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pasparse.nim
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#
#
# Pas2nim - Pascal to Nim source converter
# (c) Copyright 2012 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
#
# This module implements the parser of the Pascal variant Nim is written in.
# It transfers a Pascal module into a Nimf AST. Then the renderer can be
# used to convert the AST to its text representation.
import
os, llstream, paslex, idents, strutils, ast, astalgo, msgs, options
type
TSection = enum
seImplementation, seInterface
TContext = enum
conExpr, conStmt, conTypeDesc
TParserFlag* = enum
pfRefs, ## use "ref" instead of "ptr" for Pascal's ^typ
pfMoreReplacements, ## use more than the default replacements
pfImportBlackList ## use import blacklist
TParser*{.final.} = object
section: TSection
inParamList: bool
context: TContext # needed for the @emit command
lastVarSection: PNode
lex: TLexer
tok: TToken
repl: TIdTable # replacements
flags: set[TParserFlag]
TReplaceTuple* = array[0..1, string]
const
ImportBlackList*: array[1..3, string] = ["nsystem", "sysutils", "charsets"]
stdReplacements*: array[1..19, TReplaceTuple] = [["include", "incl"],
["exclude", "excl"], ["pchar", "cstring"], ["assignfile", "open"],
["integer", "int"], ["longword", "int32"], ["cardinal", "int"],
["boolean", "bool"], ["shortint", "int8"], ["smallint", "int16"],
["longint", "int32"], ["byte", "int8"], ["word", "int16"],
["single", "float32"], ["double", "float64"], ["real", "float"],
["length", "len"], ["len", "length"], ["setlength", "setlen"]]
nimReplacements*: array[1..35, TReplaceTuple] = [["nimread", "read"],
["nimwrite", "write"], ["nimclosefile", "close"], ["closefile", "close"],
["openfile", "open"], ["nsystem", "system"], ["ntime", "times"],
["nos", "os"], ["nmath", "math"], ["ncopy", "copy"], ["addChar", "add"],
["halt", "quit"], ["nobject", "TObject"], ["eof", "EndOfFile"],
["input", "stdin"], ["output", "stdout"], ["addu", "`+%`"],
["subu", "`-%`"], ["mulu", "`*%`"], ["divu", "`/%`"], ["modu", "`%%`"],
["ltu", "`<%`"], ["leu", "`<=%`"], ["shlu", "`shl`"], ["shru", "`shr`"],
["assigned", "not isNil"], ["eintoverflow", "EOverflow"], ["format", "`%`"],
["snil", "nil"], ["tostringf", "$"], ["ttextfile", "tfile"],
["tbinaryfile", "tfile"], ["strstart", "0"], ["nl", "\"\\n\""],
["tostring", "$"]]
proc parseUnit*(p: var TParser): PNode
proc openParser*(p: var TParser, filename: string, inputStream: PLLStream,
flags: set[TParserFlag] = {})
proc closeParser*(p: var TParser)
proc exSymbol*(n: var PNode)
proc fixRecordDef*(n: var PNode)
# XXX: move these two to an auxiliary module
# implementation
proc openParser(p: var TParser, filename: string,
inputStream: PLLStream, flags: set[TParserFlag] = {}) =
openLexer(p.lex, filename, inputStream)
initIdTable(p.repl)
for i in countup(low(stdReplacements), high(stdReplacements)):
idTablePut(p.repl, getIdent(stdReplacements[i][0]),
getIdent(stdReplacements[i][1]))
if pfMoreReplacements in flags:
for i in countup(low(nimReplacements), high(nimReplacements)):
idTablePut(p.repl, getIdent(nimReplacements[i][0]),
getIdent(nimReplacements[i][1]))
p.flags = flags
proc closeParser(p: var TParser) = closeLexer(p.lex)
proc getTok(p: var TParser) = getTok(p.lex, p.tok)
proc parMessage(p: TParser, msg: TMsgKind, arg = "") =
