[ASTImporter] Use llvm::Expected and Error in the importer API

Summary:
This is the final phase of the refactoring towards using llvm::Expected
and llvm::Error in the ASTImporter API.
This involves the following:
- remove old Import functions which returned with a pointer,
- use the Import_New functions (which return with Err or Expected) everywhere
  and handle their return value
- rename Import_New functions to Import
This affects both Clang and LLDB.

Reviewers: shafik, teemperor, aprantl, a_sidorin, balazske, a.sidorin

Subscribers: rnkovacs, dkrupp, Szelethus, gamesh411, cfe-commits, lldb-commits

Tags: #clang, #lldb

Differential Revision: https://reviews.llvm.org/D61438

llvm-svn: 360760

1 files changed, 18 insertions, 2 deletions

diff --git a/lldb/source/Plugins/ExpressionParser/Clang/ClangASTSource.cpp b/lldb/source/Plugins/ExpressionParser/Clang/ClangASTSource.cpp
index e67477440f3..92191793d19 100644
--- a/lldb/source/Plugins/ExpressionParser/Clang/ClangASTSource.cpp
+++ b/lldb/source/Plugins/ExpressionParser/Clang/ClangASTSource.cpp
@@ -1968,7 +1968,14 @@ clang::QualType ClangASTSource::CopyTypeWithMerger(
     return QualType();
   }
 
-  return merger.ImporterForOrigin(from_context).Import(type);
+  if (llvm::Expected<QualType> type_or_error =
+          merger.ImporterForOrigin(from_context).Import(type)) {
+    return *type_or_error;
+  } else {
+    Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS);
+    LLDB_LOG_ERROR(log, type_or_error.takeError(), "Couldn't import type: {0}");
+    return QualType();
+  }
 }
 
 clang::Decl *ClangASTSource::CopyDecl(Decl *src_decl) {
@@ -1981,7 +1988,16 @@ clang::Decl *ClangASTSource::CopyDecl(Decl *src_decl) {
       return nullptr;
     }
 
-    return m_merger_up->ImporterForOrigin(from_context).Import(src_decl);
+    if (llvm::Expected<Decl *> decl_or_error =
+            m_merger_up->ImporterForOrigin(from_context).Import(src_decl)) {
+      return *decl_or_error;
+    } else {
+      Log *log =
+          lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS);
+      LLDB_LOG_ERROR(log, decl_or_error.takeError(),
+                     "Couldn't import decl: {0}");
+      return nullptr;
+    }
   } else {
     lldbassert(0 && "No mechanism for copying a decl!");
     return nullptr;