#
#
# The Nim Compiler
# (c) Copyright 2015 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
#
## This module implements the code generator for the VM.
# Important things to remember:
# - The VM does not distinguish between definitions ('var x = y') and
# assignments ('x = y'). For simple data types that fit into a register
# this doesn't matter. However it matters for strings and other complex
# types that use the 'node' field; the reason is that slots are
# re-used in a register based VM. Example:
#
#.. code-block:: nim
# let s = a & b # no matter what, create fresh node
# s = a & b # no matter what, keep the node
#
# Also *stores* into non-temporary memory need to perform deep copies:
# a.b = x.y
# We used to generate opcAsgn for the *load* of 'x.y' but this is clearly
# wrong! We need to produce opcAsgn (the copy) for the *store*. This also
# solves the opcLdConst vs opcAsgnConst issue. Of course whether we need
# this copy depends on the involved types.
import tables
import
strutils, ast, types, msgs, renderer, vmdef,
intsets, magicsys, options, lowerings, lineinfos, transf
from modulegraphs import getBody
when defined(nimCompilerStacktraceHints):
import std/stackframes
const
debugEchoCode* = defined(nimVMDebug)
when debugEchoCode:
import std/private/asciitables
when hasFFI:
import evalffi
type
TGenFlag = enum
gfNode # Affects how variables are loaded - always loads as rkNode
gfNodeAddr # Affects how variables are loaded - always loads as rkNodeAddr
gfIsParam # do not deepcopy parameters, they are immutable
TGenFlags = set[TGenFlag]
proc debugInfo(c: PCtx; info: TLineInfo): string =
result = toFileLineCol(c.config, info)
proc codeListing(c: PCtx, result: var string, start=0; last = -1) =
## for debugging purposes
# first iteration: compute all necessary labels:
var jumpTargets = initIntSet()
let last = if last < 0: c.code.len-1 else: min(last, c.code.len-1)
for i in start..last:
let x = c.code[i]
if x.opcode in relativeJumps:
jumpTargets.incl(i+x.regBx-wordExcess)
template toStr(opc: TOpcode): string = ($opc).substr(3)
result.add "code listing:\n"
var i = start
while i <= last:
if i in jumpTargets: result.addf("L$1:\n", i)
let x = c.code[i]
result.add($i)
let opc = opcode(x)
if opc in {opcIndCall, opcIndCallAsgn}:
result.addf("\t$#\tr$#, r$#, nargs:$#", opc.toStr, x.regA,
x.regB, x.regC)
elif opc in {opcConv, opcCast}:
let y = c.code[i+1]
let z = c.code[i+2]
result.addf("\t$#\tr$#, r$#, $#, $#", opc.toStr, x.regA, x.regB,
c.types[y.regBx-wordExcess].typeToString,
c.types[z.regBx-wordExcess].typeToString)
inc i, 2
elif opc < firstABxInstr:
result.addf("\t$#\tr$#, r$#, r$#", opc.toStr, x.regA,
x.regB, x.regC)
elif opc in relativeJumps + {opcTry}:
result.addf("\t$#\tr$#, L$#", opc.toStr, x.regA,
i+x.regBx-wordExcess)
elif opc in {opcExcept}:
let idx = x.regBx-wordExcess
result.addf("\t$#\t$#, $#", opc.toStr, x.regA, $idx)
elif opc in {opcLdConst, opcAsgnConst}:
let idx = x.regBx-wordExcess
result.addf("\t$#\tr$#, $# ($#)", opc.toStr, x.regA,
c.constants[idx].renderTree, $idx)
elif opc in {opcMarshalLoad, opcMarshalStore}:
let y = c.code[i+1]
result.addf("\t$#\tr$#, r$#, $#", opc.toStr, x.regA, x.regB,
c.types[y.regBx-wordExcess].typeToString)
inc i
else:
result.addf("\t$#\tr$#, $#", opc.toStr, x.regA, x.regBx-wordExcess)
result.add("\t# ")
result.add(debugInfo(c, c.debug[i]))
result.add("\n")
inc i
when debugEchoCode:
result = result.alignTable
proc echoCode*(c: PCtx; start=0; last = -1) {.deprecated.} =
var buf = ""
codeListing(c, buf, start, last)
echo buf
proc gABC(ctx: PCtx; n: PNode; opc: TOpcode; a, b, c: TRegister = 0) =
## Takes the registers `b` and `c`, applies the operation `opc` to them, and
## stores the result into register `a`
## The node is needed for debug information
assert opc.ord < 255
let ins = (opc.TInstrType or (a.TInstrType shl regAShift) or
(b.TInstrType shl regBShift) or
(c.TInstrType shl regCShift)).TInstr
when false:
if ctx.code.len == 43:
writeStackTrace()
echo "generating ", opc
ctx.code.add(ins)
ctx.debug.add(n.info)
proc gABI(c: PCtx; n: PNode; opc: TOpcode; a, b: TRegister; imm: BiggestInt) =
# Takes the `b` register and the immediate `imm`, applies the operation `opc`,
# and stores the output value into `a`.
# `imm` is signed and must be within [-128, 127]
if imm >= -128 and imm <= 127:
let ins = (opc.TInstrType or (a.TInstrType shl regAShift) or
(b.TInstrType shl regBShift) or
(imm+byteExcess).TInstrType shl regCShift).TInstr
c.code.add(ins)
c.debug.add(n.info)
else:
localError(c.config, n.info,
"VM: immediate value does not fit into an int8")
proc gABx(c: PCtx; n: PNode; opc: TOpcode; a: TRegister = 0; bx: int) =
# Applies `opc` to `bx` and stores it into register `a`
# `bx` must be signed and in the range [regBxMin, regBxMax]
when false:
if c.code.len == 43:
writeStackTrace()
echo "generating ", opc
if bx >= regBxMin-1 and bx <= regBxMax:
let ins = (opc.TInstrType or a.TInstrType shl regAShift or
(bx+wordExcess).TInstrType shl regBxShift).TInstr
c.code.add(ins)
c.debug.add(n.info)
else:
localError(c.config, n.info,
"VM: immediate value does not fit into regBx")
proc xjmp(c: PCtx; n: PNode; opc: TOpcode; a: TRegister = 0): TPosition =
#assert opc in {opcJmp, opcFJmp, opcTJmp}
result = TPosition(c.code.len)
gABx(c, n, opc, a, 0)
proc genLabel(c: PCtx): TPosition =
result = TPosition(c.code.len)
#c.jumpTargets.incl(c.code.len)
proc jmpBack(c: PCtx, n: PNode, p = TPosition(0)) =
let dist = p.int - c.code.len
internalAssert(c.config, regBxMin < dist and dist < regBxMax)
gABx(c, n, opcJmpBack, 0, dist)
proc patch(c: PCtx, p: TPosition) =
# patch with current index
let p = p.int
let diff = c.code.len - p
#c.jumpTargets.incl(c.code.len)
internalAssert(c.config, regBxMin < diff and diff < regBxMax)
let oldInstr = c.code[p]
# opcode and regA stay the same:
c.code[p] = ((oldInstr.TInstrType and regBxMask).TInstrType or
TInstrType(diff+wordExcess) shl regBxShift).TInstr
proc getSlotKind(t: PType): TSlotKind =
case t.skipTypes(abstractRange-{tyTypeDesc}).kind
of tyBool, tyChar, tyEnum, tyOrdinal, tyInt..tyInt64, tyUInt..tyUInt64:
slotTempInt
of tyString, tyCstring:
slotTempStr
of tyFloat..tyFloat128:
slotTempFloat
else:
slotTempComplex
const
HighRegisterPressure = 40
proc bestEffort(c: PCtx): TLineInfo =
if c.prc != nil and c.prc.sym != nil:
c.prc.sym.info
else:
c.module.info
proc getFreeRegister(cc: PCtx; k: TSlotKind; start: int): TRegister =
let c = cc.prc
# we prefer the same slot kind here for efficiency. Unfortunately for
# discardable return types we may not know the desired type. This can happen
# for e.g. mNAdd[Multiple]:
for i in start..c.regInfo.len-1:
if c.regInfo[i].kind == k and not c.regInfo[i].inUse:
c.regInfo[i].inUse = true
return TRegister(i)
# if register pressure is high, we re-use more aggressively:
if c.regInfo.len >= high(TRegister):
for i in start..c.regInfo.len-1:
if not c.regInfo[i].inUse:
c.regInfo[i] = (inUse: true, kind: k)
return TRegister(i)
if c.regInfo.len >= high(TRegister):
globalError(cc.config, cc.bestEffort, "VM problem: too many registers required")
result = TRegister(max(c.regInfo.len, start))
c.regInfo.setLen int(result)+1
c.regInfo[result] = (inUse: true, kind: k)
proc getTemp(cc: PCtx; tt: PType): TRegister =
let typ = tt.skipTypesOrNil({tyStatic})
# we prefer the same slot kind here for efficiency. Unfortunately for
# discardable return types we may not know the desired type. This can happen
# for e.g. mNAdd[Multiple]:
let k = if typ.isNil: slotTempComplex else: typ.getSlotKind
result = getFreeRegister(cc, k, start = 0)
when false:
# enable this to find "register" leaks:
if result == 4:
echo "begin ---------------"
writeStackTrace()
echo "end ----------------"
proc freeTemp(c: PCtx; r: TRegister) =
let c = c.prc
if c.regInfo[r].kind in {slotSomeTemp..slotTempComplex}:
# this seems to cause https://github.com/nim-lang/Nim/issues/10647
c.regInfo[r].inUse = false
proc getTempRange(cc: PCtx; n: int; kind: TSlotKind): TRegister =
# if register pressure is high, we re-use more aggressively:
let c = cc.prc
# we could also customize via the following (with proper caching in ConfigRef):
# let highRegisterPressure = cc.config.getConfigVar("vm.highRegisterPressure", "40").parseInt
if c.regInfo.len >= HighRegisterPressure or c.regInfo.len+n >= high(TRegister):
for i in 0..c.regInfo.len-n:
if not c.regInfo[i].inUse:
block search:
for j in i+1..i+n-1:
if c.regInfo[j].inUse: break search
result = TRegister(i)
for k in result..result+n-1: c.regInfo[k] = (inUse: true, kind: kind)
return
if c.regInfo.len+n >= high(TRegister):
globalError(cc.config, cc.bestEffort, "VM problem: too many registers required")
result = TRegister(c.regInfo.len)
setLen c.regInfo, c.regInfo.len+n
for k in result..result+n-1: c.regInfo[k] = (inUse: true, kind: kind)
proc freeTempRange(c: PCtx; start: TRegister, n: int) =
for i in start..start+n-1: c.freeTemp(TRegister(i))
template withTemp(tmp, typ, body: untyped) {.dirty.} =
var tmp = getTemp(c, typ)
body
c.freeTemp(tmp)
proc popBlock(c: PCtx; oldLen: int) =
for f in c.prc.blocks[oldLen].fixups:
c.patch(f)
c.prc.blocks.setLen(oldLen)
template withBlock(labl: PSym; body: untyped) {.dirty.} =
var oldLen {.gensym.} = c.prc.blocks.len
c.prc.blocks.add TBlock(label: labl, fixups: @[])
body
popBlock(c, oldLen)
proc gen(c: PCtx; n: PNode; dest: var TDest; flags: TGenFlags = {})
proc gen(c: PCtx; n: PNode; dest: TRegister; flags: TGenFlags = {}) =
var d: TDest = dest
gen(c, n, d, flags)
#internalAssert c.config, d == dest # issue #7407
proc gen(c: PCtx; n: PNode; flags: TGenFlags = {}) =
var tmp: TDest = -1
gen(c, n, tmp, flags)
if tmp >= 0:
freeTemp(c, tmp)
#if n.typ.isEmptyType: internalAssert tmp < 0
proc genx(c: PCtx; n: PNode; flags: TGenFlags = {}): TRegister =
var tmp: TDest = -1
gen(c, n, tmp, flags)
#internalAssert c.config, tmp >= 0 # 'nim check' does not like this internalAssert.
