[lldb] Add `source cache dump` and `source cache clear` subcommand

Add two new source subcommands: source cache dump and source cache
clear. As the name implies the first one dumps the source cache while
the later clears the cache.

This patch was motivated by a handful of (internal) bug reports related
to sources not being available. Right now those issues can be hard to
diagnose. The new commands give users, as well as us as developers, more
insight into and control over the source cache.

Differential revision: https://reviews.llvm.org/D153685

1 files changed, 58 insertions, 0 deletions

diff --git a/lldb/source/Commands/CommandObjectSource.cpp b/lldb/source/Commands/CommandObjectSource.cpp
index bbc3142..5fdf157 100644
--- a/lldb/source/Commands/CommandObjectSource.cpp
+++ b/lldb/source/Commands/CommandObjectSource.cpp
@@ -1201,6 +1201,62 @@ protected:
   std::string m_reverse_name;
 };
 
+class CommandObjectSourceCacheDump : public CommandObjectParsed {
+public:
+  CommandObjectSourceCacheDump(CommandInterpreter &interpreter)
+      : CommandObjectParsed(interpreter, "source cache dump",
+                            "Dump the state of the source code cache. Intended "
+                            "to be used for debugging LLDB itself.",
+                            nullptr) {}
+
+  ~CommandObjectSourceCacheDump() override = default;
+
+protected:
+  bool DoExecute(Args &command, CommandReturnObject &result) override {
+    SourceManager::SourceFileCache &cache = GetDebugger().GetSourceFileCache();
+    cache.Dump(result.GetOutputStream());
+    result.SetStatus(eReturnStatusSuccessFinishResult);
+    return result.Succeeded();
+  }
+};
+
+class CommandObjectSourceCacheClear : public CommandObjectParsed {
+public:
+  CommandObjectSourceCacheClear(CommandInterpreter &interpreter)
+      : CommandObjectParsed(interpreter, "source cache clear",
+                            "Clear the source code cache.\n", nullptr) {}
+
+  ~CommandObjectSourceCacheClear() override = default;
+
+protected:
+  bool DoExecute(Args &command, CommandReturnObject &result) override {
+    SourceManager::SourceFileCache &cache = GetDebugger().GetSourceFileCache();
+    cache.Clear();
+    result.SetStatus(eReturnStatusSuccessFinishNoResult);
+    return result.Succeeded();
+  }
+};
+
+class CommandObjectSourceCache : public CommandObjectMultiword {
+public:
+  CommandObjectSourceCache(CommandInterpreter &interpreter)
+      : CommandObjectMultiword(interpreter, "source cache",
+                               "Commands for managing the source code cache.",
+                               "source cache <sub-command>") {
+    LoadSubCommand(
+        "dump", CommandObjectSP(new CommandObjectSourceCacheDump(interpreter)));
+    LoadSubCommand("clear", CommandObjectSP(new CommandObjectSourceCacheClear(
+                                interpreter)));
+  }
+
+  ~CommandObjectSourceCache() override = default;
+
+private:
+  CommandObjectSourceCache(const CommandObjectSourceCache &) = delete;
+  const CommandObjectSourceCache &
+  operator=(const CommandObjectSourceCache &) = delete;
+};
+
 #pragma mark CommandObjectMultiwordSource
 // CommandObjectMultiwordSource
 
@@ -1216,6 +1272,8 @@ CommandObjectMultiwordSource::CommandObjectMultiwordSource(
                  CommandObjectSP(new CommandObjectSourceInfo(interpreter)));
   LoadSubCommand("list",
                  CommandObjectSP(new CommandObjectSourceList(interpreter)));
+  LoadSubCommand("cache",
+                 CommandObjectSP(new CommandObjectSourceCache(interpreter)));
 }
 
 CommandObjectMultiwordSource::~CommandObjectMultiwordSource() = default;