Address review feedback

Author: andykaylor

clang/lib/CIR/CodeGen/CIRGenCleanup.cpp

@@ -38,31 +38,29 @@ void EHScopeStack::Cleanup::anchor() {}
 char *EHScopeStack::allocate(size_t size) {
   size = llvm::alignTo(size, ScopeStackAlignment);
   if (!startOfBuffer) {
-    unsigned capacity = 1024;
-    while (capacity < size)
-      capacity *= 2;
-    startOfBuffer = new char[capacity];
-    startOfData = endOfBuffer = startOfBuffer + capacity;
-  } else if (static_cast<size_t>(startOfData - startOfBuffer) < size) {
-    unsigned currentCapacity = endOfBuffer - startOfBuffer;
-    unsigned usedCapacity = currentCapacity - (startOfData - startOfBuffer);
-
-    unsigned newCapacity = currentCapacity;
-    do {
-      newCapacity *= 2;
-    } while (newCapacity < usedCapacity + size);
-
-    char *newStartOfBuffer = new char[newCapacity];
-    char *newEndOfBuffer = newStartOfBuffer + newCapacity;
+    unsigned capacity = llvm::PowerOf2Ceil(std::max(size, 1024ul));
+    startOfBuffer = std::make_unique<char[]>(capacity);
+    startOfData = endOfBuffer = startOfBuffer.get() + capacity;
+  } else if (static_cast<size_t>(startOfData - startOfBuffer.get()) < size) {
+    unsigned currentCapacity = endOfBuffer - startOfBuffer.get();
+    unsigned usedCapacity =
+        currentCapacity - (startOfData - startOfBuffer.get());
+    unsigned requiredCapacity = usedCapacity + size;
+    // We know from the 'else if' condition that requiredCapacity is greater
+    // than currentCapacity.
+    unsigned newCapacity = llvm::PowerOf2Ceil(requiredCapacity);
+
+    std::unique_ptr<char[]> newStartOfBuffer =
+        std::make_unique<char[]>(newCapacity);
+    char *newEndOfBuffer = newStartOfBuffer.get() + newCapacity;
     char *newStartOfData = newEndOfBuffer - usedCapacity;
     memcpy(newStartOfData, startOfData, usedCapacity);
-    delete[] startOfBuffer;
-    startOfBuffer = newStartOfBuffer;
+    startOfBuffer.swap(newStartOfBuffer);
     endOfBuffer = newEndOfBuffer;
     startOfData = newStartOfData;
   }
 
-  assert(startOfBuffer + size <= startOfData);
+  assert(startOfBuffer.get() + size <= startOfData);
   startOfData -= size;
   return startOfData;
 }

clang/lib/CIR/CodeGen/CIRGenCleanup.h

@@ -11,22 +11,22 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef CLANG_LIB_CIR_CODEGEN_CGCLEANUP_H
-#define CLANG_LIB_CIR_CODEGEN_CGCLEANUP_H
+#ifndef CLANG_LIB_CIR_CODEGEN_CIRGENCLEANUP_H
+#define CLANG_LIB_CIR_CODEGEN_CIRGENCLEANUP_H
 
 #include "EHScopeStack.h"
 
 namespace clang::CIRGen {
 
 /// A non-stable pointer into the scope stack.
 class EHScopeStack::iterator {
-  char *ptr;
+  char *ptr = nullptr;
 
   friend class EHScopeStack;
   explicit iterator(char *ptr) : ptr(ptr) {}
 
 public:
-  iterator() : ptr(nullptr) {}
+  iterator() = default;
 
   EHScopeStack::Cleanup *get() const {
     return reinterpret_cast<EHScopeStack::Cleanup *>(ptr);
@@ -40,4 +40,4 @@ inline EHScopeStack::iterator EHScopeStack::begin() const {
 }
 
 } // namespace clang::CIRGen
-#endif // CLANG_LIB_CIR_CODEGEN_CGCLEANUP_H
+#endif // CLANG_LIB_CIR_CODEGEN_CIRGENCLEANUP_H

clang/lib/CIR/CodeGen/EHScopeStack.h

@@ -54,13 +54,13 @@ class EHScopeStack {
     friend class EHScopeStack;
 
     /// Offset from startOfData to endOfBuffer.
-    ptrdiff_t size;
+    ptrdiff_t size = -1;
 
-    stable_iterator(ptrdiff_t size) : size(size) {}
+    explicit stable_iterator(ptrdiff_t size) : size(size) {}
 
   public:
     static stable_iterator invalid() { return stable_iterator(-1); }
-    stable_iterator() : size(-1) {}
+    stable_iterator() = default;
 
     bool isValid() const { return size >= 0; }
 
@@ -121,7 +121,7 @@ class EHScopeStack {
   /// The start of the scope-stack buffer, i.e. the allocated pointer
   /// for the buffer.  All of these pointers are either simultaneously
   /// null or simultaneously valid.
-  char *startOfBuffer = nullptr;
+  std::unique_ptr<char[]> startOfBuffer;
 
   /// The end of the buffer.
   char *endOfBuffer = nullptr;
@@ -143,7 +143,7 @@ class EHScopeStack {
 
 public:
   EHScopeStack() = default;
-  ~EHScopeStack() { delete[] startOfBuffer; }
+  ~EHScopeStack() = default;
 
   /// Push a lazily-created cleanup on the stack.
   template <class T, class... As> void pushCleanup(CleanupKind kind, As... a) {