diff options
| -rw-r--r-- | compiler/semexprs.nim | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/compiler/semexprs.nim b/compiler/semexprs.nim index 1c7115cd0..99ffa9b54 100644 --- a/compiler/semexprs.nim +++ b/compiler/semexprs.nim @@ -176,21 +176,26 @@ proc checkConvertible(c: PContext, castDest, src: PType): TConvStatus = else: discard -proc isCastable(dst, src: PType): bool = +proc isCastable(dst, src: PType): bool = + ## Checks whether the source type can be casted to the destination type. + ## Casting is very unrestrictive; casts are allowed as long as + ## castDest.size >= src.size, and typeAllowed(dst, skParam) #const # castableTypeKinds = {tyInt, tyPtr, tyRef, tyCstring, tyString, # tySequence, tyPointer, tyNil, tyOpenArray, # tyProc, tySet, tyEnum, tyBool, tyChar} - var ds, ss: BiggestInt - # this is very unrestrictive; cast is allowed if castDest.size >= src.size - ds = computeSize(dst) - ss = computeSize(src) - if ds < 0: + var dstSize, srcSize: BiggestInt + + dstSize = computeSize(dst) + srcSize = computeSize(src) + if dstSize < 0: + result = false + elif srcSize < 0: result = false - elif ss < 0: + elif not typeAllowed(dst, skParam): result = false else: - result = (ds >= ss) or + result = (dstSize >= srcSize) or (skipTypes(dst, abstractInst).kind in IntegralTypes) or (skipTypes(src, abstractInst-{tyTypeDesc}).kind in IntegralTypes) @@ -254,6 +259,7 @@ proc semConv(c: PContext, n: PNode): PNode = localError(n.info, errUseQualifier, op.sons[0].sym.name.s) proc semCast(c: PContext, n: PNode): PNode = + ## Semantically analyze a casting ("cast[type](param)") if optSafeCode in gGlobalOptions: localError(n.info, errCastNotInSafeMode) #incl(c.p.owner.flags, sfSideEffect) checkSonsLen(n, 2) |