Espruino/scripts/build_jswrapper.py

#!/usr/bin/python

# This file is part of Espruino, a JavaScript interpreter for Microcontrollers
#
# Copyright (C) 2013 Gordon Williams <gw@pur3.co.uk>
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
#
# ----------------------------------------------------------------------------------------
# Scans files for comments of the form /*JSON......*/ and then builds a tree structure of ifs to
# efficiently detect the symbols without using RAM. See common.py for formatting
# ----------------------------------------------------------------------------------------

import subprocess;
import re;
import json;
import sys;
import os;
sys.path.append(".");
import common

# Scans files for comments of the form /*JSON......*/ and then builds a tree structure of ifs to
# efficiently detect the symbols without using RAM. See common.py for formatting

jsondatas = common.get_jsondata(False)
includes = common.get_includes_from_jsondata(jsondatas)

# ------------------------------------------------------------------------------------------------------

def treewalk(tree, name, jsondata):
  if len(name)==0:
    tree[""] = jsondata
  else:	
    firstchar = name[:1]
    if not firstchar in tree: tree[firstchar] = {}
    treewalk(tree[firstchar], name[1:], jsondata)

# ------------------------------------------------------------------------------------------------------
# Creates something like 'name[0]=='s' && name[1]=='e' && name[2]=='t' && name[3]==0'
def createStringCompare(varName, checkOffsets, checkCharacters):
  checks = []
  # if we're doing multiple checks, batch up into int compare
  # NOTE: batching up into 64 bit compare doesn't help here
  # 4 byte check
  while len(checkOffsets)>3:    
    checkOffset = checkOffsets.pop(0)
    checkOffsets.pop(0)
    checkOffsets.pop(0)
    checkOffsets.pop(0)
    checkWC = [checkCharacters.pop(0),checkCharacters.pop(0),checkCharacters.pop(0),checkCharacters.pop(0)]
    checks.append("CMP4("+varName+"["+str(checkOffset)+"],'"+("','".join(checkWC))+"')")
  # 3 byte check
  while len(checkOffsets)>2:    
    checkOffset = checkOffsets.pop(0)
    checkOffsets.pop(0)
    checkOffsets.pop(0)
    checkWC = [checkCharacters.pop(0),checkCharacters.pop(0),checkCharacters.pop(0)]
    checks.append("CMP3("+varName+"["+str(checkOffset)+"],'"+("','".join(checkWC))+"')")  
  # 2 byte check
  while len(checkOffsets)>1:
    checkOffset = checkOffsets.pop(0)
    checkOffsets.pop(0)
    checkWC = [checkCharacters.pop(0),checkCharacters.pop(0)]
    checks.append("CMP2("+varName+"["+str(checkOffset)+"],'"+("','".join(checkWC))+"')")
  # finish up with single checks
  while len(checkOffsets)>0:
    checkOffset = checkOffsets.pop(0)
    checkCharacter = checkCharacters.pop(0)
    # This check is a hack for when class names are exactly the same length as the data field in varData (8 chars)
    if not "varData" in varName or checkOffset < 8: 
      checks.append(varName+"["+str(checkOffset)+"]=='"+checkCharacter+"'")
  return " && ".join(checks)
# ------------------------------------------------------------------------------------------------------

