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;
scriptdir = os.path.dirname(os.path.realpath(__file__))
basedir = scriptdir+"/../"
sys.path.append(basedir+"scripts");
sys.path.append(basedir+"boards");
import common

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

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

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

def getConstructorTestFor(className, variableName):
    # IMPORTANT - we expect built-in objects to be native functions with a pointer to
    # their constructor function inside
    for jsondata in jsondatas:
      if jsondata["type"]=="constructor" and jsondata["name"]==className:
        if variableName=="constructorPtr": # jsvIsNativeFunction/etc has already been done
          return "constructorPtr==(void*)"+jsondata["generate"];
        else:
          return "jsvIsNativeFunction("+variableName+") && (void*)"+variableName+"->varData.native.ptr==(void*)"+jsondata["generate"];
    print("No constructor found for "+className)
    exit(1)

def getTestFor(className, static):
  if static:
    return getConstructorTestFor(className, "parent");
  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)"
    return getConstructorTestFor(className, "constructorPtr");

def toArgumentType(argName):
  if argName=="": return "JSWAT_VOID";
  if argName=="JsVar": return "JSWAT_JSVAR";
  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_INT32";
  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=="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 "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]) ]
  if hasThis(jsondata): s.append("JSWAT_THIS_ARG");
  # Either it's a variable/property, in which case we need to execute the native function in order to return the correct info
  if jsondata["type"]=="variable" or common.is_property(jsondata): 
    s.append("JSWAT_EXECUTE_IMMEDIATELY")
  # Or it's an object, in which case the native function contains code that creates it - and that must be executed too. 
  # It also returns JsVar
  if jsondata["type"]=="object":
    s = [ toArgumentType("JsVar"), "JSWAT_EXECUTE_IMMEDIATELY" ]

  n = 1
  for param in params:
    s.append("("+toArgumentType(param[1])+" << (JSWAT_BITS*"+str(n)+"))");
    n=n+1
  return " | ".join(s);
  
def getCDeclaration(jsondata, name): 
  # name could be '(*)' for a C function pointer 
  params = getParams(jsondata)
  result = getResult(jsondata);
  s = [ ]
  if hasThis(jsondata): s.append("JsVar*");
  for param in params:
    s.append(toCType(param[1]));
  return toCType(result[0])+" "+name+"("+",".join(s)+")";

def codeOutSymbolTable(builtin):
  codeName = builtin["name"]
  # sort by name
  builtin["functions"] = sorted(builtin["functions"], key=lambda n: n["name"]);
  # output tables
  listSymbols = []
  listChars = ""
  strLen = 0
  for sym in builtin["functions"]:
    symName = sym["name"];

    if builtin["name"]=="global" and symName in libraries:
      continue # don't include libraries on global namespace
    if "generate" in sym:
      listSymbols.append("{"+", ".join([str(strLen), "(void (*)(void))"+sym["generate"], getArgumentSpecifier(sym)])+"}")
      listChars = listChars + symName + "\\0";
      strLen = strLen + len(symName) + 1
    else: 
      print (codeName + "." + symName+" not included in Symbol Table because no 'generate'")
  builtin["symbolTableChars"] = "\""+listChars+"\"";
  builtin["symbolTableCount"] = str(len(listSymbols));
  codeOut("static const JswSymPtr jswSymbols_"+codeName+"[] = {\n  "+",\n  ".join(listSymbols)+"\n};");

def codeOutBuiltins(indent, builtin):
  codeOut(indent+"jswBinarySearch(&jswSymbolTables["+builtin["indexName"]+"], parent, name);");

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

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

# work out what we have actually got
classes = []
constructors = []
for jsondata in jsondatas:
  if "class" in jsondata :
    if not jsondata["class"] in classes:
      classes.append(jsondata["class"])
  if jsondata["type"]=="constructor":
    if not jsondata["name"] in constructors:
      constructors.append(jsondata["name"])

# Add constructors if we need them
for className in classes:
  if not className in constructors:
    jsondatas.append({
        "type":"constructor", "class": className,  "name": className,
        "generate_full" : "jsvNewWithFlags(JSV_OBJECT)",
        "filename" : "jswrapper.c",
        "return" : [ "JsVar", "" ]
    });

# ------------------------------------------------------------------------------------------------------
#print json.dumps(tree, sort_keys=True, indent=2)
# ------------------------------------------------------------------------------------------------------    

wrapperFile = open('gen/jswrapper.c', 'w')

