Handle typeof() expressions

Before this patch, LLDB was not able to evaluate expressions that
resulted in a value with a typeof- or decltype-type. This patch fixes
that.

Before:
  (lldb) p int i; __typeof__(i) j = 1; j
  (typeof (i)) $0 =

After:
  (lldb) p int i; __typeof__(i) j = 1; j
  (typeof (i)) $0 = 1

Differential revision: https://reviews.llvm.org/D43471

rdar://37461520

1 files changed, 65 insertions, 17 deletions

diff --git a/lldb/source/Symbol/ClangASTContext.cpp b/lldb/source/Symbol/ClangASTContext.cpp
index 673124cc0de..142a7cc6255 100644
--- a/lldb/source/Symbol/ClangASTContext.cpp
+++ b/lldb/source/Symbol/ClangASTContext.cpp
@@ -3964,7 +3964,10 @@ ClangASTContext::GetTypeInfo(lldb::opaque_compiler_type_t type,
   case clang::Type::DependentTemplateSpecialization:
     return eTypeIsTemplate;
   case clang::Type::Decltype:
-    return 0;
+    return CompilerType(
+               getASTContext(),
+               llvm::cast<clang::DecltypeType>(qual_type)->getUnderlyingType())
+        .GetTypeInfo(pointee_or_element_clang_type);
 
   case clang::Type::Enum:
     if (pointee_or_element_clang_type)
@@ -4046,9 +4049,16 @@ ClangASTContext::GetTypeInfo(lldb::opaque_compiler_type_t type,
                             ->getUnderlyingType())
                .GetTypeInfo(pointee_or_element_clang_type);
   case clang::Type::TypeOfExpr:
-    return 0;
+    return CompilerType(getASTContext(),
+                        llvm::cast<clang::TypeOfExprType>(qual_type)
+                            ->getUnderlyingExpr()
+                            ->getType())
+        .GetTypeInfo(pointee_or_element_clang_type);
   case clang::Type::TypeOf:
-    return 0;
+    return CompilerType(
+               getASTContext(),
+               llvm::cast<clang::TypeOfType>(qual_type)->getUnderlyingType())
+        .GetTypeInfo(pointee_or_element_clang_type);
   case clang::Type::UnresolvedUsing:
     return 0;
 
@@ -4255,11 +4265,21 @@ ClangASTContext::GetTypeClass(lldb::opaque_compiler_type_t type) {
     break;
 
   case clang::Type::TypeOfExpr:
-    break;
+    return CompilerType(getASTContext(),
+                        llvm::cast<clang::TypeOfExprType>(qual_type)
+                            ->getUnderlyingExpr()
+                            ->getType())
+        .GetTypeClass();
   case clang::Type::TypeOf:
-    break;
+    return CompilerType(
+               getASTContext(),
+               llvm::cast<clang::TypeOfType>(qual_type)->getUnderlyingType())
+        .GetTypeClass();
   case clang::Type::Decltype:
-    break;
+    return CompilerType(
+               getASTContext(),
+               llvm::cast<clang::TypeOfType>(qual_type)->getUnderlyingType())
+        .GetTypeClass();
   case clang::Type::TemplateSpecialization:
     break;
   case clang::Type::DeducedTemplateSpecialization:
@@ -5060,7 +5080,22 @@ lldb::Encoding ClangASTContext::GetEncoding(lldb::opaque_compiler_type_t type,
     return CompilerType(getASTContext(),
                         llvm::cast<clang::ParenType>(qual_type)->desugar())
         .GetEncoding(count);
-
+  case clang::Type::TypeOfExpr:
+    return CompilerType(getASTContext(),
+                        llvm::cast<clang::TypeOfExprType>(qual_type)
+                            ->getUnderlyingExpr()
+                            ->getType())
+        .GetEncoding(count);
+  case clang::Type::TypeOf:
+    return CompilerType(
+               getASTContext(),
+               llvm::cast<clang::TypeOfType>(qual_type)->getUnderlyingType())
+        .GetEncoding(count);
+  case clang::Type::Decltype:
+    return CompilerType(
+               getASTContext(),
+               llvm::cast<clang::DecltypeType>(qual_type)->getUnderlyingType())
+        .GetEncoding(count);
   case clang::Type::DependentSizedArray:
   case clang::Type::DependentSizedExtVector:
   case clang::Type::UnresolvedUsing:
@@ -5074,9 +5109,6 @@ lldb::Encoding ClangASTContext::GetEncoding(lldb::opaque_compiler_type_t type,
   case clang::Type::PackExpansion:
   case clang::Type::ObjCObject:
 
-  case clang::Type::TypeOfExpr:
-  case clang::Type::TypeOf:
-  case clang::Type::Decltype:
   case clang::Type::TemplateSpecialization:
   case clang::Type::DeducedTemplateSpecialization:
   case clang::Type::Atomic:
@@ -5214,6 +5246,22 @@ lldb::Format ClangASTContext::GetFormat(lldb::opaque_compiler_type_t type) {
                getASTContext(),
                llvm::cast<clang::ElaboratedType>(qual_type)->getNamedType())
         .GetFormat();
+  case clang::Type::TypeOfExpr:
+    return CompilerType(getASTContext(),
+                        llvm::cast<clang::TypeOfExprType>(qual_type)
+                            ->getUnderlyingExpr()
+                            ->getType())
+        .GetFormat();
+  case clang::Type::TypeOf:
+    return CompilerType(
+               getASTContext(),
+               llvm::cast<clang::TypeOfType>(qual_type)->getUnderlyingType())
+        .GetFormat();
+  case clang::Type::Decltype:
+    return CompilerType(
+               getASTContext(),
+               llvm::cast<clang::DecltypeType>(qual_type)->getUnderlyingType())
+        .GetFormat();
   case clang::Type::DependentSizedArray:
   case clang::Type::DependentSizedExtVector:
   case clang::Type::UnresolvedUsing:
@@ -5227,9 +5275,6 @@ lldb::Format ClangASTContext::GetFormat(lldb::opaque_compiler_type_t type) {
   case clang::Type::PackExpansion:
   case clang::Type::ObjCObject:
 
-  case clang::Type::TypeOfExpr:
-  case clang::Type::TypeOf:
-  case clang::Type::Decltype:
   case clang::Type::TemplateSpecialization:
   case clang::Type::DeducedTemplateSpecialization:
   case clang::Type::Atomic:
@@ -6264,11 +6309,15 @@ uint32_t ClangASTContext::GetNumPointeeChildren(clang::QualType type) {
     return GetNumPointeeChildren(
         llvm::cast<clang::ElaboratedType>(qual_type)->getNamedType());
   case clang::Type::TypeOfExpr:
-    return 0;
+    return GetNumPointeeChildren(llvm::cast<clang::TypeOfExprType>(qual_type)
+                                     ->getUnderlyingExpr()
+                                     ->getType());
   case clang::Type::TypeOf:
-    return 0;
+    return GetNumPointeeChildren(
+        llvm::cast<clang::TypeOfType>(qual_type)->getUnderlyingType());
   case clang::Type::Decltype:
-    return 0;
+    return GetNumPointeeChildren(
+        llvm::cast<clang::DecltypeType>(qual_type)->getUnderlyingType());
   case clang::Type::Record:
     return 0;
   case clang::Type::Enum:
@@ -10086,4 +10135,3 @@ ClangASTContextForExpressions::GetMergerUnchecked() {
   lldbassert(m_scratch_ast_source_ap != nullptr);
   return m_scratch_ast_source_ap->GetMergerUnchecked();
 }
-