def getTestFor(className, static):
  if static:
    #return 'jsvIsStringEqual(parentName, "'+className+'")'
    n = 0;
    # IMPORTANT - we expect built-in objects to have their name stored
    # as a string in the varData element
    checkOffsets = []
    checkCharacters = []
    for ch in className:
      checkOffsets.append(n)
      checkCharacters.append(ch)
      n = n + 1        
    checkOffsets.append(n)
    checkCharacters.append("\\0")
    return createStringCompare("parent->varData.str", checkOffsets, checkCharacters)
  else:
    if className=="String": return "jsvIsString(parent)"
    if className=="Pin": return "jsvIsPin(parent)"
    if className=="Integer": return "jsvIsInt(parent)"
    if className=="Double": return "jsvIsFloat(parent)"
    if className=="Number": return "jsvIsInt(parent) || jsvIsFloat(parent)"
    if className=="Object": return "parent" # we assume all are objects
    if className=="Array": return "jsvIsArray(parent)"
    if className=="ArrayBufferView": return "jsvIsArrayBuffer(parent) && parent->varData.arraybuffer.type!=ARRAYBUFFERVIEW_ARRAYBUFFER"
    if className=="Function": return "jsvIsFunction(parent)"
    n = 0
    checkOffsets = []
    checkCharacters = []
    for ch in className:
      checkOffsets.append(n)
      checkCharacters.append(ch)
      n = n + 1        
    checkOffsets.append(n)
    checkCharacters.append("\\0")
    extra = ""
    if len(className) > 8:
      checkOffsets = checkOffsets[:8]
      checkCharacters = checkCharacters[:8]
      extra = " && jsvIsStringEqual(constructorName, \""+className+"\")"
    return createStringCompare("constructorName->varData.str", checkOffsets, checkCharacters)+extra
    exit(1)

print "Building decision tree"
tree = {}
for jsondata in jsondatas:
  if "name" in jsondata:
    jsondata["static"] = not (jsondata["type"]=="property" or jsondata["type"]=="method")

    className = "!parent"
    if not jsondata["type"]=="constructor":
      if "class" in jsondata: className = getTestFor(jsondata["class"], jsondata["static"])


    if not className in tree: 
      print "Adding "+className+" to tree"
      tree[className] = {}
    treewalk(tree[className], jsondata["name"], jsondata)
    classTree = tree[className]

# ------------------------------------------------------------------------------------------------------
#print json.dumps(tree, sort_keys=True, indent=2)
# ------------------------------------------------------------------------------------------------------    
print "Outputting decision tree"
wrapperFile = open('gen/jswrapper.c', 'w')

def codeOut(s): 
#  print str(s)
  wrapperFile.write(s+"\n");

def getUnLockGetter(varType, name, funcName):
  if varType=="float": return "jsvGetFloatAndUnLock("+name+")"
  if varType=="int": return "jsvGetIntegerAndUnLock("+name+")"
  if varType=="int32": return "(int)jsvGetIntegerAndUnLock("+name+")"
  if varType=="bool": return "jsvGetBoolAndUnLock("+name+")"
  if varType=="pin": return "jshGetPinFromVarAndUnLock("+name+")"
  sys.stderr.write("ERROR: getUnLockGetter: Unknown type '"+varType+"' for "+funcName+":"+name+"\n")
  exit(1)

def getGetter(varType, name, funcName):
  if varType=="float": return "jsvGetFloat("+name+")"
  if varType=="int": return "jsvGetInteger("+name+")"
  if varType=="int32": return "(int)jsvGetInteger("+name+")"
  if varType=="bool": return "jsvGetBool("+name+")"
  if varType=="pin": return "jshGetPinFromVar("+name+")"
  if varType=="JsVar" or varType=="JsVarName": return name
  sys.stderr.write("ERROR: getGetter: Unknown type '"+varType+"' for "+funcName+":"+name+"\n")
  exit(1)

def getCreator(varType, value, funcName):
  if varType=="float": return "jsvNewFromFloat("+value+")"
  if varType=="int": return "jsvNewFromInteger("+value+")"
  if varType=="int32": return "jsvNewFromInteger((JsVarInt)"+value+")"
  if varType=="bool": return "jsvNewFromBool("+value+")"
  if varType=="JsVar": return value
  sys.stderr.write("ERROR: getCreator: Unknown type '"+varType+"'"+"' for "+funcName+"\n")
  exit(1)