if tmp >= 0:
result = TRegister(tmp)
proc clearDest(c: PCtx; n: PNode; dest: var TDest) {.inline.} =
# stmt is different from 'void' in meta programming contexts.
# So we only set dest to -1 if 'void':
if dest >= 0 and (n.typ.isNil or n.typ.kind == tyVoid):
c.freeTemp(dest)
dest = -1
proc isNotOpr(n: PNode): bool =
n.kind in nkCallKinds and n[0].kind == nkSym and
n[0].sym.magic == mNot
proc isTrue(n: PNode): bool =
n.kind == nkSym and n.sym.kind == skEnumField and n.sym.position != 0 or
n.kind == nkIntLit and n.intVal != 0
proc genWhile(c: PCtx; n: PNode) =
# lab1:
# cond, tmp
# fjmp tmp, lab2
# body
# jmp lab1
# lab2:
let lab1 = c.genLabel
withBlock(nil):
if isTrue(n[0]):
c.gen(n[1])
c.jmpBack(n, lab1)
elif isNotOpr(n[0]):
var tmp = c.genx(n[0][1])
let lab2 = c.xjmp(n, opcTJmp, tmp)
c.freeTemp(tmp)
c.gen(n[1])
c.jmpBack(n, lab1)
c.patch(lab2)
else:
var tmp = c.genx(n[0])
let lab2 = c.xjmp(n, opcFJmp, tmp)
c.freeTemp(tmp)
c.gen(n[1])
c.jmpBack(n, lab1)
c.patch(lab2)
proc genBlock(c: PCtx; n: PNode; dest: var TDest) =
let oldRegisterCount = c.prc.regInfo.len
withBlock(n[0].sym):
c.gen(n[1], dest)
for i in oldRegisterCount..<c.prc.regInfo.len:
#if c.prc.regInfo[i].kind in {slotFixedVar, slotFixedLet}:
if i != dest:
when not defined(release):
if c.prc.regInfo[i].inUse and c.prc.regInfo[i].kind in {slotTempUnknown,
slotTempInt,
slotTempFloat,
slotTempStr,
slotTempComplex}:
doAssert false, "leaking temporary " & $i & " " & $c.prc.regInfo[i].kind
c.prc.regInfo[i] = (inUse: false, kind: slotEmpty)
c.clearDest(n, dest)
proc genBreak(c: PCtx; n: PNode) =
let lab1 = c.xjmp(n, opcJmp)
if n[0].kind == nkSym:
#echo cast[int](n[0].sym)
for i in countdown(c.prc.blocks.len-1, 0):
if c.prc.blocks[i].label == n[0].sym:
c.prc.blocks[i].fixups.add lab1
return
globalError(c.config, n.info, "VM problem: cannot find 'break' target")
else:
c.prc.blocks[c.prc.blocks.high].fixups.add lab1
proc genIf(c: PCtx, n: PNode; dest: var TDest) =
# if (!expr1) goto lab1;
# thenPart
# goto LEnd
# lab1:
# if (!expr2) goto lab2;
# thenPart2
# goto LEnd
# lab2:
# elsePart
# Lend:
if dest < 0 and not isEmptyType(n.typ): dest = getTemp(c, n.typ)
var endings: seq[TPosition] = @[]
for i in 0..<n.len:
var it = n[i]
if it.len == 2:
withTemp(tmp, it[0].typ):
var elsePos: TPosition
if isNotOpr(it[0]):
c.gen(it[0][1], tmp)
elsePos = c.xjmp(it[0][1], opcTJmp, tmp) # if true
else:
c.gen(it[0], tmp)
elsePos = c.xjmp(it[0], opcFJmp, tmp) # if false
c.clearDest(n, dest)
c.gen(it[1], dest) # then part
if i < n.len-1:
endings.add(c.xjmp(it[1], opcJmp, 0))
c.patch(elsePos)
else:
c.clearDest(n, dest)
c.gen(it[0], dest)
for endPos in endings: c.patch(endPos)
c.clearDest(n, dest)
proc isTemp(c: PCtx; dest: TDest): bool =
result = dest >= 0 and c.prc.regInfo[dest].kind >= slotTempUnknown
proc genAndOr(c: PCtx; n: PNode; opc: TOpcode; dest: var TDest) =
# asgn dest, a
# tjmp|fjmp lab1
# asgn dest, b
# lab1:
let copyBack = dest < 0 or not isTemp(c, dest)
let tmp = if copyBack:
getTemp(c, n.typ)
else:
TRegister dest
c.gen(n[1], tmp)
let lab1 = c.xjmp(n, opc, tmp)
c.gen(n[2], tmp)
c.patch(lab1)
if dest < 0:
dest = tmp
elif copyBack:
c.gABC(n, opcAsgnInt, dest, tmp)
freeTemp(c, tmp)
proc canonValue*(n: PNode): PNode =
result = n
proc rawGenLiteral(c: PCtx; n: PNode): int =
result = c.constants.len
#assert(n.kind != nkCall)
n.flags.incl nfAllConst
c.constants.add n.canonValue
internalAssert c.config, result < regBxMax
proc sameConstant*(a, b: PNode): bool =
result = false
if a == b:
result = true
elif a != nil and b != nil and a.kind == b.kind:
case a.kind
of nkSym: result = a.sym == b.sym
of nkIdent: result = a.ident.id == b.ident.id
of nkCharLit..nkUInt64Lit: result = a.intVal == b.intVal
of nkFloatLit..nkFloat64Lit:
result = cast[uint64](a.floatVal) == cast[uint64](b.floatVal)
# refs bug #16469
# if we wanted to only distinguish 0.0 vs -0.0:
# if a.floatVal == 0.0: result = cast[uint64](a.floatVal) == cast[uint64](b.floatVal)
# else: result = a.floatVal == b.floatVal
of nkStrLit..nkTripleStrLit: result = a.strVal == b.strVal
of nkType, nkNilLit: result = a.typ == b.typ
of nkEmpty: result = true
else:
if a.len == b.len:
for i in 0..<a.len:
if not sameConstant(a[i], b[i]): return
result = true
proc genLiteral(c: PCtx; n: PNode): int =
# types do not matter here:
for i in 0..<c.constants.len:
if sameConstant(c.constants[i], n): return i
result = rawGenLiteral(c, n)
proc unused(c: PCtx; n: PNode; x: TDest) {.inline.} =
if x >= 0:
#debug(n)
globalError(c.config, n.info, "not unused")
proc genCase(c: PCtx; n: PNode; dest: var TDest) =
# if (!expr1) goto lab1;
# thenPart
# goto LEnd
# lab1:
# if (!expr2) goto lab2;
# thenPart2
# goto LEnd
# lab2:
# elsePart
# Lend:
if not isEmptyType(n.typ):
if dest < 0: dest = getTemp(c, n.typ)
else:
unused(c, n, dest)
var endings: seq[TPosition] = @[]
withTemp(tmp, n[0].typ):
c.gen(n[0], tmp)
# branch tmp, codeIdx
# fjmp elseLabel
for i in 1..<n.len:
let it = n[i]
if it.len == 1:
# else stmt:
if it[0].kind != nkNilLit or it[0].typ != nil:
# an nkNilLit with nil for typ implies there is no else branch, this
# avoids unused related errors as we've already consumed the dest
c.gen(it[0], dest)
else:
let b = rawGenLiteral(c, it)
c.gABx(it, opcBranch, tmp, b)
let elsePos = c.xjmp(it.lastSon, opcFJmp, tmp)
c.gen(it.lastSon, dest)
if i < n.len-1:
endings.add(c.xjmp(it.lastSon, opcJmp, 0))
c.patch(elsePos)
c.clearDest(n, dest)
for endPos in endings: c.patch(endPos)
proc genType(c: PCtx; typ: PType): int =
for i, t in c.types:
if sameType(t, typ): return i
result = c.types.len
c.types.add(typ)
internalAssert(c.config, result <= regBxMax)
proc genTry(c: PCtx; n: PNode; dest: var TDest) =
if dest < 0 and not isEmptyType(n.typ): dest = getTemp(c, n.typ)
var endings: seq[TPosition] = @[]
let ehPos = c.xjmp(n, opcTry, 0)
c.gen(n[0], dest)
c.clearDest(n, dest)
# Add a jump past the exception handling code
let jumpToFinally = c.xjmp(n, opcJmp, 0)
# This signals where the body ends and where the exception handling begins
c.patch(ehPos)
for i in 1..<n.len:
let it = n[i]
if it.kind != nkFinally:
# first opcExcept contains the end label of the 'except' block:
let endExcept = c.xjmp(it, opcExcept, 0)
for j in 0..<it.len - 1:
assert(it[j].kind == nkType)
let typ = it[j].typ.skipTypes(abstractPtrs-{tyTypeDesc})
c.gABx(it, opcExcept, 0, c.genType(typ))
if it.len == 1:
# general except section:
c.gABx(it, opcExcept, 0, 0)
c.gen(it.lastSon, dest)
c.clearDest(n, dest)
if i < n.len:
endings.add(c.xjmp(it, opcJmp, 0))
c.patch(endExcept)
let fin = lastSon(n)
# we always generate an 'opcFinally' as that pops the safepoint
# from the stack if no exception is raised in the body.
c.patch(jumpToFinally)
c.gABx(fin, opcFinally, 0, 0)
for endPos in endings: c.patch(endPos)
if fin.kind == nkFinally:
c.gen(fin[0])
c.clearDest(n, dest)
c.gABx(fin, opcFinallyEnd, 0, 0)
proc genRaise(c: PCtx; n: PNode) =
let dest = genx(c, n[0])
c.gABC(n, opcRaise, dest)
c.freeTemp(dest)
proc genReturn(c: PCtx; n: PNode) =
if n[0].kind != nkEmpty:
gen(c, n[0])
c.gABC(n, opcRet)
proc genLit(c: PCtx; n: PNode; dest: var TDest) =
# opcLdConst is now always valid. We produce the necessary copy in the
# assignments now:
#var opc = opcLdConst
if dest < 0: dest = c.getTemp(n.typ)
#elif c.prc.regInfo[dest].kind == slotFixedVar: opc = opcAsgnConst
let lit = genLiteral(c, n)
c.gABx(n, opcLdConst, dest, lit)
proc genCall(c: PCtx; n: PNode; dest: var TDest) =
# it can happen that due to inlining we have a 'n' that should be
# treated as a constant (see issue #537).
#if n.typ != nil and n.typ.sym != nil and n.typ.sym.magic == mPNimrodNode:
# genLit(c, n, dest)
# return
# bug #10901: do not produce code for wrong call expressions:
if n.len == 0 or n[0].typ.isNil: return
if dest < 0 and not isEmptyType(n.typ): dest = getTemp(c, n.typ)
let x = c.getTempRange(n.len, slotTempUnknown)
# varargs need 'opcSetType' for the FFI support:
let fntyp = skipTypes(n[0].typ, abstractInst)
for i in 0..<n.len:
var r: TRegister = x+i
c.gen(n[i], r, {gfIsParam})
if i >= fntyp.len:
internalAssert c.config, tfVarargs in fntyp.flags
c.gABx(n, opcSetType, r, c.genType(n[i].typ))
if dest < 0:
c.gABC(n, opcIndCall, 0, x, n.len)
else:
c.gABC(n, opcIndCallAsgn, dest, x, n.len)
c.freeTempRange(x, n.len)
template isGlobal(s: PSym): bool = sfGlobal in s.flags and s.kind != skForVar
proc isGlobal(n: PNode): bool = n.kind == nkSym and isGlobal(n.sym)
proc needsAsgnPatch(n: PNode): bool =
n.kind in {nkBracketExpr, nkDotExpr, nkCheckedFieldExpr,
nkDerefExpr, nkHiddenDeref} or (n.kind == nkSym and n.sym.isGlobal)
proc genField(c: PCtx; n: PNode): TRegister =
if n.kind != nkSym or n.sym.kind != skField:
globalError(c.config, n.info, "no field symbol")
let s = n.sym
if s.position > high(typeof(result)):
globalError(c.config, n.info,
"too large offset! cannot generate code for: " & s.name.s)
result = s.position
proc genIndex(c: PCtx; n: PNode; arr: PType): TRegister =
if arr.skipTypes(abstractInst).kind == tyArray and (let x = firstOrd(c.config, arr);
x != Zero):
let tmp = c.genx(n)
# freeing the temporary here means we can produce: regA = regA - Imm
c.freeTemp(tmp)
result = c.getTemp(n.typ)
c.gABI(n, opcSubImmInt, result, tmp, toInt(x))
else:
result = c.genx(n)
proc genCheckedObjAccessAux(c: PCtx; n: PNode; dest: var TDest; flags: TGenFlags)
proc genAsgnPatch(c: PCtx; le: PNode, value: TRegister) =
case le.kind
of nkBracketExpr:
let dest = c.genx(le[0], {gfNode})
let idx = c.genIndex(le[1], le[0].typ)
c.gABC(le, opcWrArr, dest, idx, value)
c.freeTemp(dest)
c.freeTemp(idx)
of nkCheckedFieldExpr:
var objR: TDest = -1
genCheckedObjAccessAux(c, le, objR, {gfNode})
let idx = genField(c, le[0][1])
c.gABC(le[0], opcWrObj, objR, idx, value)
c.freeTemp(objR)
of nkDotExpr:
let dest = c.genx(le[0], {gfNode})
let idx = genField(c, le[1])
c.gABC(le, opcWrObj, dest, idx, value)
c.freeTemp(dest)
of nkDerefExpr, nkHiddenDeref:
let dest = c.genx(le[0], {gfNode})
c.gABC(le, opcWrDeref, dest, 0, value)
c.freeTemp(dest)
of nkSym:
if le.sym.isGlobal:
let dest = c.genx(le, {gfNodeAddr})
c.gABC(le, opcWrDeref, dest, 0, value)
c.freeTemp(dest)
else:
discard
proc genNew(c: PCtx; n: PNode) =
let dest = if needsAsgnPatch(n[1]): c.getTemp(n[1].typ)
else: c.genx(n[1])
