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-rw-r--r--cpukit/libdl/rtl-sym.c245
1 files changed, 245 insertions, 0 deletions
diff --git a/cpukit/libdl/rtl-sym.c b/cpukit/libdl/rtl-sym.c
new file mode 100644
index 0000000000..f8063948bd
--- /dev/null
+++ b/cpukit/libdl/rtl-sym.c
@@ -0,0 +1,245 @@
+/*
+ * COPYRIGHT (c) 2012 Chris Johns <chrisj@rtems.org>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+/**
+ * @file
+ *
+ * @ingroup rtems_rtl
+ *
+ * @brief RTEMS Run-Time Linker Object File Symbol Table.
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <errno.h>
+#include <inttypes.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include <rtems/rtl/rtl.h>
+#include "rtl-error.h"
+#include "rtl-sym.h"
+#include "rtl-trace.h"
+
+/**
+ * The single symbol forced into the global symbol table that is used to load a
+ * symbol table from an object file.
+ */
+static rtems_rtl_obj_sym_t global_sym_add =
+{
+ .name = "rtems_rtl_base_sym_global_add",
+ .value = (void*) rtems_rtl_base_sym_global_add
+};
+
+static uint_fast32_t
+rtems_rtl_symbol_hash (const char *s)
+{
+ uint_fast32_t h = 5381;
+ unsigned char c;
+ for (c = *s; c != '\0'; c = *++s)
+ h = h * 33 + c;
+ return h & 0xffffffff;
+}
+
+static void
+rtems_rtl_symbol_global_insert (rtems_rtl_symbols_t* symbols,
+ rtems_rtl_obj_sym_t* symbol)
+{
+ uint_fast32_t hash = rtems_rtl_symbol_hash (symbol->name);
+ rtems_chain_append (&symbols->buckets[hash % symbols->nbuckets],
+ &symbol->node);
+}
+
+bool
+rtems_rtl_symbol_table_open (rtems_rtl_symbols_t* symbols,
+ size_t buckets)
+{
+ symbols->buckets = rtems_rtl_alloc_new (RTEMS_RTL_ALLOC_SYMBOL,
+ buckets * sizeof (rtems_chain_control),
+ true);
+ if (!symbols->buckets)
+ {
+ rtems_rtl_set_error (ENOMEM, "no memory for global symbol table");
+ return false;
+ }
+ symbols->nbuckets = buckets;
+ for (buckets = 0; buckets < symbols->nbuckets; ++buckets)
+ rtems_chain_initialize_empty (&symbols->buckets[buckets]);
+ rtems_rtl_symbol_global_insert (symbols, &global_sym_add);
+ return true;
+}
+
+void
+rtems_rtl_symbol_table_close (rtems_rtl_symbols_t* symbols)
+{
+ rtems_rtl_alloc_del (RTEMS_RTL_ALLOC_SYMBOL, symbols->buckets);
+}
+
+bool
+rtems_rtl_symbol_global_add (rtems_rtl_obj_t* obj,
+ const unsigned char* esyms,
+ unsigned int size)
+{
+ rtems_rtl_symbols_t* symbols;
+ rtems_rtl_obj_sym_t* sym;
+ size_t count;
+ size_t s;
+ uint32_t marker;
+
+ count = 0;
+ s = 0;
+ while ((s < size) && (esyms[s] != 0))
+ {
+ int l = strlen ((char*) &esyms[s]);
+ if ((esyms[s + l] != '\0') || ((s + l) > size))
+ {
+ rtems_rtl_set_error (EINVAL, "invalid exported symbol table");
+ return false;
+ }
+ ++count;
+ s += l + sizeof (unsigned long) + 1;
+ }
+
+ /*
+ * Check this is the correct end of the table.