def toArgumentType(argName):
  if argName=="": return "JSWAT_VOID";
  if argName=="JsVar": return "JSWAT_JSVAR";
  if argName=="JsVarName": return "JSWAT_JSVARNAME";
  if argName=="JsVarArray": return "JSWAT_ARGUMENT_ARRAY";
  if argName=="bool": return "JSWAT_BOOL";
  if argName=="pin": return "JSWAT_PIN";
  if argName=="int32": return "JSWAT_INT32";
  if argName=="int": return "JSWAT_JSVARINT";
  if argName=="float": return "JSWAT_JSVARFLOAT";
  sys.stderr.write("ERROR: toArgumentType: Unknown argument name "+argName+"\n")
  exit(1)

def toCType(argName):
  if argName=="": return "void";
  if argName=="JsVar": return "JsVar*";
  if argName=="JsVarName": return "JsVar*";
  if argName=="JsVarArray": return "JsVar*";
  if argName=="bool": return "bool";
  if argName=="pin": return "Pin";
  if argName=="int32": return "int";
  if argName=="int": return "JsVarInt";
  if argName=="float": return "JsVarFloat";
  sys.stderr.write("ERROR: toCType: Unknown argument name "+argName+"\n")
  exit(1)

def hasThis(func):
  return func["type"]=="property" or func["type"]=="method"

def getParams(func):
  params = []
  if hasThis(func): params.append(["","JsVar",""]);
  if "params" in func:
    for param in func["params"]:  
      params.append(param) 
  return params

def getResult(func):
  result = [ "", "Description" ]
  if "return" in func: result = func["return"]  
  return result


def getArgumentSpecifier(jsondata):
  params = getParams(jsondata)
  result = getResult(jsondata);
  s = [ toArgumentType(result[0]) ]
  n = 1
  for param in params:
    s.append("("+toArgumentType(param[1])+" << (JSWAT_BITS*"+str(n)+"))");
    n=n+1
  return " | ".join(s);
  

def getCDeclaration(jsondata):
  params = getParams(jsondata)
  result = getResult(jsondata);
  s = [ ]
  for param in params:
    s.append(toCType(param[1]));
  return toCType(result[0])+" (*)("+",".join(s)+")";



def codeOutFunctionObject(indent, obj):
  codeOut(indent+"// Object "+obj["name"]+"  ("+obj["filename"]+")")
  if "#if" in obj: codeOut(indent+"#if "+obj["#if"]);
  codeOut(indent+"jspParseVariableName();")
  codeOut(indent+"return jspNewObject(\""+obj["name"]+"\", \""+obj["instanceof"]+"\");");
  if "#if" in obj: codeOut(indent+"#endif //"+obj["#if"]);

def codeOutFunction(indent, func):
  if func["type"]=="object":
    codeOutFunctionObject(indent, func)
    return
  name = ""
  if "class" in func:
    name = name + func["class"]+".";
  name = name + func["name"]
  print name
  codeOut(indent+"// "+name+"  ("+func["filename"]+")")
  if ("generate" in func):
    if hasThis(func):
      codeOut(indent+"argArray[0] = jsvLockAgain(parent);");
      codeOut(indent+"int argCount = jspParseFunctionIntoArray(&argArray[1], sizeof(argArray)/sizeof(argArray[0])-1)+1;");
    else:
      codeOut(indent+"int argCount = jspParseFunctionIntoArray(argArray, sizeof(argArray)/sizeof(argArray[0]));");
    codeOut(indent+"JsVar *_r = jswCallFunction("+func["generate"]+", "+getArgumentSpecifier(func)+", argArray, argCount);");
    codeOut(indent+"while (argCount--) jsvUnLock(argArray[argCount]);");
    codeOut(indent+"return _r;");
  elif ("generate_full" in func):
    argNames = ["a","b","c","d"];
    params = []
    if "params" in func: params = func["params"]

