diff options
Diffstat (limited to 'compiler/semstmts.nim')
| -rw-r--r-- | compiler/semstmts.nim | 238 |
1 files changed, 188 insertions, 50 deletions
diff --git a/compiler/semstmts.nim b/compiler/semstmts.nim index 7ccc29d7e..f5f8fea0c 100644 --- a/compiler/semstmts.nim +++ b/compiler/semstmts.nim @@ -132,17 +132,141 @@ proc semExprBranchScope(c: PContext, n: PNode; expectedType: PType = nil): PNode closeScope(c) const - skipForDiscardable = {nkIfStmt, nkIfExpr, nkCaseStmt, nkOfBranch, - nkElse, nkStmtListExpr, nkTryStmt, nkFinally, nkExceptBranch, + skipForDiscardable = {nkStmtList, nkStmtListExpr, + nkOfBranch, nkElse, nkFinally, nkExceptBranch, nkElifBranch, nkElifExpr, nkElseExpr, nkBlockStmt, nkBlockExpr, - nkHiddenStdConv, nkHiddenDeref} + nkHiddenStdConv, nkHiddenSubConv, nkHiddenDeref} proc implicitlyDiscardable(n: PNode): bool = - var n = n - while n.kind in skipForDiscardable: n = n.lastSon - result = n.kind in nkLastBlockStmts or - (isCallExpr(n) and n[0].kind == nkSym and - sfDiscardable in n[0].sym.flags) + # same traversal as endsInNoReturn + template checkBranch(branch) = + if not implicitlyDiscardable(branch): + return false + + var it = n + # skip these beforehand, no special handling needed + while it.kind in skipForDiscardable and it.len > 0: + it = it.lastSon + + case it.kind + of nkIfExpr, nkIfStmt: + for branch in it: + checkBranch: + if branch.len == 2: + branch[1] + elif branch.len == 1: + branch[0] + else: + raiseAssert "Malformed `if` statement during implicitlyDiscardable" + # all branches are discardable + result = true + of nkCaseStmt: + for i in 1 ..< it.len: + let branch = it[i] + checkBranch: + case branch.kind + of nkOfBranch: + branch[^1] + of nkElifBranch: + branch[1] + of nkElse: + branch[0] + else: + raiseAssert "Malformed `case` statement in implicitlyDiscardable" + # all branches are discardable + result = true + of nkTryStmt: + checkBranch(it[0]) + for i in 1 ..< it.len: + let branch = it[i] + if branch.kind != nkFinally: + checkBranch(branch[^1]) + # all branches are discardable + result = true + of nkCallKinds: + result = it[0].kind == nkSym and {sfDiscardable, sfNoReturn} * it[0].sym.flags != {} + of nkLastBlockStmts: + result = true + else: + result = false + +proc endsInNoReturn(n: PNode, returningNode: var PNode; discardableCheck = false): bool = + ## check if expr ends the block like raising or call of noreturn procs do + result = false # assume it does return + + template checkBranch(branch) = + if not endsInNoReturn(branch, returningNode, discardableCheck): + # proved a branch returns + return false + + var it = n + # skip these beforehand, no special handling needed + let skips = if discardableCheck: skipForDiscardable else: skipForDiscardable-{nkBlockExpr, nkBlockStmt} + while it.kind in skips and it.len > 0: + it = it.lastSon + + case it.kind + of nkIfExpr, nkIfStmt: + var hasElse = false + for branch in it: + checkBranch: + if branch.len == 2: + branch[1] + elif branch.len == 1: + hasElse = true + branch[0] + else: + raiseAssert "Malformed `if` statement during endsInNoReturn" + # none of the branches returned + result = hasElse # Only truly a no-return when it's exhaustive + of nkCaseStmt: + let caseTyp = skipTypes(it[0].typ, abstractVar-{tyTypeDesc}) + # semCase should already have checked for exhaustiveness in this case + # effectively the same as having an else + var hasElse = caseTyp.shouldCheckCaseCovered() + + # actual noreturn checks + for i in 1 ..< it.len: + let branch = it[i] + checkBranch: + case branch.kind + of nkOfBranch: + branch[^1] + of nkElifBranch: + branch[1] + of nkElse: + hasElse = true + branch[0] + else: + raiseAssert "Malformed `case` statement in endsInNoReturn" + # Can only guarantee a noreturn if there is an else or it's exhaustive + result = hasElse + of nkTryStmt: + checkBranch(it[0]) + var lastIndex = it.len - 1 + if it[lastIndex].kind == nkFinally: + # if finally is noreturn, then the entire statement is noreturn + if endsInNoReturn(it[lastIndex][^1], returningNode, discardableCheck): + return true + dec lastIndex + for i in 1 .. lastIndex: + let branch = it[i] + checkBranch(branch[^1]) + # none of the branches returned + result = true + of nkLastBlockStmts: + result = true + of nkCallKinds: + result = it[0].kind == nkSym and sfNoReturn in it[0].sym.flags + if not result: + returningNode = it + else: + result = false + returningNode = it + +proc endsInNoReturn(n: PNode): bool = + var dummy: PNode = nil + result = endsInNoReturn(n, dummy) proc fixNilType(c: PContext; n: PNode) = if isAtom(n): @@ -160,18 +284,15 @@ proc discardCheck(c: PContext, result: PNode, flags: TExprFlags) = if implicitlyDiscardable(result): var n = newNodeI(nkDiscardStmt, result.info, 1) n[0] = result + # notes that it doesn't transform nodes into discard statements elif result.typ.kind != tyError and c.config.cmd != cmdInteractive: if result.typ.kind == tyNone: localError(c.config, result.info, "expression has no type: " & renderTree(result, {renderNoComments})) else: - var n = result - while n.kind in skipForDiscardable: - if n.kind == nkTryStmt: n = n[0] - else: n = n.lastSon - # Ignore noreturn procs since they don't have a type - if n.endsInNoReturn: + var n = result + if result.endsInNoReturn(n, discardableCheck = true): return var s = "expression '" & $n & "' is of type '" & @@ -361,7 +482,7 @@ proc identWithin(n: PNode, s: PIdent): bool = proc semIdentDef(c: PContext, n: PNode, kind: TSymKind, reportToNimsuggest = true): PSym = if isTopLevel(c): - result = semIdentWithPragma(c, kind, n, {sfExported}) + result = semIdentWithPragma(c, kind, n, {sfExported}, fromTopLevel = true) incl(result.flags, sfGlobal) #if kind in {skVar, skLet}: # echo "global variable here ", n.info, " ", result.name.s @@ -501,15 +622,15 @@ proc setVarType(c: PContext; v: PSym, typ: PType) = proc isPossibleMacroPragma(c: PContext, it: PNode, key: PNode): bool = # make sure it's not a normal pragma, and calls an identifier # considerQuotedIdent below will fail on non-identifiers - result = whichPragma(it) == wInvalid and key.kind in nkIdentKinds + result = whichPragma(it) == wInvalid and key.kind in nkIdentKinds+{nkDotExpr} if result: # make sure it's not a user pragma - let ident = considerQuotedIdent(c, key) - result = strTableGet(c.userPragmas, ident) == nil + if key.kind != nkDotExpr: + let ident = considerQuotedIdent(c, key) + result = strTableGet(c.userPragmas, ident) == nil if result: # make sure it's not a custom pragma - var amb = false - let sym = searchInScopes(c, ident, amb) + let sym = qualifiedLookUp(c, key, {}) result = sym == nil or sfCustomPragma notin sym.flags proc copyExcept(n: PNode, i: int): PNode = @@ -708,6 +829,11 @@ proc semVarOrLet(c: PContext, n: PNode, symkind: TSymKind): PNode = var typFlags: TTypeAllowedFlags = {} var def: PNode = c.graph.emptyNode + if typ != nil and typ.kind == tyRange and + c.graph.config.isDefined("nimPreviewRangeDefault") and + a[^1].kind == nkEmpty: + a[^1] = firstRange(c.config, typ) + if a[^1].kind != nkEmpty: def = semExprWithType(c, a[^1], {efTypeAllowed}, typ) @@ -859,6 +985,7 @@ proc semConst(c: PContext, n: PNode): PNode = var typFlags: TTypeAllowedFlags = {} # don't evaluate here since the type compatibility check below may add a converter + openScope(c) var def = semExprWithType(c, a[^1], {efTypeAllowed}, typ) if def.kind == nkSym and def.sym.kind in {skTemplate, skMacro}: @@ -885,6 +1012,7 @@ proc semConst(c: PContext, n: PNode): PNode = if c.matchedConcept != nil: typFlags.incl taConcept typeAllowedCheck(c, a.info, typ, skConst, typFlags) + closeScope(c) if a.kind == nkVarTuple: # generate new section from tuple unpacking and embed it into this one @@ -1103,7 +1231,7 @@ proc handleCaseStmtMacro(c: PContext; n: PNode; flags: TExprFlags): PNode = toResolve.add n[0] var errors: CandidateErrors = @[] - var r = resolveOverloads(c, toResolve, toResolve, {skTemplate, skMacro}, {efNoDiagnostics}, + var r = resolveOverloads(c, toResolve, toResolve, {skTemplate, skMacro}, {efNoUndeclared}, errors, false) if r.state == csMatch: var match = r.calleeSym @@ -1117,8 +1245,6 @@ proc handleCaseStmtMacro(c: PContext; n: PNode; flags: TExprFlags): PNode = of skMacro: result = semMacroExpr(c, toExpand, toExpand, match, flags) of skTemplate: result = semTemplateExpr(c, toExpand, match, flags) else: result = errorNode(c, n[0]) - elif r.state == csNoMatch: - result = errorNode(c, n[0]) else: result = errorNode(c, n[0]) if result.kind == nkEmpty: @@ -1589,21 +1715,27 @@ proc typeSectionRightSidePass(c: PContext, n: PNode) = for