lexMessage(p.lex, msg, arg)
proc parLineInfo(p: TParser): TLineInfo =
result = getLineInfo(p.lex)
proc skipCom(p: var TParser, n: PNode) =
while p.tok.xkind == pxComment:
if (n != nil):
if n.comment == nil: n.comment = p.tok.literal
else: add(n.comment, "\n" & p.tok.literal)
else:
parMessage(p, warnCommentXIgnored, p.tok.literal)
getTok(p)
proc expectIdent(p: TParser) =
if p.tok.xkind != pxSymbol:
lexMessage(p.lex, errIdentifierExpected, $(p.tok))
proc eat(p: var TParser, xkind: TTokKind) =
if p.tok.xkind == xkind: getTok(p)
else: lexMessage(p.lex, errTokenExpected, tokKindToStr(xkind))
proc opt(p: var TParser, xkind: TTokKind) =
if p.tok.xkind == xkind: getTok(p)
proc newNodeP(kind: TNodeKind, p: TParser): PNode =
result = newNodeI(kind, getLineInfo(p.lex))
proc newIntNodeP(kind: TNodeKind, intVal: BiggestInt, p: TParser): PNode =
result = newNodeP(kind, p)
result.intVal = intVal
proc newFloatNodeP(kind: TNodeKind, floatVal: BiggestFloat,
p: TParser): PNode =
result = newNodeP(kind, p)
result.floatVal = floatVal
proc newStrNodeP(kind: TNodeKind, strVal: string, p: TParser): PNode =
result = newNodeP(kind, p)
result.strVal = strVal
proc newIdentNodeP(ident: PIdent, p: TParser): PNode =
result = newNodeP(nkIdent, p)
result.ident = ident
proc createIdentNodeP(ident: PIdent, p: TParser): PNode =
result = newNodeP(nkIdent, p)
var x = PIdent(idTableGet(p.repl, ident))
if x != nil: result.ident = x
else: result.ident = ident
proc parseExpr(p: var TParser): PNode
proc parseStmt(p: var TParser): PNode
proc parseTypeDesc(p: var TParser, definition: PNode = nil): PNode
proc parseEmit(p: var TParser, definition: PNode): PNode =
getTok(p) # skip 'emit'
result = ast.emptyNode
if p.tok.xkind != pxCurlyDirRi:
case p.context
of conExpr:
result = parseExpr(p)
of conStmt:
result = parseStmt(p)
if p.tok.xkind != pxCurlyDirRi:
var a = result
result = newNodeP(nkStmtList, p)
addSon(result, a)
while p.tok.xkind != pxCurlyDirRi:
addSon(result, parseStmt(p))
of conTypeDesc:
result = parseTypeDesc(p, definition)
eat(p, pxCurlyDirRi)
proc parseCommand(p: var TParser, definition: PNode = nil): PNode =
result = ast.emptyNode
getTok(p)
if p.tok.ident.id == getIdent("discard").id:
result = newNodeP(nkDiscardStmt, p)
getTok(p)
eat(p, pxCurlyDirRi)
addSon(result, parseExpr(p))
elif p.tok.ident.id == getIdent("set").id:
getTok(p)
eat(p, pxCurlyDirRi)
result = parseExpr(p)
if result.kind == nkEmpty: internalError("emptyNode modified")
result.kind = nkCurly
elif p.tok.ident.id == getIdent("cast").id:
getTok(p)
eat(p, pxCurlyDirRi)
var a = parseExpr(p)
if (a.kind == nkCall) and (sonsLen(a) == 2):
result = newNodeP(nkCast, p)
addSon(result, a.sons[0])
addSon(result, a.sons[1])
else:
parMessage(p, errInvalidDirectiveX, $p.tok)
result = a
elif p.tok.ident.id == getIdent("emit").id:
result = parseEmit(p, definition)
elif p.tok.ident.id == getIdent("ignore").id:
getTok(p)
eat(p, pxCurlyDirRi)
while true:
case p.tok.xkind
of pxEof:
parMessage(p, errTokenExpected, "{@emit}")
of pxCommand:
getTok(p)
if p.tok.ident.id == getIdent("emit").id:
result = parseEmit(p, definition)
break
else:
while (p.tok.xkind != pxCurlyDirRi) and (p.tok.xkind != pxEof):
getTok(p)
eat(p, pxCurlyDirRi)
else:
getTok(p) # skip token
elif p.tok.ident.id == getIdent("ptr").id:
result = newNodeP(nkPtrTy, p)
