/* Utility routines for finding and reading Java(TM) .class files.
   Copyright (C) 1996, 1998  Free Software Foundation, Inc.

This program 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 2, or (at your option)
any later version.

This program 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 GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  

Java and all Java-based marks are trademarks or registered trademarks
of Sun Microsystems, Inc. in the United States and other countries.
The Free Software Foundation is independent of Sun Microsystems, Inc.  */

/* Written by Per Bothner <bothner@cygnus.com>, February 1996. */

#include "config.h"
#include "system.h"

#define ENABLE_UNZIP 1

#include "jcf.h"
#include <sys/stat.h>
#include <sys/wait.h>

/* DOS brain-damage */
#ifndef O_BINARY
#define O_BINARY 0 /* MS-DOS brain-damage */
#endif

char *classpath;

int
DEFUN(jcf_unexpected_eof, (jcf, count),
      JCF *jcf AND int count)
{
  if (jcf->filename)
    fprintf (stderr, "Premature end of .class file %s.\n", jcf->filename);
  else
    fprintf (stderr, "Premature end of .class file <stdin>.\n");
  exit (-1);
}

void
DEFUN(jcf_trim_old_input, (jcf),
      JCF *jcf)
{
  int count = jcf->read_ptr - jcf->buffer;
  if (count > 0)
    {
      memmove (jcf->buffer, jcf->read_ptr, jcf->read_end - jcf->read_ptr);
      jcf->read_ptr -= count;
      jcf->read_end -= count;
    }
}

int
DEFUN(jcf_filbuf_from_stdio, (jcf, count),
      JCF *jcf AND int count)
{
  FILE *file = (FILE*) (jcf->read_state);
  if (count > jcf->buffer_end - jcf->read_ptr)
    {
      JCF_u4 old_read_ptr = jcf->read_ptr - jcf->buffer;
      JCF_u4 old_read_end = jcf->read_end - jcf->buffer;
      JCF_u4 old_size = jcf->buffer_end - jcf->buffer;
      JCF_u4 new_size = (old_size == 0 ? 2000 : 2 * old_size) + count;
      unsigned char *new_buffer = jcf->buffer == NULL ? ALLOC (new_size)
	: REALLOC (jcf->buffer, new_size);
      jcf->buffer = new_buffer;
      jcf->buffer_end = new_buffer + new_size;
      jcf->read_ptr = new_buffer + old_read_ptr;
      jcf->read_end = new_buffer + old_read_end;
    }
  count -= jcf->read_end - jcf->read_ptr;
  if (count <= 0)
    return 0;
  if (fread (jcf->read_end, 1, count, file) != count)
    jcf_unexpected_eof (jcf, count);
  jcf->read_end += count;
  return 0;
}

#if ENABLE_UNZIP
#include "zipfile.h"

struct ZipFileCache *SeenZipFiles = NULL;

int
DEFUN(open_in_zip, (jcf, 
zipfile, zipmember),
      JCF *jcf AND const char *zipfile AND const char *zipmember)
{
  struct ZipFileCache* zipf;
  ZipDirectory *zipd;
  int i, len;
  for (zipf = SeenZipFiles; ; zipf = zipf->next)
    {
      if (zipf == NULL)
	{
	  char magic [4];
	  int fd = open (zipfile, O_RDONLY | O_BINARY);
	  jcf_dependency_add_file (zipfile, 0);	/* FIXME: system file? */
	  if (read (fd, magic, 4) != 4 || GET_u4 (magic) != (JCF_u4)ZIPMAGIC)
	    return -1;
	  lseek (fd, 0L, SEEK_SET);
	  zipf = ALLOC (sizeof (struct ZipFileCache) + strlen (zipfile) + 1);
	  zipf->next = SeenZipFiles;
	  zipf->name = (char*)(zipf+1);
	  strcpy (zipf->name, zipfile);
	  SeenZipFiles = zipf;
	  zipf->z.fd = fd;
	  if (fd == -1)
	    {
	      /* A missing zip file is not considered an error. */
	      zipf->z.count = 0;
	      zipf->z.dir_size = 0;
	      zipf->z.central_directory = NULL;
	      return -1;
	    }
	  else
	    {
	      if (read_zip_archive (&zipf->z) != 0)
		return -2; /* This however should be an error - FIXME */
	    }
	  break;
	}
      if (strcmp (zipf->name, zipfile) == 0)
	break;
    }

  if (!zipmember)
    return 0;

  len = strlen (zipmember);
  
