diff options
| -rw-r--r-- | compiler/destroyer.nim | 59 | ||||
| -rw-r--r-- | todo.txt | 1 |
2 files changed, 58 insertions, 2 deletions
diff --git a/compiler/destroyer.nim b/compiler/destroyer.nim index 95997e3c8..e7ff00bb9 100644 --- a/compiler/destroyer.nim +++ b/compiler/destroyer.nim @@ -186,10 +186,67 @@ when false: of nkVarSection, nkLetSection: collectVarSection(c, n) else: discard +type + Con = object + owner: PSym + g: ControlFlowGraph + tmps: PType + +proc isHarmlessVar*(s: PSym; c: Con): bool = + # 's' is harmless if it used only once and its + # definition/usage are not split by any labels: + # + # let s = foo() + # while true: + # a[i] = s + # + # produces: + # + # def s + # L1: + # use s + # goto L1 + # + # let s = foo() + # if cond: + # a[i] = s + # else: + # a[j] = s + # + # produces: + # + # def s + # fork L2 + # use s + # goto L3 + # L2: + # use s + # L3 + # + # So this analysis is for now overly conservative, but correct. + discard + +template interestingSym(s: PSym): bool = + s.owner == owner and s.kind in InterestingSyms and hasDestructor(s.typ) + +proc p(n, parent: PNode; c: var Con) = + case n.kind + of nkVarSection, nkLetSection: + discard "transform; var x = y to var x; x op y where op is a move or copy" + of nkCallKinds: + if n.typ != nil and hasDestructor(n.typ): + discard "produce temp creation" + of nkAsgn, nkFastAsgn: + if n[0].kind == nkSym and interestingSym(n[0].sym): + discard "use move or assignment" + else: + for i in 0..<n.len: + p(n[i], n, c) + proc injectDestructorCalls*(owner: PSym; n: PNode; disableExceptions = false): PNode = when false: var c = Con(t: initTable[int, VarInfo](), owner: owner) collectData(c, n) var allTemps = createObj(owner, n.info) - + let cfg = constructCfg(owner, n) diff --git a/todo.txt b/todo.txt index f36a8a10c..87cb2b509 100644 --- a/todo.txt +++ b/todo.txt @@ -1,7 +1,6 @@ version 1.0 battle plan ======================= -- disallow conversions from ``array`` to ``cstring``! - make 'not nil' the default (produce warnings instead of errors for a smooth migration path) - case objects needs to be safe and need to support pattern matching |