From ce0ab9d11cec0a81c4e48645a23fa8eddea926ab Mon Sep 17 00:00:00 2001
From: Martin Braenne <mboehme@google.com>
Date: Mon, 3 Apr 2023 07:02:48 +0000
Subject: [PATCH] [clang][dataflow][NFC] Share code between Environment ctor
 and pushCallInternal().

The deduplicated code is moved into initVars().

As an added bonus, pushCallInternal() now also gets the "Add all fields
mentioned in default member initializers" behavior, which apparently had been
added to the Environment ctor but not pushCallInternal().

Reviewed By: xazax.hun, ymandel

Differential Revision: https://reviews.llvm.org/D147326
---
 .../Analysis/FlowSensitive/DataflowEnvironment.h   |  5 +-
 .../Analysis/FlowSensitive/DataflowEnvironment.cpp | 75 +++++++++-------------
 2 files changed, 32 insertions(+), 48 deletions(-)

diff --git a/clang/include/clang/Analysis/FlowSensitive/DataflowEnvironment.h b/clang/include/clang/Analysis/FlowSensitive/DataflowEnvironment.h
index 678e5b8..b4ae172 100644
--- a/clang/include/clang/Analysis/FlowSensitive/DataflowEnvironment.h
+++ b/clang/include/clang/Analysis/FlowSensitive/DataflowEnvironment.h
@@ -460,8 +460,9 @@ private:
   void pushCallInternal(const FunctionDecl *FuncDecl,
                         ArrayRef<const Expr *> Args);
 
-  /// Assigns storage locations and values to all variables in `Vars`.
-  void initVars(llvm::DenseSet<const VarDecl *> Vars);
+  /// Assigns storage locations and values to all global variables and fields
+  /// referenced in `FuncDecl`. `FuncDecl` must have a body.
+  void initFieldsAndGlobals(const FunctionDecl *FuncDecl);
 
   // `DACtx` is not null and not owned by this object.
   DataflowAnalysisContext *DACtx;
diff --git a/clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp b/clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
index e3bde37..fbb8d8a 100644
--- a/clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
+++ b/clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
@@ -203,7 +203,33 @@ static void getFieldsAndGlobalVars(const Stmt &S,
 
 // FIXME: Add support for resetting globals after function calls to enable
 // the implementation of sound analyses.
-void Environment::initVars(llvm::DenseSet<const VarDecl *> Vars) {
+void Environment::initFieldsAndGlobals(const FunctionDecl *FuncDecl) {
+  assert(FuncDecl->getBody() != nullptr);
+
+  llvm::DenseSet<const FieldDecl *> Fields;
+  llvm::DenseSet<const VarDecl *> Vars;
+
+  // Look for global variable and field references in the
+  // constructor-initializers.
+  if (const auto *CtorDecl = dyn_cast<CXXConstructorDecl>(FuncDecl)) {
+    for (const auto *Init : CtorDecl->inits()) {
+      if (const auto *M = Init->getAnyMember())
+          Fields.insert(M);
+      const Expr *E = Init->getInit();
+      assert(E != nullptr);
+      getFieldsAndGlobalVars(*E, Fields, Vars);
+    }
+    // Add all fields mentioned in default member initializers.
+    for (const FieldDecl *F : CtorDecl->getParent()->fields())
+      if (const auto *I = F->getInClassInitializer())
+          getFieldsAndGlobalVars(*I, Fields, Vars);
+  }
+  getFieldsAndGlobalVars(*FuncDecl->getBody(), Fields, Vars);
+
+  // These have to be added before the lines that follow to ensure that
+  // `create*` work correctly for structs.
+  DACtx->addModeledFields(Fields);
+
   for (const VarDecl *D : Vars) {
     if (getStorageLocation(*D, SkipPast::None) != nullptr)
       continue;
@@ -239,31 +265,7 @@ Environment::Environment(DataflowAnalysisContext &DACtx,
   if (const auto *FuncDecl = dyn_cast<FunctionDecl>(&DeclCtx)) {
     assert(FuncDecl->getBody() != nullptr);
 
-    llvm::DenseSet<const FieldDecl *> Fields;
-    llvm::DenseSet<const VarDecl *> Vars;
-
-    // Look for global variable and field references in the
-    // constructor-initializers.
-    if (const auto *CtorDecl = dyn_cast<CXXConstructorDecl>(&DeclCtx)) {
-      for (const auto *Init : CtorDecl->inits()) {
-        if (const auto *M = Init->getAnyMember())
-          Fields.insert(M);
-        const Expr *E = Init->getInit();
-        assert(E != nullptr);
-        getFieldsAndGlobalVars(*E, Fields, Vars);
-      }
-      // Add all fields mentioned in default member initializers.
-      for (const FieldDecl *F  : CtorDecl->getParent()->fields())
-        if (const auto *I = F->getInClassInitializer())
-          getFieldsAndGlobalVars(*I, Fields, Vars);
-    }
-    getFieldsAndGlobalVars(*FuncDecl->getBody(), Fields, Vars);
-
-    // These have to be added before the lines that follow to ensure that
-    // `create*` work correctly for structs.
-    DACtx.addModeledFields(Fields);
-
-    initVars(Vars);
+    initFieldsAndGlobals(FuncDecl);
 
     for (const auto *ParamDecl : FuncDecl->parameters()) {
       assert(ParamDecl != nullptr);
@@ -337,26 +339,7 @@ void Environment::pushCallInternal(const FunctionDecl *FuncDecl,
                                    ArrayRef<const Expr *> Args) {
   CallStack.push_back(FuncDecl);
 
-  // FIXME: Share this code with the constructor, rather than duplicating it.
-  llvm::DenseSet<const FieldDecl *> Fields;
-  llvm::DenseSet<const VarDecl *> Vars;
-  // Look for global variable references in the constructor-initializers.
-  if (const auto *CtorDecl = dyn_cast<CXXConstructorDecl>(FuncDecl)) {
-    for (const auto *Init : CtorDecl->inits()) {
-      if (const auto *M = Init->getAnyMember())
-        Fields.insert(M);
-      const Expr *E = Init->getInit();
-      assert(E != nullptr);
-      getFieldsAndGlobalVars(*E, Fields, Vars);
-    }
-  }
-  getFieldsAndGlobalVars(*FuncDecl->getBody(), Fields, Vars);
-
-  // These have to be added before the lines that follow to ensure that
-  // `create*` work correctly for structs.
-  DACtx->addModeledFields(Fields);
-
-  initVars(Vars);
+  initFieldsAndGlobals(FuncDecl);
 
   const auto *ParamIt = FuncDecl->param_begin();
 
-- 
2.7.4