/*  Pawn debugger interface
 *
 *  Support functions for debugger applications
 *
 *  Copyright (c) ITB CompuPhase, 2005-2011
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may not
 *  use this file except in compliance with the License. You may obtain a copy
 *  of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 *  License for the specific language governing permissions and limitations
 *  under the License.
 *
 *  Version: $Id: amxdbg.c 4523 2011-06-21 15:03:47Z thiadmer $
 */
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "osdefs.h"     /* for _MAX_PATH */
#include "amx.h"
#include "amxdbg.h"


int AMXAPI dbg_FreeInfo(AMX_DBG *amxdbg)
{
  assert(amxdbg != NULL);
  if (amxdbg->hdr != NULL)
    free(amxdbg->hdr);
  if (amxdbg->filetbl != NULL)
    free(amxdbg->filetbl);
  if (amxdbg->symboltbl != NULL)
    free(amxdbg->symboltbl);
  if (amxdbg->tagtbl != NULL)
    free(amxdbg->tagtbl);
  if (amxdbg->automatontbl != NULL)
    free(amxdbg->automatontbl);
  if (amxdbg->statetbl != NULL)
    free(amxdbg->statetbl);
  memset(amxdbg, 0, sizeof(AMX_DBG));
  return AMX_ERR_NONE;
}

int AMXAPI dbg_LoadInfo(AMX_DBG *amxdbg, FILE *fp)
{
  AMX_HEADER amxhdr;
  AMX_DBG_HDR dbghdr;
  unsigned char *ptr;
  int index, dim;
  AMX_DBG_SYMDIM *symdim;

  assert(fp != NULL);
  assert(amxdbg != NULL);

  memset(&amxhdr, 0, sizeof amxhdr);
  fseek(fp, 0L, SEEK_SET);
  fread(&amxhdr, sizeof amxhdr, 1, fp);
  #if BYTE_ORDER==BIG_ENDIAN
    amx_Align32((uint32_t*)&amxhdr.size);
    amx_Align16(&amxhdr.magic);
    amx_Align16(&dbghdr.flags);
  #endif
  if (amxhdr.magic != AMX_MAGIC)
    return AMX_ERR_FORMAT;
  if ((amxhdr.flags & AMX_FLAG_DEBUG) == 0)
    return AMX_ERR_DEBUG;

  fseek(fp, amxhdr.size, SEEK_SET);
  memset(&dbghdr, 0, sizeof(AMX_DBG_HDR));
  fread(&dbghdr, sizeof(AMX_DBG_HDR), 1, fp);

  #if BYTE_ORDER==BIG_ENDIAN
    amx_Align32((uint32_t*)&dbghdr.size);
    amx_Align16(&dbghdr.magic);
    amx_Align16(&dbghdr.files);
    amx_Align16(&dbghdr.lines);
    amx_Align16(&dbghdr.symbols);
    amx_Align16(&dbghdr.tags);
    amx_Align16(&dbghdr.automatons);
    amx_Align16(&dbghdr.states);
  #endif
  if (dbghdr.magic != AMX_DBG_MAGIC)
    return AMX_ERR_FORMAT;

  /* allocate all memory */
  memset(amxdbg, 0, sizeof(AMX_DBG));
  amxdbg->hdr = (AMX_DBG_HDR*)malloc((size_t)dbghdr.size);
  if (dbghdr.files > 0)
    amxdbg->filetbl = (AMX_DBG_FILE**)malloc(dbghdr.files * sizeof(AMX_DBG_FILE*));
  if (dbghdr.symbols > 0)
    amxdbg->symboltbl = (AMX_DBG_SYMBOL**)malloc(dbghdr.symbols * sizeof(AMX_DBG_SYMBOL*));
  if (dbghdr.tags > 0)
    amxdbg->tagtbl = (AMX_DBG_TAG**)malloc(dbghdr.tags * sizeof(AMX_DBG_TAG*));
  if (dbghdr.automatons > 0)
    amxdbg->automatontbl = (AMX_DBG_MACHINE**)malloc(dbghdr.automatons * sizeof(AMX_DBG_MACHINE*));
  if (dbghdr.states > 0)
    amxdbg->statetbl = (AMX_DBG_STATE**)malloc(dbghdr.states * sizeof(AMX_DBG_STATE*));
  if (amxdbg->hdr == NULL
      || (dbghdr.files > 0 && amxdbg->filetbl == NULL)
      || (dbghdr.symbols > 0 && amxdbg->symboltbl == NULL)
      || (dbghdr.tags > 0 && amxdbg->tagtbl == NULL)
      || (dbghdr.states > 0 && amxdbg->statetbl == NULL)
      || (dbghdr.automatons > 0 && amxdbg->automatontbl == NULL))
  {
    dbg_FreeInfo(amxdbg);
    return AMX_ERR_MEMORY;
  } /* if */

