file mode 100644
index 0000000..5703777
--- /dev/null
+++ b/unwind_prot.c
@@ -0,0 +1,382 @@
+/* unwind_prot.c - a simple unwind-protect system for internal variables */
+
+/* I can't stand it anymore!  Please can't we just write the
+   whole Unix system in lisp or something? */
+
+/* Copyright (C) 1987-2020 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash, the Bourne Again SHell.
+
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* **************************************************************** */
+/*								    */
+/*		      Unwind Protection Scheme for Bash		    */
+/*								    */
+/* **************************************************************** */
+#include "config.h"
+
+#include "bashtypes.h"
+#include "bashansi.h"
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#if STDC_HEADERS
+#  include <stddef.h>
+#endif
+
+#ifndef offsetof
+#  define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
+#endif
+
+#include "command.h"
+#include "general.h"
+#include "unwind_prot.h"
+#include "sig.h"
+#include "quit.h"
+#include "error.h"	/* for internal_warning */
+#include "ocache.h"
+
+/* Structure describing a saved variable and the value to restore it to.  */
+typedef struct {
+  char *variable;
+  int size;
+  char desired_setting[1]; /* actual size is `size' */
+} SAVED_VAR;
+
+/* If HEAD.CLEANUP is null, then ARG.V contains a tag to throw back to.
+   If HEAD.CLEANUP is restore_variable, then SV.V contains the saved
+   variable.  Otherwise, call HEAD.CLEANUP (ARG.V) to clean up.  */
+typedef union uwp {
+  struct uwp_head {
+    union uwp *next;
+    Function *cleanup;
+  } head;
+  struct {
+    struct uwp_head uwp_head;
+    char *v;
+  } arg;
+  struct {
+    struct uwp_head uwp_head;
+    SAVED_VAR v;
+  } sv;
+} UNWIND_ELT;
+
+static void without_interrupts PARAMS((VFunction *, char *, char *));
+static void unwind_frame_discard_internal PARAMS((char *, char *));
+static void unwind_frame_run_internal PARAMS((char *, char *));
+static void add_unwind_protect_internal PARAMS((Function *, char *));
+static void remove_unwind_protect_internal PARAMS((char *, char *));
+static void run_unwind_protects_internal PARAMS((char *, char *));
+static void clear_unwind_protects_internal PARAMS((char *, char *));
+static inline void restore_variable PARAMS((SAVED_VAR *));
+static void unwind_protect_mem_internal PARAMS((char *, char *));
+
+static UNWIND_ELT *unwind_protect_list = (UNWIND_ELT *)NULL;
+
+/* Allocating from a cache of unwind-protect elements */
+#define UWCACHESIZE	128
+
+sh_obj_cache_t uwcache = {0, 0, 0};
+
+#if 0
+#define uwpalloc(elt)	(elt) = (UNWIND_ELT *)xmalloc (sizeof (UNWIND_ELT))
+#define uwpfree(elt)	free(elt)
+#else
+#define uwpalloc(elt)	ocache_alloc (uwcache, UNWIND_ELT, elt)
+#define uwpfree(elt)	ocache_free (uwcache, UNWIND_ELT, elt)
+#endif
+
+void
+uwp_init ()
+{
+  ocache_create (uwcache, UNWIND_ELT, UWCACHESIZE);
+}
+
+/* Run a function without interrupts.  This relies on the fact that the
+   FUNCTION cannot call QUIT (). */
+static void
+without_interrupts (function, arg1, arg2)
+     VFunction *function;
+     char *arg1, *arg2;
+{
+  (*function)(arg1, arg2);
+}
+
+/* Start the beginning of a region. */
+void
+begin_unwind_frame (tag)
+     char *tag;
+{
+  add_unwind_protect ((Function *)NULL, tag);
+}
+
+/* Discard the unwind protects back to TAG. */
+void
+discard_unwind_frame (tag)
+     char *tag;
+{
+  if (unwind_protect_list)
+    without_interrupts (unwind_frame_discard_internal, tag, (char *)NULL);
+}
+
+/* Run the unwind protects back to TAG. */
+void
+run_unwind_frame (tag)
+     char *tag;
+{
+  if (unwind_protect_list)
+    without_interrupts (unwind_frame_run_internal, tag, (char *)NULL);
+}
+
+/* Add the function CLEANUP with ARG to the list of unwindable things. */
+void
+add_unwind_protect (cleanup, arg)
+     Function *cleanup;
+     char *arg;
+{
+  without_interrupts (add_unwind_protect_internal, (char *)cleanup, arg);
+}
+
+/* Remove the top unwind protect from the list. */
+void
+remove_unwind_protect ()
+{
+  if (unwind_protect_list)
+    without_interrupts
+      (remove_unwind_protect_internal, (char *)NULL, (char *)NULL);
+}
+
+/* Run the list of cleanup functions in unwind_protect_list. */
+void
+run_unwind_protects ()
+{
+  if (unwind_protect_list)
+    without_interrupts
+      (run_unwind_protects_internal, (char *)NULL, (char *)NULL);
+}
+
+/* Erase the unwind-protect list.  If flags is 1, free the elements. */
+void
+clear_unwind_protect_list (flags)
+     int flags;
+{
+  char *flag;
+
+  if (unwind_protect_list)
+    {
+      flag = flags ? "" : (char *)NULL;
+      without_interrupts
+        (clear_unwind_protects_internal, flag, (char *)NULL);
+    }
+}
+
+int
+have_unwind_protects ()
+{
+  return (unwind_protect_list != 0);
+}
+
+int
+unwind_protect_tag_on_stack (tag)
+     const char *tag;
+{
+  UNWIND_ELT *elt;
+
+  elt = unwind_protect_list;
+  while (elt)
+    {
+      if (elt->head.cleanup == 0 && STREQ (elt->arg.v, tag))
+	return 1;
+      elt = elt->head.next;
+    }
+  return 0;
+}
+
+/* **************************************************************** */
+/*								    */
+/*			The Actual Functions		 	    */
+/*								    */
+/* **************************************************************** */
+
+static void
+add_unwind_protect_internal (cleanup, arg)
+     Function *cleanup;
+     char *arg;
+{
+  UNWIND_ELT *elt;
+
+  uwpalloc (elt);
+  elt->head.next = unwind_protect_list;
+  elt->head.cleanup = cleanup;
+  elt->arg.v = arg;
+  unwind_protect_list = elt;
+}
+
+static void
+remove_unwind_protect_internal (ignore1, ignore2)
+     char *ignore1, *ignore2;
+{
+  UNWIND_ELT *elt;
+
+  elt = unwind_protect_list;
+  if (elt)
+    {
+      unwind_protect_list = unwind_protect_list->head.next;
+      uwpfree (elt);
+    }
+}
+
+static void
+run_unwind_protects_internal (ignore1, ignore2)
+     char *ignore1, *ignore2;
+{
+  unwind_frame_run_internal ((char *) NULL, (char *) NULL);
+}
+
+static void
+clear_unwind_protects_internal (flag, ignore)
+     char *flag, *ignore;
+{
+  if (flag)
+    {
+      while (unwind_protect_list)
+	remove_unwind_protect_internal ((char *)NULL, (char *)NULL);
+    }
+  unwind_protect_list = (UNWIND_ELT *)NULL;
+}
+
+static void
+unwind_frame_discard_internal (tag, ignore)
+     char *tag, *ignore;
+{
+  UNWIND_ELT *elt;
+  int found;
+
+  found = 0;
+  while (elt = unwind_protect_list)
+    {
+      unwind_protect_list = unwind_protect_list->head.next;
+      if (elt->head.cleanup == 0 && (STREQ (elt->arg.v, tag)))
+	{
+	  uwpfree (elt);
+	  found = 1;
+	  break;
+	}
+      else
+	uwpfree (elt);
+    }
+
+  if (found == 0)
+    internal_warning ("unwind_frame_discard: %s: frame not found", tag);
+}
+
+/* Restore the value of a variable, based on the contents of SV.
+   sv->desired_setting is a block of memory SIZE bytes long holding the
+   value itself.  This block of memory is copied back into the variable. */
+static inline void
+restore_variable (sv)
+     SAVED_VAR *sv;
+{
+  FASTCOPY (sv->desired_setting, sv->variable, sv->size);
+}
+
+static void
+unwind_frame_run_internal (tag, ignore)
+     char *tag, *ignore;
+{
+  UNWIND_ELT *elt;
+  int found;
+
+  found = 0;
+  while (elt = unwind_protect_list)
+    {
+      unwind_protect_list = elt->head.next;
+
+      /* If tag, then compare. */
+      if (elt->head.cleanup == 0)
+	{
+	  if (tag && STREQ (elt->arg.v, tag))
+	    {
+	      uwpfree (elt);
+	      found = 1;
+	      break;
+	    }
+	}
+      else
+	{
+	  if (elt->head.cleanup == (Function *) restore_variable)
+	    restore_variable (&elt->sv.v);
+	  else
+	    (*(elt->head.cleanup)) (elt->arg.v);
+	}
+
+      uwpfree (elt);
+    }
+  if (tag && found == 0)
+    internal_warning ("unwind_frame_run: %s: frame not found", tag);
+}
+
+static void
+unwind_protect_mem_internal (var, psize)
+     char *var;
+     char *psize;
+{
+  int size, allocated;
+  UNWIND_ELT *elt;
+
+  size = *(int *) psize;
+  allocated = size + offsetof (UNWIND_ELT, sv.v.desired_setting[0]);
+  if (allocated < sizeof (UNWIND_ELT))
+    allocated = sizeof (UNWIND_ELT);
+  elt = (UNWIND_ELT *)xmalloc (allocated);
+  elt->head.next = unwind_protect_list;
+  elt->head.cleanup = (Function *) restore_variable;
+  elt->sv.v.variable = var;
+  elt->sv.v.size = size;
+  FASTCOPY (var, elt->sv.v.desired_setting, size);
+  unwind_protect_list = elt;
+}
+
+/* Save the value of a variable so it will be restored when unwind-protects
+   are run.  VAR is a pointer to the variable.  SIZE is the size in
+   bytes of VAR.  */
+void
+unwind_protect_mem (var, size)
+     char *var;
+     int size;
+{
+  without_interrupts (unwind_protect_mem_internal, var, (char *) &size);
+}
+
+#if defined (DEBUG)
+#include <stdio.h>
+
+void
+print_unwind_protect_tags ()
+{
+  UNWIND_ELT *elt;
+
+  elt = unwind_protect_list;
+  while (elt)
+    {
+      if (elt->head.cleanup == 0)
+        fprintf(stderr, "tag: %s\n", elt->arg.v);
+      elt = elt->head.next;
+    }
+}
+#endif