diff options
Diffstat (limited to 'lib/Analysis/CFG.cpp')
-rw-r--r-- | lib/Analysis/CFG.cpp | 68 |
1 files changed, 61 insertions, 7 deletions
diff --git a/lib/Analysis/CFG.cpp b/lib/Analysis/CFG.cpp index 96130c25be..0928fa2786 100644 --- a/lib/Analysis/CFG.cpp +++ b/lib/Analysis/CFG.cpp @@ -1,9 +1,8 @@ //===- CFG.cpp - Classes for representing and building CFGs ---------------===// // -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// // @@ -1379,6 +1378,15 @@ void CFGBuilder::findConstructionContexts( findConstructionContexts(Layer, CO->getRHS()); break; } + case Stmt::InitListExprClass: { + auto *ILE = cast<InitListExpr>(Child); + if (ILE->isTransparent()) { + findConstructionContexts(Layer, ILE->getInit(0)); + break; + } + // TODO: Handle other cases. For now, fail to find construction contexts. + break; + } default: break; } @@ -2459,7 +2467,8 @@ CFGBlock *CFGBuilder::VisitCallExpr(CallExpr *C, AddStmtChoice asc) { NoReturn = true; if (FD->hasAttr<NoThrowAttr>()) AddEHEdge = false; - if (FD->getBuiltinID() == Builtin::BI__builtin_object_size) + if (FD->getBuiltinID() == Builtin::BI__builtin_object_size || + FD->getBuiltinID() == Builtin::BI__builtin_dynamic_object_size) OmitArguments = true; } @@ -4330,8 +4339,8 @@ CFGBlock *CFGBuilder::VisitCXXNewExpr(CXXNewExpr *NE, if (BuildOpts.AddCXXNewAllocator) appendNewAllocator(Block, NE); - if (NE->isArray()) - Block = Visit(NE->getArraySize()); + if (NE->isArray() && *NE->getArraySize()) + Block = Visit(*NE->getArraySize()); for (CXXNewExpr::arg_iterator I = NE->placement_arg_begin(), E = NE->placement_arg_end(); I != E; ++I) @@ -4668,6 +4677,51 @@ std::unique_ptr<CFG> CFG::buildCFG(const Decl *D, Stmt *Statement, return Builder.buildCFG(D, Statement); } +bool CFG::isLinear() const { + // Quick path: if we only have the ENTRY block, the EXIT block, and some code + // in between, then we have no room for control flow. + if (size() <= 3) + return true; + + // Traverse the CFG until we find a branch. + // TODO: While this should still be very fast, + // maybe we should cache the answer. + llvm::SmallPtrSet<const CFGBlock *, 4> Visited; + const CFGBlock *B = Entry; + while (B != Exit) { + auto IteratorAndFlag = Visited.insert(B); + if (!IteratorAndFlag.second) { + // We looped back to a block that we've already visited. Not linear. + return false; + } + + // Iterate over reachable successors. + const CFGBlock *FirstReachableB = nullptr; + for (const CFGBlock::AdjacentBlock &AB : B->succs()) { + if (!AB.isReachable()) + continue; + + if (FirstReachableB == nullptr) { + FirstReachableB = &*AB; + } else { + // We've encountered a branch. It's not a linear CFG. + return false; + } + } + + if (!FirstReachableB) { + // We reached a dead end. EXIT is unreachable. This is linear enough. + return true; + } + + // There's only one way to move forward. Proceed. + B = FirstReachableB; + } + + // We reached EXIT and found no branches. + return true; +} + const CXXDestructorDecl * CFGImplicitDtor::getDestructorDecl(ASTContext &astContext) const { switch (getKind()) { |