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

codeOut('// -----------------------------------------------------------------------------------------');
codeOut('// ----------------------------------------------------------------- AUTO-GENERATED WRAPPERS');
codeOut('// -----------------------------------------------------------------------------------------');
codeOut('');

for jsondata in jsondatas:
  if ("generate_full" in jsondata) or (jsondata["type"]=="object"):
    gen_name = "gen_jswrap"
    if "class" in jsondata: gen_name = gen_name + "_" + jsondata["class"];
    gen_name = gen_name + "_" + jsondata["name"];

    jsondata["generate"] = gen_name
    s = [ ]

    if jsondata["type"]=="object":
      jsondata["generate_full"] = "jspNewObject(\""+jsondata["name"]+"\", \""+jsondata["instanceof"]+"\") /* needs JSWAT_EXECUTE_IMMEDIATELY */";
      params = []
      result = ["JsVar"]
    else:
      params = getParams(jsondata)
      result = getResult(jsondata);
      if hasThis(jsondata): s.append("JsVar *parent");
      for param in params:
        s.append(toCType(param[1])+" "+param[0]);
     
    codeOut("static "+toCType(result[0])+" "+jsondata["generate"]+"("+", ".join(s)+") {");
    if result[0]:
      codeOut("  return "+jsondata["generate_full"]+";");
    else:
      codeOut("  "+jsondata["generate_full"]+";");  
    codeOut("}");
    codeOut('');        

codeOut('// -----------------------------------------------------------------------------------------');
codeOut('// -----------------------------------------------------------------------------------------');
codeOut('// -----------------------------------------------------------------------------------------');
codeOut('');

codeOut("""
JsVar *jswBinarySearch(const JswSymList *symbolsPtr, JsVar *parent, const char *name) {
  int searchMin = 0;
  int searchMax = symbolsPtr->symbolCount-1;
  while (searchMin <= searchMax) {
    int idx = (searchMin+searchMax) >> 1;
    const JswSymPtr *sym = &symbolsPtr->symbols[idx];
    int cmp = strcmp(name, &symbolsPtr->symbolChars[sym->strOffset]);
    if (cmp==0) {
      if ((sym->functionSpec & JSWAT_EXECUTE_IMMEDIATELY_MASK) == JSWAT_EXECUTE_IMMEDIATELY)
        return jsnCallFunction(sym->functionPtr, sym->functionSpec, parent, 0, 0);
      return jsvNewNativeFunction(sym->functionPtr, sym->functionSpec);
    } else {
      if (cmp<0) {
        // searchMin is the same
        searchMax = idx-1;
      } else { 
        searchMin = idx+1;
        // searchMax is the same      
      }
    }
  }
  return 0;
}
""");

codeOut('// -----------------------------------------------------------------------------------------');
codeOut('// -----------------------------------------------------------------------------------------');
codeOut('// -----------------------------------------------------------------------------------------');
codeOut('');
codeOut('');

print("Finding Libraries")
libraries = []
for jsondata in jsondatas:
  if jsondata["type"]=="library":
    print("Found library "+jsondata["class"])
    libraries.append(jsondata["class"])

print("Classifying Functions")
builtins = {}
for jsondata in jsondatas:
  if "name" in jsondata:
    jsondata["static"] = not (jsondata["type"]=="property" or jsondata["type"]=="method")

    testCode = "!parent"
    builtinName = "global"
    className = "global"
    isProto = False
    if not jsondata["type"]=="constructor":
      if "class" in jsondata: 
        testCode = getTestFor(jsondata["class"], jsondata["static"])        
        className = jsondata["class"]
        builtinName = className
        if not jsondata["static"]: 
          isProto = True
          builtinName = builtinName+"_proto";

    if not testCode in builtins: 
      print("Adding "+testCode+" to builtins")
      builtins[testCode] = { "name" : builtinName, "className" : className, "isProto" : isProto, "functions" : [] }
    builtins[testCode]["functions"].append(jsondata);


print("Outputting Symbol Tables")
idx = 0
for b in builtins:
  builtin = builtins[b]
  codeOutSymbolTable(builtin);
  builtins[b]["indexName"] = "jswSymbolIndex_"+builtin["name"];
  codeOut("static const unsigned char "+builtin["indexName"]+" = "+str(idx)+";");
  idx = idx + 1
codeOut('');
codeOut('');

codeOut('const JswSymList jswSymbolTables[] = {');
for b in builtins:
  builtin = builtins[b]
  codeOut("  {"+", ".join(["jswSymbols_"+builtin["name"], builtin["symbolTableCount"], builtin["symbolTableChars"]])+"},");
codeOut('};');

codeOut('');
codeOut('');


codeOut('JsVar *jswFindBuiltInFunction(JsVar *parent, const char *name) {')
codeOut('  JsVar *v;')
codeOut('  if (parent && !jsvIsRoot(parent)) {')