# we use the ref's base type here as the VM conflates 'ref object'
# and 'object' since internally we already have a pointer.
c.gABx(n, opcNew, dest,
c.genType(n[1].typ.skipTypes(abstractVar-{tyTypeDesc})[0]))
c.genAsgnPatch(n[1], dest)
c.freeTemp(dest)
proc genNewSeq(c: PCtx; n: PNode) =
let t = n[1].typ
let dest = if needsAsgnPatch(n[1]): c.getTemp(t)
else: c.genx(n[1])
let tmp = c.genx(n[2])
c.gABx(n, opcNewSeq, dest, c.genType(t.skipTypes(
abstractVar-{tyTypeDesc})))
c.gABx(n, opcNewSeq, tmp, 0)
c.freeTemp(tmp)
c.genAsgnPatch(n[1], dest)
c.freeTemp(dest)
proc genNewSeqOfCap(c: PCtx; n: PNode; dest: var TDest) =
let t = n.typ
if dest < 0:
dest = c.getTemp(n.typ)
let tmp = c.getTemp(n[1].typ)
c.gABx(n, opcLdNull, dest, c.genType(t))
c.gABx(n, opcLdImmInt, tmp, 0)
c.gABx(n, opcNewSeq, dest, c.genType(t.skipTypes(
abstractVar-{tyTypeDesc})))
c.gABx(n, opcNewSeq, tmp, 0)
c.freeTemp(tmp)
proc genUnaryABC(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode) =
let tmp = c.genx(n[1])
if dest < 0: dest = c.getTemp(n.typ)
c.gABC(n, opc, dest, tmp)
c.freeTemp(tmp)
proc genUnaryABI(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode; imm: BiggestInt=0) =
let tmp = c.genx(n[1])
if dest < 0: dest = c.getTemp(n.typ)
c.gABI(n, opc, dest, tmp, imm)
c.freeTemp(tmp)
proc genBinaryABC(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode) =
let
tmp = c.genx(n[1])
tmp2 = c.genx(n[2])
if dest < 0: dest = c.getTemp(n.typ)
c.gABC(n, opc, dest, tmp, tmp2)
c.freeTemp(tmp)
c.freeTemp(tmp2)
proc genBinaryABCD(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode) =
let
tmp = c.genx(n[1])
tmp2 = c.genx(n[2])
tmp3 = c.genx(n[3])
if dest < 0: dest = c.getTemp(n.typ)
c.gABC(n, opc, dest, tmp, tmp2)
c.gABC(n, opc, tmp3)
c.freeTemp(tmp)
c.freeTemp(tmp2)
c.freeTemp(tmp3)
template sizeOfLikeMsg(name): string =
"'$1' requires '.importc' types to be '.completeStruct'" % [name]
proc genNarrow(c: PCtx; n: PNode; dest: TDest) =
let t = skipTypes(n.typ, abstractVar-{tyTypeDesc})
# uint is uint64 in the VM, we we only need to mask the result for
# other unsigned types:
if t.kind in {tyUInt8..tyUInt32} or (t.kind == tyUInt and t.size < 8):
c.gABC(n, opcNarrowU, dest, TRegister(t.size*8))
elif t.kind in {tyInt8..tyInt32} or (t.kind == tyInt and t.size < 8):
c.gABC(n, opcNarrowS, dest, TRegister(t.size*8))
proc genNarrowU(c: PCtx; n: PNode; dest: TDest) =
let t = skipTypes(n.typ, abstractVar-{tyTypeDesc})
# uint is uint64 in the VM, we we only need to mask the result for
# other unsigned types:
if t.kind in {tyUInt8..tyUInt32, tyInt8..tyInt32} or
(t.kind in {tyUInt, tyInt} and t.size < 8):
c.gABC(n, opcNarrowU, dest, TRegister(t.size*8))
proc genBinaryABCnarrow(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode) =
genBinaryABC(c, n, dest, opc)
genNarrow(c, n, dest)
proc genBinaryABCnarrowU(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode) =
genBinaryABC(c, n, dest, opc)
genNarrowU(c, n, dest)
proc genSetType(c: PCtx; n: PNode; dest: TRegister) =
let t = skipTypes(n.typ, abstractInst-{tyTypeDesc})
if t.kind == tySet:
c.gABx(n, opcSetType, dest, c.genType(t))
proc genBinarySet(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode) =
let
tmp = c.genx(n[1])
tmp2 = c.genx(n[2])
if dest < 0: dest = c.getTemp(n.typ)
c.genSetType(n[1], tmp)
c.genSetType(n[2], tmp2)
c.gABC(n, opc, dest, tmp, tmp2)
c.freeTemp(tmp)
c.freeTemp(tmp2)
proc genBinaryStmt(c: PCtx; n: PNode; opc: TOpcode) =
let
dest = c.genx(n[1])
tmp = c.genx(n[2])
c.gABC(n, opc, dest, tmp, 0)
c.freeTemp(tmp)
c.freeTemp(dest)
proc genBinaryStmtVar(c: PCtx; n: PNode; opc: TOpcode) =
var x = n[1]
if x.kind in {nkAddr, nkHiddenAddr}: x = x[0]
let
dest = c.genx(x)
tmp = c.genx(n[2])
c.gABC(n, opc, dest, tmp, 0)
#c.genAsgnPatch(n[1], dest)
c.freeTemp(tmp)
c.freeTemp(dest)
proc genUnaryStmt(c: PCtx; n: PNode; opc: TOpcode) =
let tmp = c.genx(n[1])
c.gABC(n, opc, tmp, 0, 0)
c.freeTemp(tmp)
proc genVarargsABC(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode) =
if dest < 0: dest = getTemp(c, n.typ)
var x = c.getTempRange(n.len-1, slotTempStr)
for i in 1..<n.len:
var r: TRegister = x+i-1
c.gen(n[i], r)
c.gABC(n, opc, dest, x, n.len-1)
c.freeTempRange(x, n.len-1)
proc isInt8Lit(n: PNode): bool =
if n.kind in {nkCharLit..nkUInt64Lit}:
result = n.intVal >= low(int8) and n.intVal <= high(int8)
proc isInt16Lit(n: PNode): bool =
if n.kind in {nkCharLit..nkUInt64Lit}:
result = n.intVal >= low(int16) and n.intVal <= high(int16)
proc genAddSubInt(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode) =
if n[2].isInt8Lit:
let tmp = c.genx(n[1])
if dest < 0: dest = c.getTemp(n.typ)
c.gABI(n, succ(opc), dest, tmp, n[2].intVal)
c.freeTemp(tmp)
else:
genBinaryABC(c, n, dest, opc)
c.genNarrow(n, dest)
proc genConv(c: PCtx; n, arg: PNode; dest: var TDest; opc=opcConv) =
let t2 = n.typ.skipTypes({tyDistinct})
let targ2 = arg.typ.skipTypes({tyDistinct})
proc implicitConv(): bool =
if sameType(t2, targ2): return true
# xxx consider whether to use t2 and targ2 here
if n.typ.kind == arg.typ.kind and arg.typ.kind == tyProc:
# don't do anything for lambda lifting conversions:
return true
if implicitConv():
gen(c, arg, dest)
return
let tmp = c.genx(arg)
if dest < 0: dest = c.getTemp(n.typ)
c.gABC(n, opc, dest, tmp)
c.gABx(n, opc, 0, genType(c, n.typ.skipTypes({tyStatic})))
c.gABx(n, opc, 0, genType(c, arg.typ.skipTypes({tyStatic})))
c.freeTemp(tmp)
proc genCard(c: PCtx; n: PNode; dest: var TDest) =
let tmp = c.genx(n[1])
if dest < 0: dest = c.getTemp(n.typ)
c.genSetType(n[1], tmp)
c.gABC(n, opcCard, dest, tmp)
c.freeTemp(tmp)
proc genCastIntFloat(c: PCtx; n: PNode; dest: var TDest) =
const allowedIntegers = {tyInt..tyInt64, tyUInt..tyUInt64, tyChar}
var signedIntegers = {tyInt..tyInt64}
var unsignedIntegers = {tyUInt..tyUInt64, tyChar}
let src = n[1].typ.skipTypes(abstractRange)#.kind
let dst = n[0].typ.skipTypes(abstractRange)#.kind
let srcSize = getSize(c.config, src)
let dstSize = getSize(c.config, dst)
if src.kind in allowedIntegers and dst.kind in allowedIntegers:
let tmp = c.genx(n[1])
if dest < 0: dest = c.getTemp(n[0].typ)
c.gABC(n, opcAsgnInt, dest, tmp)
if dstSize != sizeof(BiggestInt): # don't do anything on biggest int types
if dst.kind in signedIntegers: # we need to do sign extensions
if dstSize <= srcSize:
# Sign extension can be omitted when the size increases.
c.gABC(n, opcSignExtend, dest, TRegister(dstSize*8))
elif dst.kind in unsignedIntegers:
if src.kind in signedIntegers or dstSize < srcSize:
# Cast from signed to unsigned always needs narrowing. Cast
# from unsigned to unsigned only needs narrowing when target
# is smaller than source.
c.gABC(n, opcNarrowU, dest, TRegister(dstSize*8))
c.freeTemp(tmp)
elif srcSize == dstSize and src.kind in allowedIntegers and
dst.kind in {tyFloat, tyFloat32, tyFloat64}:
let tmp = c.genx(n[1])
if dest < 0: dest = c.getTemp(n[0].typ)
if dst.kind == tyFloat32:
c.gABC(n, opcCastIntToFloat32, dest, tmp)
else:
c.gABC(n, opcCastIntToFloat64, dest, tmp)
c.freeTemp(tmp)
elif srcSize == dstSize and src.kind in {tyFloat, tyFloat32, tyFloat64} and
dst.kind in allowedIntegers:
let tmp = c.genx(n[1])
if dest < 0: dest = c.getTemp(n[0].typ)
if src.kind == tyFloat32:
c.gABC(n, opcCastFloatToInt32, dest, tmp)
if dst.kind in unsignedIntegers:
# integers are sign extended by default.
# since there is no opcCastFloatToUInt32, narrowing should do the trick.
c.gABC(n, opcNarrowU, dest, TRegister(32))
else:
c.gABC(n, opcCastFloatToInt64, dest, tmp)
# narrowing for 64 bits not needed (no extended sign bits available).
c.freeTemp(tmp)
elif src.kind in PtrLikeKinds + {tyRef} and dst.kind == tyInt:
let tmp = c.genx(n[1])
if dest < 0: dest = c.getTemp(n[0].typ)
var imm: BiggestInt = if src.kind in PtrLikeKinds: 1 else: 2
c.gABI(n, opcCastPtrToInt, dest, tmp, imm)
c.freeTemp(tmp)
elif src.kind in PtrLikeKinds + {tyInt} and dst.kind in PtrLikeKinds:
let tmp = c.genx(n[1])
if dest < 0: dest = c.getTemp(n[0].typ)
c.gABx(n, opcSetType, dest, c.genType(dst))
c.gABC(n, opcCastIntToPtr, dest, tmp)
c.freeTemp(tmp)
elif src.kind == tyNil and dst.kind in NilableTypes:
# supports casting nil literals to NilableTypes in VM
# see #16024
if dest < 0: dest = c.getTemp(n[0].typ)
genLit(c, n[1], dest)
else:
# todo: support cast from tyInt to tyRef
globalError(c.config, n.info, "VM does not support 'cast' from " & $src.kind & " to " & $dst.kind)
proc genVoidABC(c: PCtx, n: PNode, dest: TDest, opcode: TOpcode) =
unused(c, n, dest)
var
tmp1 = c.genx(n[1])
tmp2 = c.genx(n[2])
tmp3 = c.genx(n[3])
c.gABC(n, opcode, tmp1, tmp2, tmp3)
c.freeTemp(tmp1)
c.freeTemp(tmp2)
c.freeTemp(tmp3)
proc genBindSym(c: PCtx; n: PNode; dest: var TDest) =
# nah, cannot use c.config.features because sempass context
# can have local experimental switch
# if dynamicBindSym notin c.config.features:
if n.len == 2: # hmm, reliable?