  zipd = (struct ZipDirectory*) zipf->z.central_directory;
  for (i = 0; i < zipf->z.count; i++, zipd = ZIPDIR_NEXT (zipd))
    {
      if (len == zipd->filename_length &&
	  strncmp (ZIPDIR_FILENAME (zipd), zipmember, len) == 0)
	{
	  JCF_ZERO (jcf);
	  jcf->buffer = ALLOC (zipd->size);
	  jcf->buffer_end = jcf->buffer + zipd->size;
	  jcf->read_ptr = jcf->buffer;
	  jcf->read_end = jcf->buffer_end;
	  jcf->filbuf = jcf_unexpected_eof;
	  jcf->filename = strdup (zipfile);
	  jcf->classname = strdup (zipmember);
	  jcf->zipd = (void *)zipd;
	  if (lseek (zipf->z.fd, zipd->filestart, 0) < 0
	      || read (zipf->z.fd, jcf->buffer, zipd->size) != zipd->size)
	    return -2;
	  return 0;
	}
    }
  return -1;
}
#endif /* ENABLE_UNZIP */

#if JCF_USE_STDIO
char*
DEFUN(open_class, (filename, jcf, stream, dep_name),
      char *filename AND JCF *jcf AND FILE* stream AND char *dep_name)
{
  if (jcf)
    {
      if (dep_name != NULL)
	jcf_dependency_add_file (dep_name, 0);
      JCF_ZERO (jcf);
      jcf->buffer = NULL;
      jcf->buffer_end = NULL;
      jcf->read_ptr = NULL;
      jcf->read_end = NULL;
      jcf->read_state = stream;
      jcf->filbuf = jcf_filbuf_from_stdio;
    }
  else
    fclose (stream);
  return filename;
}
#else
char*
DEFUN(open_class, (filename, jcf, fd, dep_name),
      char *filename AND JCF *jcf AND int fd AND char *dep_name)
{
  if (jcf)
    {
      struct stat stat_buf;
      if (fstat (fd, &stat_buf) != 0
	  || ! S_ISREG (stat_buf.st_mode))
	{
	  perror ("Could not figure length of .class file");
	  return NULL;
	}
      if (dep_name != NULL)
	jcf_dependency_add_file (dep_name, 0);
      JCF_ZERO (jcf);
      jcf->buffer = ALLOC (stat_buf.st_size);
      jcf->buffer_end = jcf->buffer + stat_buf.st_size;
      jcf->read_ptr = jcf->buffer;
      jcf->read_end = jcf->buffer_end;
      jcf->read_state = NULL;
      jcf->filename = filename;
      if (read (fd, jcf->buffer, stat_buf.st_size) != stat_buf.st_size)
	{
	  perror ("Failed to read .class file");
	  return NULL;
	}
      close (fd);
      jcf->filbuf = jcf_unexpected_eof;
    }
  else
    close (fd);
  return filename;
}
#endif


char *
DEFUN(find_classfile, (filename, jcf, dep_name),
      char *filename AND JCF *jcf AND char *dep_name)
{
#if JCF_USE_STDIO
  FILE *stream = fopen (filename, "rb");
  if (stream == NULL)
    return NULL;
  return open_class (arg, jcf, stream, dep_name);
#else
  int fd = open (filename, O_RDONLY | O_BINARY);
  if (fd < 0)
    return NULL;
  return open_class (filename, jcf, fd, dep_name);
#endif
}

/* Returns a freshly malloc'd string with the fully qualified pathname
   of the .class file for the class CLASSNAME.  Returns NULL on
   failure.  If JCF != NULL, it is suitably initialized.  With
   DO_CLASS_FILE set to 1, search a .class/.java file named after
   CLASSNAME, otherwise, search a ZIP directory entry named after
   CLASSNAME.  */

char *
DEFUN(find_class, (classname, classname_length, jcf, do_class_file),
      const char *classname AND int classname_length AND JCF *jcf AND int do_class_file)

{
#if JCF_USE_STDIO
  FILE *stream;
#else
  int fd;
#endif
  int i, j, k, java, class;
  struct stat java_buf, class_buf;
  char *dep_file;

  /* A temporary buffer that we grow to be large enough to hold
     whatever class name we're working on.  */
  static int temp_len = 0;
  static char *temp_buffer = NULL;

  /* Allocate and zero out the buffer, since we don't explicitly put a
     null pointer when we're copying it below.  */
  int buflen = strlen (classpath) + classname_length + 10;
  char *buffer = (char *) ALLOC (buflen);
  bzero (buffer, buflen);

  if (buflen > temp_len)
    {
      temp_len = buflen;
      if (temp_buffer == NULL)
	temp_buffer = (char *) ALLOC (temp_len);
      else
	temp_buffer = (char *) REALLOC (temp_buffer, temp_len);
    }