getTok(p)
eat(p, pxCurlyDirRi)
elif p.tok.ident.id == getIdent("tuple").id:
result = newNodeP(nkTupleTy, p)
getTok(p)
eat(p, pxCurlyDirRi)
elif p.tok.ident.id == getIdent("acyclic").id:
result = newIdentNodeP(p.tok.ident, p)
getTok(p)
eat(p, pxCurlyDirRi)
else:
parMessage(p, errInvalidDirectiveX, $p.tok)
while true:
getTok(p)
if p.tok.xkind == pxCurlyDirRi or p.tok.xkind == pxEof: break
eat(p, pxCurlyDirRi)
result = ast.emptyNode
proc getPrecedence(kind: TTokKind): int =
case kind
of pxDiv, pxMod, pxStar, pxSlash, pxShl, pxShr, pxAnd: result = 5
of pxPlus, pxMinus, pxOr, pxXor: result = 4
of pxIn, pxEquals, pxLe, pxLt, pxGe, pxGt, pxNeq, pxIs: result = 3
else: result = -1
proc rangeExpr(p: var TParser): PNode =
var a = parseExpr(p)
if p.tok.xkind == pxDotDot:
result = newNodeP(nkRange, p)
addSon(result, a)
getTok(p)
skipCom(p, result)
addSon(result, parseExpr(p))
else:
result = a
proc bracketExprList(p: var TParser, first: PNode): PNode =
result = newNodeP(nkBracketExpr, p)
addSon(result, first)
getTok(p)
skipCom(p, result)
while true:
if p.tok.xkind == pxBracketRi:
getTok(p)
break
if p.tok.xkind == pxEof:
parMessage(p, errTokenExpected, tokKindToStr(pxBracketRi))
break
var a = rangeExpr(p)
skipCom(p, a)
if p.tok.xkind == pxComma:
getTok(p)
skipCom(p, a)
addSon(result, a)
proc exprColonEqExpr(p: var TParser, kind: TNodeKind,
tok: TTokKind): PNode =
var a = parseExpr(p)
if p.tok.xkind == tok:
result = newNodeP(kind, p)
getTok(p)
skipCom(p, result)
addSon(result, a)
addSon(result, parseExpr(p))
else:
result = a
proc exprListAux(p: var TParser, elemKind: TNodeKind,
endTok, sepTok: TTokKind, result: PNode) =
getTok(p)
skipCom(p, result)
while true:
if p.tok.xkind == endTok:
getTok(p)
break
if p.tok.xkind == pxEof:
parMessage(p, errTokenExpected, tokKindToStr(endTok))
break
var a = exprColonEqExpr(p, elemKind, sepTok)
skipCom(p, a)
if (p.tok.xkind == pxComma) or (p.tok.xkind == pxSemicolon):
getTok(p)
skipCom(p, a)
addSon(result, a)
proc qualifiedIdent(p: var TParser): PNode =
if p.tok.xkind == pxSymbol:
result = createIdentNodeP(p.tok.ident, p)
else:
parMessage(p, errIdentifierExpected, $p.tok)
return ast.emptyNode
getTok(p)
skipCom(p, result)
if p.tok.xkind == pxDot:
getTok(p)
skipCom(p, result)
if p.tok.xkind == pxSymbol:
var a = result
result = newNodeI(nkDotExpr, a.info)
addSon(result, a)
addSon(result, createIdentNodeP(p.tok.ident, p))
getTok(p)
else:
parMessage(p, errIdentifierExpected, $p.tok)
proc qualifiedIdentListAux(p: var TParser, endTok: TTokKind,
result: PNode) =
getTok(p)
skipCom(p, result)
while true:
if p.tok.xkind == endTok:
getTok(p)
break
if p.tok.xkind == pxEof:
parMessage(p, errTokenExpected, tokKindToStr(endTok))
break
var a = qualifiedIdent(p)
skipCom(p, a)
if p.tok.xkind == pxComma:
getTok(p)
skipCom(p, a)
addSon(result, a)
proc exprColonEqExprList(p: var TParser, kind, elemKind: TNodeKind,
endTok, sepTok: TTokKind): PNode =
result = newNodeP(kind, p)
exprListAux(p, elemKind, endTok, sepTok, result)
proc setBaseFlags(n: PNode, base: TNumericalBase) =
case base
of base10: discard
of base2: incl(n.flags, nfBase2)
of base8: incl(n.flags, nfBase8)
of base16: incl(n.flags, nfBase16)
proc identOrLiteral(p: var TParser): PNode =
case p.tok.xkind
of pxSymbol:
result = createIdentNodeP(p.tok.ident, p)
getTok(p)
of pxIntLit:
