692e03039d
This patch modifies context-sensitive analysis of functions to use a cache, rather than recreate the `ControlFlowContext` from a function decl on each encounter. However, this is just step 1 (of N) in adding support for a configurable map of "modeled" function decls (see issue #56879). The map will go from the actual function decl to the `ControlFlowContext` used to model it. Only functions pre-configured in the map will be modeled in a context-sensitive way. We start with a cache because it introduces the desired map, while retaining the current behavior. Here, functions are mapped to their actual implementations (when available). Differential Revision: https://reviews.llvm.org/D131039
79 lines
2.5 KiB
C++
79 lines
2.5 KiB
C++
//===- ControlFlowContext.cpp ---------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines a ControlFlowContext class that is used by dataflow
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// analyses that run over Control-Flow Graphs (CFGs).
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//
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//===----------------------------------------------------------------------===//
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#include "clang/Analysis/FlowSensitive/ControlFlowContext.h"
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#include "clang/AST/ASTContext.h"
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#include "clang/AST/Decl.h"
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#include "clang/AST/Stmt.h"
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#include "clang/Analysis/CFG.h"
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/Support/Error.h"
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#include <utility>
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namespace clang {
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namespace dataflow {
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/// Returns a map from statements to basic blocks that contain them.
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static llvm::DenseMap<const Stmt *, const CFGBlock *>
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buildStmtToBasicBlockMap(const CFG &Cfg) {
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llvm::DenseMap<const Stmt *, const CFGBlock *> StmtToBlock;
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for (const CFGBlock *Block : Cfg) {
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if (Block == nullptr)
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continue;
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for (const CFGElement &Element : *Block) {
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auto Stmt = Element.getAs<CFGStmt>();
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if (!Stmt)
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continue;
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StmtToBlock[Stmt.value().getStmt()] = Block;
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}
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if (const Stmt *TerminatorStmt = Block->getTerminatorStmt())
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StmtToBlock[TerminatorStmt] = Block;
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}
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return StmtToBlock;
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}
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llvm::Expected<ControlFlowContext>
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ControlFlowContext::build(const Decl *D, Stmt &S, ASTContext &C) {
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CFG::BuildOptions Options;
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Options.PruneTriviallyFalseEdges = false;
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Options.AddImplicitDtors = true;
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Options.AddTemporaryDtors = true;
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Options.AddInitializers = true;
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Options.AddCXXDefaultInitExprInCtors = true;
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// Ensure that all sub-expressions in basic blocks are evaluated.
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Options.setAllAlwaysAdd();
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auto Cfg = CFG::buildCFG(D, &S, &C, Options);
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if (Cfg == nullptr)
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return llvm::createStringError(
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std::make_error_code(std::errc::invalid_argument),
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"CFG::buildCFG failed");
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llvm::DenseMap<const Stmt *, const CFGBlock *> StmtToBlock =
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buildStmtToBasicBlockMap(*Cfg);
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return ControlFlowContext(D, std::move(Cfg), std::move(StmtToBlock));
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}
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llvm::Expected<ControlFlowContext>
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ControlFlowContext::build(const Decl *D, Stmt *S, ASTContext *C) {
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assert(S != nullptr);
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assert(C != nullptr);
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return build(D, *S, *C);
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}
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} // namespace dataflow
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} // namespace clang
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