# bindSym with static input
if n[1].kind in {nkClosedSymChoice, nkOpenSymChoice, nkSym}:
let idx = c.genLiteral(n[1])
if dest < 0: dest = c.getTemp(n.typ)
c.gABx(n, opcNBindSym, dest, idx)
else:
localError(c.config, n.info, "invalid bindSym usage")
else:
# experimental bindSym
if dest < 0: dest = c.getTemp(n.typ)
let x = c.getTempRange(n.len, slotTempUnknown)
# callee symbol
var tmp0 = TDest(x)
c.genLit(n[0], tmp0)
# original parameters
for i in 1..<n.len-2:
var r = TRegister(x+i)
c.gen(n[i], r)
# info node
var tmp1 = TDest(x+n.len-2)
c.genLit(n[^2], tmp1)
# payload idx
var tmp2 = TDest(x+n.len-1)
c.genLit(n[^1], tmp2)
c.gABC(n, opcNDynBindSym, dest, x, n.len)
c.freeTempRange(x, n.len)
proc fitsRegister*(t: PType): bool =
assert t != nil
t.skipTypes(abstractInst + {tyStatic} - {tyTypeDesc}).kind in {
tyRange, tyEnum, tyBool, tyInt..tyUInt64, tyChar}
proc ldNullOpcode(t: PType): TOpcode =
assert t != nil
if fitsRegister(t): opcLdNullReg else: opcLdNull
proc whichAsgnOpc(n: PNode; requiresCopy = true): TOpcode =
case n.typ.skipTypes(abstractRange+{tyOwned}-{tyTypeDesc}).kind
of tyBool, tyChar, tyEnum, tyOrdinal, tyInt..tyInt64, tyUInt..tyUInt64:
opcAsgnInt
of tyFloat..tyFloat128:
opcAsgnFloat
of tyRef, tyNil, tyVar, tyLent, tyPtr:
opcAsgnRef
else:
(if requiresCopy: opcAsgnComplex else: opcFastAsgnComplex)
proc genMagic(c: PCtx; n: PNode; dest: var TDest; m: TMagic) =
case m
of mAnd: c.genAndOr(n, opcFJmp, dest)
of mOr: c.genAndOr(n, opcTJmp, dest)
of mPred, mSubI:
c.genAddSubInt(n, dest, opcSubInt)
of mSucc, mAddI:
c.genAddSubInt(n, dest, opcAddInt)
of mInc, mDec:
unused(c, n, dest)
let isUnsigned = n[1].typ.skipTypes(abstractVarRange).kind in {tyUInt..tyUInt64}
let opc = if not isUnsigned:
if m == mInc: opcAddInt else: opcSubInt
else:
if m == mInc: opcAddu else: opcSubu
let d = c.genx(n[1])
if n[2].isInt8Lit and not isUnsigned:
c.gABI(n, succ(opc), d, d, n[2].intVal)
else:
let tmp = c.genx(n[2])
c.gABC(n, opc, d, d, tmp)
c.freeTemp(tmp)
c.genNarrow(n[1], d)
c.genAsgnPatch(n[1], d)
c.freeTemp(d)
of mOrd, mChr, mArrToSeq, mUnown: c.gen(n[1], dest)
of mIsolate:
genCall(c, n, dest)
of mNew, mNewFinalize:
unused(c, n, dest)
c.genNew(n)
of mNewSeq:
unused(c, n, dest)
c.genNewSeq(n)
of mNewSeqOfCap: c.genNewSeqOfCap(n, dest)
of mNewString:
genUnaryABC(c, n, dest, opcNewStr)
# XXX buggy
of mNewStringOfCap:
# we ignore the 'cap' argument and translate it as 'newString(0)'.
# eval n[1] for possible side effects:
c.freeTemp(c.genx(n[1]))
var tmp = c.getTemp(n[1].typ)
c.gABx(n, opcLdImmInt, tmp, 0)
if dest < 0: dest = c.getTemp(n.typ)
c.gABC(n, opcNewStr, dest, tmp)
c.freeTemp(tmp)
# XXX buggy
of mLengthOpenArray, mLengthArray, mLengthSeq:
genUnaryABI(c, n, dest, opcLenSeq)
of mLengthStr:
case n[1].typ.kind
of tyString: genUnaryABI(c, n, dest, opcLenStr)
of tyCstring: genUnaryABI(c, n, dest, opcLenCstring)
else: doAssert false, $n[1].typ.kind
of mIncl, mExcl:
unused(c, n, dest)
var d = c.genx(n[1])
var tmp = c.genx(n[2])
c.genSetType(n[1], d)
c.gABC(n, if m == mIncl: opcIncl else: opcExcl, d, tmp)
c.freeTemp(d)
c.freeTemp(tmp)
of mCard: genCard(c, n, dest)
of mMulI: genBinaryABCnarrow(c, n, dest, opcMulInt)
of mDivI: genBinaryABCnarrow(c, n, dest, opcDivInt)
of mModI: genBinaryABCnarrow(c, n, dest, opcModInt)
of mAddF64: genBinaryABC(c, n, dest, opcAddFloat)
of mSubF64: genBinaryABC(c, n, dest, opcSubFloat)
of mMulF64: genBinaryABC(c, n, dest, opcMulFloat)
of mDivF64: genBinaryABC(c, n, dest, opcDivFloat)
of mShrI:
# modified: genBinaryABC(c, n, dest, opcShrInt)
# narrowU is applied to the left operandthe idea here is to narrow the left operand
let tmp = c.genx(n[1])
c.genNarrowU(n, tmp)
let tmp2 = c.genx(n[2])
if dest < 0: dest = c.getTemp(n.typ)
c.gABC(n, opcShrInt, dest, tmp, tmp2)
c.freeTemp(tmp)
c.freeTemp(tmp2)
of mShlI:
genBinaryABC(c, n, dest, opcShlInt)
# genNarrowU modified
let t = skipTypes(n.typ, abstractVar-{tyTypeDesc})
if t.kind in {tyUInt8..tyUInt32} or (t.kind == tyUInt and t.size < 8):
c.gABC(n, opcNarrowU, dest, TRegister(t.size*8))
elif t.kind in {tyInt8..tyInt32} or (t.kind == tyInt and t.size < 8):
c.gABC(n, opcSignExtend, dest, TRegister(t.size*8))
of mAshrI: genBinaryABC(c, n, dest, opcAshrInt)
of mBitandI: genBinaryABC(c, n, dest, opcBitandInt)
of mBitorI: genBinaryABC(c, n, dest, opcBitorInt)
of mBitxorI: genBinaryABC(c, n, dest, opcBitxorInt)
of mAddU: genBinaryABCnarrowU(c, n, dest, opcAddu)
of mSubU: genBinaryABCnarrowU(c, n, dest, opcSubu)
of mMulU: genBinaryABCnarrowU(c, n, dest, opcMulu)
of mDivU: genBinaryABCnarrowU(c, n, dest, opcDivu)
of mModU: genBinaryABCnarrowU(c, n, dest, opcModu)
of mEqI, mEqB, mEqEnum, mEqCh:
genBinaryABC(c, n, dest, opcEqInt)
of mLeI, mLeEnum, mLeCh, mLeB:
genBinaryABC(c, n, dest, opcLeInt)
of mLtI, mLtEnum, mLtCh, mLtB:
genBinaryABC(c, n, dest, opcLtInt)
of mEqF64: genBinaryABC(c, n, dest, opcEqFloat)
of mLeF64: genBinaryABC(c, n, dest, opcLeFloat)
of mLtF64: genBinaryABC(c, n, dest, opcLtFloat)
of mLePtr, mLeU: genBinaryABC(c, n, dest, opcLeu)
of mLtPtr, mLtU: genBinaryABC(c, n, dest, opcLtu)
of mEqProc, mEqRef:
genBinaryABC(c, n, dest, opcEqRef)
of mXor: genBinaryABC(c, n, dest, opcXor)
of mNot: genUnaryABC(c, n, dest, opcNot)
of mUnaryMinusI, mUnaryMinusI64:
genUnaryABC(c, n, dest, opcUnaryMinusInt)
genNarrow(c, n, dest)
of mUnaryMinusF64: genUnaryABC(c, n, dest, opcUnaryMinusFloat)
of mUnaryPlusI, mUnaryPlusF64: gen(c, n[1], dest)
of mBitnotI:
genUnaryABC(c, n, dest, opcBitnotInt)
#genNarrowU modified, do not narrow signed types
let t = skipTypes(n.typ, abstractVar-{tyTypeDesc})
if t.kind in {tyUInt8..tyUInt32} or (t.kind == tyUInt and t.size < 8):
c.gABC(n, opcNarrowU, dest, TRegister(t.size*8))
of mCharToStr, mBoolToStr, mIntToStr, mInt64ToStr, mCStrToStr, mStrToStr, mEnumToStr:
genConv(c, n, n[1], dest)
of mEqStr, mEqCString: genBinaryABC(c, n, dest, opcEqStr)
of mLeStr: genBinaryABC(c, n, dest, opcLeStr)
of mLtStr: genBinaryABC(c, n, dest, opcLtStr)
of mEqSet: genBinarySet(c, n, dest, opcEqSet)
of mLeSet: genBinarySet(c, n, dest, opcLeSet)
of mLtSet: genBinarySet(c, n, dest, opcLtSet)
of mMulSet: genBinarySet(c, n, dest, opcMulSet)
of mPlusSet: genBinarySet(c, n, dest, opcPlusSet)
of mMinusSet: genBinarySet(c, n, dest, opcMinusSet)
of mConStrStr: genVarargsABC(c, n, dest, opcConcatStr)
of mInSet: genBinarySet(c, n, dest, opcContainsSet)
of mRepr: genUnaryABC(c, n, dest, opcRepr)
of mExit:
unused(c, n, dest)
var tmp = c.genx(n[1])
c.gABC(n, opcQuit, tmp)
c.freeTemp(tmp)
of mSetLengthStr, mSetLengthSeq:
unused(c, n, dest)
var d = c.genx(n[1])
var tmp = c.genx(n[2])
c.gABC(n, if m == mSetLengthStr: opcSetLenStr else: opcSetLenSeq, d, tmp)
c.genAsgnPatch(n[1], d)
c.freeTemp(tmp)
c.freeTemp(d)
of mSwap:
unused(c, n, dest)
c.gen(lowerSwap(c.graph, n, c.idgen, if c.prc == nil or c.prc.sym == nil: c.module else: c.prc.sym))
of mIsNil: genUnaryABC(c, n, dest, opcIsNil)
of mParseBiggestFloat:
if dest < 0: dest = c.getTemp(n.typ)
var d2: TRegister
# skip 'nkHiddenAddr':
let d2AsNode = n[2][0]
if needsAsgnPatch(d2AsNode):
d2 = c.getTemp(getSysType(c.graph, n.info, tyFloat))
else:
d2 = c.genx(d2AsNode)
var
tmp1 = c.genx(n[1])
tmp3 = c.genx(n[3])
c.gABC(n, opcParseFloat, dest, tmp1, d2)
c.gABC(n, opcParseFloat, tmp3)
c.freeTemp(tmp1)
c.freeTemp(tmp3)
c.genAsgnPatch(d2AsNode, d2)
c.freeTemp(d2)
of mReset:
unused(c, n, dest)
var d = c.genx(n[1])