result = newIntNodeP(nkIntLit, p.tok.iNumber, p)
setBaseFlags(result, p.tok.base)
getTok(p)
of pxInt64Lit:
result = newIntNodeP(nkInt64Lit, p.tok.iNumber, p)
setBaseFlags(result, p.tok.base)
getTok(p)
of pxFloatLit:
result = newFloatNodeP(nkFloatLit, p.tok.fNumber, p)
setBaseFlags(result, p.tok.base)
getTok(p)
of pxStrLit:
if len(p.tok.literal) != 1: result = newStrNodeP(nkStrLit, p.tok.literal, p)
else: result = newIntNodeP(nkCharLit, ord(p.tok.literal[0]), p)
getTok(p)
of pxNil:
result = newNodeP(nkNilLit, p)
getTok(p)
of pxParLe:
# () constructor
result = exprColonEqExprList(p, nkPar, nkExprColonExpr, pxParRi, pxColon)
#if hasSonWith(result, nkExprColonExpr) then
# replaceSons(result, nkExprColonExpr, nkExprEqExpr)
if (sonsLen(result) > 1) and not hasSonWith(result, nkExprColonExpr):
result.kind = nkBracket # is an array constructor
of pxBracketLe:
# [] constructor
result = newNodeP(nkBracket, p)
getTok(p)
skipCom(p, result)
while (p.tok.xkind != pxBracketRi) and (p.tok.xkind != pxEof):
var a = rangeExpr(p)
if a.kind == nkRange:
result.kind = nkCurly # it is definitely a set literal
opt(p, pxComma)
skipCom(p, a)
assert(a != nil)
addSon(result, a)
eat(p, pxBracketRi)
of pxCommand:
result = parseCommand(p)
else:
parMessage(p, errExprExpected, $(p.tok))
getTok(p) # we must consume a token here to prevend endless loops!
result = ast.emptyNode
if result.kind != nkEmpty: skipCom(p, result)
proc primary(p: var TParser): PNode =
# prefix operator?
if (p.tok.xkind == pxNot) or (p.tok.xkind == pxMinus) or
(p.tok.xkind == pxPlus):
result = newNodeP(nkPrefix, p)
var a = newIdentNodeP(getIdent($p.tok), p)
addSon(result, a)
getTok(p)
skipCom(p, a)
addSon(result, primary(p))
return
elif p.tok.xkind == pxAt:
result = newNodeP(nkAddr, p)
var a = newIdentNodeP(getIdent($p.tok), p)
getTok(p)
if p.tok.xkind == pxBracketLe:
result = newNodeP(nkPrefix, p)
addSon(result, a)
addSon(result, identOrLiteral(p))
else:
addSon(result, primary(p))
return
result = identOrLiteral(p)
while true:
case p.tok.xkind
of pxParLe:
var a = result
result = newNodeP(nkCall, p)
addSon(result, a)
exprListAux(p, nkExprEqExpr, pxParRi, pxEquals, result)
of pxDot:
var a = result
result = newNodeP(nkDotExpr, p)
addSon(result, a)
getTok(p) # skip '.'
skipCom(p, result)
if p.tok.xkind == pxSymbol:
addSon(result, createIdentNodeP(p.tok.ident, p))
getTok(p)
else:
parMessage(p, errIdentifierExpected, $p.tok)
of pxHat:
var a = result
result = newNodeP(nkBracketExpr, p)
addSon(result, a)
getTok(p)
of pxBracketLe:
result = bracketExprList(p, result)
else: break
proc lowestExprAux(p: var TParser, v: var PNode, limit: int): TTokKind =
var
nextop: TTokKind
v2, node, opNode: PNode
v = primary(p) # expand while operators have priorities higher than 'limit'
var op = p.tok.xkind
var opPred = getPrecedence(op)
while (opPred > limit):
node = newNodeP(nkInfix, p)
opNode = newIdentNodeP(getIdent($(p.tok)), p) # skip operator:
getTok(p)
case op
of pxPlus:
case p.tok.xkind
of pxPer:
getTok(p)
eat(p, pxCurlyDirRi)
opNode.ident = getIdent("+%")
of pxAmp:
getTok(p)
eat(p, pxCurlyDirRi)
opNode.ident = getIdent("&")
else:
discard
of pxMinus:
if p.tok.xkind == pxPer:
getTok(p)
eat(p, pxCurlyDirRi)
opNode.ident = getIdent("-%")
of pxEquals:
opNode.ident = getIdent("==")
of pxNeq:
opNode.ident = getIdent("!=")
else:
discard
