diff --git a/changelog.md b/changelog.md index 8ebcd066e3..67877183c6 100644 --- a/changelog.md +++ b/changelog.md @@ -30,30 +30,38 @@ slots when enlarging a sequence. -- An experimental option `genericsOpenSym` has been added to allow captured - symbols in generic routine bodies to be replaced by symbols injected locally - by templates/macros at instantiation time. `bind` may be used to keep the - captured symbols over the injected ones regardless of enabling the option, - but other methods like renaming the captured symbols should be used instead - so that the code is not affected by context changes. +- The experimental option `--experimental:openSym` has been added to allow + captured symbols in generic routine and template bodies respectively to be + replaced by symbols injected locally by templates/macros at instantiation + time. `bind` may be used to keep the captured symbols over the injected ones + regardless of enabling the option, but other methods like renaming the + captured symbols should be used instead so that the code is not affected by + context changes. Since this change may affect runtime behavior, the experimental switch - `genericsOpenSym` needs to be enabled, and a warning is given in the case - where an injected symbol would replace a captured symbol not bound by `bind` - and the experimental switch isn't enabled. + `openSym`, or `genericsOpenSym` and `templateOpenSym` for only the respective + routines, needs to be enabled; and a warning is given in the case where an + injected symbol would replace a captured symbol not bound by `bind` and + the experimental switch isn't enabled. ```nim const value = "captured" - template foo(x: int, body: untyped) = + template foo(x: int, body: untyped): untyped = let value {.inject.} = "injected" body proc old[T](): string = foo(123): - return value # warning: a new `value` has been injected, use `bind` or turn on `experimental:genericsOpenSym` + return value # warning: a new `value` has been injected, use `bind` or turn on `experimental:openSym` echo old[int]() # "captured" - {.experimental: "genericsOpenSym".} + template oldTempl(): string = + block: + foo(123): + value # warning: a new `value` has been injected, use `bind` or turn on `experimental:openSym` + echo oldTempl() # "captured" + + {.experimental: "openSym".} # or {.experimental: "genericsOpenSym".} for just generic procs proc bar[T](): string = foo(123): @@ -65,14 +73,28 @@ slots when enlarging a sequence. foo(123): return value assert baz[int]() == "captured" + + # {.experimental: "templateOpenSym".} would be needed here if genericsOpenSym was used + + template barTempl(): string = + block: + foo(123): + value + assert barTempl() == "injected" # previously it would be "captured" + + template bazTempl(): string = + bind value + block: + foo(123): + value + assert bazTempl() == "captured" ``` This option also generates a new node kind `nnkOpenSym` which contains - exactly 1 of either an `nnkSym` or an `nnkOpenSymChoice` node. In the future - this might be merged with a slightly modified `nnkOpenSymChoice` node but - macros that want to support the experimental feature should still handle - `nnkOpenSym`, as the node kind would simply not be generated as opposed to - being removed. + exactly 1 `nnkSym` node. In the future this might be merged with a slightly + modified `nnkOpenSymChoice` node but macros that want to support the + experimental feature should still handle `nnkOpenSym`, as the node kind would + simply not be generated as opposed to being removed. ## Compiler changes