  jcf->java_source = jcf->outofsynch = 0;
  for (j = 0; classpath[j] != '\0'; )
    {
      for (i = 0; classpath[j] != ':' && classpath[j] != '\0'; i++, j++)
	buffer[i] = classpath[j];
      if (classpath[j] == ':')
	j++;
      if (i > 0)  /* Empty directory is redundant */
	{
	  int dir_len;
	  if (buffer[i-1] != '/')
	    buffer[i++] = '/';
	  dir_len = i-1;
	  for (k = 0; k < classname_length; k++, i++)
	    {
	      char ch = classname[k];
	      buffer[i] = ch == '.' ? '/' : ch;
	    }
	  if (do_class_file)
	    strcpy (buffer+i, ".class");
#if ENABLE_UNZIP
	  if (dir_len > 4
	      && buffer[dir_len-4] == '.' && buffer[dir_len-3] == 'z'
	      && buffer[dir_len-2] == 'i' && buffer[dir_len-1] == 'p')
	    {
	      int err_code;
	      JCF _jcf;
	      if (!do_class_file)
		strcpy (buffer+i, "/");
	      buffer[dir_len] = '\0';
	      if (do_class_file)
		SOURCE_FRONTEND_DEBUG 
		  (("Trying [...%s]:%s", 
		    &buffer[dir_len-(dir_len > 15 ? 15 : dir_len)], 
		    buffer+dir_len+1));
	      if (jcf == NULL)
		jcf = &_jcf;
	      err_code = open_in_zip (jcf, buffer, buffer+dir_len+1);
	      if (err_code == 0)
		{
		  if (!do_class_file)
		    jcf->seen_in_zip = 1;
		  else
		    {
		      buffer[dir_len] = '(';
		      strcpy (buffer+i, ".class)");
		    }
		  if (jcf == &_jcf)
		    JCF_FINISH (jcf);
		  return buffer;
		}
	      else
		continue;
	    }
#endif
	  /* If we do directories, do them here */
	  if (!do_class_file)
	    {
	      struct stat dir_buff;
	      int dir;
	      buffer[i] = '\0';	/* Was previously unterminated here. */
	      if (!(dir = stat (buffer, &dir_buff)))
		{
		  jcf->seen_in_zip = 0;
		  goto found;
		}
	    }

	  /* Check for out of synch .class/.java files */
	  class = stat (buffer, &class_buf);
	  strcpy (buffer+i, ".java");
	  /* Stash the name of the .java file in the temp buffer.  */
	  strcpy (temp_buffer, buffer);
	  java = stat (buffer, &java_buf);
	  if ((!java && !class) && java_buf.st_mtime >= class_buf.st_mtime)
	    jcf->outofsynch = 1;

	  if (! java)
	    dep_file = temp_buffer;
	  else
	    dep_file = buffer;
#if JCF_USE_STDIO
	  if (!class)
	    {
	      strcpy (buffer+i, ".class");
	      SOURCE_FRONTEND_DEBUG (("Trying %s", buffer));
	      stream = fopen (buffer, "rb");
	      if (stream)
		goto found;
	    }
	  /* Give .java a try, if necessary */
	  if (!java)
	    {
	      strcpy (buffer+i, ".java");
	      SOURCE_FRONTEND_DEBUG (("Trying %s", buffer));
	      stream = fopen (buffer, "r");
	      if (stream)
		{
		  jcf->java_source = 1;
		  goto found;
		}
	    }
#else
	  if (!class)
	    {
	      strcpy (buffer+i, ".class");
	      SOURCE_FRONTEND_DEBUG (("Trying %s", buffer));
	      fd = open (buffer, O_RDONLY | O_BINARY);
	      if (fd >= 0)
		goto found;
	    }
	  /* Give .java a try, if necessary */
	  if (!java)
	    {
	      if (do_class_file)
		strcpy (buffer+i, ".java");
	      SOURCE_FRONTEND_DEBUG (("Trying %s", buffer));
	      fd = open (buffer, O_RDONLY | O_BINARY);
	      if (fd >= 0)
		{
		  jcf->java_source = 1;
		  goto found;
		}
	    }
#endif
	}
    }
  free (buffer);
  return NULL;
 found:
#if JCF_USE_STDIO
  if (jcf->java_source)
    return NULL;		/* FIXME */
  else
    return open_class (buffer, jcf, stream, dep_file);
#else
  if (jcf->java_source)
    {
      JCF_ZERO (jcf);		/* JCF_FINISH relies on this */
      jcf->java_source = 1;
      jcf->filename = (char *) strdup (buffer);
      close (fd);		/* We use STDIO for source file */
    }
  else if (do_class_file)
    buffer = open_class (buffer, jcf, fd, dep_file);
  jcf->classname = (char *) ALLOC (classname_length + 1);
  strncpy (jcf->classname, classname, classname_length + 1);
  jcf->classname = (char *) strdup (classname);
  return buffer;
#endif
}

void
DEFUN(jcf_print_char, (stream, ch),
      FILE *stream AND int ch)
{
  switch (ch)
    {
    case '\'':
    case '\\':
    case '\"':
      fprintf (stream, "\\%c", ch);
      break;
    case '\n':
      fprintf (stream, "\\n");
      break;
    case '\t':
      fprintf (stream, "\\t");
      break;
    case '\r':
      fprintf (stream, "\\r");
      break;
    default:
      if (ch >= ' ' && ch < 127)
	putc (ch, stream);
      else if (ch < 256)
	fprintf (stream, "\\%03x", ch);
      else
	fprintf (stream, "\\u%04x", ch);
    }
}