skipCom(p, opNode) # read sub-expression with higher priority
nextop = lowestExprAux(p, v2, opPred)
addSon(node, opNode)
addSon(node, v)
addSon(node, v2)
v = node
op = nextop
opPred = getPrecedence(nextop)
result = op # return first untreated operator
proc fixExpr(n: PNode): PNode =
result = n
case n.kind
of nkInfix:
if n.sons[1].kind == nkBracket: n.sons[1].kind = nkCurly
if n.sons[2].kind == nkBracket: n.sons[2].kind = nkCurly
if (n.sons[0].kind == nkIdent):
if (n.sons[0].ident.id == getIdent("+").id):
if (n.sons[1].kind == nkCharLit) and (n.sons[2].kind == nkStrLit) and
(n.sons[2].strVal == ""):
result = newStrNode(nkStrLit, chr(int(n.sons[1].intVal)) & "")
result.info = n.info
return # do not process sons as they don't exist anymore
elif (n.sons[1].kind in {nkCharLit, nkStrLit}) or
(n.sons[2].kind in {nkCharLit, nkStrLit}):
n.sons[0].ident = getIdent("&") # fix operator
else:
discard
if not (n.kind in {nkEmpty..nkNilLit}):
for i in countup(0, sonsLen(n) - 1): result.sons[i] = fixExpr(n.sons[i])
proc parseExpr(p: var TParser): PNode =
var oldcontext = p.context
p.context = conExpr
if p.tok.xkind == pxCommand:
result = parseCommand(p)
else:
discard lowestExprAux(p, result, - 1)
result = fixExpr(result)
p.context = oldcontext
proc parseExprStmt(p: var TParser): PNode =
var info = parLineInfo(p)
var a = parseExpr(p)
if p.tok.xkind == pxAsgn:
getTok(p)
skipCom(p, a)
var b = parseExpr(p)
result = newNodeI(nkAsgn, info)
addSon(result, a)
addSon(result, b)
else:
result = a
proc inImportBlackList(ident: PIdent): bool =
for i in countup(low(ImportBlackList), high(ImportBlackList)):
if ident.id == getIdent(ImportBlackList[i]).id:
return true
proc parseUsesStmt(p: var TParser): PNode =
var a: PNode
result = newNodeP(nkImportStmt, p)
getTok(p) # skip `import`
skipCom(p, result)
while true:
case p.tok.xkind
of pxEof: break
of pxSymbol: a = newIdentNodeP(p.tok.ident, p)
else:
parMessage(p, errIdentifierExpected, $(p.tok))
break
getTok(p) # skip identifier, string
skipCom(p, a)
if pfImportBlackList notin p.flags or not inImportBlackList(a.ident):
addSon(result, createIdentNodeP(a.ident, p))
if p.tok.xkind == pxComma:
getTok(p)
skipCom(p, a)
else:
break
if sonsLen(result) == 0: result = ast.emptyNode
proc parseIncludeDir(p: var TParser): PNode =
result = newNodeP(nkIncludeStmt, p)
getTok(p) # skip `include`
var filename = ""
while true:
case p.tok.xkind
of pxSymbol, pxDot, pxDotDot, pxSlash:
add(filename, $p.tok)
getTok(p)
of pxStrLit:
filename = p.tok.literal
getTok(p)
break
of pxCurlyDirRi:
break
else:
parMessage(p, errIdentifierExpected, $p.tok)
break
addSon(result, newStrNodeP(nkStrLit, changeFileExt(filename, "nim"), p))
if filename == "config.inc": result = ast.emptyNode
proc definedExprAux(p: var TParser): PNode =
result = newNodeP(nkCall, p)
addSon(result, newIdentNodeP(getIdent("defined"), p))
expectIdent(p)
addSon(result, createIdentNodeP(p.tok.ident, p))
getTok(p)
proc isHandledDirective(p: TParser): bool =
if p.tok.xkind in {pxCurlyDirLe, pxStarDirLe}:
case toLower(p.tok.ident.s)
of "else", "endif": result = false
else: result = true
proc parseStmtList(p: var TParser): PNode =
result = newNodeP(nkStmtList, p)
while true:
case p.tok.xkind
of pxEof:
break
of pxCurlyDirLe, pxStarDirLe:
if not isHandledDirective(p): break
else:
discard
addSon(result, parseStmt(p))