    if len(params)==0: 
      if func["type"]=="variable" or common.is_property(func):
        codeOut(indent+"jspParseVariableName();")
      else:
        codeOut(indent+"jspParseEmptyFunction();")
    elif len(params)==1 and params[0][1]=="JsVarArray": 
      codeOut(indent+"JsVar *"+params[0][0]+" = jspParseFunctionAsArray();")
      codeOut(indent+"if (!"+params[0][0]+") return 0; // if parse error")
    elif len(params)==1 and params[0][1]!="JsVarName": 
      codeOut(indent+"JsVar *"+params[0][0]+" = jspParseSingleFunction();")
    elif len(params)<9:
      funcName = "jspParseFunction8"
      paramCount = 8
      if len(params)<5:  
        funcName = "jspParseFunction"
        paramCount = 4
      paramDefs = []
      paramPtrs = []
      skipNames = "0"
      n = 0
      letters = ["A","B","C","D","E","F","G","H"];
      for param in params:
        paramDefs.append("*"+param[0])
        paramPtrs.append("&"+param[0])
        if param[1]=="JsVarName": skipNames = skipNames + "|JSP_NOSKIP_"+letters[n]
        n = n + 1
      while len(paramPtrs)<paramCount: paramPtrs.append("0")
      codeOut(indent+"JsVar "+', '.join(paramDefs)+";");
      codeOut(indent+funcName+"("+skipNames+", "+', '.join(paramPtrs)+");");
    else:
      print "ERROR: codeOutFunction unknown number of args "+str(len(params))
      exit(1)

    command = func["generate_full"];    
    if "return" in func: 
      codeOut(indent+"JsVar *_r = " + getCreator(func["return"][0], command, func["name"])+";");
    else:
      codeOut(indent+command+";");
    # note: generate_full doesn't use commandargs, so doesn't unlock
    for param in params:
      if "generate_full" in func or param[1]=="JsVar" or param[1]=="JsVarName" or param[1]=="JsVarArray":
        codeOut(indent+"jsvUnLock("+param[0]+");");

    if "return" in func: 
      codeOut(indent+"return _r;");
    else:
      codeOut(indent+"return 0;");
  elif "wrap" in func:
    codeOut(indent+"return "+func["wrap"]+"(parent, parentName);")
  else:
    sys.stderr.write("ERROR: codeOutFunction: Function '"+func["name"]+"' does not have generate, generate_full or wrap elements'\n")
    exit(1)

def codeOutTree(indent, tree, offset):
  first = True
  for char in tree:
    if char!="":
      charOffset = offset
      charTree = tree[char]
      line = indent
      if first: first = False
      else: line = line + "} else "
      checkOffsets = [charOffset]
      checkCharacters = [char]
      while len(charTree)==1:
        charOffset = charOffset + 1
        char = charTree.keys()[0]
        charTree = charTree[char]        
        checkOffsets.append(charOffset)
        if char=='': checkCharacters.append('\\0')
        else: checkCharacters.append(char)
      line = line + "if (" + createStringCompare("name", checkOffsets, checkCharacters) + ") {"
      codeOut(line)   
      if char=='':
        codeOutFunction(indent+"  ", charTree)
      else:
        codeOutTree(indent+"  ", charTree, charOffset+1)
      # Now we do the handling part!
  if "" in tree:
    func = tree[""]
    line = indent;
    if first: first = False
    if not first: line = line + "} else "
    line = line + "if (name["+str(offset)+"]==0) {";
    codeOut(line)
    codeOutFunction(indent+"  ", func)
  if not first:
    codeOut(indent+'}')




print ""
print "" 

codeOut('// Automatically generated wrapper file ')
codeOut('// Generated by scripts/build_jswrapper.py');
codeOut('');
codeOut('#include "jswrapper.h"');
for include in includes:
  codeOut('#include "'+include+'"');
codeOut('');

