library.js

// An implementation of a libc for the web. Basically, implementations of
// the various standard C libraries, that can be called from compiled code,
// and work using the actual JavaScript environment.
//
// We search the Library object when there is an external function. If the
// entry in the Library is a function, we insert it. If it is a string, we
// do another lookup in the library (a simple way to write a function once,
// if it can be called by different names). We also allow dependencies,
// using __deps. Initialization code to be run after allocating all
// global constants can be defined by __postset.
//
// Note that the full function name will be '_' + the name in the Library
// object. For convenience, the short name appears here. Note that if you add a
// new function with an '_', it will not be found.

var Library = {
  // stdio.h

  _scanString: function() {
    // Supports %x, %4x, %d.%d
    var str = Pointer_stringify(arguments[0]);
    var stri = 0;
    var fmt = Pointer_stringify(arguments[1]);
    var fmti = 0;
    var args = Array.prototype.slice.call(arguments, 2);
    var argsi = 0;
    var read = 0;
    while (fmti < fmt.length) {
      if (fmt[fmti] === '%') {
        fmti++;
        var max_ = parseInt(fmt[fmti]);
        if (!isNaN(max_)) fmti++;
        var type = fmt[fmti];
        fmti++;
        var curr = 0;
        while ((curr < max_ || isNaN(max_)) && stri+curr < str.length) {
          if ((type === 'd' && parseInt(str[stri+curr]) >= 0) ||
              (type === 'x' && parseInt(str[stri+curr].replace(/[a-fA-F]/, 5)) >= 0)) {
            curr++;
          } else {
            break;
          }
        }
        if (curr === 0) { print("FAIL"); break; }
        var text = str.substr(stri, curr);
        stri += curr;
        var value = type === 'd' ? parseInt(text) : eval('0x' + text);
        {{{ makeSetValue('args[argsi]', '0', 'value', 'i32') }}}
        argsi++;
        read++;
      } else { // not '%'
        if (fmt[fmti] === str[stri]) {
          fmti++;
          stri++;
        } else {
          break;
        }
      }
    }
    return read; // XXX Possibly we should return EOF (-1) sometimes
  },
  sscanf: '_scanString',

  _formatString__deps: ['STDIO'],
  _formatString: function() {
    function isFloatArg(type) {
      return String.fromCharCode(type) in Runtime.set('f', 'e', 'g');
    }
    var cStyle = false;
    var textIndex = arguments[0];
    var argIndex = 1;
    if (textIndex < 0) {
      cStyle = true;
      textIndex = -textIndex;
      slab = null;
      argIndex = arguments[1];
    } else {
      var _arguments = arguments;
    }
    function getNextArg(type) {
      var ret;
      if (!cStyle) {
        ret = _arguments[argIndex];
        argIndex++;
      } else {
        if (isFloatArg(type)) {
          ret = {{{ makeGetValue(0, 'argIndex', 'double') }}};
        } else {
          ret = {{{ makeGetValue(0, 'argIndex', 'i32') }}};
        }
        argIndex += type === 'l'.charCodeAt(0) ? 8 : 4; // XXX hardcoded native sizes
      }
      return ret;
    }

    var ret = [];
    var curr, next, currArg;
    while(1) {
      curr = {{{ makeGetValue(0, 'textIndex', 'i8') }}};
      if (curr === 0) break;
      next = {{{ makeGetValue(0, 'textIndex+1', 'i8') }}};
      if (curr == '%'.charCodeAt(0)) {
        // Handle very very simply formatting, namely only %.X[f|d|u|etc.]
        var precision = -1;
        if (next == '.'.charCodeAt(0)) {
          textIndex++;
          precision = 0;
          while(1) {
            var precisionChr = {{{ makeGetValue(0, 'textIndex+1', 'i8') }}};
            if (!(precisionChr >= '0'.charCodeAt(0) && precisionChr <= '9'.charCodeAt(0))) break;
            precision *= 10;
            precision += precisionChr - '0'.charCodeAt(0);
            textIndex++;
          }
          next = {{{ makeGetValue(0, 'textIndex+1', 'i8') }}};
        }
        if (next == 'l'.charCodeAt(0)) {
          textIndex++;
          next = {{{ makeGetValue(0, 'textIndex+1', 'i8') }}};
        }
        if (isFloatArg(next)) {
          next = 'f'.charCodeAt(0); // no support for 'e'
        }
        if (['d', 'i', 'u', 'p', 'f'].indexOf(String.fromCharCode(next)) != -1) {
          var currArg;
          var argText;
          currArg = getNextArg(next);
          argText = String(+currArg); // +: boolean=>int
          if (next == 'u'.charCodeAt(0)) {
            argText = String(unSign(currArg, 32));
          } else if (next == 'p'.charCodeAt(0)) {
            argText = '0x' + currArg.toString(16);
          } else {
            argText = String(+currArg); // +: boolean=>int
          }
          if (precision >= 0) {
            if (isFloatArg(next)) {
              var dotIndex = argText.indexOf('.');
              if (dotIndex == -1 && next == 'f'.charCodeAt(0)) {
                dotIndex = argText.length;
                argText += '.';
              }
              argText += '00000000000'; // padding
              argText = argText.substr(0, dotIndex+1+precision);
            } else {
              while (argText.length < precision) {
                argText = '0' + argText;
              }
            }
          }
          argText.split('').forEach(function(chr) {
            ret.push(chr.charCodeAt(0));
          });
          textIndex += 2;
        } else if (next == 's'.charCodeAt(0)) {
          ret = ret.concat(String_copy(getNextArg(next)));
          textIndex += 2;
        } else if (next == 'c'.charCodeAt(0)) {
          ret = ret.concat(getNextArg(next));
          textIndex += 2;
        } else {
          ret.push(next);
          textIndex += 2; // not sure what to do with this %, so print it
        }
      } else {
        ret.push(curr);
        textIndex += 1;
      }
    }
    return Pointer_make(ret.concat(0), 0, ALLOC_STACK); // NB: Stored on the stack
    //var len = ret.length+1;
    //var ret = Pointer_make(ret.concat(0), 0, ALLOC_STACK); // NB: Stored on the stack
    //STACKTOP -= len; // XXX horrible hack. we rewind the stack, to 'undo' the alloc we just did.
    //                 // the point is that this works if nothing else allocs on the stack before
    //                 // the string is read, which should be true - it is very transient, see the *printf* functions below.
    //return ret;
  },

