/**********************************************************************
* plsym.c
* Symbol management for the P-Code Linker
*
* Copyright (C) 2008-2009 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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 <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "keywords.h"
#include "pdefs.h"
#include "podefs.h"
#include "pedefs.h"
#include "pofflib.h"
#include "paslib.h"
#include "perr.h"
#include "plsym.h"
/**********************************************************************
* Pre-processor Definitions
**********************************************************************/
#define INITIAL_SYMBOL_LIST_SIZE (1024*sizeof(symContainer_t*))
#define SYMBOL_LIST_INCREMENT (256*sizeof(symContainer_t*))
/**********************************************************************
* Private Types
**********************************************************************/
/* This structure just contains a POFF library symbol */
struct symContainer_s
{
struct symContainer_s *next;
struct symContainer_s *prev;
poffLibSymbol_t s;
};
typedef struct symContainer_s symContainer_t;
/**********************************************************************
* Private Variables
**********************************************************************/
static symContainer_t *symHead = NULL;
static symContainer_t *symTail = NULL;
static symContainer_t **symList = NULL;
static uint32_t symListAlloc = 0;
static int nUndefined = 0;
static int nMultiplyDefined = 0;
/**********************************************************************
* Private Function Prototypes
**********************************************************************/
static void offsetSymbolValue(poffLibSymbol_t *sym,
uint32_t pcOffset);
static symContainer_t *insertSymbol(poffLibSymbol_t *sym);
static void addSymbolToList(symContainer_t *symbol,
uint32_t index);
/**********************************************************************
* Public Functions
**********************************************************************/
uint32_t mergeSymbols(poffHandle_t inHandle, uint32_t pcOffset, uint32_t symOffset)
{
poffLibSymbol_t symbol;
symContainer_t *container;
int32_t inIndex;
uint32_t outIndex;
do
{
/* Read each symbol from the input File */
inIndex = poffGetSymbol(inHandle, &symbol);
if (inIndex >= 0)
{
/* If the symbol carries a "payload" that is a program
* section offset, then apply the pcOffset value to
* that "payload"
*/
offsetSymbolValue(&symbol, pcOffset);
/* Create a container for the symbol information */
container = insertSymbol(&symbol);
/* Add the symbol to the linearly indexed list */
outIndex = inIndex + symOffset;
addSymbolToList(container, outIndex);
}
}
while (inIndex >= 0);
/* Return the offset to the last symbol inserted */
return outIndex;
}
/***********************************************************************/
void verifySymbols(void)
{
symContainer_t *sym;
/* At the conclusion the link, there should be no undefined symbols.
* This function simply asserts that condition. It traverses the
* symbol container list and if any undefined symbol is found, it
* errors out.
*/
for (sym = symHead; (sym); sym = sym->next)
{
if ((sym->s.flags & STF_UNDEFINED) != 0)
{
fprintf(stderr, "ERROR: Undefined symbol '%s'\n",
sym->s.name);
nUndefined++;
}
}
if (nUndefined) fatal(eUNDEFINEDSYMBOL);
if (nMultiplyDefined) fatal(eMULTIDEFSYMBOL);
}
/***********************************************************************/
void writeSymbols(poffHandle_t outHandle)
{
symContainer_t *sym;
/* Transfer all buffered symbol information to the output file */
for (sym = symHead; (sym); sym = sym->next)
{
(void)poffAddSymbol(outHandle, &sym->s);
}
}
/***********************************************************************/
poffLibSymbol_t *getSymbolByIndex(uint32_t symIndex)
{
if (symIndex * sizeof(symContainer_t*) >= symListAlloc)
fatal(ePOFFCONFUSION);
return &symList[symIndex]->s;
}
/***********************************************************************/
void releaseSymbols(void)
{
static symContainer_t *curr;
static symContainer_t *next;
for (curr = symHead; (curr); curr = next)
{
/* Get the next pointer from the container -- we are going
* to deallocate the container!
*/
next = curr->next;
/* Deallocate the name string copy */
if (curr->s.name) free((void*)curr->s.name);
/* Free the container */
free(curr);
}
/* Free the index-able symbol list */
if (symList) free((void*)symList);
symHead = NULL;
symTail = NULL;
symList = NULL;
}
/**********************************************************************/
static void offsetSymbolValue(poffLibSymbol_t *sym, uint32_t pcOffset)
{
/* Don't do anything with undefined symbols. By definition, these
* cannot cannot any meaning values.