codeOut('    // ------------------------------------------ INSTANCE + STATIC METHODS')
nativeCheck = "jsvIsNativeFunction(parent) && "
codeOut('    if (jsvIsNativeFunction(parent)) {')
first = True
for className in builtins:
  if className.startswith(nativeCheck):    
    codeOut('      '+("" if first else "} else ")+'if ('+className[len(nativeCheck):]+') {')
    first = False
    codeOutBuiltins("        v = ", builtins[className])
    codeOut('        if (v) return v;');
if not first:
  codeOut("      }")
codeOut('    }')
for className in builtins:
  if className!="parent" and  className!="!parent" and not "constructorPtr" in className and not className.startswith(nativeCheck):
    codeOut('    if ('+className+') {')
    codeOutBuiltins("      v = ", builtins[className])
    codeOut('      if (v) return v;');
    codeOut("    }")
codeOut('    // ------------------------------------------ INSTANCE METHODS WE MUST CHECK CONSTRUCTOR FOR')
codeOut('    JsVar *proto = jsvIsObject(parent)?jsvSkipNameAndUnLock(jsvFindChildFromString(parent, JSPARSE_INHERITS_VAR, false)):0;')
codeOut('    JsVar *constructor = jsvIsObject(proto)?jsvSkipNameAndUnLock(jsvFindChildFromString(proto, JSPARSE_CONSTRUCTOR_VAR, false)):0;')
codeOut('    jsvUnLock(proto);')
codeOut('    if (constructor && jsvIsNativeFunction(constructor)) {')
codeOut('      void *constructorPtr = constructor->varData.native.ptr;')
codeOut('      jsvUnLock(constructor);')
first = True
for className in builtins:
  if "constructorPtr" in className:
    if first:
      codeOut('      if ('+className+') {')
      first = False
    else:
      codeOut('      } else if ('+className+') {')
    codeOutBuiltins("        v = ", builtins[className])
    codeOut('        if (v) return v;')
if not first:
  codeOut("      }")
codeOut('    } else {')
codeOut('      jsvUnLock(constructor);')
codeOut('    }')
codeOut('    // ------------------------------------------ METHODS ON OBJECT')
if "parent" in builtins:
  codeOutBuiltins("    v = ", builtins["parent"])
  codeOut('    if (v) return v;');
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('      return jsvNewFromPin(pin);')
codeOut('    }')
if "!parent" in builtins:
  codeOutBuiltins("    return ", builtins["!parent"])
codeOut('  }');

codeOut('  return 0;')
codeOut('}')

codeOut('')
codeOut('')

codeOut('const JswSymList *jswGetSymbolListForObject(JsVar *parent) {') 
for className in builtins:
  builtin = builtins[className]
  if not className in ["parent","!parent"] and not builtin["isProto"]:
    codeOut("  if ("+className+") return &jswSymbolTables["+builtin["indexName"]+"];");
codeOut("  if (parent==execInfo.root) return &jswSymbolTables[jswSymbolIndex_global];");
codeOut("  return 0;")
codeOut('}')

codeOut('')
codeOut('')

codeOut('const JswSymList *jswGetSymbolListForObjectProto(JsVar *parent) {')
codeOut('  if (jsvIsNativeFunction(parent)) {')
for className in builtins:
  builtin = builtins[className]
  if builtin["isProto"] and not "constructorPtr" in className and not className in ["parent","!parent"] :
    check = className
    for jsondata in jsondatas:
      if jsondata["type"]=="constructor" and jsondata["name"]==builtin["className"]:
        check = "(void*)parent->varData.native.ptr==(void*)"+jsondata["generate"]

    codeOut("    if ("+check+") return &jswSymbolTables["+builtin["indexName"]+"];");
codeOut('  }')
codeOut('  JsVar *constructor = jsvIsObject(parent)?jsvSkipNameAndUnLock(jsvFindChildFromString(parent, JSPARSE_CONSTRUCTOR_VAR, false)):0;')
codeOut('  if (constructor && jsvIsNativeFunction(constructor)) {')
codeOut('    void *constructorPtr = constructor->varData.native.ptr;')
codeOut('   jsvUnLock(constructor);')
for className in builtins:
  builtin = builtins[className]
  if builtin["isProto"] and "constructorPtr" in className:
    codeOut("    if ("+className+") return &jswSymbolTables["+builtin["indexName"]+"];");
codeOut('  }')
nativeCheck = "jsvIsNativeFunction(parent) && "
for className in builtins:
  if className!="parent" and  className!="!parent" and not "constructorPtr" in className and not className.startswith(nativeCheck):
    codeOut('    if ('+className+") return &jswSymbolTables["+builtins[className]["indexName"]+"];");
codeOut("  return &jswSymbolTables["+builtins["parent"]["indexName"]+"];")
codeOut('}')

codeOut('')
codeOut('')

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


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

codeOut('')
codeOut('')


codeOut('void *jswGetBuiltInLibrary(const char *name) {') 
for lib in libraries:
  codeOut('if (strcmp(name, "'+lib+'")==0) return (void*)gen_jswrap_'+lib+'_'+lib+';');
codeOut('  return 0;')
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('')