  printf__deps: ['_formatString'],
  printf: function() {
    __print__(Pointer_stringify(__formatString.apply(null, arguments)));
  },

  fprintf__deps: ['_formatString'],
  fprintf: function() {
    var file = arguments[0]; // TODO: something clever with this
    var args = Array.prototype.slice.call(arguments, 1);
    __print__(Pointer_stringify(__formatString.apply(null, args)));
  },

  sprintf__deps: ['strcpy', '_formatString'],
  sprintf: function() {
    var str = arguments[0];
    var args = Array.prototype.slice.call(arguments, 1);
    _strcpy(str, __formatString.apply(null, args)); // not terribly efficient
  },

  snprintf__deps: ['strncpy', '_formatString'],
  snprintf: function() {
    var str = arguments[0];
    var num = arguments[1];
    var args = Array.prototype.slice.call(arguments, 2);
    _strncpy(str, __formatString.apply(null, args), num); // not terribly efficient
  },

  fflush: function(file) {
    __print__(null);
  },

  puts: function(p) {
    __print__(Pointer_stringify(p) + '\n');
  },

  fputs: function(p, stream) {
    __print__(Pointer_stringify(p) + '\n');
  },

  fputc: function(chr, stream) {
    __print__(String.fromCharCode(chr));
  },

  putchar: function(p) {
    __print__(String.fromCharCode(p));
  },
  _ZNSo3putEc: 'putchar',

  getc: function(file) {
    return -1; // EOF
  },
  getc_unlocked: 'getc',
  _IO_getc: 'getc',

  ungetc: function(chr, stream) {
    return chr;
  },

  _ZNSo5flushEv: function() {
    __print__('\n');
  },

  vsnprintf__deps: ['_formatString'],
  vsnprintf: function(dst, num, src, ptr) {
    var text = __formatString(-src, ptr); // |-|src tells formatstring to use C-style params (typically they are from varargs)
    var i;
    for (i = 0; i < num; i++) {
      {{{ makeCopyValue('dst', 'i', 'text', 'i', 'i8') }}}
      if ({{{ makeGetValue('dst', 'i', 'i8') }}} == 0) break;
    }
    return i; // Actually, should return how many *would* have been written, if the |num| had not stopped us.
  },