# XXX use ldNullOpcode() here?
c.gABx(n, opcLdNull, d, c.genType(n[1].typ))
c.gABx(n, opcNodeToReg, d, d)
c.genAsgnPatch(n[1], d)
of mDefault:
if dest < 0: dest = c.getTemp(n.typ)
c.gABx(n, ldNullOpcode(n.typ), dest, c.genType(n.typ))
of mOf, mIs:
if dest < 0: dest = c.getTemp(n.typ)
var tmp = c.genx(n[1])
var idx = c.getTemp(getSysType(c.graph, n.info, tyInt))
var typ = n[2].typ
if m == mOf: typ = typ.skipTypes(abstractPtrs)
c.gABx(n, opcLdImmInt, idx, c.genType(typ))
c.gABC(n, if m == mOf: opcOf else: opcIs, dest, tmp, idx)
c.freeTemp(tmp)
c.freeTemp(idx)
of mHigh:
if dest < 0: dest = c.getTemp(n.typ)
let tmp = c.genx(n[1])
case n[1].typ.skipTypes(abstractVar-{tyTypeDesc}).kind:
of tyString: c.gABI(n, opcLenStr, dest, tmp, 1)
of tyCstring: c.gABI(n, opcLenCstring, dest, tmp, 1)
else: c.gABI(n, opcLenSeq, dest, tmp, 1)
c.freeTemp(tmp)
of mEcho:
unused(c, n, dest)
let n = n[1].skipConv
if n.kind == nkBracket:
# can happen for nim check, see bug #9609
let x = c.getTempRange(n.len, slotTempUnknown)
for i in 0..<n.len:
var r: TRegister = x+i
c.gen(n[i], r)
c.gABC(n, opcEcho, x, n.len)
c.freeTempRange(x, n.len)
of mAppendStrCh:
unused(c, n, dest)
genBinaryStmtVar(c, n, opcAddStrCh)
of mAppendStrStr:
unused(c, n, dest)
genBinaryStmtVar(c, n, opcAddStrStr)
of mAppendSeqElem:
unused(c, n, dest)
genBinaryStmtVar(c, n, opcAddSeqElem)
of mParseExprToAst:
genUnaryABC(c, n, dest, opcParseExprToAst)
of mParseStmtToAst:
genUnaryABC(c, n, dest, opcParseStmtToAst)
of mTypeTrait:
let tmp = c.genx(n[1])
if dest < 0: dest = c.getTemp(n.typ)
c.gABx(n, opcSetType, tmp, c.genType(n[1].typ))
c.gABC(n, opcTypeTrait, dest, tmp)
c.freeTemp(tmp)
of mSlurp: genUnaryABC(c, n, dest, opcSlurp)
of mStaticExec: genBinaryABCD(c, n, dest, opcGorge)
of mNLen: genUnaryABI(c, n, dest, opcLenSeq, nimNodeFlag)
of mGetImpl: genUnaryABC(c, n, dest, opcGetImpl)
of mGetImplTransf: genUnaryABC(c, n, dest, opcGetImplTransf)
of mSymOwner: genUnaryABC(c, n, dest, opcSymOwner)
of mSymIsInstantiationOf: genBinaryABC(c, n, dest, opcSymIsInstantiationOf)
of mNChild: genBinaryABC(c, n, dest, opcNChild)
of mNSetChild: genVoidABC(c, n, dest, opcNSetChild)
of mNDel: genVoidABC(c, n, dest, opcNDel)
of mNAdd: genBinaryABC(c, n, dest, opcNAdd)
of mNAddMultiple: genBinaryABC(c, n, dest, opcNAddMultiple)
of mNKind: genUnaryABC(c, n, dest, opcNKind)
of mNSymKind: genUnaryABC(c, n, dest, opcNSymKind)
of mNccValue: genUnaryABC(c, n, dest, opcNccValue)
of mNccInc: genBinaryABC(c, n, dest, opcNccInc)
of mNcsAdd: genBinaryABC(c, n, dest, opcNcsAdd)
of mNcsIncl: genBinaryABC(c, n, dest, opcNcsIncl)
of mNcsLen: genUnaryABC(c, n, dest, opcNcsLen)
of mNcsAt: genBinaryABC(c, n, dest, opcNcsAt)
of mNctPut: genVoidABC(c, n, dest, opcNctPut)
of mNctLen: genUnaryABC(c, n, dest, opcNctLen)
of mNctGet: genBinaryABC(c, n, dest, opcNctGet)
of mNctHasNext: genBinaryABC(c, n, dest, opcNctHasNext)
of mNctNext: genBinaryABC(c, n, dest, opcNctNext)
of mNIntVal: genUnaryABC(c, n, dest, opcNIntVal)
of mNFloatVal: genUnaryABC(c, n, dest, opcNFloatVal)
of mNSymbol: genUnaryABC(c, n, dest, opcNSymbol)
of mNIdent: genUnaryABC(c, n, dest, opcNIdent)
of mNGetType:
let tmp = c.genx(n[1])
if dest < 0: dest = c.getTemp(n.typ)
let rc = case n[0].sym.name.s:
of "getType": 0
of "typeKind": 1
of "getTypeInst": 2
else: 3 # "getTypeImpl"
c.gABC(n, opcNGetType, dest, tmp, rc)
c.freeTemp(tmp)
#genUnaryABC(c, n, dest, opcNGetType)
of mNSizeOf:
let imm = case n[0].sym.name.s:
of "getSize": 0
of "getAlign": 1
else: 2 # "getOffset"
c.genUnaryABI(n, dest, opcNGetSize, imm)
of mNStrVal: genUnaryABC(c, n, dest, opcNStrVal)
of mNSigHash: genUnaryABC(c, n , dest, opcNSigHash)
of mNSetIntVal:
unused(c, n, dest)
genBinaryStmt(c, n, opcNSetIntVal)
of mNSetFloatVal:
unused(c, n, dest)
genBinaryStmt(c, n, opcNSetFloatVal)
of mNSetSymbol:
unused(c, n, dest)
genBinaryStmt(c, n, opcNSetSymbol)
of mNSetIdent:
unused(c, n, dest)
genBinaryStmt(c, n, opcNSetIdent)
of mNSetType:
unused(c, n, dest)
genBinaryStmt(c, n, opcNSetType)
of mNSetStrVal:
unused(c, n, dest)
genBinaryStmt(c, n, opcNSetStrVal)
of mNNewNimNode: genBinaryABC(c, n, dest, opcNNewNimNode)
of mNCopyNimNode: genUnaryABC(c, n, dest, opcNCopyNimNode)
of mNCopyNimTree: genUnaryABC(c, n, dest, opcNCopyNimTree)
of mNBindSym: genBindSym(c, n, dest)
of mStrToIdent: genUnaryABC(c, n, dest, opcStrToIdent)
of mEqIdent: genBinaryABC(c, n, dest, opcEqIdent)
of mEqNimrodNode: genBinaryABC(c, n, dest, opcEqNimNode)
of mSameNodeType: genBinaryABC(c, n, dest, opcSameNodeType)
of mNLineInfo:
case n[0].sym.name.s
of "getFile": genUnaryABI(c, n, dest, opcNGetLineInfo, 0)
of "getLine": genUnaryABI(c, n, dest, opcNGetLineInfo, 1)
of "getColumn": genUnaryABI(c, n, dest, opcNGetLineInfo, 2)
of "copyLineInfo":
internalAssert c.config, n.len == 3
unused(c, n, dest)
genBinaryStmt(c, n, opcNSetLineInfo)
else: internalAssert c.config, false
of mNHint:
unused(c, n, dest)
genBinaryStmt(c, n, opcNHint)
of mNWarning:
unused(c, n, dest)
genBinaryStmt(c, n, opcNWarning)
of mNError:
if n.len <= 1:
# query error condition:
c.gABC(n, opcQueryErrorFlag, dest)
else:
# setter
unused(c, n, dest)
genBinaryStmt(c, n, opcNError)
of mNCallSite:
if dest < 0: dest = c.getTemp(n.typ)
c.gABC(n, opcCallSite, dest)
of mNGenSym: genBinaryABC(c, n, dest, opcGenSym)
of mMinI, mMaxI, mAbsI, mDotDot:
c.genCall(n, dest)
of mExpandToAst:
if n.len != 2:
globalError(c.config, n.info, "expandToAst requires 1 argument")
let arg = n[1]
if arg.kind in nkCallKinds:
#if arg[0].kind != nkSym or arg[0].sym.kind notin {skTemplate, skMacro}:
# "ExpandToAst: expanded symbol is no macro or template"
if dest < 0: dest = c.getTemp(n.typ)
c.genCall(arg, dest)
# do not call clearDest(n, dest) here as getAst has a meta-type as such
# produces a value
else:
globalError(c.config, n.info, "expandToAst requires a call expression")
of mSizeOf:
globalError(c.config, n.info, sizeOfLikeMsg("sizeof"))
of mAlignOf:
globalError(c.config, n.info, sizeOfLikeMsg("alignof"))
of mOffsetOf:
globalError(c.config, n.info, sizeOfLikeMsg("offsetof"))
of mRunnableExamples:
discard "just ignore any call to runnableExamples"
of mDestroy, mTrace: discard "ignore calls to the default destructor"
of mMove:
let arg = n[1]
let a = c.genx(arg)
if dest < 0: dest = c.getTemp(arg.typ)
gABC(c, arg, whichAsgnOpc(arg, requiresCopy=false), dest, a)
