diff options
Diffstat (limited to 'compiler/dfa.nim')
| -rw-r--r-- | compiler/dfa.nim | 40 |
1 files changed, 15 insertions, 25 deletions
diff --git a/compiler/dfa.nim b/compiler/dfa.nim index 61a921ba0..5534d07e7 100644 --- a/compiler/dfa.nim +++ b/compiler/dfa.nim @@ -22,8 +22,9 @@ ## "A Graph–Free Approach to Data–Flow Analysis" by Markus Mohnen. ## https://link.springer.com/content/pdf/10.1007/3-540-45937-5_6.pdf -import ast, intsets, lineinfos, renderer, aliasanalysis +import ast, lineinfos, renderer, aliasanalysis import std/private/asciitables +import std/intsets when defined(nimPreviewSlimSystem): import std/assertions @@ -45,10 +46,10 @@ type case isTryBlock: bool of false: label: PSym - breakFixups: seq[(TPosition, seq[PNode])] #Contains the gotos for the breaks along with their pending finales + breakFixups: seq[(TPosition, seq[PNode])] # Contains the gotos for the breaks along with their pending finales of true: finale: PNode - raiseFixups: seq[TPosition] #Contains the gotos for the raises + raiseFixups: seq[TPosition] # Contains the gotos for the raises Con = object code: ControlFlowGraph @@ -60,6 +61,7 @@ type proc codeListing(c: ControlFlowGraph, start = 0; last = -1): string = # for debugging purposes # first iteration: compute all necessary labels: + result = "" var jumpTargets = initIntSet() let last = if last < 0: c.len-1 else: min(last, c.len-1) for i in start..last: @@ -111,7 +113,7 @@ proc patch(c: var Con, p: TPosition) = proc gen(c: var Con; n: PNode) proc popBlock(c: var Con; oldLen: int) = - var exits: seq[TPosition] + var exits: seq[TPosition] = @[] exits.add c.gotoI() for f in c.blocks[oldLen].breakFixups: c.patch(f[0]) @@ -128,10 +130,6 @@ template withBlock(labl: PSym; body: untyped) = body popBlock(c, oldLen) -proc isTrue(n: PNode): bool = - n.kind == nkSym and n.sym.kind == skEnumField and n.sym.position != 0 or - n.kind == nkIntLit and n.intVal != 0 - template forkT(body) = let lab1 = c.forkI() body @@ -183,14 +181,6 @@ proc genIf(c: var Con, n: PNode) = goto Lend3 L3: D - goto Lend3 # not eliminated to simplify the join generation - Lend3: - join F3 - Lend2: - join F2 - Lend: - join F1 - ]# var endings: seq[TPosition] = @[] let oldInteresting = c.interestingInstructions @@ -215,7 +205,6 @@ proc genAndOr(c: var Con; n: PNode) = # fork lab1 # asgn dest, b # lab1: - # join F1 c.gen(n[1]) forkT: c.gen(n[2]) @@ -263,8 +252,9 @@ proc genBreakOrRaiseAux(c: var Con, i: int, n: PNode) = if c.blocks[i].isTryBlock: c.blocks[i].raiseFixups.add lab1 else: - var trailingFinales: seq[PNode] - if c.inTryStmt > 0: #Ok, we are in a try, lets see which (if any) try's we break out from: + var trailingFinales: seq[PNode] = @[] + if c.inTryStmt > 0: + # Ok, we are in a try, lets see which (if any) try's we break out from: for b in countdown(c.blocks.high, i): if c.blocks[b].isTryBlock: trailingFinales.add c.blocks[b].finale @@ -325,7 +315,7 @@ proc genRaise(c: var Con; n: PNode) = if c.blocks[i].isTryBlock: genBreakOrRaiseAux(c, i, n) return - assert false #Unreachable + assert false # Unreachable else: genNoReturn(c) @@ -381,16 +371,16 @@ proc genCall(c: var Con; n: PNode) = if t != nil: t = t.skipTypes(abstractInst) for i in 1..<n.len: gen(c, n[i]) - if t != nil and i < t.len and isOutParam(t[i]): + if t != nil and i < t.signatureLen and isOutParam(t[i]): # Pass by 'out' is a 'must def'. Good enough for a move optimizer. genDef(c, n[i]) # every call can potentially raise: - if false: # c.inTryStmt > 0 and canRaiseConservative(n[0]): + if c.inTryStmt > 0 and canRaiseConservative(n[0]): + inc c.interestingInstructions # we generate the instruction sequence: # fork lab1 # goto exceptionHandler (except or finally) # lab1: - # join F1 forkT: for i in countdown(c.blocks.high, 0): if c.blocks[i].isTryBlock: @@ -467,7 +457,7 @@ proc gen(c: var Con; n: PNode) = of nkConv, nkExprColonExpr, nkExprEqExpr, nkCast, PathKinds1: gen(c, n[1]) of nkVarSection, nkLetSection: genVarSection(c, n) - of nkDefer: doAssert false, "dfa construction pass requires the elimination of 'defer'" + of nkDefer: raiseAssert "dfa construction pass requires the elimination of 'defer'" else: discard when false: @@ -493,7 +483,7 @@ proc constructCfg*(s: PSym; body: PNode; root: PSym): ControlFlowGraph = gen(c, body) if root.kind == skResult: genImplicitReturn(c) - when defined(gcArc) or defined(gcOrc): + when defined(gcArc) or defined(gcOrc) or defined(gcAtomicArc): result = c.code # will move else: shallowCopy(result, c.code) |