diff --git a/compiler/ast.nim b/compiler/ast.nim index ad3c1578cf..b0a8ee6398 100644 --- a/compiler/ast.nim +++ b/compiler/ast.nim @@ -519,7 +519,7 @@ type nfHasComment # node has a comment nfSkipFieldChecking # node skips field visable checking nfDisabledOpenSym # temporary: node should be nkOpenSym but cannot - # because genericsOpenSym experimental switch is disabled + # because openSym experimental switch is disabled # gives warning instead TNodeFlags* = set[TNodeFlag] @@ -1110,7 +1110,7 @@ const nkCallKinds* = {nkCall, nkInfix, nkPrefix, nkPostfix, nkCommand, nkCallStrLit, nkHiddenCallConv} nkIdentKinds* = {nkIdent, nkSym, nkAccQuoted, nkOpenSymChoice, - nkClosedSymChoice} + nkClosedSymChoice, nkOpenSym} nkPragmaCallKinds* = {nkExprColonExpr, nkCall, nkCallStrLit} nkLiterals* = {nkCharLit..nkTripleStrLit} @@ -1457,6 +1457,9 @@ proc newSymNode*(sym: PSym, info: TLineInfo): PNode = result.typ = sym.typ result.info = info +proc newOpenSym*(n: PNode): PNode {.inline.} = + result = newTreeI(nkOpenSym, n.info, n) + proc newIntNode*(kind: TNodeKind, intVal: BiggestInt): PNode = result = newNode(kind) result.intVal = intVal diff --git a/compiler/lineinfos.nim b/compiler/lineinfos.nim index 589ef98b60..42e08339d0 100644 --- a/compiler/lineinfos.nim +++ b/compiler/lineinfos.nim @@ -91,7 +91,7 @@ type warnStmtListLambda = "StmtListLambda", warnBareExcept = "BareExcept", warnImplicitDefaultValue = "ImplicitDefaultValue", - warnGenericsIgnoredInjection = "GenericsIgnoredInjection", + warnIgnoredSymbolInjection = "IgnoredSymbolInjection", warnUser = "User", # hints hintSuccess = "Success", hintSuccessX = "SuccessX", @@ -195,7 +195,7 @@ const warnStmtListLambda: "statement list expression assumed to be anonymous proc; this is deprecated, use `do (): ...` or `proc () = ...` instead", warnBareExcept: "$1", warnImplicitDefaultValue: "$1", - warnGenericsIgnoredInjection: "$1", + warnIgnoredSymbolInjection: "$1", warnUser: "$1", hintSuccess: "operation successful: $#", # keep in sync with `testament.isSuccess` diff --git a/compiler/lookups.nim b/compiler/lookups.nim index 20e2442f87..d9a23eeb55 100644 --- a/compiler/lookups.nim +++ b/compiler/lookups.nim @@ -48,7 +48,7 @@ proc considerQuotedIdent*(c: PContext; n: PNode, origin: PNode = nil): PIdent = case x.kind of nkIdent: id.add(x.ident.s) of nkSym: id.add(x.sym.name.s) - of nkSymChoices: + of nkSymChoices, nkOpenSym: if x[0].kind == nkSym: id.add(x[0].sym.name.s) else: @@ -664,6 +664,8 @@ proc qualifiedLookUp*(c: PContext, n: PNode, flags: set[TLookupFlag]): PSym = c.isAmbiguous = amb of nkSym: result = n.sym + of nkOpenSym: + result = qualifiedLookUp(c, n[0], flags) of nkDotExpr: result = nil var m = qualifiedLookUp(c, n[0], (flags * {checkUndeclared}) + {checkModule}) diff --git a/compiler/options.nim b/compiler/options.nim index 255bd5d94b..7b5f55bbd2 100644 --- a/compiler/options.nim +++ b/compiler/options.nim @@ -221,7 +221,9 @@ type flexibleOptionalParams, strictDefs, strictCaseObjects, - genericsOpenSym # remove nfDisabledOpenSym when this switch is default + openSym, # remove nfDisabledOpenSym when this is default + # separated alternatives to above: + genericsOpenSym, templateOpenSym LegacyFeature* = enum allowSemcheckedAstModification, diff --git a/compiler/semexprs.nim b/compiler/semexprs.nim index 80c5fd0840..62bae7ab84 100644 --- a/compiler/semexprs.nim +++ b/compiler/semexprs.nim @@ -138,25 +138,6 @@ proc resolveSymChoice(c: PContext, n: var PNode, flags: TExprFlags = {}, expecte # to mirror behavior before overloadable enums n = n[0] -proc