Author: Eduardo Caldas Date: 2020-10-14T09:18:32Z New Revision: 4178f8f2f08e14abb341fb32dd0f4cc9320df072
URL: https://github.com/llvm/llvm-project/commit/4178f8f2f08e14abb341fb32dd0f4cc9320df072 DIFF: https://github.com/llvm/llvm-project/commit/4178f8f2f08e14abb341fb32dd0f4cc9320df072.diff LOG: [SyntaxTree] Improve safety of `replaceChildRangeLowLevel` * Add assertions for other preconditions. * If nothing is modified, don't mark it. Differential Revision: https://reviews.llvm.org/D89303 Added: Modified: clang/lib/Tooling/Syntax/Tree.cpp Removed: ################################################################################ diff --git a/clang/lib/Tooling/Syntax/Tree.cpp b/clang/lib/Tooling/Syntax/Tree.cpp index b558e7ab9a1b..74cd3c1f68b1 100644 --- a/clang/lib/Tooling/Syntax/Tree.cpp +++ b/clang/lib/Tooling/Syntax/Tree.cpp @@ -94,48 +94,65 @@ void syntax::Tree::prependChildLowLevel(Node *Child) { void syntax::Tree::replaceChildRangeLowLevel(Node *BeforeBegin, Node *End, Node *New) { - assert(!BeforeBegin || BeforeBegin->Parent == this); + assert((!BeforeBegin || BeforeBegin->Parent == this) && + "`BeforeBegin` is not a child of `this`."); + assert((!End || End->Parent == this) && "`End` is not a child of `this`."); + assert(canModify() && "Cannot modify `this`."); #ifndef NDEBUG - for (auto *N = New; N; N = N->getNextSibling()) { + for (auto *N = New; N; N = N->NextSibling) { assert(N->Parent == nullptr); assert(N->getRole() != NodeRole::Detached && "Roles must be set"); // FIXME: sanity-check the role. } + + auto Reachable = [](Node *From, Node *N) { + if (!N) + return true; + for (auto *It = From; It; It = It->NextSibling) + if (It == N) + return true; + return false; + }; + assert(Reachable(FirstChild, BeforeBegin) && + "`BeforeBegin` is not reachable."); + assert(Reachable(BeforeBegin ? BeforeBegin->NextSibling : FirstChild, End) && + "`End` is not after `BeforeBegin`."); #endif + Node *&Begin = BeforeBegin ? BeforeBegin->NextSibling : FirstChild; + + if (!New && Begin == End) + return; + + // Mark modification. + for (auto *T = this; T && T->Original; T = T->Parent) + T->Original = false; // Detach old nodes. - for (auto *N = !BeforeBegin ? FirstChild : BeforeBegin->getNextSibling(); - N != End;) { + for (auto *N = Begin; N != End;) { auto *Next = N->NextSibling; N->setRole(NodeRole::Detached); N->Parent = nullptr; N->NextSibling = nullptr; if (N->Original) - traverse(N, [&](Node *C) { C->Original = false; }); + traverse(N, [](Node *C) { C->Original = false; }); N = Next; } + if (!New) { + Begin = End; + return; + } // Attach new nodes. - if (BeforeBegin) - BeforeBegin->NextSibling = New ? New : End; - else - FirstChild = New ? New : End; - - if (New) { - auto *Last = New; - for (auto *N = New; N != nullptr; N = N->getNextSibling()) { - Last = N; - N->Parent = this; - } - Last->NextSibling = End; + Begin = New; + auto *Last = New; + for (auto *N = New; N != nullptr; N = N->NextSibling) { + Last = N; + N->Parent = this; } - - // Mark the node as modified. - for (auto *T = this; T && T->Original; T = T->Parent) - T->Original = false; + Last->NextSibling = End; } namespace { _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits