Add symbol table support

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@1918 42af7a65-404d-4744-a932-0658087f49c3

binfmt/symtab_findbyname.c

@@ -40,6 +40,7 @@
 #include <nuttx/config.h>
 #include <sys/types.h>
 
+#include <string.h>
 #include <debug.h>
 #include <assert.h>
 #include <errno.h>

binfmt/symtab_findbyvalue.c

+/****************************************************************************
+ * binfmt/symtab_findbyvalue.c
+ *
+ *   Copyright (C) 2009 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/types.h>
+
+#include <debug.h>
+#include <assert.h>
+#include <errno.h>
+
+#include <nuttx/symtab.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/***********************************************************************
+ * Public Functions
+ ***********************************************************************/
+
+/****************************************************************************
+ * Name: symtab_findbyvalue
+ *
+ * Description:
+ *   Find the symbol in the symbol table whose value closest (but not greater
+ *   than), the provided value. This version assumes that table is not ordered
+ *   with respect to symbol name and, hence, access time will be linear with
+ *   respect to nsyms.
+ *
+ * Returned Value:
+ *   A reference to the symbol table entry if an entry with the matching
+ *   name is found; NULL is returned if the entry is not found.
+ *
+ ****************************************************************************/
+
+FAR const struct symtab_s *
+symtab_findbyvalue(FAR const struct symtab_s *symtab,
+                   FAR void *value, int nsyms)
+{
+  FAR const struct symtab_s *retval = NULL;
+
+  DEBUGASSERT(symtab != NULL);
+  for (; nsyms > 0; symtab++, nsyms--)
+    {
+      /* Look for symbols of lesser or equal value (probably address) to value */
+
+      if (symtab->sym_value <= value)
+        {
+          /* Found one.  Is it the largest we have found so far? */
+
+          if (!retval || symtab->sym_value > retval->sym_value)
+            {
+              /* Yes, then it is the new candidate for the symbol whose value
+               * just below 'value'
+               */
+
+              retval = symtab;
+
+              /* If it is exactly equal to the search 'value', then we might as
+               * well terminate early because we can't do any better than that.
+               */
+
+              if (retval->sym_value == value)
+                {
+                  break;
+                }
+            }
+        }
+    }
+
+  return retval;
+}
+

binfmt/symtab_findorderedbyname.c

+/****************************************************************************
+ * binfmt/symtab_findorderedbyname.c
+ *
+ *   Copyright (C) 2009 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/types.h>
+
+#include <string.h>
+#include <debug.h>
+#include <assert.h>
+#include <errno.h>
+
+#include <nuttx/symtab.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/***********************************************************************
+ * Public Functions
+ ***********************************************************************/
+
+/****************************************************************************
+ * Name: symtab_findorderedbyname
+ *
+ * Description:
+ *   Find the symbol in the symbol table with the matching name.
+ *   This version assumes that table ordered with respect to symbol name.
+ *
+ *   This function uses qsort() to implement the search and, hence, is a lot
+ *   larger than symbtab_findbyname().  This function not be used, unless
+ *   the symbol table is large and the performance benefit is worth the
+ *   increased size.
+ *
+ * Returned Value:
+ *   A reference to the symbol table entry if an entry with the matching
+ *   name is found; NULL is returned if the entry is not found.
+ *
+ ****************************************************************************/
+
+FAR const struct symtab_s *
+symtab_findorderedbyname(FAR const struct symtab_s *symtab,
+                         FAR const char *name, int nsyms)
+{
+  int low  = 0;
+  int high = nsyms -1;
+  int mid;
+  int cmp;
+
+  /* Loop until the range has been isolated to a single symbol table
+   * entry that may or may not match the search name.
+   */
+
+  DEBUGASSERT(symtab != NULL && name != NULL);
+  while (low < high)
+    {
+      /* Compare the name to the one in the middle.  (or just below
+       * the middle in the case where one is even and one is odd).
+       */
+
+      mid = (low + high) >> 1;
+      cmp = strcmp(name, symtab[mid].sym_name);
+      if (cmp < 0)
+        {
+          /* name < symtab[mid].sym_name */
+
+          high = mid - 1;
+        }
+      else if (cmp > 0)
+        {
+          /* name > symtab[mid].sym_name */
+
+          low = mid + 1;
+        }
+      else
+        {
+          /* symtab[mid].sym_name == name */
+
+          return &symtab[mid];
+        }
+    }
+
+ /* low == high... One final check.  We might not have actually tested
+  * the final symtab[] name.
+  *
+  *   Example: Only the last pass through loop, suppose low = 1, high = 2,
+  *   mid = 1, and symtab[high].sym_name == name.  Then we would get here with
+  *   low = 2, high = 2, but symtab[2].sym_name was never tested.
+  */
+
+  return strcmp(name, symtab[low].sym_name) == 0 ? &symtab[low] : NULL;
+}
+

binfmt/symtab_findorderedbyvalue.c

+/****************************************************************************
+ * binfmt/symtab_findorderedbyvalue.c
+ *
+ *   Copyright (C) 2009 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/types.h>
+
+#include <debug.h>
+#include <assert.h>
+#include <errno.h>
+
+#include <nuttx/symtab.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/***********************************************************************
+ * Public Functions
+ ***********************************************************************/
+
+/****************************************************************************
+ * Name: symtab_findorderedbyvalue
+ *
+ * Description:
+ *   Find the symbol in the symbol table whose value closest (but not greater
+ *   than), the provided value. This version assumes that table is ordered
+ *   with respect to symbol name.
+ *
+ * Returned Value:
+ *   A reference to the symbol table entry if an entry with the matching
+ *   name is found; NULL is returned if the entry is not found.
+ *
+ ****************************************************************************/
+
+FAR const struct symtab_s *
+symtab_findorderedbyvalue(FAR const struct symtab_s *symtab,
+                          FAR void *value, int nsyms)
+{
+  int low  = 0;
+  int high = nsyms -1;
+  int mid;
+
+  /* Loop until the range has been isolated to a single symbol table
+   * entry that may or may not match the search name.
+   */
+
+  DEBUGASSERT(symtab != NULL);
+  while (low < high)
+    {
+      /* Compare the name to the one in the middle.  (or just below
+       * the middle in the case where one is even and one is odd).
+       */
+
+      mid = (low + high) >> 1;
+      if ( value < symtab[mid].sym_value)
+        {
+          high = mid - 1;
+        }
+      else if (value > symtab[mid].sym_value)
+        {
+          low = mid + 1;
+        }
+      else /* if (value == symtab[mid].sym_value) */
+        {
+          return &symtab[mid];
+        }
+    }
+
+ /* low == high... One final check.  We might not have actually tested
+  * the final symtab[] name.
+  *
+  *   Example: Only the last pass through loop, suppose low = 1, high = 2,
+  *   mid = 1, and symtab[high].sym_name == name.  Then we would get here with
+  *   low = 2, high = 2, but symtab[2].sym_name was never tested.
+  */
+
+  return value == symtab[low].sym_value ? &symtab[low] : NULL;
+}
+

include/nuttx/symtab.h

+/****************************************************************************
+ * include/nuttx/symtab.h
+ *
+ *   Copyright (C) 2009 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#ifndef __INCLUDE_NUTTX_SYMTAB_H
+#define __INCLUDE_NUTTX_SYMTAB_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/types.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+/* struct symbtab_s describes one entry in the symbol table.  A symbol table
+ * is a fixed size array of struct symtab_s.  The information is intentionally
+ * minimal and supports only:
+ *
+ * 1. Function points as sym_values.  Of other kinds of values need to be
+ *    supported, then typing information would also need to be included in
+ *    the structure.
+ *
+ * 2. Fixed size arrays.  There is no explicit provisional for dyanamically
+ *    adding or removing entries from the symbol table (realloc might be
+ *    used for that purpose if needed).  The intention is to support only
+ *    fixed size arrays completely defined at compilation or link time.
+ */
+
+struct symtab_s
+{
+  FAR const char *sym_name;          /* A pointer to the symbol name string */
+  FAR const void *sym_value;         /* The value associated witht the string */
+};
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C" {
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Name: symtab_findbyname
+ *
+ * Description:
+ *   Find the symbol in the symbol table with the matching name.
+ *   This version assumes that table is not ordered with respect to symbol
+ *   name and, hence, access time will be linear with respect to nsyms.
+ *
+ * Returned Value:
+ *   A reference to the symbol table entry if an entry with the matching
+ *   name is found; NULL is returned if the entry is not found.
+ *
+ ****************************************************************************/
+
+EXTERN FAR const struct symtab_s *
+symtab_findbyname(FAR const struct symtab_s *symtab,
+                  FAR const char *name, int nsyms);
+
+/****************************************************************************
+ * Name: symtab_findorderedbyname
+ *
+ * Description:
+ *   Find the symbol in the symbol table with the matching name.
+ *   This version assumes that table ordered with respect to symbol name.
+ *
+ * Returned Value:
+ *   A reference to the symbol table entry if an entry with the matching
+ *   name is found; NULL is returned if the entry is not found.
+ *
+ ****************************************************************************/
+
+EXTERN FAR const struct symtab_s *
+symtab_findorderedbyname(FAR const struct symtab_s *symtab,
+                         FAR const char *name, int nsyms);
+
+/****************************************************************************
+ * Name: symtab_findbyvalue
+ *
+ * Description:
+ *   Find the symbol in the symbol table whose value closest (but not greater
+ *   than), the provided value. This version assumes that table is not ordered
+ *   with respect to symbol name and, hence, access time will be linear with
+ *   respect to nsyms.
+ *
+ * Returned Value:
+ *   A reference to the symbol table entry if an entry with the matching
+ *   name is found; NULL is returned if the entry is not found.
+ *
+ ****************************************************************************/
+
+EXTERN FAR const struct symtab_s *
+symtab_findbyvalue(FAR const struct symtab_s *symtab,
+                   FAR void *value, int nsyms);
+
+/****************************************************************************
+ * Name: symtab_findorderedbyvalue
+ *
+ * Description:
+ *   Find the symbol in the symbol table whose value closest (but not greater
+ *   than), the provided value. This version assumes that table is ordered
+ *   with respect to symbol name.
+ *
+ * Returned Value:
+ *   A reference to the symbol table entry if an entry with the matching
+ *   name is found; NULL is returned if the entry is not found.
+ *
+ ****************************************************************************/
+
+EXTERN FAR const struct symtab_s *
+symtab_findorderedbyvalue(FAR const struct symtab_s *symtab,
+                          FAR void *value, int nsyms);
+
+#undef EXTERN
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* __INCLUDE_NUTTX_SYMTAB_H */
+