Mojo + NaCl prototype.

mojo/monacl/gen/generate_monacl_bindings.py

+#!/usr/bin/python
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import os.path
+import string
+import sys
+
+import interface
+
+class CodeWriter(object):
+  def __init__(self):
+    self.lines = []
+    self.margin = ""
+    self.margin_stack = []
+
+  def __lshift__(self, line):
+    self.lines.append((self.margin + line).rstrip())
+
+  def pushMargin(self):
+    self.margin_stack.append(self.margin)
+    self.margin += "  "
+
+  def popMargin(self):
+    self.margin = self.margin_stack.pop()
+
+  def getValue(self):
+    return "\n".join(self.lines).rstrip() + "\n"
+
+class Indent(object):
+  def __init__(self, writer):
+    self.writer = writer
+
+  def __enter__(self):
+    self.writer.pushMargin()
+
+  def __exit__(self, type, value, traceback):
+    self.writer.popMargin()
+
+def templateFile(name):
+  return os.path.join(os.path.dirname(__file__), name)
+
+def wrap(pre, items, post):
+  complete = pre + ", ".join(items) + post
+  if len(complete) <= 80:
+    return [complete]
+  lines = [pre]
+  indent = "    "
+  for i, item in enumerate(items):
+    if i < len(items) - 1:
+      lines.append(indent + item + ",")
+    else:
+      lines.append(indent + item + post)
+  return lines
+
+def iovDecl(param):
+  if param.isPassedByValue():
+    return "{&%s, sizeof(%s)}" % (param.name, param.name)
+  elif param.isArray:
+    sp = param.getSizeParam()
+    if sp.isPassedByValue():
+      size = sp.name
+    else:
+      # TODO volatile read?
+      size = "(*%s)" % sp.name
+    if param.baseType == "void":
+      return "{(void*)%s, %s}" % (param.name, size)
+    else:
+      return "{(void*)%s, sizeof(*%s)*%s}" % (param.name, param.name, size)
+  else:
+    return "{(void*)%s, sizeof(*%s)}" % (param.name, param.name)
+
+def loadTemplate(filename):
+  data = open(templateFile(filename)).read()
+  template = string.Template(data)
+  return template
+
+def generateLibMojo(functions, out):
+  template = loadTemplate("libmojo.cc.template")
+
+  code = CodeWriter()
+
+  for f in functions:
+    for line in wrap("%s %s(" % (f.returnType, f.name), f.paramList(), "){"):
+      code << line
+    numParams = len(f.params) + 2
+
+    with Indent(code):
+      code << "uint32_t params[%d];" % numParams
+      if f.returnType == "MojoResult":
+        default = "MOJO_RESULT_INVALID_ARGUMENT"
+      elif f.returnType == "MojoTimeTicks":
+        default = "0"
+      else:
+        raise Exception("Unhandled return type: " + f.returnType)
+      code << "%s result = %s;" % (f.returnType, default);
+
+      # Message ID
+      code << "params[0] = %d;" % f.uid
+      # Parameter pointers
+      castTemplate = "params[%d] = reinterpret_cast<uint32_t>(%s);"
+      for p in f.params:
+        ptr = p.name
+        if p.isPassedByValue():
+          ptr = "&" + ptr
+        code <<  castTemplate % (p.uid + 1, ptr)
+      # Return value pointer
+      code << castTemplate % (numParams - 1, "&result")
+
+      code << "DoMojoCall(params, sizeof(params));";
+      code << "return result;"
+
+    code << "}"
+    code << ""
+
+  body = code.getValue()
+
+
+  text = template.substitute(
+    script_name=os.path.basename(__file__),
+    body=body)
+
+  print >>out, text
+
+def paramPtr(param):
+  ptr = param.paramType
+  if param.isPassedByValue():
+    ptr += " volatile*"
+  return ptr
+
+def generateMojoSyscall(functions, out):
+  template = loadTemplate("mojo_syscall.cc.template")
+
+  code = CodeWriter()
+  code.pushMargin()
+
+  for f in functions:
+    code << "case %d:" % f.uid
+
+    code.pushMargin()
+
+    code << "{"
+
+    with Indent(code):
+      numParams = len(f.params) + 2
+      code << "if (numParams != %d) {" % numParams
+      with Indent(code):
+        code << "return -1;"
+      code << "}"
+
+      def scalarNull(param):
+        code << "%s_ptr = NULL;" % (param.name)
+        if param.isInput:
+          if param.isScalar():
+            # TODO can we alway zero scalar values?
