diff options
Diffstat (limited to 'compiler/semmagic.nim')
| -rw-r--r-- | compiler/semmagic.nim | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/compiler/semmagic.nim b/compiler/semmagic.nim index 3c9784152..93170e530 100644 --- a/compiler/semmagic.nim +++ b/compiler/semmagic.nim @@ -130,6 +130,11 @@ proc semLocals(c: PContext, n: PNode): PNode = result.add(a) proc semShallowCopy(c: PContext, n: PNode, flags: TExprFlags): PNode + +proc isStrangeArray(t: PType): bool = + let t = t.skipTypes(abstractInst) + result = t.kind == tyArray and t.firstOrd != 0 + proc magicsAfterOverloadResolution(c: PContext, n: PNode, flags: TExprFlags): PNode = case n[0].sym.magic @@ -153,4 +158,29 @@ proc magicsAfterOverloadResolution(c: PContext, n: PNode, of mProcCall: result = n result.typ = n[1].typ + of mRoof: + # error correction: + result = n.sons[1] + if c.p.bracketExpr.isNil: + localError(n.info, "no surrounding array access context for '^'") + elif c.p.bracketExpr.checkForSideEffects != seNoSideEffect: + localError(n.info, "invalid context for '^' as '$#' has side effects" % + renderTree(c.p.bracketExpr)) + elif c.p.bracketExpr.typ.isStrangeArray: + localError(n.info, "invalid context for '^' as len!=high+1 for '$#'" % + renderTree(c.p.bracketExpr)) + else: + # ^x is rewritten to: len(a)-x + let lenExpr = newNodeI(nkCall, n.info) + lenExpr.add newIdentNode(getIdent"len", n.info) + lenExpr.add c.p.bracketExpr + let lenExprB = semExprWithType(c, lenExpr) + if lenExprB.typ.isNil or not isOrdinalType(lenExprB.typ): + localError(n.info, "'$#' has to be of an ordinal type for '^'" % + renderTree(lenExpr)) + else: + result = newNodeIT(nkCall, n.info, getSysType(tyInt)) + result.add newSymNode(createMagic("-", mSubI), n.info) + result.add lenExprB + result.add n.sons[1] else: result = n |