  /* load the entire symbolic information block into memory */
  memcpy(amxdbg->hdr, &dbghdr, sizeof dbghdr);
  fread(amxdbg->hdr + 1, 1, (size_t)(dbghdr.size - sizeof dbghdr), fp);

  /* run through the file, fix alignment issues and set up table pointers */
  ptr = (unsigned char *)(amxdbg->hdr + 1);

  /* file table */
  for (index = 0; index < dbghdr.files; index++) {
    assert(amxdbg->filetbl != NULL);
    amxdbg->filetbl[index] = (AMX_DBG_FILE *)ptr;
    #if BYTE_ORDER==BIG_ENDIAN
      amx_Align32(&amxdbg->filetbl[index]->address);
    #endif
    for (ptr = ptr + sizeof(AMX_DBG_FILE); *ptr != '\0'; ptr++)
      /* nothing */;
    ptr++;              /* skip '\0' too */
  } /* for */

  /* line table */
  amxdbg->linetbl = (AMX_DBG_LINE*)ptr;
  #if BYTE_ORDER==BIG_ENDIAN
    for (index = 0; index < dbghdr.lines; index++) {
      amx_Align32(&amxdbg->linetbl[index].address);
      amx_Align32((uint32_t*)&amxdbg->linetbl[index].line);
    } /* for */
  #endif
  ptr += dbghdr.lines * sizeof(AMX_DBG_LINE);

  /* symbol table (plus index tags) */
  for (index = 0; index < dbghdr.symbols; index++) {
    assert(amxdbg->symboltbl != NULL);
    amxdbg->symboltbl[index] = (AMX_DBG_SYMBOL *)ptr;
    #if BYTE_ORDER==BIG_ENDIAN
      amx_Align32(&amxdbg->symboltbl[index]->address);
      amx_Align16((uint16_t*)&amxdbg->symboltbl[index]->tag);
      amx_Align32(&amxdbg->symboltbl[index]->codestart);
      amx_Align32(&amxdbg->symboltbl[index]->codeend);
      amx_Align16((uint16_t*)&amxdbg->symboltbl[index]->dim);
    #endif
    for (ptr = ptr + sizeof(AMX_DBG_SYMBOL); *ptr != '\0'; ptr++)
      /* nothing */;
    ptr++;              /* skip '\0' too */
    for (dim = 0; dim < amxdbg->symboltbl[index]->dim; dim++) {
      symdim = (AMX_DBG_SYMDIM *)ptr;
      amx_Align16((uint16_t*)&symdim->tag);
      amx_Align32(&symdim->size);
      ptr += sizeof(AMX_DBG_SYMDIM);
    } /* for */
  } /* for */

  /* tag name table */
  for (index = 0; index < dbghdr.tags; index++) {
    assert(amxdbg->tagtbl != NULL);
    amxdbg->tagtbl[index] = (AMX_DBG_TAG *)ptr;
    #if BYTE_ORDER==BIG_ENDIAN
      amx_Align16(&amxdbg->tagtbl[index]->tag);
    #endif
    for (ptr = ptr + sizeof(AMX_DBG_TAG) - 1; *ptr != '\0'; ptr++)
      /* nothing */;
    ptr++;              /* skip '\0' too */
  } /* for */

  /* automaton name table */
  for (index = 0; index < dbghdr.automatons; index++) {
    assert(amxdbg->automatontbl != NULL);
    amxdbg->automatontbl[index] = (AMX_DBG_MACHINE *)ptr;
    #if BYTE_ORDER==BIG_ENDIAN
      amx_Align16(&amxdbg->automatontbl[index]->automaton);
      amx_Align32(&amxdbg->automatontbl[index]->address);
    #endif
    for (ptr = ptr + sizeof(AMX_DBG_MACHINE) - 1; *ptr != '\0'; ptr++)
      /* nothing */;
    ptr++;              /* skip '\0' too */
  } /* for */