  fileno: function(file) {
    return 1; // TODO
  },

  isatty: function(file) {
    return 0; // TODO
  },

  clearerr: function(stream) {
  },

  flockfile: function(file) {
  },
  funlockfile: function(file) {
  },

  // stdio.h - file functions

  STDIO__postset: '_STDIO.init()',
  STDIO: { // TODO: Rewrite this so it works with closure compiler, allowing us to use ADVANCED optimizations there
    streams: {},
    filenames: {},
    counter: 1,
    SEEK_SET: 0, /* Beginning of file.  */
    SEEK_CUR: 1, /* Current position.   */
    SEEK_END: 2, /* End of file.        */
    init: function() {
      _stdin = Pointer_make([0], null, ALLOC_STATIC);
      IHEAP[_stdin] = this.prepare('<<stdin>>');
      _stdout = Pointer_make([0], null, ALLOC_STATIC);
      IHEAP[_stdout] = this.prepare('<<stdout>>', null, true);
      _stderr = Pointer_make([0], null, ALLOC_STATIC);
      IHEAP[_stderr] = this.prepare('<<stderr>>', null, true);
    },
    prepare: function(filename, data, print_) {
      var stream = this.counter++;
      this.streams[stream] = {
        filename: filename,
        data: data ? data : [],
        position: 0,
        eof: 0,
        error: 0,
        print: print_ // true for stdout and stderr - we print when receiving data for them
      };
      this.filenames[filename] = stream;
      return stream;
    },
    open: function(filename) {
      var stream = _STDIO.filenames[filename];
      if (!stream) return -1; // assert(false, 'No information for file: ' + filename);
      var info = _STDIO.streams[stream];
      info.position = info.error = info.eof = 0;
      return stream;
    },
    read: function(stream, ptr, size) {
      var info = _STDIO.streams[stream];
      if (!info) return -1;
      for (var i = 0; i < size; i++) {
        if (info.position >= info.data.length) {
          info.eof = 1;
          return 0; // EOF
        }
        {{{ makeSetValue('ptr', '0', 'info.data[info.position]', 'i8') }}}
        info.position++;
        ptr++;
      }
      return size;
    },
  },

  fopen__deps: ['STDIO'],
  fopen: function(filename, mode) {
    filename = Pointer_stringify(filename);
    mode = Pointer_stringify(mode);
    if (mode.indexOf('r') >= 0) {
      return _STDIO.open(filename);
    } else if (mode.indexOf('w') >= 0) {
      return _STDIO.prepare(filename);
    } else {
      assert(false, 'fopen with odd params: ' + mode);
    }
  },
  __01fopen64_: 'fopen',

  rewind__deps: ['STDIO'],
  rewind: function(stream) {
    var info = _STDIO.streams[stream];
    info.position = 0;
    info.error = 0;
  },

  fseek__deps: ['STDIO'],
  fseek: function(stream, offset, whence) {
    var info = _STDIO.streams[stream];
    if (whence === _STDIO.SEEK_CUR) {
      offset += info.position;
    } else if (whence === _STDIO.SEEK_END) {
      offset += info.data.length;
    }
    info.position = offset;
    info.eof = 0;
    return 0;
  },
  __01fseeko64_: 'fseek',

  ftell__deps: ['STDIO'],
  ftell: function(stream) {
    return _STDIO.streams[stream].position;
  },
  __01ftello64_: 'ftell',

  fread__deps: ['STDIO'],
  fread: function(ptr, size, count, stream) {
    var info = _STDIO.streams[stream];
    for (var i = 0; i < count; i++) {
      if (info.position + size > info.data.length) {
        info.eof = 1;
        return i;
      }
      _STDIO.read(stream, ptr, size);
      ptr += size;
    }
    return count;
  },

  fwrite__deps: ['STDIO'],
  fwrite: function(ptr, size, count, stream) {
    var info = _STDIO.streams[stream];
    if (info.print) {
      __print__(intArrayToString(Array_copy(ptr, count*size)));
    } else {
      for (var i = 0; i < size*count; i++) {
        info.data[info.position] = HEAP[ptr];
        info.position++;
        ptr++;
      }
    }
    return count;
  },

  fclose__deps: ['STDIO'],
  fclose: function(stream) {
    return 0;
  },

  feof__deps: ['STDIO'],
  feof: function(stream) {
    return _STDIO.streams[stream].eof;
  },

  ferror__deps: ['STDIO'],
  ferror: function(stream) {
    return _STDIO.streams[stream].error;
  },

  // unix file IO, see http://rabbit.eng.miami.edu/info/functions/unixio.html

  open: function(filename, flags, mode) {
    filename = Pointer_stringify(filename);
    if (flags === 0) { // RDONLY
      return _STDIO.open(filename);
    } else if (flags === 1) { // WRONLY
      return _STDIO.prepare(filename);
    } else {
      assert(false, 'open with odd params: ' + [flags, mode]);
    }
  },

  close: function(stream) {
    return 0;
  },

  read: function(stream, ptr, numbytes) {
    return _STDIO.read(stream, ptr, numbytes);
  },

  fcntl: function() { }, // TODO...

  fstat: function(stream, ptr) {
    var info = _STDIO.streams[stream];
    if (!info) return -1;
    {{{ makeSetValue('ptr', '$struct_stat___FLATTENER[9]', 'info.data.length', 'i32') }}} // st_size. XXX: hardcoded index 9 into the structure.
    // TODO: other fields
    return 0;
  },

  mmap: function(start, num, prot, flags, stream, offset) {
    // Leaky and non-shared... FIXME
    var info = _STDIO.streams[stream];
    if (!info) return -1;
    return Pointer_make(info.data.slice(offset, offset+num), null, ALLOC_NORMAL);
  },

  munmap: function(start, num) {
    _free(start); // FIXME: not really correct at all
  },