if sonsLen(result) == 1: result = result.sons[0]
proc parseIfDirAux(p: var TParser, result: PNode) =
addSon(result.sons[0], parseStmtList(p))
if p.tok.xkind in {pxCurlyDirLe, pxStarDirLe}:
var endMarker = succ(p.tok.xkind)
if toLower(p.tok.ident.s) == "else":
var s = newNodeP(nkElse, p)
while p.tok.xkind != pxEof and p.tok.xkind != endMarker: getTok(p)
eat(p, endMarker)
addSon(s, parseStmtList(p))
addSon(result, s)
if p.tok.xkind in {pxCurlyDirLe, pxStarDirLe}:
endMarker = succ(p.tok.xkind)
if toLower(p.tok.ident.s) == "endif":
while p.tok.xkind != pxEof and p.tok.xkind != endMarker: getTok(p)
eat(p, endMarker)
else:
parMessage(p, errXExpected, "{$endif}")
else:
parMessage(p, errXExpected, "{$endif}")
proc parseIfdefDir(p: var TParser, endMarker: TTokKind): PNode =
result = newNodeP(nkWhenStmt, p)
addSon(result, newNodeP(nkElifBranch, p))
getTok(p)
addSon(result.sons[0], definedExprAux(p))
eat(p, endMarker)
parseIfDirAux(p, result)
proc parseIfndefDir(p: var TParser, endMarker: TTokKind): PNode =
result = newNodeP(nkWhenStmt, p)
addSon(result, newNodeP(nkElifBranch, p))
getTok(p)
var e = newNodeP(nkCall, p)
addSon(e, newIdentNodeP(getIdent("not"), p))
addSon(e, definedExprAux(p))
eat(p, endMarker)
addSon(result.sons[0], e)
parseIfDirAux(p, result)
proc parseIfDir(p: var TParser, endMarker: TTokKind): PNode =
result = newNodeP(nkWhenStmt, p)
addSon(result, newNodeP(nkElifBranch, p))
getTok(p)
addSon(result.sons[0], parseExpr(p))
eat(p, endMarker)
parseIfDirAux(p, result)
proc parseDirective(p: var TParser): PNode =
result = ast.emptyNode
if not (p.tok.xkind in {pxCurlyDirLe, pxStarDirLe}): return
var endMarker = succ(p.tok.xkind)
if p.tok.ident != nil:
case toLower(p.tok.ident.s)
of "include":
result = parseIncludeDir(p)
eat(p, endMarker)
of "if": result = parseIfDir(p, endMarker)
of "ifdef": result = parseIfdefDir(p, endMarker)
of "ifndef": result = parseIfndefDir(p, endMarker)
else:
# skip unknown compiler directive
while p.tok.xkind != pxEof and p.tok.xkind != endMarker: getTok(p)
eat(p, endMarker)
else:
eat(p, endMarker)
proc parseRaise(p: var TParser): PNode =
result = newNodeP(nkRaiseStmt, p)
getTok(p)
skipCom(p, result)
if p.tok.xkind != pxSemicolon: addSon(result, parseExpr(p))
else: addSon(result, ast.emptyNode)
proc parseIf(p: var TParser): PNode =
result = newNodeP(nkIfStmt, p)
while true:
getTok(p) # skip ``if``
var branch = newNodeP(nkElifBranch, p)
skipCom(p, branch)
addSon(branch, parseExpr(p))
eat(p, pxThen)
skipCom(p, branch)
addSon(branch, parseStmt(p))
skipCom(p, branch)
addSon(result, branch)
if p.tok.xkind == pxElse:
getTok(p)
if p.tok.xkind != pxIf:
# ordinary else part:
branch = newNodeP(nkElse, p)
skipCom(p, result) # BUGFIX
addSon(branch, parseStmt(p))
addSon(result, branch)
break
else:
break
proc parseWhile(p: var TParser): PNode =
result = newNodeP(nkWhileStmt, p)
getTok(p)
skipCom(p, result)
addSon(result, parseExpr(p))
eat(p, pxDo)
skipCom(p, result)
addSon(result, parseStmt(p))
proc parseRepeat(p: var TParser): PNode =
result = newNodeP(nkWhileStmt, p)
getTok(p)
skipCom(p, result)
addSon(result, newIdentNodeP(getIdent("true"), p))
var s = newNodeP(nkStmtList, p)
while p.tok.xkind != pxEof and p.tok.xkind != pxUntil:
addSon(s, parseStmt(p))
eat(p, pxUntil)
var a = newNodeP(nkIfStmt, p)
skipCom(p, a)
var b = newNodeP(nkElifBranch, p)
