Add BreakTarget

Author: lucic71

cpp2rust/converter/converter.cpp

@@ -990,6 +990,7 @@ bool Converter::VisitIfStmt(clang::IfStmt *stmt) {
 }
 
 bool Converter::VisitWhileStmt(clang::WhileStmt *stmt) {
+  PushBreakTarget push(break_target_stack_, BreakTarget::Loop);
   StrCat("'loop_:");
   StrCat(keyword::kWhile);
   ConvertCondition(stmt->getCond());
@@ -1002,6 +1003,7 @@ bool Converter::VisitWhileStmt(clang::WhileStmt *stmt) {
 }
 
 bool Converter::VisitDoStmt(clang::DoStmt *stmt) {
+  PushBreakTarget push(break_target_stack_, BreakTarget::Loop);
   StrCat("'loop_:");
   StrCat(keyword::kLoop, token::kOpenCurlyBracket);
   curr_for_inc_.emplace(nullptr);
@@ -1016,6 +1018,7 @@ bool Converter::VisitDoStmt(clang::DoStmt *stmt) {
 }
 
 bool Converter::VisitForStmt(clang::ForStmt *stmt) {
+  PushBreakTarget push(break_target_stack_, BreakTarget::Loop);
   Convert(stmt->getInit());
   StrCat("'loop_:");
   StrCat(keyword::kWhile);
@@ -1055,6 +1058,7 @@ void Converter::ConvertLoopVariable(clang::VarDecl *decl,
 
 void Converter::ConvertForRangeBody(clang::CXXForRangeStmt *stmt,
                                     const clang::VarDecl *map_iter_decl) {
+  PushBreakTarget push(break_target_stack_, BreakTarget::Loop);
   std::optional<ScopedMapIterDecl> skip;
   if (map_iter_decl)
     skip.emplace(*this, map_iter_decl);
@@ -1136,10 +1140,12 @@ bool Converter::VisitCXXForRangeStmtIndexBased(clang::CXXForRangeStmt *stmt,
 }
 
 bool Converter::VisitBreakStmt([[maybe_unused]] clang::BreakStmt *stmt) {
-  StrCat(keyword::kBreak);
-  if (switch_depth_ > 0) {
+  if (break_target_stack_.isRegularSwitch()) {
+    StrCat(keyword::kBreak);
     StrCat("'switch");
+    return false;
   }
+  StrCat(keyword::kBreak);
   return false;
 }
 
@@ -2657,9 +2663,9 @@ bool Converter::VisitSwitchStmt(clang::SwitchStmt *stmt) {
     StrCat("{");
   }
 
-  if (!has_fallthrough) {
-    ++switch_depth_;
-  }
+  PushBreakTarget push(break_target_stack_, has_fallthrough
+                                                ? BreakTarget::FallthroughSwitch
+                                                : BreakTarget::RegularSwitch);
 
   clang::SwitchCase *default_case = nullptr;
   for (auto *sc : GetTopLevelSwitchCases(stmt)) {
@@ -2685,10 +2691,6 @@ bool Converter::VisitSwitchStmt(clang::SwitchStmt *stmt) {
     StrCat(R"( _ => {})");
   }
 
-  if (!has_fallthrough) {
-    --switch_depth_;
-  }
-
   if (has_fallthrough) {
     StrCat("})");
   } else {

cpp2rust/converter/converter.h

@@ -463,7 +463,35 @@ class Converter : public clang::RecursiveASTVisitor<Converter> {
   clang::ASTContext &ctx_;
   clang::FunctionDecl *curr_function_ = nullptr;
   bool in_function_formals_ = false;
-  int switch_depth_ = 0;
+
+  enum class BreakTarget { Loop, RegularSwitch, FallthroughSwitch };
+  class BreakTargetStack {
+  public:
+    void push(BreakTarget t) { stack_.push(t); }
+    void pop() { stack_.pop(); }
+    bool isRegularSwitch() const {
+      return !stack_.empty() && stack_.top() == BreakTarget::RegularSwitch;
+    }
+
+  private:
+    std::stack<BreakTarget> stack_;
+  };
+  BreakTargetStack break_target_stack_;
+
+  class PushBreakTarget {
+  public:
+    PushBreakTarget(BreakTargetStack &stack, BreakTarget target)
+        : stack_(stack) {
+      stack_.push(target);
+    }
+    ~PushBreakTarget() { stack_.pop(); }
+    PushBreakTarget(const PushBreakTarget &) = delete;
+    PushBreakTarget &operator=(const PushBreakTarget &) = delete;
+
+  private:
+    BreakTargetStack &stack_;
+  };
+
   std::stack<clang::Expr *> curr_for_inc_;
   std::stack<clang::QualType> curr_init_type_;