  // stdlib.h

  abs: 'Math.abs',

  atoi: function(s) {
    return Math.floor(Number(Pointer_stringify(s)));
  },

  exit: function(status) {
    __shutdownRuntime__();
    ABORT = true;
    throw 'exit(' + status + ') called, at ' + new Error().stack;
  },

  atexit: function(func) {
    __ATEXIT__.push(func);
  },
  __cxa_atexit: 'atexit',

  abort: function(code) {
    ABORT = true;
    throw 'ABORT: ' + code + ', at ' + (new Error().stack);
  },

  realloc__deps: ['memcpy'],
  realloc: function(ptr, size) {
    // Very simple, inefficient implementation - if you use a real malloc, best to use
    // a real realloc with it
    if (!size) {
      if (ptr) _free(ptr);
      return 0;
    }
    var ret = _malloc(size);
    if (ptr) {
      _memcpy(ret, ptr, size); // might be some invalid reads
      _free(ptr);
    }
    return ret;
  },

  getenv: function(name_) {
    return 0; // TODO
  },

  strtod__deps: ['isspace', 'isdigit'],
  strtod: function(str, endptr) {
    // FIXME handles only whitespace + |[0-9]+(.[0.9]+)?|, no e+
    while (_isspace(str)) str++;
    var chr;
    var ret = 0;
    while(1) {
      chr = {{{ makeGetValue('str', 0, 'i8') }}};
      if (!_isdigit(chr)) break;
      ret = ret*10 + chr - '0'.charCodeAt(0);
      str++;
    }
    if ({{{ makeGetValue('str', 0, 'i8') }}} == '.'.charCodeAt(0)) {
      str++;
      var mul=1/10;
      while(1) {
        chr = {{{ makeGetValue('str', 0, 'i8') }}};
        if (!_isdigit(chr)) break;
        ret += mul*(chr - '0'.charCodeAt(0));
        mul /= 10;
        str++;
      }
    }
    if (endptr) {
      {{{ makeSetValue('endptr', 0, 'str', '*') }}}
    }
    return ret;
  },

  qsort__deps: ['memcpy'],
  qsort: function(base, num, size, comparator) {
    // forward calls to the JavaScript sort method
    // first, sort the items logically
    comparator = FUNCTION_TABLE[comparator];
    var keys = [];
    for (var i = 0; i < num; i++) keys.push(i);
    keys.sort(function(a, b) {
      return comparator(base+a*size, base+b*size);
    });
    // apply the sort
    var temp = _malloc(num*size);
    _memcpy(temp, base, num*size);
    for (var i = 0; i < num; i++) {
      if (keys[i] == i) continue; // already in place
      _memcpy(base+i*size, temp+keys[i]*size, size);
    }
    _free(temp);
  },

  // string.h

  memcpy: function (dest, src, num, idunno) {
    var curr;
    for (var i = 0; i < num; i++) {
      // TODO: optimize for the typed arrays case
      // || 0, since memcpy sometimes copies uninitialized areas XXX: Investigate why initializing alloc'ed memory does not fix that too
      {{{ makeCopyValue('dest', 'i', 'src', 'i', 'null', ' || 0') }}};
    }
  },
  llvm_memcpy_i32: 'memcpy',
  llvm_memcpy_i64: 'memcpy',
  llvm_memcpy_p0i8_p0i8_i32: 'memcpy',
  llvm_memcpy_p0i8_p0i8_i64: 'memcpy',

  memmove: function(dest, src, num, idunno) {
    // not optimized!
    if (num === 0) return; // will confuse malloc if 0
    var tmp = _malloc(num);
    _memcpy(tmp, src, num);
    _memcpy(dest, tmp, num);
    _free(tmp);
  },
  llvm_memmove_i32: 'memmove',
  llvm_memmove_i64: 'memmove',
  llvm_memmove_p0i8_p0i8_i32: 'memmove',
  llvm_memmove_p0i8_p0i8_i64: 'memmove',

  memset: function(ptr, value, num) {
    for (var i = 0; i < num; i++) {
      {{{ makeSetValue('ptr', 'i', 'value', 'null') }}}
    }
  },
  llvm_memset_i32: 'memset',
  llvm_memset_p0i8_i32: 'memset',
  llvm_memset_p0i8_i64: 'memset',

  strlen: function(ptr) {
    return String_len(ptr);
  },

  strspn: function(pstr, pset) {
    var str = String_copy(pstr, true);
    var set = String_copy(pset);
    var i = 0;
    while (set.indexOf(str[i]) != -1) i++; // Must halt, as 0 is in str but not set
    return i;
  },

  strcspn: function(pstr, pset) {
    var str = String_copy(pstr, true);
    var set = String_copy(pset, true);
    var i = 0;
    while (set.indexOf(str[i]) == -1) i++; // Must halt, as 0 is in both
    return i;
  },

  strcpy: function(pdest, psrc) {
    var i = 0;
    do {
      {{{ makeCopyValue('pdest', 'i', 'psrc', 'i', 'i8') }}}
      i ++;
    } while ({{{ makeGetValue('psrc', 'i-1', 'i8') }}} != 0);
  },