var c = newNodeP(nkBreakStmt, p)
addSon(c, ast.emptyNode)
addSon(b, parseExpr(p))
skipCom(p, a)
addSon(b, c)
addSon(a, b)
if b.sons[0].kind == nkIdent and b.sons[0].ident.id == getIdent("false").id:
discard
else:
addSon(s, a)
addSon(result, s)
proc parseCase(p: var TParser): PNode =
var b: PNode
result = newNodeP(nkCaseStmt, p)
getTok(p)
addSon(result, parseExpr(p))
eat(p, pxOf)
skipCom(p, result)
while (p.tok.xkind != pxEnd) and (p.tok.xkind != pxEof):
if p.tok.xkind == pxElse:
b = newNodeP(nkElse, p)
getTok(p)
else:
b = newNodeP(nkOfBranch, p)
while (p.tok.xkind != pxEof) and (p.tok.xkind != pxColon):
addSon(b, rangeExpr(p))
opt(p, pxComma)
skipCom(p, b)
eat(p, pxColon)
skipCom(p, b)
addSon(b, parseStmt(p))
addSon(result, b)
if b.kind == nkElse: break
eat(p, pxEnd)
proc parseTry(p: var TParser): PNode =
result = newNodeP(nkTryStmt, p)
getTok(p)
skipCom(p, result)
var b = newNodeP(nkStmtList, p)
while not (p.tok.xkind in {pxFinally, pxExcept, pxEof, pxEnd}):
addSon(b, parseStmt(p))
addSon(result, b)
if p.tok.xkind == pxExcept:
getTok(p)
while p.tok.ident.id == getIdent("on").id:
b = newNodeP(nkExceptBranch, p)
getTok(p)
var e = qualifiedIdent(p)
if p.tok.xkind == pxColon:
getTok(p)
e = qualifiedIdent(p)
addSon(b, e)
eat(p, pxDo)
addSon(b, parseStmt(p))
addSon(result, b)
if p.tok.xkind == pxCommand: discard parseCommand(p)
if p.tok.xkind == pxElse:
b = newNodeP(nkExceptBranch, p)
getTok(p)
addSon(b, parseStmt(p))
addSon(result, b)
if p.tok.xkind == pxFinally:
b = newNodeP(nkFinally, p)
getTok(p)
var e = newNodeP(nkStmtList, p)
while (p.tok.xkind != pxEof) and (p.tok.xkind != pxEnd):
addSon(e, parseStmt(p))
if sonsLen(e) == 0: addSon(e, newNodeP(nkNilLit, p))
addSon(result, e)
eat(p, pxEnd)
proc parseFor(p: var TParser): PNode =
result = newNodeP(nkForStmt, p)
getTok(p)
skipCom(p, result)
expectIdent(p)
addSon(result, createIdentNodeP(p.tok.ident, p))
getTok(p)
eat(p, pxAsgn)
var a = parseExpr(p)
var b = ast.emptyNode
var c = newNodeP(nkCall, p)
if p.tok.xkind == pxTo:
addSon(c, newIdentNodeP(getIdent("countup"), p))
getTok(p)
b = parseExpr(p)
elif p.tok.xkind == pxDownto:
addSon(c, newIdentNodeP(getIdent("countdown"), p))
getTok(p)
b = parseExpr(p)
else:
parMessage(p, errTokenExpected, tokKindToStr(pxTo))
addSon(c, a)
addSon(c, b)
eat(p, pxDo)
skipCom(p, result)
addSon(result, c)
addSon(result, parseStmt(p))
proc parseParam(p: var TParser): PNode =
var a: PNode
result = newNodeP(nkIdentDefs, p)
var v = ast.emptyNode
case p.tok.xkind
of pxConst:
getTok(p)
of pxVar:
getTok(p)
v = newNodeP(nkVarTy, p)
of pxOut:
getTok(p)
v = newNodeP(nkVarTy, p)
else:
discard
while true:
case p.tok.xkind
of pxSymbol: a = createIdentNodeP(p.tok.ident, p)
of pxColon, pxEof, pxParRi, pxEquals: break
else:
parMessage(p, errIdentifierExpected, $p.tok)
return
getTok(p) # skip identifier
skipCom(p, a)
if p.tok.xkind == pxComma:
getTok(p)
skipCom(p, a)
addSon(result, a)
if p.tok.xkind == pxColon:
getTok(p)
skipCom(p, result)
if v.kind != nkEmpty: addSon(v, parseTypeDesc(p))
else: v = parseTypeDesc(p)
addSon(result, v)
else:
addSon(result, ast.emptyNode)
if p.tok.xkind != pxEquals:
parMessage(p, errColonOrEqualsExpected, $p.tok)
if p.tok.xkind == pxEquals:
getTok(p)
skipCom(p, result)
addSon(result, parseExpr(p))
else:
addSon(result, ast.emptyNode)