semSymChoice(c: PContext, n: PNode, flags: TExprFlags = {}, expectedType: PType = nil): PNode = - result = n - resolveSymChoice(c, result, flags, expectedType) - if isSymChoice(result) and result.len == 1: - # resolveSymChoice can leave 1 sym - result = result[0] - if isSymChoice(result) and efAllowSymChoice notin flags: - var err = "ambiguous identifier: '" & result[0].sym.name.s & - "' -- use one of the following:\n" - for child in n: - let candidate = child.sym - err.add " " & candidate.owner.name.s & "." & candidate.name.s - err.add ": " & typeToString(candidate.typ) & "\n" - localError(c.config, n.info, err) - n.typ = errorType(c) - result = n - if result.kind == nkSym: - result = semSym(c, result, result.sym, flags) - proc semOpenSym(c: PContext, n: PNode, flags: TExprFlags, expectedType: PType, warnDisabled = false): PNode = ## sem the child of an `nkOpenSym` node, that is, captured symbols that can be @@ -189,23 +170,24 @@ proc semOpenSym(c: PContext, n: PNode, flags: TExprFlags, expectedType: PType, else: var msg = "a new symbol '" & ident.s & "' has been injected during " & - "instantiation of " & c.p.owner.name.s & ", however " + # msgContext should show what is being instantiated: + "template or generic instantiation, however " if isSym: msg.add( getSymRepr(c.config, n.sym) & " captured at " & "the proc declaration will be used instead; " & - "either enable --experimental:genericsOpenSym to use the " & - "injected symbol or `bind` this captured symbol explicitly") + "either enable --experimental:openSym to use the injected symbol, " & + "or `bind` this captured symbol explicitly") else: msg.add( "overloads of " & ident.s & " will be used instead; " & - "either enable --experimental:genericsOpenSym to use the " & - "injected symbol or `bind` this symbol explicitly") - message(c.config, n.info, warnGenericsIgnoredInjection, msg) + "either enable --experimental:openSym to use the injected symbol, " & + "or `bind` this symbol explicitly") + message(c.config, n.info, warnIgnoredSymbolInjection, msg) break o = o.owner # nothing found - if not warnDisabled: + if not warnDisabled and isSym: result = semExpr(c, n, flags, expectedType) else: result = nil @@ -213,6 +195,29 @@ proc semOpenSym(c: PContext, n: PNode, flags: TExprFlags, expectedType: PType, # set symchoice node type back to None n.typ = newTypeS(tyNone, c) +proc semSymChoice(c: PContext, n: PNode, flags: TExprFlags = {}, expectedType: PType = nil): PNode = + if n.kind == nkOpenSymChoice: + result = semOpenSym(c, n, flags, expectedType, warnDisabled = nfDisabledOpenSym in n.flags) + if result != nil: + return + result = n + resolveSymChoice(c, result, flags, expectedType) + if isSymChoice(result) and result.len == 1: + # resolveSymChoice can leave 1 sym + result = result[0] + if isSymChoice(result) and efAllowSymChoice notin flags: + var err = "ambiguous identifier: '" & result[0].sym.name.s & + "' -- use one of the following:\n" + for child in n: + let candidate = child.sym + err.add " " & candidate.owner.name.s & "." & candidate.name.s + err.add ": " & typeToString(candidate.typ) & "\n" + localError(c.config, n.info, err) + n.typ = errorType(c) + result = n + if result.kind == nkSym: + result = semSym(c, result, result.sym, flags) + proc inlineConst(c: PContext, n: PNode, s: PSym): PNode {.inline.