codeOut("#if( 'q\\0\\0\\0' & 'q' )")
codeOut('  #error( "architecture is big-endian. need to test and make sure this still works" )')
codeOut("#endif")
codeOut('// beware big endian!');
codeOut('#define CH2(a,b) ( ((b)<<8) | (a) )');
codeOut('#define CH4(a,b,c,d) ( ((d)<<24) | ((c)<<16) | ((b)<<8) | (a) )');
codeOut('#define CMP2(var, a,b) ((*(unsigned short*)&(var))==CH2(a,b))');
codeOut('#define CMP3(var, a,b,c) (((*(unsigned int*)&(var))&0x00FFFFFF)==CH4(a,b,c,0))');
codeOut('#define CMP4(var, a,b,c,d) ((*(unsigned int*)&(var))==CH4(a,b,c,d))');
codeOut('');
codeOut('JsVar *jswHandleFunctionCall(JsVar *parent, JsVar *parentName, const char *name) {')
codeOut('  JsVar *argArray[16];')
codeOut('  if (parent) {')
codeOut('    // ------------------------------------------ METHODS ON OBJECT')
if "parent" in tree:
  codeOutTree("    ", tree["parent"], 0)
codeOut('    // ------------------------------------------ INSTANCE + STATIC METHODS')
for className in tree:
  if className!="parent" and  className!="!parent" and not "parentName" in className and not "constructorName" in className:
    codeOut('    if ('+className+') {')
    codeOutTree("      ", tree[className], 0)
    codeOut("    }")
codeOut('    // ------------------------------------------ INSTANCE METHODS WE MUST CHECK CONSTRUCTOR FOR')
codeOut('    JsVar *constructorName = jsvIsObject(parent)?jsvSkipOneNameAndUnLock(jsvFindChildFromString(parent, JSPARSE_CONSTRUCTOR_VAR, false)):0;')
codeOut('    if (constructorName && jsvIsName(constructorName)) {')
first = True
for className in tree:
  if "constructorName" in className:
    if first:
      codeOut('    if ('+className+') {')
      first = False
    else:
      codeOut('    } else if ('+className+') {')
    codeOut('      jsvUnLock(constructorName);constructorName=0;')
    codeOutTree("          ", tree[className], 0)
if not first:
  codeOut("    } else ")
codeOut('      jsvUnLock(constructorName);');
codeOut('    }')
codeOut('  } else { /* if (!parent) */')
codeOut('    // ------------------------------------------ FUNCTIONS')
codeOut('    // Handle pin names - eg LED1 or D5 (this is hardcoded in build_jsfunctions.py)')
codeOut('    Pin pin = jshGetPinFromString(name);')
codeOut('    if (pin != PIN_UNDEFINED) {')
codeOut('      jspParseVariableName();')
codeOut('      return jsvNewFromPin(pin);')
codeOut('    }')
if "!parent" in tree:
  codeOutTree("    ", tree["!parent"], 0)
codeOut('  }');

codeOut('  return JSW_HANDLEFUNCTIONCALL_UNHANDLED;')
codeOut('}')

codeOut('')
codeOut('')


builtinLibraryChecks = []
for jsondata in jsondatas:
  if jsondata["type"]=="library":
    check = 'strcmp(name, "'+jsondata["class"]+'")==0';
    builtinLibraryChecks.append(check)


builtinChecks = []
notRealObjects = []
for jsondata in jsondatas:
  if "class" in jsondata:
    check = 'strcmp(name, "'+jsondata["class"]+'")==0';
    if not check in builtinLibraryChecks:
      if "not_real_object" in jsondata:
        notRealObjects.append(check)
      if not check in builtinChecks:
        builtinChecks.append(check)


codeOut('bool jswIsBuiltInObject(const char *name) {') 
codeOut('  return\n'+" ||\n    ".join(builtinChecks)+';')
codeOut('}')

codeOut('')
codeOut('')


codeOut('bool jswIsBuiltInLibrary(const char *name) {') 
if len(builtinLibraryChecks)==0:
  codeOut('  return false;')
else:
  codeOut('  return\n'+" ||\n    ".join(builtinLibraryChecks)+';')
codeOut('}')

