Nim/compiler/vmops.nim

#
#
#           The Nim Compiler
#        (c) Copyright 2015 Andreas Rumpf
#
#    See the file "copying.txt", included in this
#    distribution, for details about the copyright.
#

# Unfortunately this cannot be a module yet:
#import vmdeps, vm
from math import sqrt, ln, log10, log2, exp, round, arccos, arcsin,
  arctan, arctan2, cos, cosh, hypot, sinh, sin, tan, tanh, pow, trunc,
  floor, ceil, `mod`

from os import getEnv, existsEnv, dirExists, fileExists, putEnv, walkDir, getAppFilename
from md5 import getMD5
from sighashes import symBodyDigest
from times import cpuTime

from hashes import hash
from osproc import nil

import vmconv

template mathop(op) {.dirty.} =
  registerCallback(c, "stdlib.math." & astToStr(op), `op Wrapper`)

template osop(op) {.dirty.} =
  registerCallback(c, "stdlib.os." & astToStr(op), `op Wrapper`)

template timesop(op) {.dirty.} =
  registerCallback(c, "stdlib.times." & astToStr(op), `op Wrapper`)

template systemop(op) {.dirty.} =
  registerCallback(c, "stdlib.system." & astToStr(op), `op Wrapper`)

template ioop(op) {.dirty.} =
  registerCallback(c, "stdlib.io." & astToStr(op), `op Wrapper`)

template macrosop(op) {.dirty.} =
  registerCallback(c, "stdlib.macros." & astToStr(op), `op Wrapper`)

template md5op(op) {.dirty.} =
  registerCallback(c, "stdlib.md5." & astToStr(op), `op Wrapper`)

template wrap1f_math(op) {.dirty.} =
  proc `op Wrapper`(a: VmArgs) {.nimcall.} =
    setResult(a, op(getFloat(a, 0)))
  mathop op

template wrap2f_math(op) {.dirty.} =
  proc `op Wrapper`(a: VmArgs) {.nimcall.} =
    setResult(a, op(getFloat(a, 0), getFloat(a, 1)))
  mathop op

template wrap0(op, modop) {.dirty.} =
  proc `op Wrapper`(a: VmArgs) {.nimcall.} =
    setResult(a, op())
  modop op

template wrap1s(op, modop) {.dirty.} =
  proc `op Wrapper`(a: VmArgs) {.nimcall.} =
    setResult(a, op(getString(a, 0)))
  modop op

template wrap2s(op, modop) {.dirty.} =
  proc `op Wrapper`(a: VmArgs) {.nimcall.} =
    setResult(a, op(getString(a, 0), getString(a, 1)))
  modop op

template wrap2si(op, modop) {.dirty.} =
  proc `op Wrapper`(a: VmArgs) {.nimcall.} =
    setResult(a, op(getString(a, 0), getInt(a, 1)))
  modop op

template wrap1svoid(op, modop) {.dirty.} =
  proc `op Wrapper`(a: VmArgs) {.nimcall.} =
    op(getString(a, 0))
  modop op

template wrap2svoid(op, modop) {.dirty.} =
  proc `op Wrapper`(a: VmArgs) {.nimcall.} =
    op(getString(a, 0), getString(a, 1))
  modop op

template wrapDangerous(op, modop) {.dirty.} =
  if vmopsDanger notin c.config.features and (defined(nimsuggest) or c.config.cmd == cmdCheck):
    proc `op Wrapper`(a: VmArgs) {.nimcall.} =
      discard
    modop op
  else:
    proc `op Wrapper`(a: VmArgs) {.nimcall.} =
      op(getString(a, 0), getString(a, 1))
    modop op

proc getCurrentExceptionMsgWrapper(a: VmArgs) {.nimcall.} =
  setResult(a, if a.currentException.isNil: ""
               else: a.currentException[3].skipColon.strVal)

proc getCurrentExceptionWrapper(a: VmArgs) {.nimcall.} =
  setResult(a, a.currentException)

proc staticWalkDirImpl(path: string, relative: bool): PNode =
  result = newNode(nkBracket)
  for k, f in walkDir(path, relative):
    result.add toLit((k, f))

when defined(nimHasInvariant):
  from std / compilesettings import SingleValueSetting, MultipleValueSetting

