diff options
Diffstat (limited to 'compiler/parampatterns.nim')
| -rw-r--r-- | compiler/parampatterns.nim | 49 |
1 files changed, 28 insertions, 21 deletions
diff --git a/compiler/parampatterns.nim b/compiler/parampatterns.nim index 300abea1e..8c0875ab1 100644 --- a/compiler/parampatterns.nim +++ b/compiler/parampatterns.nim @@ -24,7 +24,7 @@ type ppEof = 1, # end of compiled pattern ppOr, # we could short-cut the evaluation for 'and' and 'or', ppAnd, # but currently we don't - ppNot, + ppNot, ppSym, ppAtom, ppLit, @@ -41,7 +41,7 @@ type const MaxStackSize* = 64 ## max required stack size by the VM -proc patternError(n: PNode) = +proc patternError(n: PNode) = localError(n.info, errIllFormedAstX, renderTree(n, {renderNoComments})) proc add(code: var TPatternCode, op: TOpcode) {.inline.} = @@ -56,7 +56,7 @@ proc whichAlias*(p: PSym): TAliasRequest = proc compileConstraints(p: PNode, result: var TPatternCode) = case p.kind of nkCallKinds: - if p.sons[0].kind != nkIdent: + if p.sons[0].kind != nkIdent: patternError(p.sons[0]) return let op = p.sons[0].ident @@ -168,13 +168,14 @@ proc checkForSideEffects(n: PNode): TSideEffectAnalysis = elif ret == seUnknown and result == seNoSideEffect: result = seUnknown -type - TAssignableResult* = enum +type + TAssignableResult* = enum arNone, # no l-value and no discriminant arLValue, # is an l-value arLocalLValue, # is an l-value, but local var; must not escape # its stack frame! - arDiscriminant # is a discriminant + arDiscriminant, # is a discriminant + arStrange # it is a strange beast like 'typedesc[var T]' proc isAssignable*(owner: PSym, n: PNode): TAssignableResult = ## 'owner' can be nil! @@ -183,26 +184,29 @@ proc isAssignable*(owner: PSym, n: PNode): TAssignableResult = of nkSym: # don't list 'skLet' here: if n.sym.kind in {skVar, skResult, skTemp}: - if owner != nil and owner.id == n.sym.owner.id and + if owner != nil and owner.id == n.sym.owner.id and sfGlobal notin n.sym.flags: result = arLocalLValue else: result = arLValue - of nkDotExpr: - if skipTypes(n.sons[0].typ, abstractInst-{tyTypeDesc}).kind in - {tyVar, tyPtr, tyRef}: + elif n.sym.kind == skType: + let t = n.sym.typ.skipTypes({tyTypeDesc}) + if t.kind == tyVar: result = arStrange + of nkDotExpr: + if skipTypes(n.sons[0].typ, abstractInst-{tyTypeDesc}).kind in + {tyVar, tyPtr, tyRef}: result = arLValue else: result = isAssignable(owner, n.sons[0]) - if result != arNone and sfDiscriminant in n.sons[1].sym.flags: + if result != arNone and sfDiscriminant in n.sons[1].sym.flags: result = arDiscriminant - of nkBracketExpr: + of nkBracketExpr: if skipTypes(n.sons[0].typ, abstractInst-{tyTypeDesc}).kind in - {tyVar, tyPtr, tyRef}: + {tyVar, tyPtr, tyRef}: result = arLValue else: result = isAssignable(owner, n.sons[0]) - of nkHiddenStdConv, nkHiddenSubConv, nkConv: + of nkHiddenStdConv, nkHiddenSubConv, nkConv: # Object and tuple conversions are still addressable, so we skip them # XXX why is 'tyOpenArray' allowed here? if skipTypes(n.typ, abstractPtrs-{tyTypeDesc}).kind in @@ -211,9 +215,9 @@ proc isAssignable*(owner: PSym, n: PNode): TAssignableResult = elif compareTypes(n.typ, n.sons[1].typ, dcEqIgnoreDistinct): # types that are equal modulo distinction preserve l-value: result = isAssignable(owner, n.sons[1]) - of nkHiddenDeref, nkDerefExpr: + of nkHiddenDeref, nkDerefExpr, nkHiddenAddr: result = arLValue - of nkObjUpConv, nkObjDownConv, nkCheckedFieldExpr: + of nkObjUpConv, nkObjDownConv, nkCheckedFieldExpr: result = isAssignable(owner, n.sons[0]) of nkCallKinds: # builtin slice keeps lvalue-ness: @@ -221,24 +225,27 @@ proc isAssignable*(owner: PSym, n: PNode): TAssignableResult = else: discard +proc isLValue*(n: PNode): bool = + isAssignable(nil, n) in {arLValue, arLocalLValue, arStrange} + proc matchNodeKinds*(p, n: PNode): bool = - # matches the parameter constraint 'p' against the concrete AST 'n'. + # matches the parameter constraint 'p' against the concrete AST 'n'. # Efficiency matters here. var stack {.noinit.}: array[0..MaxStackSize, bool] # empty patterns are true: stack[0] = true var sp = 1 - + template push(x: bool) = stack[sp] = x inc sp - + let code = p.strVal var pc = 1 while true: case TOpcode(code[pc]) of ppEof: break - of ppOr: + of ppOr: stack[sp-2] = stack[sp-1] or stack[sp-2] dec sp of ppAnd: @@ -264,4 +271,4 @@ proc matchNodeKinds*(p, n: PNode): bool = of ppNoSideEffect: push checkForSideEffects(n) != seSideEffect inc pc result = stack[sp-1] - + |