  strncpy: function(pdest, psrc, num) {
    var padding = false, curr;
    for (var i = 0; i < num; i++) {
      curr = padding ? 0 : {{{ makeGetValue('psrc', 'i', 'i8') }}};
      {{{ makeSetValue('pdest', 'i', 'curr', 'i8') }}}
      padding = padding || {{{ makeGetValue('psrc', 'i', 'i8') }}} == 0;
    }
  },

  strcat: function(pdest, psrc) {
    var len = Pointer_stringify(pdest).length; // TODO: use strlen, but need dependencies system
    var i = 0;
    do {
      {{{ makeCopyValue('pdest', 'len+i', 'psrc', 'i', 'i8') }}}
      i ++;
    } while ({{{ makeGetValue('psrc', 'i-1', 'i8') }}} != 0);
    return pdest;
  },

  strncat: function(pdest, psrc, num) {
    var len = Pointer_stringify(pdest).length; // TODO: use strlen, but need dependencies system
    var i = 0;
    while(1) {
      {{{ makeCopyValue('pdest', 'len+i', 'psrc', 'i', 'i8') }}}
      if ({{{ makeGetValue('pdest', 'len+i', 'i8') }}} == 0) break;
      i ++;
      if (i == num) {
        {{{ makeSetValue('pdest', 'len+i', 0, 'i8') }}}
        break;
      }
    }
    return pdest;
  },

  strtol: function(ptr) {
    assert(!arguments[1] && !arguments[2], "We don't support all strtol params yet");
    return parseInt(Pointer_stringify(ptr));
  },

  strcmp: function(px, py) {
    var i = 0;
    while (true) {
      var x = {{{ makeGetValue('px', 'i', 'i8') }}};
      var y = {{{ makeGetValue('py', 'i', 'i8') }}};
      if (x == y && x == 0) return 0;
      if (x == 0) return -1;
      if (y == 0) return 1;
      if (x == y) {
        i ++;
        continue;
      } else {
        return x > y ? 1 : -1;
      }
    }
  },

  strncmp: function(px, py, n) {
    var i = 0;
    while (i < n) {
      var x = {{{ makeGetValue('px', 'i', 'i8') }}};
      var y = {{{ makeGetValue('py', 'i', 'i8') }}};
      if (x == y && x == 0) return 0;
      if (x == 0) return -1;
      if (y == 0) return 1;
      if (x == y) {
        i ++;
        continue;
      } else {
        return x > y ? 1 : -1;
      }
    }
    return 0;
  },

  memcmp: function(p1, p2, num) {
    for (var i = 0; i < num; i++) {
      var v1 = {{{ makeGetValue('p1', 'i', 'i8') }}};
      var v2 = {{{ makeGetValue('p2', 'i', 'i8') }}};
      if (v1 != v2) return v1 > v2 ? 1 : -1;
    }
    return 0;
  },

  memchr: function(ptr, chr, num) {
    chr = unSign(chr);
    for (var i = 0; i < num; i++) {
      if ({{{ makeGetValue('ptr', 0, 'i8') }}} == chr) return ptr;
      ptr++;
    }
    return 0;
  },

  strstr: function(ptr1, ptr2) {
    var str1 = Pointer_stringify(ptr1);
    var str2 = Pointer_stringify(ptr2);
    var ret = str1.search(str2);
    return ret >= 0 ? ptr1 + ret : 0;
  },

  strchr: function(ptr, chr) {
    ptr--;
    do {
      ptr++;
      var val = {{{ makeGetValue('ptr', 0, 'i8') }}};
      if (val == chr) return ptr;
    } while (val);
    return 0;
  },

  strrchr: function(ptr, chr) {
    var ptr2 = ptr + Pointer_stringify(ptr).length; // TODO: use strlen, but need dependencies system
    do {
      if ({{{ makeGetValue('ptr2', 0, 'i8') }}} == chr) return ptr2;
      ptr2--;
    } while (ptr2 >= ptr);
    return 0;
  },

  strdup: function(ptr) {
    return Pointer_make(String_copy(ptr, true), 0, ALLOC_NORMAL);
  },

  strpbrk: function(ptr1, ptr2) {
    var searchSet = Runtime.set.apply(null, String_copy(ptr2));
    while ({{{ makeGetValue('ptr1', 0, 'i8') }}}) {
      if ({{{ makeGetValue('ptr1', 0, 'i8') }}} in searchSet) return ptr1;
      ptr1++;
    }
    return 0;
  },

  // Compiled from newlib; for the original source and licensing, see library_strtok_r.c
  strtok_r: function(b,j,f){var a;a=null;var c,e;b=b;var i=b!=0;a:do if(i)a=0;else{b=IHEAP[f];if(b!=0){a=0;break a}c=0;a=3;break a}while(0);if(a==0){a:for(;;){e=IHEAP[b];b+=1;a=j;var g=e;i=a;a=2;b:for(;;){d=a==5?d:0;a=IHEAP[i+d];if(a!=0==0){a=9;break a}var d=d+1;if(g==a)break b;else a=5}a=2}if(a==9)if(g==0)c=IHEAP[f]=0;else{c=b+-1;a:for(;;){e=IHEAP[b];b+=1;a=j;g=e;d=a;a=10;b:for(;;){h=a==13?h:0;a=IHEAP[d+h];if(a==g!=0)break a;var h=h+1;if(a!=0)a=13;else break b}}if(e==0)b=0;else IHEAP[b+-1]=0; IHEAP[f]=b;c=c}else if(a==7){IHEAP[f]=b;IHEAP[b+-1]=0;c=b+-1}}return c},