  /* state name table */
  for (index = 0; index < dbghdr.states; index++) {
    assert(amxdbg->statetbl != NULL);
    amxdbg->statetbl[index] = (AMX_DBG_STATE *)ptr;
    #if BYTE_ORDER==BIG_ENDIAN
      amx_Align16(&amxdbg->statetbl[index]->state);
      amx_Align16(&amxdbg->automatontbl[index]->automaton);
    #endif
    for (ptr = ptr + sizeof(AMX_DBG_STATE) - 1; *ptr != '\0'; ptr++)
      /* nothing */;
    ptr++;              /* skip '\0' too */
  } /* for */

  return AMX_ERR_NONE;
}

/* dbg_LinearAddress() returns the linear address that matches the given
 * relative address for the current overlay. The linear address is relative
 * to the code section (as if the code section were a single block).
 * Linearizing addresses is only needed for debugging hooks when overlays
 * are active. On a non-overlay file, dbg_LinearAddress() returns the same
 * address as its input.
 */
int AMXAPI dbg_LinearAddress(AMX *amx, ucell relative_addr, ucell *linear_addr)
{
  AMX_HEADER *hdr;

  assert(amx!=NULL);
  hdr=(AMX_HEADER *)amx->base;
  assert(hdr!=NULL);
  assert(linear_addr!=NULL);
  if ((hdr->flags & AMX_FLAG_OVERLAY)==0) {
    *linear_addr=relative_addr;
  } else {
    AMX_OVERLAYINFO *tbl;
    assert(hdr->overlays!=0 && hdr->overlays!=hdr->nametable);
    if ((size_t)amx->ovl_index >= (hdr->nametable-hdr->overlays)/sizeof(AMX_OVERLAYINFO))
      return AMX_ERR_OVERLAY;
    tbl=(AMX_OVERLAYINFO*)(amx->base+hdr->overlays)+amx->ovl_index;
    *linear_addr=tbl->offset+relative_addr;
  } /* if */
  return AMX_ERR_NONE;
}

int AMXAPI dbg_LookupFile(AMX_DBG *amxdbg, ucell address, const char **filename)
{
  int index;

  assert(amxdbg != NULL);
  assert(filename != NULL);
  *filename = NULL;
  /* this is a simple linear look-up; a binary search would be possible too */
  for (index = 0; index < amxdbg->hdr->files && amxdbg->filetbl[index]->address <= address; index++)
    /* nothing */;
  /* reset for overrun */
  if (--index < 0)
    return AMX_ERR_NOTFOUND;

  *filename = amxdbg->filetbl[index]->name;
  return AMX_ERR_NONE;
}

int AMXAPI dbg_LookupLine(AMX_DBG *amxdbg, ucell address, long *line)
{
  int index;

  assert(amxdbg != NULL);
  assert(line != NULL);
  *line = 0;
  /* this is a simple linear look-up; a binary search would be possible too */
  for (index = 0; index < amxdbg->hdr->lines && amxdbg->linetbl[index].address <= address; index++)
    /* nothing */;
  /* reset for overrun */
  if (--index < 0)
    return AMX_ERR_NOTFOUND;

  *line = (long)amxdbg->linetbl[index].line;
  return AMX_ERR_NONE;
}

int AMXAPI dbg_LookupFunction(AMX_DBG *amxdbg, ucell address, const char **funcname)
{
  /* dbg_LookupFunction() finds the function a code address is in. It can be
   * used for stack walking, and for stepping through a function while stepping
   * over sub-functions
   */
  int index;

  assert(amxdbg != NULL);
  assert(funcname != NULL);
  *funcname = NULL;
  for (index = 0; index < amxdbg->hdr->symbols; index++) {
    if (amxdbg->symboltbl[index]->ident == iFUNCTN
        && amxdbg->symboltbl[index]->codestart <= address
        && amxdbg->symboltbl[index]->codeend > address)
      break;
  } /* for */
  if (index >= amxdbg->hdr->symbols)
    return AMX_ERR_NOTFOUND;

