vendor/llvm-project/llvmorg-14-init-17616-g024a1fab5c35

1 files changed, 69 insertions, 0 deletions

diff --git a/clang/lib/Analysis/FlowSensitive/ControlFlowContext.cpp b/clang/lib/Analysis/FlowSensitive/ControlFlowContext.cpp
new file mode 100644
index 000000000000..3ad2ed640cc1
--- /dev/null
+++ b/clang/lib/Analysis/FlowSensitive/ControlFlowContext.cpp
@@ -0,0 +1,69 @@
+//===- ControlFlowContext.cpp ---------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines a ControlFlowContext class that is used by dataflow
+//  analyses that run over Control-Flow Graphs (CFGs).
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Analysis/FlowSensitive/ControlFlowContext.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/Stmt.h"
+#include "clang/Analysis/CFG.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/Support/Error.h"
+#include <utility>
+
+namespace clang {
+namespace dataflow {
+
+/// Returns a map from statements to basic blocks that contain them.
+static llvm::DenseMap<const Stmt *, const CFGBlock *>
+buildStmtToBasicBlockMap(const CFG &Cfg) {
+  llvm::DenseMap<const Stmt *, const CFGBlock *> StmtToBlock;
+  for (const CFGBlock *Block : Cfg) {
+    if (Block == nullptr)
+      continue;
+
+    for (const CFGElement &Element : *Block) {
+      auto Stmt = Element.getAs<CFGStmt>();
+      if (!Stmt.hasValue())
+        continue;
+
+      StmtToBlock[Stmt.getValue().getStmt()] = Block;
+    }
+  }
+  return StmtToBlock;
+}
+
+llvm::Expected<ControlFlowContext>
+ControlFlowContext::build(const Decl *D, Stmt *S, ASTContext *C) {
+  CFG::BuildOptions Options;
+  Options.PruneTriviallyFalseEdges = false;
+  Options.AddImplicitDtors = true;
+  Options.AddTemporaryDtors = true;
+  Options.AddInitializers = true;
+  Options.AddCXXDefaultInitExprInCtors = true;
+
+  // Ensure that all sub-expressions in basic blocks are evaluated.
+  Options.setAllAlwaysAdd();
+
+  auto Cfg = CFG::buildCFG(D, S, C, Options);
+  if (Cfg == nullptr)
+    return llvm::createStringError(
+        std::make_error_code(std::errc::invalid_argument),
+        "CFG::buildCFG failed");
+
+  llvm::DenseMap<const Stmt *, const CFGBlock *> StmtToBlock =
+      buildStmtToBasicBlockMap(*Cfg);
+  return ControlFlowContext(std::move(Cfg), std::move(StmtToBlock));
+}
+
+} // namespace dataflow
+} // namespace clang