*/
if ((sym->flags & STF_UNDEFINED) == 0)
{
switch (sym->type)
{
case STT_PROC:
case STT_FUNC:
sym->value += pcOffset;
break;
default:
break;
}
}
}
/**********************************************************************/
static inline symContainer_t *makeSymContainer(poffLibSymbol_t *psym)
{
symContainer_t *sym;
sym = (symContainer_t*)malloc(sizeof(symContainer_t));
if (sym == NULL)
{
fatal(eNOMEMORY);
}
/* The next container is not linked to anything yet */
sym->next = NULL;
sym->prev = NULL;
/* Copy the whole symbol record */
sym->s = *psym;
/* Duplicate the symbol name -- the reference in the symbol entry
* belongs to the input file and will be lost if/when the input file
* is released.
*/
if (psym->name)
{
sym->s.name = strdup(psym->name);
}
return sym;
}
static symContainer_t *insertSymbol(poffLibSymbol_t *sym)
{
symContainer_t *prev;
symContainer_t *curr;
symContainer_t *newsym;
int compare;
/* Find where to insert the symbol */
for (prev = NULL, curr = symHead; (curr); prev = curr, curr = curr->next)
{
/* Compare the names of the symbols */
compare = strcmp(curr->s.name, sym->name);
/* Break out of the loop if curr->name > sym_name or
* if curr->name == sym_name AND the types of the
* symbols are the same.
*/
if (compare > 0)
{
/* Break out... curr refers to a symbol AFTER the position
* where we want to put the new symbol.
*/
break;
}
else if (compare == 0)
{
/* The symbols are the same. break out only if the types
* are the same or this is where we need to insert the new
* symbol (same name different type)
*/
if (curr->s.type > sym->type)
{
compare = 1;
break;
}
else if (curr->s.type == sym->type)
{
break;
}
}
}
/* We get here if:
* a. curr == NULL meaning that the symbol goes at the end of the
* list. (special case, prev == NULL as well. This happens when
* the list is empty).
* b. curr != NULL mean that the symbol goes between prev and curr
* (special cases: (i) compare == 0 meaning that the symbol is
* already in the list, or (ii) compare > 0 with prev == NULL
* meaning that the new entry goes at the beginning of the list).
*/
if (curr == NULL)
{
/* The symbol goes at the end of the list */
newsym = makeSymContainer(sym);
newsym->next = NULL;
newsym->prev = prev;
symTail = newsym;
if (prev)
prev->next = newsym;
else
symHead = newsym;
}
else if (compare == 0)
{
/* curr is non-NULL and refers to the same symbol (of the same
* type). If both are undefined, then just discard the new
* symbol.
*/
if ((curr->s.flags & STF_UNDEFINED) != 0)
{
/* The symbol in the table is undefined */
if ((sym->flags & STF_UNDEFINED) != 0)
{
/* Both symbols are undefined. Just ignore the new one */
}
else
{
/* The symbol in the table is undefined, but the new
* one is defined. Replace the one in the table (retaining
* the allocated symbol name).
*/
const char *save = curr->s.name;
curr->s = *sym;
curr->s.name = save;
}
}
else
{
/* The symbol in the table is defined */
if ((sym->flags & STF_UNDEFINED) != 0)
{
/* But the new symbol is undefined. Just ignore the
* new symbol
*/
}
else
{
/* OOPS! both symbols are defined */
fprintf(stderr,
"ERROR: Multiply defined symbol: '%s'\n",
sym->name);
nMultiplyDefined++;
}
/* In any case, return the pointer to the old container */
newsym = curr;
}
}
else
{
/* curr is non-NULL and the symbol goes between prev and curr */
newsym = makeSymContainer(sym);
newsym->next = curr;
newsym->prev = prev;
if (prev)
prev->next = newsym;
else
symHead = newsym;
}
return newsym;
}
/***********************************************************************/
/* Add a symbol to the linear symbol table list. This list is necessary
* to quickly mapped a symbol index value (as might be found in the
* relocation data) to the unique representation of the symbol as
* deterimed by insertSymbol().
*/
static void addSymbolToList(symContainer_t *symbol, uint32_t index)
{
/* Check if we have allocated a symbol table buffer yet */
if (!symList)
{
/* No, allocate it now */
symList = (symContainer_t**)malloc(INITIAL_SYMBOL_LIST_SIZE);
if (!symList)
{
fatal(eNOMEMORY);
}
symListAlloc = INITIAL_SYMBOL_LIST_SIZE;
}
/* Check if there is room for a new symbol */
if ((index + 1) * sizeof(symContainer_t*) > symListAlloc)
{
uint32_t newAlloc = symListAlloc + SYMBOL_LIST_INCREMENT;
symContainer_t **tmp;
/* Reallocate the file name buffer */
tmp = (symContainer_t**)realloc(symList, newAlloc);
if (!tmp)
{
fatal(eNOMEMORY);
}
/* And set the new size */
symListAlloc = newAlloc;
symList = tmp;
}
/* Save the new symbol information in the symbol table data */
symList[index] = symbol;
}
/***********************************************************************/