} = result = copyTree(s.astdef) if result.isNil: @@ -1758,7 +1763,7 @@ proc semSubscript(c: PContext, n: PNode, flags: TExprFlags): PNode = result = nil else: let s = if n[0].kind == nkSym: n[0].sym - elif n[0].kind in nkSymChoices: n[0][0].sym + elif n[0].kind in nkSymChoices + {nkOpenSym}: n[0][0].sym else: nil if s != nil: case s.kind @@ -3201,9 +3206,6 @@ proc semExpr(c: PContext, n: PNode, flags: TExprFlags = {}, expectedType: PType if isSymChoice(result): result = semSymChoice(c, result, flags, expectedType) of nkClosedSymChoice, nkOpenSymChoice: - if nfDisabledOpenSym in n.flags: - let res = semOpenSym(c, n, flags, expectedType, warnDisabled = true) - assert res == nil result = semSymChoice(c, n, flags, expectedType) of nkSym: let s = n.sym diff --git a/compiler/semgnrc.nim b/compiler/semgnrc.nim index d4482b1c3a..b93944c772 100644 --- a/compiler/semgnrc.nim +++ b/compiler/semgnrc.nim @@ -59,9 +59,6 @@ template isMixedIn(sym): bool = template canOpenSym(s): bool = {withinMixin, withinConcept} * flags == {withinMixin} and s.id notin ctx.toBind -proc newOpenSym*(n: PNode): PNode {.inline.} = - result = newTreeI(nkOpenSym, n.info, n) - proc semGenericStmtSymbol(c: PContext, n: PNode, s: PSym, ctx: var GenericCtx; flags: TSemGenericFlags, fromDotExpr=false): PNode = @@ -75,8 +72,11 @@ proc semGenericStmtSymbol(c: PContext, n: PNode, s: PSym, else: result = symChoice(c, n, s, scOpen) if canOpenSym(s): - if genericsOpenSym in c.features: - result = newOpenSym(result) + if {openSym, genericsOpenSym} * c.features != {}: + if result.kind == nkSym: + result = newOpenSym(result) + else: + result.typ = nil else: result.flags.incl nfDisabledOpenSym result.typ = nil @@ -108,7 +108,7 @@ proc semGenericStmtSymbol(c: PContext, n: PNode, s: PSym, else: result = newSymNodeTypeDesc(s, c.idgen, n.info) if canOpenSym(result.sym): - if genericsOpenSym in c.features: + if {openSym, genericsOpenSym} * c.features != {}: result = newOpenSym(result) else: result.flags.incl nfDisabledOpenSym @@ -122,7 +122,7 @@ proc semGenericStmtSymbol(c: PContext, n: PNode, s: PSym, (s.typ.flags * {tfGenericTypeParam, tfImplicitTypeParam} == {}): result = newSymNodeTypeDesc(s, c.idgen, n.info) if canOpenSym(result.sym): - if genericsOpenSym in c.features: + if {openSym, genericsOpenSym} * c.features != {}: result = newOpenSym(result) else: result.flags.incl nfDisabledOpenSym @@ -133,7 +133,7 @@ proc semGenericStmtSymbol(c: PContext, n: PNode, s: PSym, else: result = newSymNode(s, n.info) if canOpenSym(result.sym): - if genericsOpenSym in c.features: + if {openSym, genericsOpenSym} * c.features != {}: result = newOpenSym(result) else: result.flags.incl nfDisabledOpenSym diff --git a/compiler/semtempl.nim b/compiler/semtempl.nim index 0fc8f36366..581e2b98fb 100644 --- a/compiler/semtempl.nim +++ b/compiler/semtempl.nim @@ -217,43 +217,60 @@ proc addLocalDecl(c: var TemplCtx, n: var PNode, k: TSymKind) = if k == skParam and c.inTemplateHeader > 0: local.flags.incl sfTemplateParam -proc semTemplSymbol(c: PContext, n: PNode, s: PSym; isField: bool): PNode = +proc semTemplSymbol(c: var TemplCtx, n: PNode, s: PSym; isField: bool): PNode = incl(s.flags, sfUsed) # bug #12885; ideally sem'checking is performed again afterwards marking # the symbol as used properly, but the nfSem mechanism currently prevents # that from happening, so we mark the module as used here already: - markOwnerModuleAsUsed(c, s) + markOwnerModuleAsUsed(c.c, s) # we do not call onUse here, as the identifier is not really # resolved here. We will fixup the used identifiers later. case s.kind of skUnknown: # Introduced in this pass! Leave it as an identifier. result = n - of OverloadableSyms-{skTemplate,skMacro}: - result = symChoice(c, n, s, scOpen, isField) - of skTemplate, skMacro: - result = symChoice(c, n, s, scOpen, isField) - if