[lldb] Make SBProgress move-only

[bulbazord]

I wanted to clarify the semantics around SBProgress. Given the nature of Progress events, copying seems like the wrong idea. Making SBProgress move-only (like SBStream) seems like the better choice here.

[llvmbot]

@llvm/pr-subscribers-lldb

Author: Alex Langford (bulbazord)

Changes

I wanted to clarify the semantics around SBProgress. Given the nature of Progress events, copying seems like the wrong idea. Making SBProgress move-only (like SBStream) seems like the better choice here.

---

Full diff: https://github.com/llvm/llvm-project/pull/124843.diff

2 Files Affected:

• (modified) lldb/include/lldb/API/SBProgress.h (+7)
• (modified) lldb/source/API/SBProgress.cpp (+3)

diff --git a/lldb/include/lldb/API/SBProgress.h b/lldb/include/lldb/API/SBProgress.h
index d2eaf0a743cb3a..d574d1d2982b96 100644
--- a/lldb/include/lldb/API/SBProgress.h
+++ b/lldb/include/lldb/API/SBProgress.h
@@ -51,6 +51,10 @@ class LLDB_API SBProgress {
   SBProgress(const char *title, const char *details, uint64_t total_units,
              SBDebugger &debugger);
 
+#ifndef SWIG
+  SBProgress(SBProgress &&rhs);
+#endif
+
   ~SBProgress();
 
   void Increment(uint64_t amount, const char *description = nullptr);
@@ -59,6 +63,9 @@ class LLDB_API SBProgress {
   lldb_private::Progress &ref() const;
 
 private:
+  SBProgress(const SBProgress &rhs) = delete;
+  const SBProgress &operator=(const SBProgress &rhs) = delete;
+
   std::unique_ptr<lldb_private::Progress> m_opaque_up;
 }; // SBProgress
 } // namespace lldb
diff --git a/lldb/source/API/SBProgress.cpp b/lldb/source/API/SBProgress.cpp
index d6ed5f0d15fc94..e67e289a60eff4 100644
--- a/lldb/source/API/SBProgress.cpp
+++ b/lldb/source/API/SBProgress.cpp
@@ -32,6 +32,9 @@ SBProgress::SBProgress(const char *title, const char *details,
       lldb_private::Progress::Origin::eExternal);
 }
 
+SBProgress::SBProgress(SBProgress &&rhs)
+    : m_opaque_up(std::move(rhs.m_opaque_up)) {}
+
 SBProgress::~SBProgress() = default;
 
 void SBProgress::Increment(uint64_t amount, const char *description) {

[Jlalond]

LGTM, left you one comment @bulbazord that is mostly a question

[Jlalond]

Oh! I didn't originally do this because I thought we weren't adding deletes in the header.

[bulbazord]

SBStream does this to enforce no copying. :)

[Jlalond]

Why the move operator for only Swig? Wouldn't this be useful if say DAP wanted to grab it's own progress object and then potentially move it?

[bulbazord]

This is a preprocessor guard that prevents SWIG from processing the move constructor. SWIG generates the bindings by reading the API headers and doesn't handle move constructors well. SBStream does the same thing.

When the headers are installed for distribution, this header guard is removed with unifdef.