codeOut('')
codeOut('')


objectChecks = {}
for jsondata in jsondatas:
  if "type" in jsondata and jsondata["type"]=="class":
    if "check" in jsondata:
      objectChecks[jsondata["class"]] = jsondata["check"]

codeOut('/** Given a variable, return the basic object name of it */')
codeOut('const char *jswGetBasicObjectName(JsVar *var) {') 
for className in objectChecks.keys():
  codeOut("  if ("+objectChecks[className]+") return \""+className+"\";")
codeOut('  return 0;')
codeOut('}')

codeOut('')
codeOut('')


codeOut("/** Given the name of a Basic Object, eg, Uint8Array, String, etc. Return the prototype object's name - or 0. */")
codeOut('const char *jswGetBasicObjectPrototypeName(const char *objectName) {') 
for jsondata in jsondatas:
  if "type" in jsondata and jsondata["type"]=="class":
    if "prototype" in jsondata:
      #print json.dumps(jsondata, sort_keys=True, indent=2)
      codeOut("  if (!strcmp(objectName, \""+jsondata["class"]+"\")) return \""+jsondata["prototype"]+"\";")
codeOut('  return strcmp(objectName,"Object") ? "Object" : 0;')
codeOut('}')

codeOut('')
codeOut('')

codeOut("/** Tasks to run on Idle. Returns true if either one of the tasks returned true (eg. they're doing something and want to avoid sleeping) */")
codeOut('bool jswIdle() {')
codeOut('  bool wasBusy = false;')  
for jsondata in jsondatas:
  if "type" in jsondata and jsondata["type"]=="idle":
    codeOut("  if ("+jsondata["generate"]+"()) wasBusy = true;")
codeOut('  return wasBusy;')
codeOut('}')

codeOut('')
codeOut('')

codeOut("/** Tasks to run on Initialisation */")
codeOut('void jswInit() {')
for jsondata in jsondatas:
  if "type" in jsondata and jsondata["type"]=="init":
    codeOut("  "+jsondata["generate"]+"();")
codeOut('}')

codeOut('')
codeOut('')

codeOut("/** Tasks to run on Deinitialisation */")
codeOut('void jswKill() {')
for jsondata in jsondatas:
  if "type" in jsondata and jsondata["type"]=="kill":
    codeOut("  "+jsondata["generate"]+"();")
codeOut('}')

codeOut('')
codeOut('')

codeOut("/** Call a function with the given argument specifiers */")
codeOut('JsVar *jswCallFunction(void *function, unsigned int argumentSpecifier, JsVar **paramData, int paramCount) {')
argSpecs = []
for jsondata in jsondatas:
#  if "generate" in jsondata:
    argSpec = getArgumentSpecifier(jsondata)
    if not argSpec in argSpecs:
      codeOut('  if (argumentSpecifier == ('+argSpec+')) {')

      params = getParams(jsondata)
      result = getResult(jsondata);

      n = 0
      argList = [ ]
      for param in params:
        if param[1]=="JsVarArray":
          argList.append("jsvNewArray(&paramData["+str(n)+"], paramCount-"+str(n)+")");
        else:
          argList.append(getGetter(param[1] , str(n)+"<paramCount ? paramData["+str(n)+"] : 0", "jswCallFunction"));
        n = n+1;


      if result[0]!="":
        codeOut('    return '+getCreator(result[0], '(('+getCDeclaration(jsondata)+')function)('+', '.join(argList)+')',"jswCallFunction")+';')
      else:      
        codeOut('    (('+getCDeclaration(jsondata)+')function)('+', '.join(argList)+');')
        codeOut('    return 0/*undefined*/;')            
      codeOut('  }') 

      argSpecs.append(argSpec)
codeOut('  jsError("No caller for argument specifier %d", argumentSpecifier);')
codeOut('  return 0;')
codeOut('}')

codeOut('')
codeOut('')