  proc querySettingImpl(conf: ConfigRef, switch: BiggestInt): string =
    case SingleValueSetting(switch)
    of arguments: result = conf.arguments
    of outFile: result = conf.outFile.string
    of outDir: result = conf.outDir.string
    of nimcacheDir: result = conf.getNimcacheDir().string
    of projectName: result = conf.projectName
    of projectPath: result = conf.projectPath.string
    of projectFull: result = conf.projectFull.string
    of command: result = conf.command
    of commandLine: result = conf.commandLine
    of linkOptions: result = conf.linkOptions
    of compileOptions: result = conf.compileOptions
    of ccompilerPath: result = conf.cCompilerPath
    of backend: result = $conf.backend

  proc querySettingSeqImpl(conf: ConfigRef, switch: BiggestInt): seq[string] =
    template copySeq(field: untyped): untyped =
      for i in field: result.add i.string

    case MultipleValueSetting(switch)
    of nimblePaths: copySeq(conf.nimblePaths)
    of searchPaths: copySeq(conf.searchPaths)
    of lazyPaths: copySeq(conf.lazyPaths)
    of commandArgs: result = conf.commandArgs
    of cincludes: copySeq(conf.cIncludes)
    of clibs: copySeq(conf.cLibs)

proc registerAdditionalOps*(c: PCtx) =
  proc gorgeExWrapper(a: VmArgs) =
    let ret = opGorge(getString(a, 0), getString(a, 1), getString(a, 2),
                         a.currentLineInfo, c.config)
    setResult a, ret.toLit

  proc getProjectPathWrapper(a: VmArgs) =
    setResult a, c.config.projectPath.string

  wrap1f_math(sqrt)
  wrap1f_math(ln)
  wrap1f_math(log10)
  wrap1f_math(log2)
  wrap1f_math(exp)
  wrap1f_math(round)
  wrap1f_math(arccos)
  wrap1f_math(arcsin)
  wrap1f_math(arctan)
  wrap2f_math(arctan2)
  wrap1f_math(cos)
  wrap1f_math(cosh)
  wrap2f_math(hypot)
  wrap1f_math(sinh)
  wrap1f_math(sin)
  wrap1f_math(tan)
  wrap1f_math(tanh)
  wrap2f_math(pow)
  wrap1f_math(trunc)
  wrap1f_math(floor)
  wrap1f_math(ceil)

  wrap1s(getMD5, md5op)

  proc `mod Wrapper`(a: VmArgs) {.nimcall.} =
    setResult(a, `mod`(getFloat(a, 0), getFloat(a, 1)))
  registerCallback(c, "stdlib.math.mod", `mod Wrapper`)

  when defined(nimcore):
    wrap2s(getEnv, osop)
    wrap1s(existsEnv, osop)
    wrap2svoid(putEnv, osop)
    wrap1s(dirExists, osop)
    wrap1s(fileExists, osop)
    wrapDangerous(writeFile, ioop)
    wrap1s(readFile, ioop)
    wrap2si(readLines, ioop)
    systemop getCurrentExceptionMsg
    systemop getCurrentException
    registerCallback c, "stdlib.*.staticWalkDir", proc (a: VmArgs) {.nimcall.} =
      setResult(a, staticWalkDirImpl(getString(a, 0), getBool(a, 1)))
    when defined(nimHasInvariant):
      registerCallback c, "stdlib.compilesettings.querySetting", proc (a: VmArgs) =
        setResult(a, querySettingImpl(c.config, getInt(a, 0)))
      registerCallback c, "stdlib.compilesettings.querySettingSeq", proc (a: VmArgs) =
        setResult(a, querySettingSeqImpl(c.config, getInt(a, 0)))

    if defined(nimsuggest) or c.config.cmd == cmdCheck:
      discard "don't run staticExec for 'nim suggest'"
    else:
      systemop gorgeEx
  macrosop getProjectPath

  registerCallback c, "stdlib.os.getCurrentCompilerExe", proc (a: VmArgs) {.nimcall.} =
    setResult(a, getAppFilename())

  registerCallback c, "stdlib.macros.symBodyHash", proc (a: VmArgs) =
    let n = getNode(a, 0)
    if n.kind != nkSym:
      stackTrace(c, PStackFrame(prc: c.prc.sym, comesFrom: 0, next: nil), c.exceptionInstr,
                  "symBodyHash() requires a symbol. '" & $n & "' is of kind '" & $n.kind & "'", n.info)
    setResult(a, $symBodyDigest(c.graph, n.sym))

