diff options
Diffstat (limited to 'compiler/semexprs.nim')
| -rw-r--r-- | compiler/semexprs.nim | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/compiler/semexprs.nim b/compiler/semexprs.nim index 49beadc8b..f6226ad77 100644 --- a/compiler/semexprs.nim +++ b/compiler/semexprs.nim @@ -1301,13 +1301,20 @@ proc propertyWriteAccess(c: PContext, n, nOrig, a: PNode): PNode = #analyseIfAddressTakenInCall(c, result) proc takeImplicitAddr(c: PContext, n: PNode; isLent: bool): PNode = + # See RFC #7373, calls returning 'var T' are assumed to + # return a view into the first argument (if there is one): + let root = exprRoot(n) + if root != nil and root.owner == c.p.owner and + root.kind in {skLet, skVar, skTemp} and sfGlobal notin root.flags: + localError(n.info, "'$1' escapes its stack frame; context: '$2'" % [ + root.name.s, renderTree(n, {renderNoComments})]) case n.kind of nkHiddenAddr, nkAddr: return n of nkHiddenDeref, nkDerefExpr: return n.sons[0] of nkBracketExpr: if len(n) == 1: return n.sons[0] else: discard - var valid = isAssignable(c, n) + let valid = isAssignable(c, n) if valid != arLValue: if valid == arLocalLValue: localError(n.info, errXStackEscape, renderTree(n, {renderNoComments})) |