  *funcname = amxdbg->symboltbl[index]->name;
  return AMX_ERR_NONE;
}

int AMXAPI dbg_GetTagName(AMX_DBG *amxdbg, int tag, const char **name)
{
  int index;

  assert(amxdbg != NULL);
  assert(name != NULL);
  *name = NULL;
  for (index = 0; index < amxdbg->hdr->tags && amxdbg->tagtbl[index]->tag != tag; index++)
    /* nothing */;
  if (index >= amxdbg->hdr->tags)
    return AMX_ERR_NOTFOUND;

  *name = amxdbg->tagtbl[index]->name;
  return AMX_ERR_NONE;
}

int AMXAPI dbg_GetAutomatonName(AMX_DBG *amxdbg, int automaton, const char **name)
{
  int index;

  assert(amxdbg != NULL);
  assert(name != NULL);
  *name = NULL;
  for (index = 0; index < amxdbg->hdr->automatons && amxdbg->automatontbl[index]->automaton != automaton; index++)
    /* nothing */;
  if (index >= amxdbg->hdr->automatons)
    return AMX_ERR_NOTFOUND;

  *name = amxdbg->automatontbl[index]->name;
  return AMX_ERR_NONE;
}

int AMXAPI dbg_GetStateName(AMX_DBG *amxdbg, int state, const char **name)
{
  int index;

  assert(amxdbg != NULL);
  assert(name != NULL);
  *name = NULL;
  for (index = 0; index < amxdbg->hdr->states && amxdbg->statetbl[index]->state != state; index++)
    /* nothing */;
  if (index >= amxdbg->hdr->states)
    return AMX_ERR_NOTFOUND;

  *name = amxdbg->statetbl[index]->name;
  return AMX_ERR_NONE;
}

int AMXAPI dbg_GetLineAddress(AMX_DBG *amxdbg, long line, const char *filename, ucell *address)
{
  /* Find a suitable "breakpoint address" close to the indicated line (and in
   * the specified file). The address is moved up to the next "breakable" line
   * if no "breakpoint" is available on the specified line. You can use function
   * dbg_LookupLine() to find out at which precise line the breakpoint was set.
   *
   * The filename comparison is strict (case sensitive and path sensitive); the
   * "filename" parameter should point into the "filetbl" of the AMX_DBG
   * structure.
   */
  int file, index;
  ucell bottomaddr,topaddr;

  assert(amxdbg != NULL);
  assert(filename != NULL);
  assert(address != NULL);
  *address = 0;

  index = 0;
  for (file = 0; file < amxdbg->hdr->files; file++) {
    /* find the (next) mathing instance of the file */
    if (strcmp(amxdbg->filetbl[file]->name, filename) != 0)
      continue;
    /* get address range for the current file */
    bottomaddr = amxdbg->filetbl[file]->address;
    topaddr = (file + 1 < amxdbg->hdr->files) ? amxdbg->filetbl[file+1]->address : (ucell)(cell)-1;
    /* go to the starting address in the line table */
    while (index < amxdbg->hdr->lines && amxdbg->linetbl[index].address < bottomaddr)
      index++;
    /* browse until the line is found or until the top address is exceeded */
    while (index < amxdbg->hdr->lines
           && amxdbg->linetbl[index].line < line
           && amxdbg->linetbl[index].address < topaddr)
      index++;
    if (index >= amxdbg->hdr->lines)
      return AMX_ERR_NOTFOUND;
    if (amxdbg->linetbl[index].line >= line)
      break;
    /* if not found (and the line table is not yet exceeded) try the next
     * instance of the same file (a file may appear twice in the file table)
     */
  } /* for */

  if (strcmp(amxdbg->filetbl[file]->name, filename) != 0)
    return AMX_ERR_NOTFOUND;

  assert(index < amxdbg->hdr->lines);
  *address = amxdbg->linetbl[index].address;
  return AMX_ERR_NONE;
}

