Refactor GetNextPersistentVariableName into a non-virtual method

that takes a prefix string. This simplifies the implementation and
allows plugins such as the Swift plugin to supply different prefixes
for return and error variables.

rdar://problem/39299889

Differential Revision: https://reviews.llvm.org/D46088

llvm-svn: 331235

3 files changed, 7 insertions, 19 deletions

diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangPersistentVariables.cpp b/lldb/source/Plugins/ExpressionParser/Clang/ClangPersistentVariables.cpp
index 34fc7a19f11..bb73d55a9a4 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangPersistentVariables.cpp
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangPersistentVariables.cpp
@@ -53,15 +53,6 @@ void ClangPersistentVariables::RemovePersistentVariable(
     m_next_persistent_variable_id--;
 }
 
-ConstString
-ClangPersistentVariables::GetNextPersistentVariableName(Target &target) {
-  char name_cstr[256];
-  ::snprintf(name_cstr, sizeof(name_cstr), "$%u",
-             target.GetNextPersistentVariableIndex());
-  ConstString name(name_cstr);
-  return name;
-}
-
 void ClangPersistentVariables::RegisterPersistentDecl(const ConstString &name,
                                                       clang::NamedDecl *decl) {
   m_persistent_decls.insert(
diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangPersistentVariables.h b/lldb/source/Plugins/ExpressionParser/Clang/ClangPersistentVariables.h
index a9a4a3c1a5f..1432fae711e 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangPersistentVariables.h
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangPersistentVariables.h
@@ -54,16 +54,11 @@ public:
       const CompilerType &compiler_type, lldb::ByteOrder byte_order,
       uint32_t addr_byte_size) override;
 
-  //----------------------------------------------------------------------
-  /// Return the next entry in the sequence of strings "$0", "$1", ... for
-  /// use naming persistent expression convenience variables.
-  ///
-  /// @return
-  ///     A string that contains the next persistent variable name.
-  //----------------------------------------------------------------------
-  ConstString GetNextPersistentVariableName(Target &target) override;
-
   void RemovePersistentVariable(lldb::ExpressionVariableSP variable) override;
+  llvm::StringRef
+  GetPersistentVariablePrefix(bool is_error) const override {
+    return "$";
+  }
 
   void RegisterPersistentDecl(const ConstString &name, clang::NamedDecl *decl);
 
diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangUserExpression.cpp b/lldb/source/Plugins/ExpressionParser/Clang/ClangUserExpression.cpp
index 0062bb8661e..4da5492b14d 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangUserExpression.cpp
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangUserExpression.cpp
@@ -665,7 +665,9 @@ void ClangUserExpression::ClangUserExpressionHelper::CommitPersistentDecls() {
 }
 
 ConstString ClangUserExpression::ResultDelegate::GetName() {
-  return m_persistent_state->GetNextPersistentVariableName(*m_target_sp);
+  auto prefix = m_persistent_state->GetPersistentVariablePrefix();
+  return m_persistent_state->GetNextPersistentVariableName(*m_target_sp,
+                                                           prefix);
 }
 
 void ClangUserExpression::ResultDelegate::DidDematerialize(