result.kind == nkSym: - # template/macro symbols might need to be semchecked again - # prepareOperand etc don't do this without setting the type to nil - result.typ = nil + of OverloadableSyms: + result = symChoice(c.c, n, s, scOpen, isField) + if not isField and result.kind in {nkSym, nkOpenSymChoice}: + if {openSym, templateOpenSym} * c.c.features != {}: + if result.kind == nkSym: + result = newOpenSym(result) + else: + result.typ = nil + else: + result.flags.incl nfDisabledOpenSym + result.typ = nil of skGenericParam: if isField and sfGenSym in s.flags: result = n - else: result = newSymNodeTypeDesc(s, c.idgen, n.info) + else: + result = newSymNodeTypeDesc(s, c.c.idgen, n.info) + if not isField and s.owner != c.owner: + if {openSym, templateOpenSym} * c.c.features != {}: + result = newOpenSym(result) + else: + result.flags.incl nfDisabledOpenSym + result.typ = nil of skParam: result = n of skType: if isField and sfGenSym in s.flags: result = n - else: result = newSymNodeTypeDesc(s, c.idgen, n.info) + else: result = newSymNodeTypeDesc(s, c.c.idgen, n.info) else: if isField and sfGenSym in s.flags: result = n - else: result = newSymNode(s, n.info) + else: + result = newSymNode(s, n.info) + if not isField: + if {openSym, templateOpenSym} * c.c.features != {}: + result = newOpenSym(result) + else: + result.flags.incl nfDisabledOpenSym + result.typ = nil # Issue #12832 when defined(nimsuggest): - suggestSym(c.graph, n.info, s, c.graph.usageSym, false) + suggestSym(c.c.graph, n.info, s, c.c.graph.usageSym, false) # field access (dot expr) will be handled by builtinFieldAccess if not isField: - styleCheckUse(c, n.info, s) + styleCheckUse(c.c, n.info, s) proc semRoutineInTemplName(c: var TemplCtx, n: PNode, explicitInject: bool): PNode = result = n @@ -363,7 +380,7 @@ proc semTemplBody(c: var TemplCtx, n: PNode): PNode = else: if s.kind in {skType, skVar, skLet, skConst}: discard qualifiedLookUp(c.c, n, {checkAmbiguity, checkModule}) - result = semTemplSymbol(c.c, n, s, c.noGenSym > 0) + result = semTemplSymbol(c, n, s, c.noGenSym > 0) of nkBind: result = semTemplBody(c, n[0]) of nkBindStmt: @@ -573,7 +590,7 @@ proc semTemplBody(c: var TemplCtx, n: PNode): PNode = else: if s.kind in {skType, skVar, skLet, skConst}: discard qualifiedLookUp(c.c, n, {checkAmbiguity, checkModule}) - return semTemplSymbol(c.c, n, s, c.noGenSym > 0) + return semTemplSymbol(c, n, s, c.noGenSym > 0) if n.kind == nkDotExpr: result = n result[0] = semTemplBody(c, n[0]) diff --git a/compiler/semtypes.nim b/compiler/semtypes.nim index 9deb090b50..be05c7d1f7 100644 --- a/compiler/semtypes.nim +++ b/compiler/semtypes.nim @@ -1251,7 +1251,7 @@ proc semParamType(c: PContext, n: PNode, constraint: var PNode): PType = result = semTypeNode(c, n[0], nil) constraint = semNodeKindConstraints(n, c.config, 1) elif n.kind == nkCall and - n[0].kind in {nkIdent, nkSym, nkOpenSymChoice, nkClosedSymChoice} and + n[0].kind in {nkIdent, nkSym, nkOpenSymChoice, nkClosedSymChoice, nkOpenSym} and considerQuotedIdent(c, n[0]).s == "{}": result = semTypeNode(c, n[1], nil) constraint = semNodeKindConstraints(n, c.config, 2) @@ -1916,11 +1916,7 @@ proc semTypeNode(c: PContext, n: PNode, prev: PType): PType = of nkTupleConstr: result = semAnonTuple(c, n, prev) of nkCallKinds: let x = n[0] - let ident = case x.kind - of nkIdent: x.ident - of nkSym: x.sym.name - of nkClosedSymChoice, nkOpenSymChoice: x[0].sym.name - else: nil + let ident = x.getPIdent if ident != nil and ident.s == "[]": let b = newNodeI(nkBracketExpr, n.info) for i in 1..