diff options
Diffstat (limited to 'compiler/injectdestructors.nim')
| -rw-r--r-- | compiler/injectdestructors.nim | 60 |
1 files changed, 37 insertions, 23 deletions
diff --git a/compiler/injectdestructors.nim b/compiler/injectdestructors.nim index db4053fb3..033d5f3f9 100644 --- a/compiler/injectdestructors.nim +++ b/compiler/injectdestructors.nim @@ -139,7 +139,7 @@ import lineinfos, parampatterns const - InterestingSyms = {skVar, skResult, skLet, skForVar} + InterestingSyms = {skVar, skResult, skLet, skForVar, skTemp} type Con = object @@ -153,17 +153,24 @@ type uninit: IntSet # set of uninit'ed vars uninitComputed: bool -proc isLastRead(s: PSym; c: var Con; pc, comesFrom: int): int = +const toDebug = "" + +template dbg(body) = + when toDebug.len > 0: + if c.owner.name.s == toDebug or toDebug == "always": + body + +proc isLastRead(location: PNode; c: var Con; pc, comesFrom: int): int = var pc = pc while pc < c.g.len: case c.g[pc].kind of def: - if c.g[pc].sym == s: + if instrTargets(c.g[pc], location): # the path lead to a redefinition of 's' --> abandon it. return high(int) inc pc of use: - if c.g[pc].sym == s: + if instrTargets(c.g[pc], location): c.otherRead = c.g[pc].n return -1 inc pc @@ -171,9 +178,9 @@ proc isLastRead(s: PSym; c: var Con; pc, comesFrom: int): int = pc = pc + c.g[pc].dest of fork: # every branch must lead to the last read of the location: - var variantA = isLastRead(s, c, pc+1, pc) + var variantA = isLastRead(location, c, pc+1, pc) if variantA < 0: return -1 - let variantB = isLastRead(s, c, pc + c.g[pc].dest, pc) + let variantB = isLastRead(location, c, pc + c.g[pc].dest, pc) if variantB < 0: return -1 elif variantA == high(int): variantA = variantB @@ -186,11 +193,11 @@ proc isLastRead(s: PSym; c: var Con; pc, comesFrom: int): int = proc isLastRead(n: PNode; c: var Con): bool = # first we need to search for the instruction that belongs to 'n': - doAssert n.kind == nkSym c.otherRead = nil var instr = -1 for i in 0..<c.g.len: - if c.g[i].n == n: + # This comparison is correct and MUST not be ``instrTargets``: + if c.g[i].kind == use and c.g[i].n == n: if instr < 0: instr = i break @@ -199,8 +206,11 @@ proc isLastRead(n: PNode; c: var Con): bool = # we go through all paths beginning from 'instr+1' and need to # ensure that we don't find another 'use X' instruction. if instr+1 >= c.g.len: return true + dbg: + echo "beginning here ", instr + when true: - result = isLastRead(n.sym, c, instr+1, -1) >= 0 + result = isLastRead(n, c, instr+1, -1) >= 0 else: let s = n.sym var pcs: seq[int] = @[instr+1] @@ -507,6 +517,8 @@ proc pArg(arg: PNode; c: var Con; isSink: bool): PNode = branch = copyNode(arg[i]) branch.add pArgIfTyped(arg[i][0]) result.add branch + elif isAnalysableFieldAccess(arg, c.owner) and isLastRead(arg, c): + result = destructiveMoveVar(arg, c) else: # an object that is not temporary but passed to a 'sink' parameter # results in a copy. @@ -647,9 +659,15 @@ proc moveOrCopy(dest, ri: PNode; c: var Con): PNode = result = genCopy(c, dest.typ, dest, ri) result.add p(ri, c) else: - # XXX At least string literals can be moved? - result = genCopy(c, dest.typ, dest, ri) - result.add p(ri, c) + if isAnalysableFieldAccess(ri, c.owner) and isLastRead(ri, c): + # Rule 3: `=sink`(x, z); wasMoved(z) + var snk = genSink(c, dest.typ, dest, ri) + snk.add ri + result = newTree(nkStmtList, snk, genWasMoved(ri, c)) + else: + # XXX At least string literals can be moved? + result = genCopy(c, dest.typ, dest, ri) + result.add p(ri, c) proc computeUninit(c: var Con) = if not c.uninitComputed: @@ -785,10 +803,6 @@ proc p(n: PNode; c: var Con): PNode = recurse(n, result) proc injectDestructorCalls*(g: ModuleGraph; owner: PSym; n: PNode): PNode = - const toDebug = "" - when toDebug.len > 0: - if owner.name.s == toDebug or toDebug == "always": - echo "injecting into ", n if sfGeneratedOp in owner.flags or isInlineIterator(owner): return n var c: Con c.owner = owner @@ -802,8 +816,9 @@ proc injectDestructorCalls*(g: ModuleGraph; owner: PSym; n: PNode): PNode = for i in 0..<c.g.len: if c.g[i].kind in {goto, fork}: c.jumpTargets.incl(i+c.g[i].dest) - #if owner.name.s == "test0p1": - # echoCfg(c.g) + dbg: + echo "injecting into ", n + echoCfg(c.g) if owner.kind in {skProc, skFunc, skMethod, skIterator, skConverter}: let params = owner.typ.n for i in 1 ..< params.len: @@ -822,8 +837,7 @@ proc injectDestructorCalls*(g: ModuleGraph; owner: PSym; n: PNode): PNode = else: result.add body - when toDebug.len > 0: - if owner.name.s == toDebug or toDebug == "always": - echo "------------------------------------" - echo owner.name.s, " transformed to: " - echo result + dbg: + echo "------------------------------------" + echo owner.name.s, " transformed to: " + echo result |