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#
#
# The Nimrod Compiler
# (c) Copyright 2011 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
#
# This module implements the searching for procs and iterators.
# This is needed for proper handling of forward declarations.
import
ast, astalgo, msgs, semdata, types, trees
proc SearchForProc*(c: PContext, fn: PSym, tos: int): PSym
# Searchs for the fn in the symbol table. If the parameter lists are exactly
# the same the sym in the symbol table is returned, else nil.
proc SearchForBorrowProc*(c: PContext, fn: PSym, tos: int): PSym
# Searchs for the fn in the symbol table. If the parameter lists are suitable
# for borrowing the sym in the symbol table is returned, else nil.
# implementation
proc equalGenericParams(procA, procB: PNode): bool =
var a, b: PSym
result = procA == procB
if result: return
if (procA == nil) or (procB == nil): return
if sonsLen(procA) != sonsLen(procB): return
for i in countup(0, sonsLen(procA) - 1):
if procA.sons[i].kind != nkSym:
InternalError(procA.info, "equalGenericParams")
if procB.sons[i].kind != nkSym:
InternalError(procB.info, "equalGenericParams")
a = procA.sons[i].sym
b = procB.sons[i].sym
if (a.name.id != b.name.id) or not sameTypeOrNil(a.typ, b.typ): return
if (a.ast != nil) and (b.ast != nil):
if not ExprStructuralEquivalent(a.ast, b.ast): return
result = true
proc SearchForProc(c: PContext, fn: PSym, tos: int): PSym =
var it: TIdentIter
result = initIdentIter(it, c.tab.stack[tos], fn.Name)
while result != nil:
if (result.Kind == fn.kind):
if equalGenericParams(result.ast.sons[genericParamsPos],
fn.ast.sons[genericParamsPos]):
case equalParams(result.typ.n, fn.typ.n)
of paramsEqual:
return
of paramsIncompatible:
LocalError(fn.info, errNotOverloadable, fn.name.s)
return
of paramsNotEqual:
nil
result = NextIdentIter(it, c.tab.stack[tos])
proc paramsFitBorrow(a, b: PNode): bool =
var length = sonsLen(a)
result = false
if length == sonsLen(b):
for i in countup(1, length - 1):
var m = a.sons[i].sym
var n = b.sons[i].sym
assert((m.kind == skParam) and (n.kind == skParam))
if not equalOrDistinctOf(m.typ, n.typ): return
if not equalOrDistinctOf(a.sons[0].typ, b.sons[0].typ): return
result = true
proc SearchForBorrowProc(c: PContext, fn: PSym, tos: int): PSym =
# Searchs for the fn in the symbol table. If the parameter lists are suitable
# for borrowing the sym in the symbol table is returned, else nil.
var it: TIdentIter
for scope in countdown(tos, 0):
result = initIdentIter(it, c.tab.stack[scope], fn.Name)
while result != nil:
# watchout! result must not be the same as fn!
if (result.Kind == fn.kind) and (result.id != fn.id):
if equalGenericParams(result.ast.sons[genericParamsPos],
fn.ast.sons[genericParamsPos]):
if paramsFitBorrow(fn.typ.n, result.typ.n): return
result = NextIdentIter(it, c.tab.stack[scope])
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