+ */
+ marker = esyms[s + 1];
+ marker <<= 8;
+ marker |= esyms[s + 2];
+ marker <<= 8;
+ marker |= esyms[s + 3];
+ marker <<= 8;
+ marker |= esyms[s + 4];
+
+ if (marker != 0xdeadbeefUL)
+ {
+ rtems_rtl_set_error (ENOMEM, "invalid export symbol table");
+ return false;
+ }
+
+ if (rtems_rtl_trace (RTEMS_RTL_TRACE_GLOBAL_SYM))
+ printf ("rtl: global symbol add: %zi\n", count);
+
+ obj->global_size = count * sizeof (rtems_rtl_obj_sym_t);
+ obj->global_table = rtems_rtl_alloc_new (RTEMS_RTL_ALLOC_SYMBOL,
+ obj->global_size, true);
+ if (!obj->global_table)
+ {
+ obj->global_size = 0;
+ rtems_rtl_set_error (ENOMEM, "no memory for global symbols");
+ return false;
+ }
+
+ symbols = rtems_rtl_global_symbols ();
+
+ s = 0;
+ sym = obj->global_table;
+
+ while ((s < size) && (esyms[s] != 0))
+ {
+ /*
+ * Copy the void* using a union and memcpy to avoid any strict aliasing or
+ * alignment issues. The variable length of the label and the packed nature
+ * of the table means casting is not suitable.
+ */
+ union {
+ uint8_t data[sizeof (void*)];
+ void* value;
+ } copy_voidp;
+ int b;
+
+ sym->name = (const char*) &esyms[s];
+ s += strlen (sym->name) + 1;
+ for (b = 0; b < sizeof (void*); ++b, ++s)
+ copy_voidp.data[b] = esyms[s];
+ sym->value = copy_voidp.value;
+ if (rtems_rtl_trace (RTEMS_RTL_TRACE_GLOBAL_SYM))
+ printf ("rtl: esyms: %s -> %8p\n", sym->name, sym->value);
+ if (rtems_rtl_symbol_global_find (sym->name) == NULL)
+ rtems_rtl_symbol_global_insert (symbols, sym);
+ ++sym;
+ }
+
+ obj->global_syms = count;
+
+ return true;
+}
+
+rtems_rtl_obj_sym_t*
+rtems_rtl_symbol_global_find (const char* name)
+{
+ rtems_rtl_symbols_t* symbols;
+ uint_fast32_t hash;
+ rtems_chain_control* bucket;
+ rtems_chain_node* node;
+
+ symbols = rtems_rtl_global_symbols ();
+
+ hash = rtems_rtl_symbol_hash (name);
+ bucket = &symbols->buckets[hash % symbols->nbuckets];
+ node = rtems_chain_first (bucket);
+
+ while (!rtems_chain_is_tail (bucket, node))
+ {
+ rtems_rtl_obj_sym_t* sym = (rtems_rtl_obj_sym_t*) node;
+ /*
+ * Use the hash. I could add this to the symbol but it uses more memory.
+ */
+ if (strcmp (name, sym->name) == 0)
+ return sym;
+ node = rtems_chain_next (node);
+ }
+
+ return NULL;
+}
+
+rtems_rtl_obj_sym_t*
+rtems_rtl_symbol_obj_find (rtems_rtl_obj_t* obj, const char* name)
+{
+ rtems_rtl_obj_sym_t* sym;
+ size_t s;
+ /*
+ * Check the object file's symbols first. If not found search the
+ * global symbol table.
+ */
+ for (s = 0, sym = obj->global_table; s < obj->global_syms; ++s, ++sym)
+ if (strcmp (name, sym->name) == 0)
+ return sym;
+ return rtems_rtl_symbol_global_find (name);
+}
+
+void
+rtems_rtl_symbol_obj_add (rtems_rtl_obj_t* obj)
+{
+ rtems_rtl_symbols_t* symbols;
+ rtems_rtl_obj_sym_t* sym;
+ size_t s;
+
+ symbols = rtems_rtl_global_symbols ();
+
+ for (s = 0, sym = obj->global_table; s < obj->global_syms; ++s, ++sym)
+ rtems_rtl_symbol_global_insert (symbols, sym);
+}
+
+void
+rtems_rtl_symbol_obj_erase (rtems_rtl_obj_t* obj)
+{
+ if (obj->global_table)
+ {
+ rtems_rtl_obj_sym_t* sym;
+ size_t s;
+ for (s = 0, sym = obj->global_table; s < obj->global_syms; ++s, ++sym)
+ if (!rtems_chain_is_node_off_chain (&sym->node))
+ rtems_chain_extract (&sym->node);
+ rtems_rtl_alloc_del (RTEMS_RTL_ALLOC_SYMBOL, obj->global_table);
+ obj->global_table = NULL;
+ obj->global_size = 0;
+ obj->global_syms = 0;
+ }
+}
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