# XXX use ldNullOpcode() here?
# Don't zero out the arg for now #17199
# c.gABx(n, opcLdNull, a, c.genType(arg.typ))
# c.gABx(n, opcNodeToReg, a, a)
# c.genAsgnPatch(arg, a)
c.freeTemp(a)
of mNodeId:
c.genUnaryABC(n, dest, opcNodeId)
else:
# mGCref, mGCunref,
globalError(c.config, n.info, "cannot generate code for: " & $m)
proc genMarshalLoad(c: PCtx, n: PNode, dest: var TDest) =
## Signature: proc to*[T](data: string): T
if dest < 0: dest = c.getTemp(n.typ)
var tmp = c.genx(n[1])
c.gABC(n, opcMarshalLoad, dest, tmp)
c.gABx(n, opcMarshalLoad, 0, c.genType(n.typ))
c.freeTemp(tmp)
proc genMarshalStore(c: PCtx, n: PNode, dest: var TDest) =
## Signature: proc `$$`*[T](x: T): string
if dest < 0: dest = c.getTemp(n.typ)
var tmp = c.genx(n[1])
c.gABC(n, opcMarshalStore, dest, tmp)
c.gABx(n, opcMarshalStore, 0, c.genType(n[1].typ))
c.freeTemp(tmp)
proc unneededIndirection(n: PNode): bool =
n.typ.skipTypes(abstractInstOwned-{tyTypeDesc}).kind == tyRef
proc canElimAddr(n: PNode): PNode =
if n[0].typ.skipTypes(abstractInst).kind in {tyObject, tyTuple, tyArray}:
# objects are reference types in the VM
return n[0]
case n[0].kind
of nkObjUpConv, nkObjDownConv, nkChckRange, nkChckRangeF, nkChckRange64:
var m = n[0][0]
if m.kind in {nkDerefExpr, nkHiddenDeref}:
# addr ( nkConv ( deref ( x ) ) ) --> nkConv(x)
result = copyNode(n[0])
result.add m[0]
of nkHiddenStdConv, nkHiddenSubConv, nkConv:
var m = n[0][1]
if m.kind in {nkDerefExpr, nkHiddenDeref}:
# addr ( nkConv ( deref ( x ) ) ) --> nkConv(x)
result = copyNode(n[0])
result.add m[0]
else:
if n[0].kind in {nkDerefExpr, nkHiddenDeref}:
# addr ( deref ( x )) --> x
result = n[0][0]
proc genAddr(c: PCtx, n: PNode, dest: var TDest, flags: TGenFlags) =
if (let m = canElimAddr(n); m != nil):
gen(c, m, dest, flags)
return
let newflags = flags-{gfNode}+{gfNodeAddr}
if isGlobal(n[0]) or n[0].kind in {nkDotExpr, nkCheckedFieldExpr, nkBracketExpr}:
# checking for this pattern: addr(obj.field) / addr(array[i])
gen(c, n[0], dest, newflags)
else:
let tmp = c.genx(n[0], newflags)
if dest < 0: dest = c.getTemp(n.typ)
if c.prc.regInfo[tmp].kind >= slotTempUnknown:
gABC(c, n, opcAddrNode, dest, tmp)
# hack ahead; in order to fix bug #1781 we mark the temporary as
# permanent, so that it's not used for anything else:
c.prc.regInfo[tmp].kind = slotTempPerm
# XXX this is still a hack
#message(c.congig, n.info, warnUser, "suspicious opcode used")
else:
gABC(c, n, opcAddrReg, dest, tmp)
c.freeTemp(tmp)
proc genDeref(c: PCtx, n: PNode, dest: var TDest, flags: TGenFlags) =
if unneededIndirection(n[0]):
gen(c, n[0], dest, flags)
if {gfNodeAddr, gfNode} * flags == {} and fitsRegister(n.typ):
c.gABC(n, opcNodeToReg, dest, dest)
else:
let tmp = c.genx(n[0], flags)
if dest < 0: dest = c.getTemp(n.typ)
gABC(c, n, opcLdDeref, dest, tmp)
assert n.typ != nil
if {gfNodeAddr, gfNode} * flags == {} and fitsRegister(n.typ):
c.gABC(n, opcNodeToReg, dest, dest)
c.freeTemp(tmp)
proc genAsgn(c: PCtx; dest: TDest; ri: PNode; requiresCopy: bool) =
let tmp = c.genx(ri)
assert dest >= 0
gABC(c, ri, whichAsgnOpc(ri, requiresCopy), dest, tmp)
c.freeTemp(tmp)
proc setSlot(c: PCtx; v: PSym) =
# XXX generate type initialization here?
if v.position == 0:
v.position = getFreeRegister(c, if v.kind == skLet: slotFixedLet else: slotFixedVar, start = 1)
proc cannotEval(c: PCtx; n: PNode) {.noinline.} =
globalError(c.config, n.info, "cannot evaluate at compile time: " &
n.renderTree)
proc isOwnedBy(a, b: PSym): bool =
var a = a.owner
while a != nil and a.kind != skModule:
if a == b: return true
a = a.owner
proc getOwner(c: PCtx): PSym =
result = c.prc.sym
if result.isNil: result = c.module
proc importcCondVar*(s: PSym): bool {.inline.} =
# see also importcCond
if sfImportc in s.flags:
return s.kind in {skVar, skLet, skConst}
proc checkCanEval(c: PCtx; n: PNode) =
# we need to ensure that we don't evaluate 'x' here:
# proc foo() = var x ...
let s = n.sym
if {sfCompileTime, sfGlobal} <= s.flags: return
if s.importcCondVar: return
if s.kind in {skVar, skTemp, skLet, skParam, skResult} and
not s.isOwnedBy(c.prc.sym) and s.owner != c.module and c.mode != emRepl:
# little hack ahead for bug #12612: assume gensym'ed variables
# are in the right scope:
if sfGenSym in s.flags and c.prc.sym == nil: discard
else: cannotEval(c, n)
elif s.kind in {skProc, skFunc, skConverter, skMethod,
skIterator} and sfForward in s.flags:
cannotEval(c, n)
template needsAdditionalCopy(n): untyped =
not c.isTemp(dest) and not fitsRegister(n.typ)
proc genAdditionalCopy(c: PCtx; n: PNode; opc: TOpcode;
dest, idx, value: TRegister) =
var cc = c.getTemp(n.typ)
c.gABC(n, whichAsgnOpc(n), cc, value)
c.gABC(n, opc, dest, idx, cc)
c.freeTemp(cc)
proc preventFalseAlias(c: PCtx; n: PNode; opc: TOpcode;
dest, idx, value: TRegister) =
# opcLdObj et al really means "load address". We sometimes have to create a
# copy in order to not introduce false aliasing:
# mylocal = a.b # needs a copy of the data!
assert n.typ != nil
if needsAdditionalCopy(n):
genAdditionalCopy(c, n, opc, dest, idx, value)
else:
c.gABC(n, opc, dest, idx, value)
proc genAsgn(c: PCtx; le, ri: PNode; requiresCopy: bool) =
case le.kind
of nkBracketExpr:
let dest = c.genx(le[0], {gfNode})
let idx = c.genIndex(le[1], le[0].typ)
let tmp = c.genx(ri)
if le[0].typ.skipTypes(abstractVarRange-{tyTypeDesc}).kind in {
tyString, tyCstring}:
c.preventFalseAlias(le, opcWrStrIdx, dest, idx, tmp)
else:
c.preventFalseAlias(le, opcWrArr, dest, idx, tmp)
c.freeTemp(tmp)
c.freeTemp(idx)
c.freeTemp(dest)
of nkCheckedFieldExpr:
var objR: TDest = -1
genCheckedObjAccessAux(c, le, objR, {gfNode})
let idx = genField(c, le[0][1])
let tmp = c.genx(ri)
c.preventFalseAlias(le[0], opcWrObj, objR, idx, tmp)
c.freeTemp(tmp)
# c.freeTemp(idx) # BUGFIX, see nkDotExpr
c.freeTemp(objR)
of nkDotExpr:
let dest = c.genx(le[0], {gfNode})
let idx = genField(c, le[1])
let tmp = c.genx(ri)
c.preventFalseAlias(le, opcWrObj, dest, idx, tmp)
# c.freeTemp(idx) # BUGFIX: idx is an immediate (field position), not a register
c.freeTemp(tmp)
c.freeTemp(dest)
of nkDerefExpr, nkHiddenDeref:
let dest = c.genx(le[0], {gfNode})
let tmp = c.genx(ri)
c.preventFalseAlias(le, opcWrDeref, dest, 0, tmp)
c.freeTemp(dest)
c.freeTemp(tmp)
of nkSym:
let s = le.sym
checkCanEval(c, le)
if s.isGlobal:
withTemp(tmp, le.typ):
c.gen(le, tmp, {gfNodeAddr})
let val = c.genx(ri)
c.preventFalseAlias(le, opcWrDeref, tmp, 0, val)
c.freeTemp(val)
else:
if s.kind == skForVar: c.setSlot s
internalAssert c.config, s.position > 0 or (s.position == 0 and
s.kind in {skParam, skResult})
var dest: TRegister = s.position + ord(s.kind == skParam)
assert le.typ != nil
if needsAdditionalCopy(le) and s.kind in {skResult, skVar, skParam}:
var cc = c.getTemp(le.typ)
gen(c, ri, cc)
c.gABC(le, whichAsgnOpc(le), dest, cc)
c.freeTemp(cc)
else:
gen(c, ri, dest)
else:
let dest = c.genx(le, {gfNodeAddr})
genAsgn(c, dest, ri, requiresCopy)
c.freeTemp(dest)
proc genTypeLit(c: PCtx; t: PType; dest: var TDest) =
var n = newNode(nkType)
n.typ = t
genLit(c, n, dest)
proc importcCond*(c: PCtx; s: PSym): bool {.inline.} =
## return true to importc `s`, false to execute its body instead (refs #8405)
if sfImportc in s.flags:
if s.kind in routineKinds:
return getBody(c.graph, s).kind == nkEmpty
proc importcSym(c: PCtx; info: TLineInfo; s: PSym) =
when hasFFI:
if compiletimeFFI in c.config.features:
c.globals.add(importcSymbol(c.config, s))
s.position = c.globals.len
else:
localError(c.config, info,
"VM is not allowed to 'importc' without --experimental:compiletimeFFI")
else:
localError(c.config, info,
"cannot 'importc' variable at compile time; " & s.name.s)
proc getNullValue*(typ: PType, info: TLineInfo; conf: ConfigRef): PNode
proc genGlobalInit(c: PCtx; n: PNode; s: PSym) =
c.globals.add(getNullValue(s.typ, n.info, c.config))
s.position = c.globals.len
# This is rather hard to support, due to the laziness of the VM code
# generator. See tests/compile/tmacro2 for why this is necessary:
# var decls{.compileTime.}: seq[NimNode] = @[]
let dest = c.getTemp(s.typ)
c.gABx(n, opcLdGlobal, dest, s.position)
if s.astdef != nil:
let tmp = c.genx(s.astdef)
c.genAdditionalCopy(n, opcWrDeref, dest, 0, tmp)
c.freeTemp(dest)
c.freeTemp(tmp)
proc genRdVar(c: PCtx; n: PNode; dest: var TDest; flags: TGenFlags) =
# gfNodeAddr and gfNode are mutually exclusive
assert card(flags * {gfNodeAddr, gfNode}) < 2
let s = n.sym
if s.isGlobal:
let isImportcVar = importcCondVar(s)
if sfCompileTime in s.flags or c.mode == emRepl or isImportcVar:
discard
elif s.position == 0:
cannotEval(c, n)
if s.position == 0:
if importcCond(c, s) or isImportcVar: c.importcSym(n.info, s)
else: genGlobalInit(c, n, s)
if dest < 0: dest = c.getTemp(n.typ)
assert s.typ != nil
if gfNodeAddr in flags:
if isImportcVar:
c.gABx(n, opcLdGlobalAddrDerefFFI, dest, s.position)
else:
c.gABx(n, opcLdGlobalAddr, dest, s.position)
elif isImportcVar:
c.gABx(n, opcLdGlobalDerefFFI, dest, s.position)
elif fitsRegister(s.typ) and gfNode notin flags:
var cc = c.getTemp(n.typ)
c.gABx(n, opcLdGlobal, cc, s.position)
c.gABC(n, opcNodeToReg, dest, cc)
c.freeTemp(cc)
else:
c.gABx(n, opcLdGlobal, dest, s.position)
else:
if s.kind == skForVar and c.mode == emRepl: c.setSlot(s)
if s.position > 0 or (s.position == 0 and
s.kind in {skParam, skResult}):
if dest < 0:
dest = s.position + ord(s.kind == skParam)
internalAssert(c.config, c.prc.regInfo[dest].kind < slotSomeTemp)
else:
# we need to generate an assignment:
let requiresCopy = c.prc.regInfo[dest].kind >= slotSomeTemp and
gfIsParam notin flags
genAsgn(c, dest, n, requiresCopy)
else:
