[lldb] Move redundant persistent variable counter to ClangPersistentVariables

Currently Target::m_next_persistent_variable_index is counting up
for our persistent variables ($0, $1, ...) but we also have a
unused counter that is supposed to do this in
ClangPersistentVariables but that stays always at 0 (because
we currently increase the target counter when we should increase
that unused counter).

This patch removes the counter in Target and lets the documented
counter in ClangPersistentVariables do the variable counting.

Patch *should* be NFC, but it might unexpectedly bring LLDB to
new code paths that could contain exciting new bugs to fix.

llvm-svn: 367842

4 files changed, 14 insertions, 20 deletions

diff --git a/lldb/include/lldb/Expression/ExpressionVariable.h b/lldb/include/lldb/Expression/ExpressionVariable.h
index 08c987270bf..1e3b38d6054 100644
--- a/lldb/include/lldb/Expression/ExpressionVariable.h
+++ b/lldb/include/lldb/Expression/ExpressionVariable.h
@@ -223,8 +223,8 @@ public:
                            uint32_t addr_byte_size) = 0;
 
   /// Return a new persistent variable name with the specified prefix.
-  ConstString GetNextPersistentVariableName(Target &target,
-                                            llvm::StringRef prefix);
+  virtual ConstString GetNextPersistentVariableName(Target &target,
+                        llvm::StringRef prefix) = 0;
 
   virtual llvm::StringRef
   GetPersistentVariablePrefix(bool is_error = false) const = 0;
diff --git a/lldb/include/lldb/Target/Target.h b/lldb/include/lldb/Target/Target.h
index fc76f580fc8..e365c72737f 100644
--- a/lldb/include/lldb/Target/Target.h
+++ b/lldb/include/lldb/Target/Target.h
@@ -1106,11 +1106,6 @@ public:
 
   lldb::ExpressionVariableSP GetPersistentVariable(ConstString name);
 
-  /// Return the next available number for numbered persistent variables.
-  unsigned GetNextPersistentVariableIndex() {
-    return m_next_persistent_variable_index++;
-  }
-
   lldb::addr_t GetPersistentSymbol(ConstString name);
 
   /// This method will return the address of the starting function for
@@ -1320,7 +1315,6 @@ protected:
   bool m_valid;
   bool m_suppress_stop_hooks;
   bool m_is_dummy_target;
-  unsigned m_next_persistent_variable_index = 0;
 
   static void ImageSearchPathsChanged(const PathMappingList &path_list,
                                       void *baton);
diff --git a/lldb/source/Expression/ExpressionVariable.cpp b/lldb/source/Expression/ExpressionVariable.cpp
index ed8da0ad867..61df940b2ad 100644
--- a/lldb/source/Expression/ExpressionVariable.cpp
+++ b/lldb/source/Expression/ExpressionVariable.cpp
@@ -76,13 +76,3 @@ void PersistentExpressionState::RegisterExecutionUnit(
     }
   }
 }
-
-ConstString PersistentExpressionState::GetNextPersistentVariableName(
-    Target &target, llvm::StringRef Prefix) {
-  llvm::SmallString<64> name;
-  {
-    llvm::raw_svector_ostream os(name);
-    os << Prefix << target.GetNextPersistentVariableIndex();
-  }
-  return ConstString(name);
-}
diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangPersistentVariables.h b/lldb/source/Plugins/ExpressionParser/Clang/ClangPersistentVariables.h
index b39f89ad7ee..3aad351ccc3 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangPersistentVariables.h
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangPersistentVariables.h
@@ -45,8 +45,18 @@ public:
       uint32_t addr_byte_size) override;
 
   void RemovePersistentVariable(lldb::ExpressionVariableSP variable) override;
-  llvm::StringRef
-  GetPersistentVariablePrefix(bool is_error) const override {
+
+  ConstString GetNextPersistentVariableName(Target &target,
+  llvm::StringRef prefix) override {
+    llvm::SmallString<64> name;
+    {
+      llvm::raw_svector_ostream os(name);
+      os << prefix << m_next_persistent_variable_id++;
+    }
+    return ConstString(name);
+  }
+
+  llvm::StringRef GetPersistentVariablePrefix(bool is_error) const override {
     return "$";
   }