/* Print UTF8 string at STR of length LENGTH bytes to STREAM. */

void
DEFUN(jcf_print_utf8, (stream, str, length),
      FILE *stream AND register unsigned char *str AND int length)
{
  unsigned char* limit = str + length;
  while (str < limit)
    {
      int ch = UTF8_GET (str, limit);
      if (ch < 0)
	{
	  fprintf (stream, "\\<invalid>");
	  return;
	}
      jcf_print_char (stream, ch);
    }
}

/* Same as jcf_print_utf8, but print IN_CHAR as OUT_CHAR. */

void
DEFUN(jcf_print_utf8_replace, (stream, str, length, in_char, out_char),
      FILE *stream AND unsigned char *str AND int length
      AND int in_char AND int out_char)
{

  int i;/* FIXME - actually handle Unicode! */
  for (i = 0; i < length; i++)
    {
      int ch = str[i];
      jcf_print_char (stream, ch == in_char ? out_char : ch);
    }
}

/* Check that all the cross-references in the constant pool are
   valid.  Returns 0 on success.
   Otherwise, returns the index of the (first) invalid entry. */

int
DEFUN(verify_constant_pool, (jcf),
      JCF *jcf)
{
  int i, n;
  for (i = 1; i < JPOOL_SIZE (jcf); i++)
    {
      switch (JPOOL_TAG (jcf, i))
	{
	case CONSTANT_NameAndType:
	  n = JPOOL_USHORT2 (jcf, i);
	  if (n <= 0 || n >= JPOOL_SIZE(jcf)
	      || JPOOL_TAG (jcf, n) != CONSTANT_Utf8)
	    return i;
	  /* ... fall through ... */
	case CONSTANT_Class:
	case CONSTANT_String:
	  n = JPOOL_USHORT1 (jcf, i);
	  if (n <= 0 || n >= JPOOL_SIZE(jcf)
	      || JPOOL_TAG (jcf, n) != CONSTANT_Utf8)
	    return i;
	  break;
	case CONSTANT_Fieldref:
	case CONSTANT_Methodref:
	case CONSTANT_InterfaceMethodref:
	  n = JPOOL_USHORT1 (jcf, i);
	  if (n <= 0 || n >= JPOOL_SIZE(jcf)
	      || JPOOL_TAG (jcf, n) != CONSTANT_Class)
	    return i;
	  n = JPOOL_USHORT2 (jcf, i);
	  if (n <= 0 || n >= JPOOL_SIZE(jcf)
	      || JPOOL_TAG (jcf, n) != CONSTANT_NameAndType)
	    return i;
	  break;
	case CONSTANT_Long:
	case CONSTANT_Double:
	  i++;
	  break;
	case CONSTANT_Float:
	case CONSTANT_Integer:
	case CONSTANT_Utf8:
	case CONSTANT_Unicode:
	  break;
	default:
	  return i;
	}
    }
  return 0;
}

void
DEFUN(format_uint, (buffer, value, base),
      char *buffer AND uint64 value AND int base)
{
#define WRITE_BUF_SIZE (4 + sizeof(uint64) * 8)
  char buf[WRITE_BUF_SIZE];
  register char *buf_ptr = buf+WRITE_BUF_SIZE; /* End of buf. */
  int chars_written;
  int i;

  /* Now do the actual conversion, placing the result at the *end* of buf. */
  /* Note this code does not pretend to be optimized. */
  do {
    int digit = value % base;
    static char digit_chars[] = "0123456789abcdefghijklmnopqrstuvwxyz";
    *--buf_ptr = digit_chars[digit];
    value /= base;
  } while (value != 0);

  chars_written = buf+WRITE_BUF_SIZE - buf_ptr;
  for (i = 0; i < chars_written; i++)
    buffer[i] = *buf_ptr++;
  buffer[i] = 0;
}

void
DEFUN(format_int, (buffer, value, base),
      char *buffer AND jlong value AND int base)
{
  uint64 abs_value;
  if (value < 0)
    {
      abs_value = -(uint64)value;
      *buffer++ = '-';
    }
  else
    abs_value = (uint64) value;
  format_uint (buffer, abs_value, base);
}