# see tests/t99bott for an example that triggers it:
cannotEval(c, n)
template needsRegLoad(): untyped =
{gfNode, gfNodeAddr} * flags == {} and
fitsRegister(n.typ.skipTypes({tyVar, tyLent, tyStatic}))
proc genArrAccessOpcode(c: PCtx; n: PNode; dest: var TDest; opc: TOpcode;
flags: TGenFlags) =
let a = c.genx(n[0], flags)
let b = c.genIndex(n[1], n[0].typ)
if dest < 0: dest = c.getTemp(n.typ)
if opc in {opcLdArrAddr, opcLdStrIdxAddr} and gfNodeAddr in flags:
c.gABC(n, opc, dest, a, b)
elif needsRegLoad():
var cc = c.getTemp(n.typ)
c.gABC(n, opc, cc, a, b)
c.gABC(n, opcNodeToReg, dest, cc)
c.freeTemp(cc)
else:
#message(c.config, n.info, warnUser, "argh")
#echo "FLAGS ", flags, " ", fitsRegister(n.typ), " ", typeToString(n.typ)
c.gABC(n, opc, dest, a, b)
c.freeTemp(a)
c.freeTemp(b)
proc genObjAccess(c: PCtx; n: PNode; dest: var TDest; flags: TGenFlags) =
let a = c.genx(n[0], flags)
let b = genField(c, n[1])
if dest < 0: dest = c.getTemp(n.typ)
if {gfNodeAddr} * flags != {}:
c.gABC(n, opcLdObjAddr, dest, a, b)
elif needsRegLoad():
var cc = c.getTemp(n.typ)
c.gABC(n, opcLdObj, cc, a, b)
c.gABC(n, opcNodeToReg, dest, cc)
c.freeTemp(cc)
else:
c.gABC(n, opcLdObj, dest, a, b)
c.freeTemp(a)
proc genCheckedObjAccessAux(c: PCtx; n: PNode; dest: var TDest; flags: TGenFlags) =
internalAssert c.config, n.kind == nkCheckedFieldExpr
# nkDotExpr to access the requested field
let accessExpr = n[0]
# nkCall to check if the discriminant is valid
var checkExpr = n[1]
let negCheck = checkExpr[0].sym.magic == mNot
if negCheck:
checkExpr = checkExpr[^1]
# Discriminant symbol
let disc = checkExpr[2]
internalAssert c.config, disc.sym.kind == skField
# Load the object in `dest`
c.gen(accessExpr[0], dest, flags)
# Load the discriminant
var discVal = c.getTemp(disc.typ)
c.gABC(n, opcLdObj, discVal, dest, genField(c, disc))
# Check if its value is contained in the supplied set
let setLit = c.genx(checkExpr[1])
var rs = c.getTemp(getSysType(c.graph, n.info, tyBool))
c.gABC(n, opcContainsSet, rs, setLit, discVal)
c.freeTemp(discVal)
c.freeTemp(setLit)
# If the check fails let the user know
let lab1 = c.xjmp(n, if negCheck: opcFJmp else: opcTJmp, rs)
c.freeTemp(rs)
let strType = getSysType(c.graph, n.info, tyString)
var fieldNameRegister: TDest = c.getTemp(strType)
let strLit = newStrNode($accessExpr[1], accessExpr[1].info)
strLit.typ = strType
c.genLit(strLit, fieldNameRegister)
c.gABC(n, opcInvalidField, fieldNameRegister)
c.freeTemp(fieldNameRegister)
c.patch(lab1)
proc genCheckedObjAccess(c: PCtx; n: PNode; dest: var TDest; flags: TGenFlags) =
var objR: TDest = -1
genCheckedObjAccessAux(c, n, objR, flags)
let accessExpr = n[0]
# Field symbol
var field = accessExpr[1]
internalAssert c.config, field.sym.kind == skField
# Load the content now
if dest < 0: dest = c.getTemp(n.typ)
let fieldPos = genField(c, field)
if {gfNodeAddr} * flags != {}:
c.gABC(n, opcLdObjAddr, dest, objR, fieldPos)
elif needsRegLoad():
var cc = c.getTemp(accessExpr.typ)
c.gABC(n, opcLdObj, cc, objR, fieldPos)
c.gABC(n, opcNodeToReg, dest, cc)
c.freeTemp(cc)
else:
c.gABC(n, opcLdObj, dest, objR, fieldPos)
c.freeTemp(objR)
proc genArrAccess(c: PCtx; n: PNode; dest: var TDest; flags: TGenFlags) =
let arrayType = n[0].typ.skipTypes(abstractVarRange-{tyTypeDesc}).kind
if arrayType in {tyString, tyCstring}:
let opc = if gfNodeAddr in flags: opcLdStrIdxAddr else: opcLdStrIdx
genArrAccessOpcode(c, n, dest, opc, flags)
elif arrayType == tyTypeDesc:
c.genTypeLit(n.typ, dest)
else:
let opc = if gfNodeAddr in flags: opcLdArrAddr else: opcLdArr
genArrAccessOpcode(c, n, dest, opc, flags)
proc getNullValueAux(t: PType; obj: PNode, result: PNode; conf: ConfigRef; currPosition: var int) =
if t != nil and t.len > 0 and t[0] != nil:
let b = skipTypes(t[0], skipPtrs)
getNullValueAux(b, b.n, result, conf, currPosition)
case obj.kind
of nkRecList:
for i in 0..<obj.len: getNullValueAux(nil, obj[i], result, conf, currPosition)
of nkRecCase:
getNullValueAux(nil, obj[0], result, conf, currPosition)
for i in 1..<obj.len:
getNullValueAux(nil, lastSon(obj[i]), result, conf, currPosition)
of nkSym:
let field = newNodeI(nkExprColonExpr, result.info)
field.add(obj)
field.add(getNullValue(obj.sym.typ, result.info, conf))
result.add field
doAssert obj.sym.position == currPosition
inc currPosition
else: globalError(conf, result.info, "cannot create null element for: " & $obj)
proc getNullValue(typ: PType, info: TLineInfo; conf: ConfigRef): PNode =
var t = skipTypes(typ, abstractRange+{tyStatic, tyOwned}-{tyTypeDesc})
case t.kind
of tyBool, tyEnum, tyChar, tyInt..tyInt64:
result = newNodeIT(nkIntLit, info, t)
of tyUInt..tyUInt64:
result = newNodeIT(nkUIntLit, info, t)
of tyFloat..tyFloat128:
result = newNodeIT(nkFloatLit, info, t)
of tyCstring, tyString:
result = newNodeIT(nkStrLit, info, t)
result.strVal = ""
of tyVar, tyLent, tyPointer, tyPtr, tyUntyped,
tyTyped, tyTypeDesc, tyRef, tyNil:
result = newNodeIT(nkNilLit, info, t)
of tyProc:
if t.callConv != ccClosure:
result = newNodeIT(nkNilLit, info, t)
else:
result = newNodeIT(nkTupleConstr, info, t)
result.add(newNodeIT(nkNilLit, info, t))
result.add(newNodeIT(nkNilLit, info, t))
of tyObject:
result = newNodeIT(nkObjConstr, info, t)
result.add(newNodeIT(nkEmpty, info, t))
# initialize inherited fields, and all in the correct order:
var currPosition = 0
getNullValueAux(t, t.n, result, conf, currPosition)
of tyArray:
result = newNodeIT(nkBracket, info, t)
for i in 0..<toInt(lengthOrd(conf, t)):
result.add getNullValue(elemType(t), info, conf)
of tyTuple:
result = newNodeIT(nkTupleConstr, info, t)
for i in 0..<t.len:
result.add getNullValue(t[i], info, conf)
of tySet:
result = newNodeIT(nkCurly, info, t)
of tySequence, tyOpenArray:
result = newNodeIT(nkBracket, info, t)
else:
globalError(conf, info, "cannot create null element for: " & $t.kind)
result = newNodeI(nkEmpty, info)
proc genVarSection(c: PCtx; n: PNode) =
for a in n:
if a.kind == nkCommentStmt: continue
#assert(a[0].kind == nkSym) can happen for transformed vars
if a.kind == nkVarTuple:
for i in 0..<a.len-2:
if a[i].kind == nkSym:
if not a[i].sym.isGlobal: setSlot(c, a[i].sym)
checkCanEval(c, a[i])
c.gen(lowerTupleUnpacking(c.graph, a, c.idgen, c.getOwner))
elif a[0].kind == nkSym:
let s = a[0].sym
checkCanEval(c, a[0])
if s.isGlobal:
if s.position == 0:
if importcCond(c, s): c.importcSym(a.info, s)
else:
let sa = getNullValue(s.typ, a.info, c.config)
#if s.ast.isNil: getNullValue(s.typ, a.info)
#else: canonValue(s.ast)
assert sa.kind != nkCall
c.globals.add(sa)
s.position = c.globals.len
if a[2].kind != nkEmpty:
let tmp = c.genx(a[0], {gfNodeAddr})
let val = c.genx(a[2])
c.genAdditionalCopy(a[2], opcWrDeref, tmp, 0, val)
c.freeTemp(val)
c.freeTemp(tmp)
else:
setSlot(c, s)
if a[2].kind == nkEmpty:
c.gABx(a, ldNullOpcode(s.typ), s.position, c.genType(s.typ))
else:
assert s.typ != nil
if not fitsRegister(s.typ):
c.gABx(a, ldNullOpcode(s.typ), s.position, c.genType(s.typ))
let le = a[0]
assert le.typ != nil
if not fitsRegister(le.typ) and s.kind in {skResult, skVar, skParam}:
var cc = c.getTemp(le.typ)
gen(c, a[2], cc)
c.gABC(le, whichAsgnOpc(le), s.position.TRegister, cc)
c.freeTemp(cc)
else:
gen(c, a[2], s.position.TRegister)
else:
# assign to a[0]; happens for closures
if a[2].kind == nkEmpty:
let tmp = genx(c, a[0])
c.gABx(a, ldNullOpcode(a[0].typ), tmp, c.genType(a[0].typ))
c.freeTemp(tmp)
else:
genAsgn(c, a[0], a[2], true)
proc genArrayConstr(c: PCtx, n: PNode, dest: var TDest) =
if dest < 0: dest = c.getTemp(n.typ)
c.gABx(n, opcLdNull, dest, c.genType(n.typ))
let intType = getSysType(c.graph, n.info, tyInt)
let seqType = n.typ.skipTypes(abstractVar-{tyTypeDesc})
if seqType.kind == tySequence:
var tmp = c.getTemp(intType)
c.gABx(n, opcLdImmInt, tmp, n.len)
c.gABx(n, opcNewSeq, dest, c.genType(seqType))
c.gABx(n, opcNewSeq, tmp, 0)
c.freeTemp(tmp)
if n.len > 0:
var tmp = getTemp(c, intType)
c.gABx(n, opcLdNullReg, tmp, c.genType(intType))
for x in n:
let a = c.genx(x)
c.preventFalseAlias(n, opcWrArr, dest, tmp, a)
c.gABI(n, opcAddImmInt, tmp, tmp, 1)
c.freeTemp(a)
c.freeTemp(tmp)
proc genSetConstr(c: PCtx, n: PNode, dest: var TDest) =
if dest < 0: dest = c.getTemp(n.typ)
c.gABx(n, opcLdNull, dest, c.genType(n.typ))
for x in n:
if x.kind == nkRange:
let a = c.genx(x[0])
let b = c.genx(x[1])
c.gABC(n, opcInclRange, dest, a, b)
c.freeTemp(b)
c.freeTemp(a)
else:
let a = c.genx(x)
c.gABC(n, opcIncl, dest, a)
c.freeTemp(a)
proc genObjConstr(c: PCtx, n: PNode, dest: var TDest) =
if dest < 0: dest = c.getTemp(n.typ)
let t = n.typ.skipTypes(abstractRange+{tyOwned}-{tyTypeDesc})
if t.kind == tyRef:
c.gABx(n, opcNew, dest, c.genType(t[0]))
else:
c.gABx(n, opcLdNull, dest, c.genType(n.typ))
for i in 1..<n.len:
let it = n[i]
if it.kind == nkExprColonExpr and it[0].kind == nkSym:
let idx = genField(c, it[0])
let tmp = c.genx(it[1])
c.preventFalseAlias(it[1], opcWrObj,
dest, idx, tmp)
c.freeTemp(tmp)
else:
globalError(c.config, n.info, "invalid object constructor")
proc genTupleConstr(c: PCtx, n: PNode, dest: var TDest) =
if dest < 0: dest = c.getTemp(n.typ)
if n.typ.kind != tyTypeDesc:
c.gABx(n, opcLdNull, dest, c.genType(n.typ))
# XXX x = (x.old, 22) produces wrong code ... stupid self assignments
for i in 0..<n.len:
let it = n[i]
if it.kind == nkExprColonExpr:
let idx = genField(c, it[0])
let tmp = c.genx(it[1])
c.preventFalseAlias(it[1], opcWrObj,
dest, idx, tmp)
c.freeTemp(tmp)
else:
let tmp = c.genx(it)
c.preventFalseAlias(it, opcWrObj, dest, i.TRegister, tmp)
c.freeTemp(tmp)
proc genProc*(c: PCtx; s: PSym): int
proc matches(s: PSym; x: string): bool =
let y = x.split('.')