  // ctype.h

  isdigit: function(chr) {
    return chr >= '0'.charCodeAt(0) && chr <= '9'.charCodeAt(0);
  },

  isxdigit: function(chr) {
    return (chr >= '0'.charCodeAt(0) && chr <= '9'.charCodeAt(0)) ||
           (chr >= 'a'.charCodeAt(0) && chr <= 'f'.charCodeAt(0)) ||
           (chr >= 'A'.charCodeAt(0) && chr <= 'F'.charCodeAt(0));
  },

  isalpha: function(chr) {
    return (chr >= 'a'.charCodeAt(0) && chr <= 'z'.charCodeAt(0)) ||
           (chr >= 'A'.charCodeAt(0) && chr <= 'Z'.charCodeAt(0));
  },

  isalnum: function(chr) {
    return (chr >= '0'.charCodeAt(0) && chr <= '9'.charCodeAt(0)) ||
           (chr >= 'a'.charCodeAt(0) && chr <= 'z'.charCodeAt(0)) ||
           (chr >= 'A'.charCodeAt(0) && chr <= 'Z'.charCodeAt(0));
  },

  isspace: function(chr) {
    return chr in { 32: 0, 9: 0, 10: 0, 11: 0, 12: 0, 13: 0 };
  },

  iscntrl: function(chr) {
    return (chr >= 0 && chr <= 0x1f) || chr === 0x7f;
  },

  toupper: function(chr) {
    if (chr >= 'a'.charCodeAt(0) && chr <= 'z'.charCodeAt(0)) {
      return chr - 'a'.charCodeAt(0) + 'A'.charCodeAt(0);
    }
    return chr;
  },

  tolower: function(chr) {
    if (chr >= 'A'.charCodeAt(0) && chr <= 'Z'.charCodeAt(0)) {
      return chr - 'A'.charCodeAt(0) + 'a'.charCodeAt(0);
    }
    return chr;
  },

  // ctype.h Linux specifics

  __ctype_b_loc: function() { // http://refspecs.freestandards.org/LSB_3.0.0/LSB-Core-generic/LSB-Core-generic/baselib---ctype-b-loc.html
    var me = arguments.callee;
    if (!me.ret) {
      var values = [
        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,8195,0,8194,0,8194,0,8194,0,8194,0,2,0,2,
        0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,24577,0,49156,0,49156,0,49156,0,49156,0,49156,0,49156,
        0,49156,0,49156,0,49156,0,49156,0,49156,0,49156,0,49156,0,49156,0,49156,0,55304,0,55304,0,55304,0,55304,0,55304,0,55304,
        0,55304,0,55304,0,55304,0,55304,0,49156,0,49156,0,49156,0,49156,0,49156,0,49156,0,49156,0,54536,0,54536,0,54536,0,54536,
        0,54536,0,54536,0,50440,0,50440,0,50440,0,50440,0,50440,0,50440,0,50440,0,50440,0,50440,0,50440,0,50440,0,50440,0,50440,
        0,50440,0,50440,0,50440,0,50440,0,50440,0,50440,0,50440,0,49156,0,49156,0,49156,0,49156,0,49156,0,49156,0,54792,0,54792,
        0,54792,0,54792,0,54792,0,54792,0,50696,0,50696,0,50696,0,50696,0,50696,0,50696,0,50696,0,50696,0,50696,0,50696,0,50696,
        0,50696,0,50696,0,50696,0,50696,0,50696,0,50696,0,50696,0,50696,0,50696,0,49156,0,49156,0,49156,0,49156,0,2,0,0,0,0,0,0,
        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
        0,0,0,0,0,0,0,0,0,0,0
      ];
      me.ret = Pointer_make([Pointer_make(values, 0, ALLOC_STATIC)+256], 0, ALLOC_STATIC);
      assert(IHEAP[IHEAP[me.ret]] == 2);
      assert(IHEAP[IHEAP[me.ret]-2] == 0);
      assert(IHEAP[IHEAP[me.ret]+18] == 8195);
    }
    return me.ret;
  },