sk in c.skipTypes: discard semTypeNode(c, sk, nil) c.skipTypes = @[] -proc checkForMetaFields(c: PContext; n: PNode) = - proc checkMeta(c: PContext; n: PNode; t: PType) = - if t != nil and t.isMetaType and tfGenericTypeParam notin t.flags: + +proc checkForMetaFields(c: PContext; n: PNode; hasError: var bool) = + proc checkMeta(c: PContext; n: PNode; t: PType; hasError: var bool; parent: PType) = + if t != nil and (t.isMetaType or t.kind == tyNone) and tfGenericTypeParam notin t.flags: if t.kind == tyBuiltInTypeClass and t.len == 1 and t.elementType.kind == tyProc: localError(c.config, n.info, ("'$1' is not a concrete type; " & "for a callback without parameters use 'proc()'") % t.typeToString) + elif t.kind == tyNone and parent != nil: + # TODO: openarray has the `tfGenericTypeParam` flag & generics + # TODO: handle special cases (sink etc.) and views + localError(c.config, n.info, errTIsNotAConcreteType % parent.typeToString) else: localError(c.config, n.info, errTIsNotAConcreteType % t.typeToString) + hasError = true if n.isNil: return case n.kind of nkRecList, nkRecCase: - for s in n: checkForMetaFields(c, s) + for s in n: checkForMetaFields(c, s, hasError) of nkOfBranch, nkElse: - checkForMetaFields(c, n.lastSon) + checkForMetaFields(c, n.lastSon, hasError) of nkSym: let t = n.sym.typ case t.kind @@ -1611,9 +1743,9 @@ proc checkForMetaFields(c: PContext; n: PNode) = tyProc, tyGenericInvocation, tyGenericInst, tyAlias, tySink, tyOwned: let start = ord(t.kind in {tyGenericInvocation, tyGenericInst}) for i in start..<t.len: - checkMeta(c, n, t[i]) + checkMeta(c, n, t[i], hasError, t) else: - checkMeta(c, n, t) + checkMeta(c, n, t, hasError, nil) else: internalAssert c.config, false @@ -1648,13 +1780,16 @@ proc typeSectionFinalPass(c: PContext, n: PNode) = assert s.typ != nil assignType(s.typ, t) s.typ.itemId = t.itemId # same id - checkConstructedType(c.config, s.info, s.typ) - if s.typ.kind in {tyObject, tyTuple} and not s.typ.n.isNil: - checkForMetaFields(c, s.typ.n) - - # fix bug #5170, bug #17162, bug #15526: ensure locally scoped types get a unique name: - if s.typ.kind in {tyEnum, tyRef, tyObject} and not isTopLevel(c): - incl(s.flags, sfGenSym) + var hasError = false + let baseType = s.typ.safeSkipTypes(abstractPtrs) + if baseType.kind in {tyObject, tyTuple} and not baseType.n.isNil and + (x.kind in {nkObjectTy, nkTupleTy} or + (x.kind in {nkRefTy, nkPtrTy} and x.len == 1 and + x[0].kind in {nkObjectTy, nkTupleTy}) + ): + checkForMetaFields(c, baseType.n, hasError) + if not hasError: + checkConstructedType(c.config, s.info, s.typ) #instAllTypeBoundOp(c, n.info) @@ -2600,20 +2735,23 @@ proc incMod(c: PContext, n: PNode, it: PNode, includeStmtResult: PNode) = proc evalInclude(c: PContext, n: PNode): PNode = result = newNodeI(nkStmtList, n.info) result.add n + template checkAs(it: PNode) = + if it.kind == nkInfix and it.len == 3: + let op = it[0].getPIdent + if op != nil and op.id == ord(wAs): + localError(c.config, it.info, "Cannot use '" & it[0].renderTree & "' in 'include'.") for i in 0..<n.len: - var imp: PNode let it = n[i] - if it.kind == nkInfix and it.len == 3 and it[0].ident.s != "/": - localError(c.config, it.info, "Cannot use '" & it[0].ident.s & "' in 'include'.") - if it.kind == nkInfix and it.len == 3 and it[2].kind == nkBracket: - let sep = it[0] - let dir = it[1] - imp = newNodeI(nkInfix, it.info) - imp.add sep - imp.add dir - imp.add sep # dummy entry, replaced in the loop - for x in it[2]: - imp[2] = x + checkAs(it) + if it.kind in {nkInfix, nkPrefix} and it[^1].kind == nkBracket: + let lastPos = it.len - 1 + var imp = copyNode(it) + newSons(imp, it.len) + for i in 0 ..< lastPos: imp[i] = it[i] + imp[lastPos] = imp[0] # dummy entry, replaced in the loop + for x in it[lastPos]: + checkAs(x) + imp[lastPos] = x incMod(c, n, imp, result) else: incMod(c, n, it, result) @@ -2724,7 +2862,7 @@ proc semStmtList(c: PContext, n: PNode, flags: TExprFlags, expectedType: PType = let verdict = semConstExpr(c, n[i]) if verdict == nil or verdict.kind != nkIntLit or verdict.intVal == 0: localError(c.config, result.info, "concept predicate failed") - of tyUnknown: continue + of tyFromExpr: continue else: discard if n[i].typ == c.enforceVoidContext: #or usesResult(n[i]): voidContext = true |