[clang] [clang][ExprConst] Remove `State::getBottomFrame()` (PR #202277)

[via cfe-commits]

llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Timm Baeder (tbaederr)

<details>
<summary>Changes</summary>

This is not necessary since `Frame` already has a `getCaller()` function, which can be used to identify the bottom frame.
And the current code never needs the bottom frame for anything other than checking if another frame is the bottom frame.

---
Full diff: https://github.com/llvm/llvm-project/pull/202277.diff


4 Files Affected:

- (modified) clang/lib/AST/ByteCode/InterpState.h (-2) 
- (modified) clang/lib/AST/ByteCode/State.cpp (+2-2) 
- (modified) clang/lib/AST/ByteCode/State.h (-1) 
- (modified) clang/lib/AST/ExprConstant.cpp (+1-2) 


``````````diff
diff --git a/clang/lib/AST/ByteCode/InterpState.h b/clang/lib/AST/ByteCode/InterpState.h
index 499a21a094e2c..b6ef985095907 100644
--- a/clang/lib/AST/ByteCode/InterpState.h
+++ b/clang/lib/AST/ByteCode/InterpState.h
@@ -54,8 +54,6 @@ class InterpState final : public State, public SourceMapper {
   unsigned getCallStackDepth() override {
     return Current ? (Current->getDepth() + 1) : 1;
   }
-  const Frame *getBottomFrame() const override { return &BottomFrame; }
-
   bool stepsLeft() const override { return true; }
   bool inConstantContext() const;
 
diff --git a/clang/lib/AST/ByteCode/State.cpp b/clang/lib/AST/ByteCode/State.cpp
index 00e3b1a331172..e612c6863e60f 100644
--- a/clang/lib/AST/ByteCode/State.cpp
+++ b/clang/lib/AST/ByteCode/State.cpp
@@ -122,8 +122,8 @@ void State::addCallStack(unsigned Limit) {
   // Walk the call stack and add the diagnostics.
   unsigned CallIdx = 0;
   const Frame *Top = getCurrentFrame();
-  const Frame *Bottom = getBottomFrame();
-  for (const Frame *F = Top; F != Bottom; F = F->getCaller(), ++CallIdx) {
+  for (const Frame *F = Top; F->getCaller() != nullptr;
+       F = F->getCaller(), ++CallIdx) {
     SourceRange CallRange = F->getCallRange();
     assert(CallRange.isValid());
 
diff --git a/clang/lib/AST/ByteCode/State.h b/clang/lib/AST/ByteCode/State.h
index a720033c7914b..df3afdf8cbc24 100644
--- a/clang/lib/AST/ByteCode/State.h
+++ b/clang/lib/AST/ByteCode/State.h
@@ -85,7 +85,6 @@ class State {
   virtual ~State();
 
   virtual const Frame *getCurrentFrame() = 0;
-  virtual const Frame *getBottomFrame() const = 0;
   virtual unsigned getCallStackDepth() = 0;
   virtual bool stepsLeft() const = 0;
 
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 33df4cab06e7c..ab30a0874d95f 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -1032,7 +1032,7 @@ namespace {
     };
 
     StdAllocatorCaller getStdAllocatorCaller(StringRef FnName) const {
-      for (const CallStackFrame *Call = CurrentCall; Call != &BottomFrame;
+      for (const CallStackFrame *Call = CurrentCall; Call->Caller != nullptr;
            Call = Call->Caller) {
         const auto *MD = dyn_cast_or_null<CXXMethodDecl>(Call->Callee);
         if (!MD)
@@ -1080,7 +1080,6 @@ namespace {
 
   private:
     const interp::Frame *getCurrentFrame() override { return CurrentCall; }
-    const interp::Frame *getBottomFrame() const override { return &BottomFrame; }
 
     unsigned getCallStackDepth() override { return CallStackDepth; }
     bool stepsLeft() const override { return StepsLeft > 0; }

``````````

</details>


https://github.com/llvm/llvm-project/pull/202277