int AMXAPI dbg_GetFunctionAddress(AMX_DBG *amxdbg, const char *funcname, const char *filename, ucell *address)
{
  /* Find a suitable "breakpoint address" close to the indicated line (and in
   * the specified file). The address is moved up to the first "breakable" line
   * in the function. You can use function dbg_LookupLine() to find out at which
   * precise line the breakpoint was set.
   *
   * The filename comparison is strict (case sensitive and path sensitive); the
   * "filename" parameter should point into the "filetbl" of the AMX_DBG
   * structure. The function name comparison is case sensitive too.
   */
  int index, err;
  const char *tgtfile;
  ucell funcaddr;

  assert(amxdbg != NULL);
  assert(funcname != NULL);
  assert(filename != NULL);
  assert(address != NULL);
  *address = 0;

  index = 0;
  for ( ;; ) {
    /* find (next) matching function */
    while (index < amxdbg->hdr->symbols
           && (amxdbg->symboltbl[index]->ident != iFUNCTN || strcmp(amxdbg->symboltbl[index]->name, funcname) != 0))
      index++;
    if (index >= amxdbg->hdr->symbols)
      return AMX_ERR_NOTFOUND;
    /* verify that this line falls in the appropriate file */
    err = dbg_LookupFile(amxdbg, amxdbg->symboltbl[index]->address, &tgtfile);
    if (err == AMX_ERR_NONE || strcmp(filename, tgtfile) == 0)
      break;
    index++;            /* line is the wrong file, search further */
  } /* for */

  /* now find the first line in the function where we can "break" on */
  assert(index < amxdbg->hdr->symbols);
  funcaddr = amxdbg->symboltbl[index]->address;
  for (index = 0; index < amxdbg->hdr->lines && amxdbg->linetbl[index].address < funcaddr; index++)
    /* nothing */;

  if (index >= amxdbg->hdr->lines)
    return AMX_ERR_NOTFOUND;
  *address = amxdbg->linetbl[index].address;

  return AMX_ERR_NONE;
}

int AMXAPI dbg_GetVariable(AMX_DBG *amxdbg, const char *symname, ucell scopeaddr, const AMX_DBG_SYMBOL **sym)
{
  ucell codestart,codeend;
  int index;

  assert(amxdbg != NULL);
  assert(symname != NULL);
  assert(sym != NULL);
  *sym = NULL;

  codestart = codeend = 0;
  index = 0;
  for ( ;; ) {
    /* find (next) matching variable */
    while (index < amxdbg->hdr->symbols
           && (amxdbg->symboltbl[index]->ident == iFUNCTN || strcmp(amxdbg->symboltbl[index]->name, symname) != 0)
           && (amxdbg->symboltbl[index]->codestart > scopeaddr || amxdbg->symboltbl[index]->codeend < scopeaddr))
      index++;
    if (index >= amxdbg->hdr->symbols)
      break;
    /* check the range, keep a pointer to the symbol with the smallest range */
    if (strcmp(amxdbg->symboltbl[index]->name, symname) == 0
        && (codestart == 0 && codeend == 0
            || amxdbg->symboltbl[index]->codestart >= codestart && amxdbg->symboltbl[index]->codeend <= codeend))
    {
      *sym = amxdbg->symboltbl[index];
      codestart = amxdbg->symboltbl[index]->codestart;
      codeend = amxdbg->symboltbl[index]->codeend;
    } /* if */
    index++;
  } /* for */

  return (*sym == NULL) ? AMX_ERR_NOTFOUND : AMX_ERR_NONE;
}

int AMXAPI dbg_GetArrayDim(AMX_DBG *amxdbg, const AMX_DBG_SYMBOL *sym, const AMX_DBG_SYMDIM **symdim)
{
  /* retrieves a pointer to the array dimensions structures of an array symbol */
  const char *ptr;

  assert(amxdbg != NULL);
  assert(sym != NULL);
  assert(symdim != NULL);
  *symdim = NULL;

  if (sym->ident != iARRAY && sym->ident != iREFARRAY)
    return AMX_ERR_PARAMS;
  assert(sym->dim > 0); /* array must have at least one dimension */

  /* find the end of the symbol name */
  for (ptr = sym->name; *ptr != '\0'; ptr++)
    /* nothing */;
  *symdim = (AMX_DBG_SYMDIM *)(ptr + 1);/* skip '\0' too */

  return AMX_ERR_NONE;
}