  // LLVM specifics

  llvm_va_copy: function(ppdest, ppsrc) {
    {{{ makeCopyValue('ppdest', 0, 'ppsrc', 0, 'null') }}}
    /* Alternate implementation that copies the actual DATA; it assumes the va_list is prefixed by its size
    var psrc = IHEAP[ppsrc]-1;
    var num = IHEAP[psrc]; // right before the data, is the number of (flattened) values
    var pdest = _malloc(num+1);
    _memcpy(pdest, psrc, num+1);
    IHEAP[ppdest] = pdest+1;
    */
  },

  llvm_bswap_i32: function(x) {
    x = unSign(x, 32);
    var bytes = [];
    for (var i = 0; i < 4; i++) {
      bytes[i] = x & 255;
      x >>= 8;
    }
    var ret = 0;
    for (i = 0; i < 4; i++) {
      ret <<= 8;
      ret += bytes[i];
    }
    return ret;
  },

  __assert_fail: function(condition, file, line) {
    ABORT = true;
    throw 'Assertion failed: ' + Pointer_stringify(condition);//JSON.stringify(arguments)//condition;
  },

  __cxa_guard_acquire: function() {
    return 1;
  },
  __cxa_guard_release: function() {
    return 1;
  },

  // Exceptions - minimal support, only (...) for now (no actual exception objects can be caught)
  __cxa_allocate_exception: function(size) {
    return _malloc(size); // warning: leaked
  },
  __cxa_throw: function(ptr, data, dunno) {
#if EXCEPTION_DEBUG
    print('Compiled code throwing an exception, ' + [ptr,data,dunno] + ', at ' + new Error().stack);
#endif
    throw ptr;
  },
  llvm_eh_exception: function() {
    return 'code-generated exception: ' + (new Error().stack);
  },
  llvm_eh_selector: function(exception, personality, num) {
    return 0;
  },
  __cxa_begin_catch: function(ptr) {
  },
  __cxa_end_catch: function(ptr) {
  },

  __cxa_call_unexpected: function(exception) {
    ABORT = true;
    throw exception;
  },

  __gxx_personality_v0: function() {
  },

  llvm_umul_with_overflow_i32: function(x, y) {
    return {
      f0: x*y,
      f1: 0 // We never overflow... for now
    };
  },

  llvm_stacksave: function() {
    var self = _llvm_stacksave;
    if (!self.LLVM_SAVEDSTACKS) {
      self.LLVM_SAVEDSTACKS = [];
    }
    self.LLVM_SAVEDSTACKS.push(STACKTOP);
    return self.LLVM_SAVEDSTACKS.length-1;
  },
  llvm_stackrestore: function(p) {
    var self = _llvm_stacksave;
    var ret = self.LLVM_SAVEDSTACKS[p];
    self.LLVM_SAVEDSTACKS.splice(p, 1);
    return ret;
  },

  __cxa_pure_virtual: function() {
    ABORT = true;
    throw 'Pure virtual function called!';
  },

  llvm_flt_rounds: function() {
    return -1; // 'indeterminable' for FLT_ROUNDS
  },

  // iostream

  _ZNSt8ios_base4InitC1Ev: function() {
    // need valid 'file descriptors'
    __ZSt4cout = 1;
    __ZSt4cerr = 2;
  },
  _ZNSt8ios_base4InitD1Ev: '_ZNSt8ios_base4InitC1Ev',
  _ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_: 0, // endl
  _ZNSolsEi: function(stream, data) {
    __print__(data);
  },
  _ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc: function(stream, data) {
    __print__(Pointer_stringify(data));
  },
  _ZNSolsEd: function(stream, data) {
    __print__('\n');
  },
  _ZNSolsEPFRSoS_E: function(stream, data) {
    __print__('\n');
  },
  _ZSt16__ostream_insertIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_PKS3_i: function(stream, data, call_) {
    __print__(Pointer_stringify(data));
  },

  // math.h

  cos: 'Math.cos',
  cosf: 'Math.cos',
  sin: 'Math.sin',
  sinf: 'Math.sin',
  tan: 'Math.tan',
  tanf: 'Math.tan',
  acos: 'Math.acos',
  acosf: 'Math.acos',
  asin: 'Math.asin',
  asinf: 'Math.asin',
  atan: 'Math.atan',
  atanf: 'Math.atan',
  atan2: 'Math.atan2',
  atan2f: 'Math.atan2',
  sqrt: 'Math.sqrt',
  sqrtf: 'Math.sqrt',
  fabs: 'Math.abs',
  fabsf: 'Math.abs',
  ceil: 'Math.ceil',
  floor: 'Math.floor',
  llvm_sqrt_f32: 'Math.sqrt',
  llvm_sqrt_f64: 'Math.sqrt',
  llvm_pow_f32: 'Math.pow',
  llvm_pow_f64: 'Math.pow',
  llvm_log_f32: 'Math.log',
  llvm_log_f64: 'Math.log',
  ldexp: function(x, exp_) {
    return x*Math.pow(2, exp_);
  },

  modf: function(x, intpart) {
    {{{ makeSetValue('intpart', 0, 'Math.floor(x)', 'double') }}}
    return x - {{{ makeGetValue('intpart', 0, 'double') }}};
  },

  frexp: function(x, exp_addr) {
    var sig = 0, exp_ = 0;
    if (x !== 0) {
      var raw_exp = Math.log(x)/Math.log(2);
      exp_ = Math.ceil(raw_exp);
      if (exp_ === raw_exp) exp_ += 1;
      sig = x/Math.pow(2, exp_);
    }
    {{{ makeSetValue('exp_addr', 0, 'exp_', 'i32') }}}
    return sig;
  },