var s = s
for i in 1..y.len:
if s == nil or (y[^i].cmpIgnoreStyle(s.name.s) != 0 and y[^i] != "*"):
return false
s = if sfFromGeneric in s.flags: s.owner.owner else: s.owner
while s != nil and s.kind == skPackage and s.owner != nil: s = s.owner
result = true
proc procIsCallback(c: PCtx; s: PSym): bool =
if s.offset < -1: return true
var i = -2
for key, value in items(c.callbacks):
if s.matches(key):
doAssert s.offset == -1
s.offset = i
return true
dec i
proc gen(c: PCtx; n: PNode; dest: var TDest; flags: TGenFlags = {}) =
when defined(nimCompilerStacktraceHints):
setFrameMsg c.config$n.info & " " & $n.kind & " " & $flags
case n.kind
of nkSym:
let s = n.sym
checkCanEval(c, n)
case s.kind
of skVar, skForVar, skTemp, skLet, skParam, skResult:
genRdVar(c, n, dest, flags)
of skProc, skFunc, skConverter, skMacro, skTemplate, skMethod, skIterator:
# 'skTemplate' is only allowed for 'getAst' support:
if s.kind == skIterator and s.typ.callConv == TCallingConvention.ccClosure:
globalError(c.config, n.info, "Closure iterators are not supported by VM!")
if procIsCallback(c, s): discard
elif importcCond(c, s): c.importcSym(n.info, s)
genLit(c, n, dest)
of skConst:
let constVal = if s.ast != nil: s.ast else: s.typ.n
gen(c, constVal, dest)
of skEnumField:
# we never reach this case - as of the time of this comment,
# skEnumField is folded to an int in semfold.nim, but this code
# remains for robustness
if dest < 0: dest = c.getTemp(n.typ)
if s.position >= low(int16) and s.position <= high(int16):
c.gABx(n, opcLdImmInt, dest, s.position)
else:
var lit = genLiteral(c, newIntNode(nkIntLit, s.position))
c.gABx(n, opcLdConst, dest, lit)
of skType:
genTypeLit(c, s.typ, dest)
of skGenericParam:
if c.prc.sym != nil and c.prc.sym.kind == skMacro:
genRdVar(c, n, dest, flags)
else:
globalError(c.config, n.info, "cannot generate code for: " & s.name.s)
else:
globalError(c.config, n.info, "cannot generate code for: " & s.name.s)
of nkCallKinds:
if n[0].kind == nkSym:
let s = n[0].sym
if s.magic != mNone:
genMagic(c, n, dest, s.magic)
elif s.kind == skMethod:
localError(c.config, n.info, "cannot call method " & s.name.s &
" at compile time")
elif matches(s, "stdlib.marshal.to"):
# XXX marshal load&store should not be opcodes, but use the
# general callback mechanisms.
genMarshalLoad(c, n, dest)
elif matches(s, "stdlib.marshal.$$"):
genMarshalStore(c, n, dest)
else:
genCall(c, n, dest)
clearDest(c, n, dest)
else:
genCall(c, n, dest)
clearDest(c, n, dest)
of nkCharLit..nkInt64Lit:
if isInt16Lit(n):
if dest < 0: dest = c.getTemp(n.typ)
c.gABx(n, opcLdImmInt, dest, n.intVal.int)
else:
genLit(c, n, dest)
of nkUIntLit..pred(nkNilLit): genLit(c, n, dest)
of nkNilLit:
if not n.typ.isEmptyType: genLit(c, getNullValue(n.typ, n.info, c.config), dest)
else: unused(c, n, dest)
of nkAsgn, nkFastAsgn:
unused(c, n, dest)
genAsgn(c, n[0], n[1], n.kind == nkAsgn)
of nkDotExpr: genObjAccess(c, n, dest, flags)
of nkCheckedFieldExpr: genCheckedObjAccess(c, n, dest, flags)
of nkBracketExpr: genArrAccess(c, n, dest, flags)
of nkDerefExpr, nkHiddenDeref: genDeref(c, n, dest, flags)
of nkAddr, nkHiddenAddr: genAddr(c, n, dest, flags)
of nkIfStmt, nkIfExpr: genIf(c, n, dest)
of nkWhenStmt:
# This is "when nimvm" node. Chose the first branch.
gen(c, n[0][1], dest)
of nkCaseStmt: genCase(c, n, dest)
of nkWhileStmt:
unused(c, n, dest)
genWhile(c, n)
of nkBlockExpr, nkBlockStmt: genBlock(c, n, dest)
of nkReturnStmt:
genReturn(c, n)
of nkRaiseStmt:
genRaise(c, n)
of nkBreakStmt:
genBreak(c, n)
of nkTryStmt, nkHiddenTryStmt: genTry(c, n, dest)
of nkStmtList:
#unused(c, n, dest)
# XXX Fix this bug properly, lexim triggers it
for x in n: gen(c, x)
of nkStmtListExpr:
for i in 0..<n.len-1: gen(c, n[i])
gen(c, n[^1], dest, flags)
of nkPragmaBlock:
gen(c, n.lastSon, dest, flags)
of nkDiscardStmt:
unused(c, n, dest)
gen(c, n[0])
of nkHiddenStdConv, nkHiddenSubConv, nkConv:
genConv(c, n, n[1], dest)
of nkObjDownConv:
genConv(c, n, n[0], dest)
of nkObjUpConv:
genConv(c, n, n[0], dest)
of nkVarSection, nkLetSection:
unused(c, n, dest)
genVarSection(c, n)
of declarativeDefs, nkMacroDef:
unused(c, n, dest)
of nkLambdaKinds:
#let s = n[namePos].sym
#discard genProc(c, s)
genLit(c, newSymNode(n[namePos].sym), dest)
of nkChckRangeF, nkChckRange64, nkChckRange:
let
tmp0 = c.genx(n[0])
tmp1 = c.genx(n[1])
tmp2 = c.genx(n[2])
c.gABC(n, opcRangeChck, tmp0, tmp1, tmp2)
c.freeTemp(tmp1)
c.freeTemp(tmp2)
if dest >= 0:
gABC(c, n, whichAsgnOpc(n), dest, tmp0)
c.freeTemp(tmp0)
else:
dest = tmp0
of nkEmpty, nkCommentStmt, nkTypeSection, nkConstSection, nkPragma,
nkTemplateDef, nkIncludeStmt, nkImportStmt, nkFromStmt, nkExportStmt,
nkMixinStmt, nkBindStmt:
unused(c, n, dest)
of nkStringToCString, nkCStringToString:
gen(c, n[0], dest)
of nkBracket: genArrayConstr(c, n, dest)
of nkCurly: genSetConstr(c, n, dest)
of nkObjConstr: genObjConstr(c, n, dest)
of nkPar, nkClosure, nkTupleConstr: genTupleConstr(c, n, dest)
of nkCast:
if allowCast in c.features:
genConv(c, n, n[1], dest, opcCast)
else:
genCastIntFloat(c, n, dest)
of nkTypeOfExpr:
genTypeLit(c, n.typ, dest)
of nkComesFrom:
discard "XXX to implement for better stack traces"
else:
if n.typ != nil and n.typ.isCompileTimeOnly:
genTypeLit(c, n.typ, dest)
else:
globalError(c.config, n.info, "cannot generate VM code for " & $n)
proc removeLastEof(c: PCtx) =
let last = c.code.len-1
if last >= 0 and c.code[last].opcode == opcEof:
# overwrite last EOF:
assert c.code.len == c.debug.len
c.code.setLen(last)
c.debug.setLen(last)
proc genStmt*(c: PCtx; n: PNode): int =
c.removeLastEof
result = c.code.len
var d: TDest = -1
c.gen(n, d)
c.gABC(n, opcEof)
if d >= 0:
globalError(c.config, n.info, "VM problem: dest register is set")
proc genExpr*(c: PCtx; n: PNode, requiresValue = true): int =
c.removeLastEof
result = c.code.len
var d: TDest = -1
c.gen(n, d)
if d < 0:
if requiresValue:
globalError(c.config, n.info, "VM problem: dest register is not set")
d = 0
c.gABC(n, opcEof, d)
#echo renderTree(n)
#c.echoCode(result)
proc genParams(c: PCtx; params: PNode) =
# res.sym.position is already 0
setLen(c.prc.regInfo, max(params.len, 1))
c.prc.regInfo[0] = (inUse: true, kind: slotFixedVar)
for i in 1..<params.len:
c.prc.regInfo[i] = (inUse: true, kind: slotFixedLet)
proc finalJumpTarget(c: PCtx; pc, diff: int) =
internalAssert(c.config, regBxMin < diff and diff < regBxMax)
let oldInstr = c.code[pc]
# opcode and regA stay the same:
c.code[pc] = ((oldInstr.TInstrType and ((regOMask shl regOShift) or (regAMask shl regAShift))).TInstrType or
TInstrType(diff+wordExcess) shl regBxShift).TInstr
proc genGenericParams(c: PCtx; gp: PNode) =
var base = c.prc.regInfo.len
setLen c.prc.regInfo, base + gp.len
for i in 0..<gp.len:
var param = gp[i].sym
param.position = base + i # XXX: fix this earlier; make it consistent with templates
c.prc.regInfo[base + i] = (inUse: true, kind: slotFixedLet)
proc optimizeJumps(c: PCtx; start: int) =
const maxIterations = 10
for i in start..<c.code.len:
let opc = c.code[i].opcode
case opc
of opcTJmp, opcFJmp:
var reg = c.code[i].regA
var d = i + c.code[i].jmpDiff
for iters in countdown(maxIterations, 0):
case c.code[d].opcode
of opcJmp:
d += c.code[d].jmpDiff
of opcTJmp, opcFJmp:
if c.code[d].regA != reg: break
# tjmp x, 23
# ...
# tjmp x, 12
# -- we know 'x' is true, and so can jump to 12+13:
if c.code[d].opcode == opc:
d += c.code[d].jmpDiff
else:
# tjmp x, 23
# fjmp x, 22
# We know 'x' is true so skip to the next instruction:
d += 1
else: break
if d != i + c.code[i].jmpDiff:
c.finalJumpTarget(i, d - i)
of opcJmp, opcJmpBack:
var d = i + c.code[i].jmpDiff
var iters = maxIterations
while c.code[d].opcode == opcJmp and iters > 0:
d += c.code[d].jmpDiff
dec iters
if c.code[d].opcode == opcRet:
# optimize 'jmp to ret' to 'ret' here
c.code[i] = c.code[d]
elif d != i + c.code[i].jmpDiff:
c.finalJumpTarget(i, d - i)
else: discard
proc genProc(c: PCtx; s: PSym): int =
let pos = c.procToCodePos.getOrDefault(s.id)
if pos == 0:
#if s.name.s == "outterMacro" or s.name.s == "innerProc":
# echo "GENERATING CODE FOR ", s.name.s
let last = c.code.len-1
var eofInstr: TInstr
if last >= 0 and c.code[last].opcode == opcEof:
eofInstr = c.code[last]
c.code.setLen(last)
c.debug.setLen(last)
#c.removeLastEof
result = c.code.len+1 # skip the jump instruction
c.procToCodePos[s.id] = result
# thanks to the jmp we can add top level statements easily and also nest
# procs easily:
let body = transformBody(c.graph, c.idgen, s, cache = not isCompileTimeProc(s))
let procStart = c.xjmp(body, opcJmp, 0)
var p = PProc(blocks: @[], sym: s)
let oldPrc = c.prc
c.prc = p
# iterate over the parameters and allocate space for them:
genParams(c, s.typ.n)
# allocate additional space for any generically bound parameters
if s.kind == skMacro and s.isGenericRoutineStrict:
genGenericParams(c, s.ast[genericParamsPos])
if tfCapturesEnv in s.typ.flags:
#let env = s.ast[paramsPos].lastSon.sym
#assert env.position == 2
c.prc.regInfo.add (inUse: true, kind: slotFixedLet)
gen(c, body)
# generate final 'return' statement:
c.gABC(body, opcRet)
c.patch(procStart)
c.gABC(body, opcEof, eofInstr.regA)
c.optimizeJumps(result)
s.offset = c.prc.regInfo.len
#if s.name.s == "main" or s.name.s == "[]":
# echo renderTree(body)
# c.echoCode(result)
c.prc = oldPrc
else:
c.prc.regInfo.setLen s.offset
result = pos