proc parseParamList(p: var TParser): PNode =
var a: PNode
result = newNodeP(nkFormalParams, p)
addSon(result, ast.emptyNode) # return type
if p.tok.xkind == pxParLe:
p.inParamList = true
getTok(p)
skipCom(p, result)
while true:
case p.tok.xkind
of pxSymbol, pxConst, pxVar, pxOut:
a = parseParam(p)
of pxParRi:
getTok(p)
break
else:
parMessage(p, errTokenExpected, ")")
break
skipCom(p, a)
if p.tok.xkind == pxSemicolon:
getTok(p)
skipCom(p, a)
addSon(result, a)
p.inParamList = false
if p.tok.xkind == pxColon:
getTok(p)
skipCom(p, result)
result.sons[0] = parseTypeDesc(p)
proc parseCallingConvention(p: var TParser): PNode =
result = ast.emptyNode
if p.tok.xkind == pxSymbol:
case toLower(p.tok.ident.s)
of "stdcall", "cdecl", "safecall", "syscall", "inline", "fastcall":
result = newNodeP(nkPragma, p)
addSon(result, newIdentNodeP(p.tok.ident, p))
getTok(p)
opt(p, pxSemicolon)
of "register":
result = newNodeP(nkPragma, p)
addSon(result, newIdentNodeP(getIdent("fastcall"), p))
getTok(p)
opt(p, pxSemicolon)
else:
discard
proc parseRoutineSpecifiers(p: var TParser, noBody: var bool): PNode =
var e: PNode
result = parseCallingConvention(p)
noBody = false
while p.tok.xkind == pxSymbol:
case toLower(p.tok.ident.s)
of "assembler", "overload", "far":
getTok(p)
opt(p, pxSemicolon)
of "forward":
noBody = true
getTok(p)
opt(p, pxSemicolon)
of "importc":
# This is a fake for platform module. There is no ``importc``
# directive in Pascal.
if result.kind == nkEmpty: result = newNodeP(nkPragma, p)
addSon(result, newIdentNodeP(getIdent("importc"), p))
noBody = true
getTok(p)
opt(p, pxSemicolon)
of "noconv":
# This is a fake for platform module. There is no ``noconv``
# directive in Pascal.
if result.kind == nkEmpty: result = newNodeP(nkPragma, p)
addSon(result, newIdentNodeP(getIdent("noconv"), p))
noBody = true
getTok(p)
opt(p, pxSemicolon)
of "procvar":
# This is a fake for the Nim compiler. There is no ``procvar``
# directive in Pascal.
if result.kind == nkEmpty: result = newNodeP(nkPragma, p)
addSon(result, newIdentNodeP(getIdent("procvar"), p))
getTok(p)
opt(p, pxSemicolon)
of "varargs":
if result.kind == nkEmpty: result = newNodeP(nkPragma, p)
addSon(result, newIdentNodeP(getIdent("varargs"), p))
getTok(p)
opt(p, pxSemicolon)
of "external":
if result.kind == nkEmpty: result = newNodeP(nkPragma, p)
getTok(p)
noBody = true
e = newNodeP(nkExprColonExpr, p)
addSon(e, newIdentNodeP(getIdent("dynlib"), p))
addSon(e, parseExpr(p))
addSon(result, e)
opt(p, pxSemicolon)
if (p.tok.xkind == pxSymbol) and
(p.tok.ident.id == getIdent("name").id):
e = newNodeP(nkExprColonExpr, p)
getTok(p)
addSon(e, newIdentNodeP(getIdent("importc"), p))
addSon(e, parseExpr(p))
addSon(result, e)
else:
addSon(result, newIdentNodeP(getIdent("importc"), p))
opt(p, pxSemicolon)
else:
e = parseCallingConvention(p)
if e.kind == nkEmpty: break
if result.kind == nkEmpty: result = newNodeP(nkPragma, p)
addSon(result, e.sons[0])
proc parseRoutineType(p: var TParser): PNode =
result = newNodeP(nkProcTy, p)
getTok(p)
skipCom(p, result)
addSon(result, parseParamList(p))
opt(p, pxSemicolon)
addSon(result, parseCallingConvention(p))
skipCom(p, result)
proc parseEnum(p: var TParser): PNode =
var a: PNode
result = newNodeP(nkEnumTy, p)
getTok(p)
skipCom(p, result)
addSon(result, ast.emptyNode) # it does not inherit from any enumeration