  registerCallback c, "stdlib.macros.isExported", proc(a: VmArgs) =
    let n = getNode(a, 0)
    if n.kind != nkSym:
      stackTrace(c, PStackFrame(prc: c.prc.sym, comesFrom: 0, next: nil), c.exceptionInstr,
                  "isExported() requires a symbol. '" & $n & "' is of kind '" & $n.kind & "'", n.info)
    setResult(a, sfExported in n.sym.flags)

  proc hashVmImpl(a: VmArgs) =
    var res = hashes.hash(a.getString(0), a.getInt(1).int, a.getInt(2).int)
    if c.config.backend == backendJs:
      # emulate JS's terrible integers:
      res = cast[int32](res)
    setResult(a, res)

  registerCallback c, "stdlib.hashes.hashVmImpl", hashVmImpl

  proc hashVmImplByte(a: VmArgs) =
    # nkBracket[...]
    let sPos = a.getInt(1).int
    let ePos = a.getInt(2).int
    let arr = a.getNode(0)
    var bytes = newSeq[byte](arr.len)
    for i in 0..<arr.len:
      bytes[i] = byte(arr[i].intVal and 0xff)

    var res = hashes.hash(bytes, sPos, ePos)
    if c.config.backend == backendJs:
      # emulate JS's terrible integers:
      res = cast[int32](res)
    setResult(a, res)

  registerCallback c, "stdlib.hashes.hashVmImplByte", hashVmImplByte
  registerCallback c, "stdlib.hashes.hashVmImplChar", hashVmImplByte

  if optBenchmarkVM in c.config.globalOptions or vmopsDanger in c.config.features:
    wrap0(cpuTime, timesop)
  else:
    proc cpuTime(): float = 5.391245e-44  # Randomly chosen
    wrap0(cpuTime, timesop)

  if vmopsDanger in c.config.features:
    ## useful procs but these should be opt-in because they may impact
    ## reproducible builds and users need to understand that this runs at CT.
    ## Note that `staticExec` can already do equal amount of damage so it's more
    ## of a semantic issue than a security issue.
    registerCallback c, "stdlib.os.getCurrentDir", proc (a: VmArgs) {.nimcall.} =
      setResult(a, os.getCurrentDir())
    registerCallback c, "stdlib.osproc.execCmdEx", proc (a: VmArgs) {.nimcall.} =
      let options = getNode(a, 1).fromLit(set[osproc.ProcessOption])
      a.setResult osproc.execCmdEx(getString(a, 0), options).toLit
    registerCallback c, "stdlib.times.getTime", proc (a: VmArgs) {.nimcall.} =
      setResult(a, times.getTime().toLit)

  proc getEffectList(c: PCtx; a: VmArgs; effectIndex: int) =
    let fn = getNode(a, 0)
    if fn.typ != nil and fn.typ.n != nil and fn.typ.n[0].len >= effectListLen and
        fn.typ.n[0][effectIndex] != nil:
      var list = newNodeI(nkBracket, fn.info)
      for e in fn.typ.n[0][effectIndex]:
        list.add opMapTypeInstToAst(c.cache, e.typ.skipTypes({tyRef}), e.info)
      setResult(a, list)

  registerCallback c, "stdlib.effecttraits.getRaisesListImpl", proc (a: VmArgs) =
    getEffectList(c, a, exceptionEffects)
  registerCallback c, "stdlib.effecttraits.getTagsListImpl", proc (a: VmArgs) =
    getEffectList(c, a, tagEffects)

  registerCallback c, "stdlib.effecttraits.isGcSafeImpl", proc (a: VmArgs) =
    let fn = getNode(a, 0)
    setResult(a, fn.typ != nil and tfGcSafe in fn.typ.flags)

  registerCallback c, "stdlib.effecttraits.hasNoSideEffectsImpl", proc (a: VmArgs) =
    let fn = getNode(a, 0)
    setResult(a, (fn.typ != nil and tfNoSideEffect in fn.typ.flags) or
                 (fn.kind == nkSym and fn.sym.kind == skFunc))