[lldb] Remove FileSpec->CompileUnit inheritance

Summary:
CompileUnit is a complicated class. Having it be implicitly convertible
to a FileSpec makes reasoning about it even harder.

This patch replaces the inheritance by a simple member and an accessor
function. This avoid the need for casting in places where one needed to
force a CompileUnit to be treated as a FileSpec, and does not add much
verbosity elsewhere.

It also fixes a bug where we were wrongly comparing CompileUnit& and a
CompileUnit*, which compiled due to a combination of this inheritance
and the FileSpec*->FileSpec implicit constructor.

Reviewers: teemperor, JDevlieghere, jdoerfert

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D70827

1 files changed, 6 insertions, 5 deletions

diff --git a/lldb/source/Core/SourceManager.cpp b/lldb/source/Core/SourceManager.cpp
index 42741e4ba4f..e3780e0b071 100644
--- a/lldb/source/Core/SourceManager.cpp
+++ b/lldb/source/Core/SourceManager.cpp
@@ -399,24 +399,25 @@ void SourceManager::File::CommonInitializer(const FileSpec &file_spec,
         if (num_matches != 0) {
           if (num_matches > 1) {
             SymbolContext sc;
-            FileSpec *test_cu_spec = nullptr;
+            CompileUnit *test_cu = nullptr;
 
             for (unsigned i = 0; i < num_matches; i++) {
               sc_list.GetContextAtIndex(i, sc);
               if (sc.comp_unit) {
-                if (test_cu_spec) {
-                  if (test_cu_spec != static_cast<FileSpec *>(sc.comp_unit))
+                if (test_cu) {
+                  if (test_cu != sc.comp_unit)
                     got_multiple = true;
                   break;
                 } else
-                  test_cu_spec = sc.comp_unit;
+                  test_cu = sc.comp_unit;
               }
             }
           }
           if (!got_multiple) {
             SymbolContext sc;
             sc_list.GetContextAtIndex(0, sc);
-            m_file_spec = sc.comp_unit;
+            if (sc.comp_unit)
+              m_file_spec = sc.comp_unit->GetPrimaryFile();
             m_mod_time = FileSystem::Instance().GetModificationTime(m_file_spec);
           }
         }