  __finite: function(x) {
    return x !== Infinity && x !== -Infinity;
  },

  __isinf: function(x) {
    return x === Infinity || x === -Infinity;
  },

  __isnan: function(x) {
    return isNaN(x);
  },

  copysign: function(a, b) {
      if (a<0 === b<0) return a;
      return -a;
  },

  hypot: function(a, b) {
     return Math.sqrt(a*a + b*b);
  },

  // unistd.h

  sysconf: function(name_) {
    // XXX we only handle _SC_PAGE_SIZE/PAGESIZE for now, 30 on linux, 29 on OS X... be careful here!
    switch(name_) {
      case 29: case 30: return PAGE_SIZE;
      default: throw 'unknown sysconf param: ' + name_;
    }
  },

  sbrk: function(bytes) {
    // Implement a Linux-like 'memory area' for our 'process'.
    // Changes the size of the memory area by |bytes|; returns the
    // address of the previous top ('break') of the memory area

    // We need to make sure no one else allocates unfreeable memory!
    // We must control this entirely. So we don't even need to do
    // unfreeable allocations - the HEAP is ours, from STATICTOP up.
    // TODO: We could in theory slice off the top of the HEAP when
    // sbrk gets a negative increment in |bytes|...
    var self = arguments.callee;
    if (!self.STATICTOP) {
      STATICTOP = alignMemoryPage(STATICTOP);
      self.STATICTOP = STATICTOP;
      self.DATASIZE = 0;
    } else {
      assert(self.STATICTOP == STATICTOP, "Noone should touch the heap!");
    }
    var ret = STATICTOP + self.DATASIZE;
    self.DATASIZE += alignMemoryPage(bytes);
    return ret; // previous break location
  },

  readlink: function(path, buf, bufsiz) {
    return -1;
  },

  getuid: function() {
    return 100;
  },

  getpwuid: function(uid) {
    return 0; // NULL
  },

  // time.h

  time: function(ptr) {
    var ret = Math.floor(Date.now()/1000);
    if (ptr) {
      {{{ makeSetValue('ptr', 0, 'ret', 'i32') }}}
    }
    return ret;
  },

  gettimeofday: function(ptr) {
    // %struct.timeval = type { i32, i32 }
    var indexes = Runtime.calculateStructAlignment({ fields: ['i32', 'i32'] });
    var now = Date.now();
    {{{ makeSetValue('ptr', 'indexes[0]', 'Math.floor(now/1000)', 'i32') }}} // seconds
    {{{ makeSetValue('ptr', 'indexes[1]', 'Math.floor((now-1000*Math.floor(now/1000))*1000)', 'i32') }}} // microseconds
    return 0;
  },

  // setjmp.h

  _setjmp: function(env) {
    print('WARNING: setjmp() not really implemented, will fail if longjmp() is actually called');
    return 0;
  },

  _longjmp: function(env, val) {
    // not really working...
    assert(0);
  },

  // signal.h

  signal: function(sig, func) {
    // TODO
    return 0;
  },

  __libc_current_sigrtmin: function() {
    return 0;
  },
  __libc_current_sigrtmax: function() {
    return 0;
  },

  // stat.h

  __01stat64_: function() { return -1 },
  __01fstat64_: function() { return -1 },

  // locale.h

  setlocale: function(category, locale) {
    return 0;
  },

  localeconv: function() {
    // %struct.timeval = type { char* decimal point, other stuff... }
    // var indexes = Runtime.calculateStructAlignment({ fields: ['i32', 'i32'] });
    var me = arguments.callee;
    if (!me.ret) {
      me.ret = Pointer_make([Pointer_make(intArrayFromString('.'), null)], null); // just decimal point, for now
    }
    return me.ret;
  },

  // langinfo.h

  nl_langinfo: function(item) {
    var me = arguments.callee;
    if (!me.ret) {
      me.ret = Pointer_make(intArrayFromString("eh?"), null); 
    }
    return me.ret;
  },

  // errno.h

  __errno_location: function() { 
    var me = arguments.callee;
    if (!me.ret) {
      me.ret = Pointer_make([0], 0, ALLOC_STATIC);
    }
    return me.ret;
  },

  // pthread.h (stubs for mutexes only - no thread support yet!)

  pthread_mutex_init: function() {},
  pthread_mutex_destroy: function() {},
  pthread_mutex_lock: function() {},
  pthread_mutex_unlock: function() {},

  // dirent.h

  opendir: function(pname) {
    return 0;
  },

  // ** emscripten.h **
  _Z21emscripten_run_scriptPKc: function(ptr) {
    eval(Pointer_stringify(ptr));
  }
};