+            code << "%s = 0;" % (param.name)
+
+      def scalarFinalize(param, src):
+        if param.isOutput:
+          # For outputs, we need to retain the pointer for later.
+          code << "%s_ptr = reinterpret_cast<%s>(%s);" % (param.name, paramPtr(param), src)
+          if param.isInput:
+            code << "// In/Out"
+            code << "%s = *%s_ptr;" % (param.name, param.name)
+        else:
+          # For pure inputs, no need to retain the pointer
+          code << "%s = *reinterpret_cast<%s>(%s);" % (param.name, paramPtr(param), src)
+
+      def convertParam(param):
+        if param.isScalar():
+          code << "uintptr_t temp = NaClUserToSysAddrRange(nap, params[%d], sizeof(%s));" % (param.uid + 1, param.name)
+        elif param.isArray:
+          if param.baseType == "void":
+            code << "uintptr_t temp = NaClUserToSysAddrRange(nap, params[%d], %s);" % (param.uid + 1, param.size)
+          else:
+            code << "uintptr_t temp = NaClUserToSysAddrArray(nap, params[%d], %s, sizeof(*%s));" % (param.uid + 1, param.size, param.name)
+        else:
+          code << "uintptr_t temp = NaClUserToSysAddrRange(nap, params[%d], sizeof(*%s));" % (param.uid + 1, param.name)
+
+        code << "if (temp == kNaClBadAddress) {"
+        with Indent(code):
+          code << "return -1;"
+        code << "}"
+        if param.isScalar():
+          scalarFinalize(param, 'temp')
+        else:
+          code << "%s = reinterpret_cast<%s>(%s);" % (param.name, param.paramType, 'temp')
+
+      def convertPtr(param):
+        if param.isScalar():
+          if param.isOutput:
+            code << "%s %s_ptr;" % (paramPtr(param), param.name)
+          code << "%s %s;" % (param.baseType, param.name)
+        else:
+          code << "%s %s;" % (param.paramType, param.name)
+
+        code << "if (params[%d] == 0) {" % (param.uid + 1)
+        with Indent(code):
+          if param.isOptional:
+            if param.isScalar():
+              scalarNull(param)
+            else:
+              code << "%s = NULL;" % (param.name)
+          else:
+            code << "return -1;"
+        code << "} else {"
+        with Indent(code):
+          convertParam(param)
+        code << "}"
+
+      # Convert and validate pointers in two passes.
+      # Arrays cannot be validated util the size parameter has been converted.
+      code << "NaClCopyTakeLock(nap);"
+      for param in f.params:
+        if not param.isArray:
+          convertPtr(param)
+      for param in f.params:
+        if param.isArray:
+          convertPtr(param)
+      convertPtr(f.resultParam)
+      code << "NaClCopyDropLock(nap);"
+      code << ""
+
+      # Call
+      getParams = []
+      for param in f.params:
+        if param.isScalar() and not param.isPassedByValue():
+          if param.isOptional:
+            getParams.append("%s_ptr ? &%s : NULL" % (param.name, param.name))
+          else:
+            getParams.append("&%s" % (param.name))
+        else:
+          getParams.append(param.name)
+
+      code << "result = %s(%s);" % (f.name, ", ".join(getParams))
+      code << ""
+
+      def copyOut(param):
+        if param.isScalar():
+          if param.isOutput:
+            if param.isOptional:
+              code << "if (%s_ptr != NULL) {" % (param.name)
+              with Indent(code):
+                code << "*%s_ptr = %s;" % (param.name, param.name)
+              code << "}"
+            else:
+              code << "*%s_ptr = %s;" % (param.name, param.name)
+
+      # Write outputs
+      code << "NaClCopyTakeLock(nap);"
+      for param in f.params:
+        copyOut(param)
+      copyOut(f.resultParam)
+      code << "NaClCopyDropLock(nap);"
+      code << ""
+
+      code << "return 0;"
+    code << "}"
+
+    code.popMargin()
+
+  body = code.getValue()
+
+  text = template.substitute(
+    script_name=os.path.basename(__file__),
+    body=body)
+
+  print >>out, text
+
+def main():
+  outdir = os.path.dirname(os.path.dirname(__file__))
+
+  mojo = interface.makeInterface()
+  generateLibMojo(mojo.functions, open(os.path.join(outdir, "libmojo.cc"), "w"))
+  generateMojoSyscall(mojo.functions, open(os.path.join(outdir, "mojo_syscall.cc"), "w"))
+
+if __name__ == "__main__":
+  main()