[lldb] Fix evaluation of nested classes with parent from other CU

This makes sure that we associate DIEs that are imported from other CUs with the appropriate decl context.

Without this fix, nested classes can be dumped directly into their CU context if their parent was imported from another CU.

Reviewed By: teemperor, labath

Differential Revision: https://reviews.llvm.org/D68278

Patch by Jaroslav Sevcik!

llvm-svn: 373470

5 files changed, 81 insertions, 0 deletions

diff --git a/lldb/packages/Python/lldbsuite/test/lang/cpp/nested-class-other-compilation-unit/Makefile b/lldb/packages/Python/lldbsuite/test/lang/cpp/nested-class-other-compilation-unit/Makefile
new file mode 100644
index 00000000000..020dce7c31d
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/lang/cpp/nested-class-other-compilation-unit/Makefile
@@ -0,0 +1,3 @@
+CXX_SOURCES := main.cpp other.cpp
+
+include Makefile.rules
diff --git a/lldb/packages/Python/lldbsuite/test/lang/cpp/nested-class-other-compilation-unit/TestNestedClassWithParentInAnotherCU.py b/lldb/packages/Python/lldbsuite/test/lang/cpp/nested-class-other-compilation-unit/TestNestedClassWithParentInAnotherCU.py
new file mode 100644
index 00000000000..5b590d6363a
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/lang/cpp/nested-class-other-compilation-unit/TestNestedClassWithParentInAnotherCU.py
@@ -0,0 +1,29 @@
+"""
+Test that the expression evaluator can access members of nested classes even if
+the parents of the nested classes were imported from another compilation unit.
+"""
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+class TestNestedClassWithParentInAnotherCU(TestBase):
+    mydir = TestBase.compute_mydir(__file__)
+
+    def test_nested_class_with_parent_in_another_cu(self):
+        self.main_source_file = lldb.SBFileSpec("main.cpp")
+        self.build()
+        (_, _, thread, _) = lldbutil.run_to_source_breakpoint(self, "// break here", self.main_source_file)
+        frame = thread.GetSelectedFrame()
+        # Parse the DIEs of the parent classes and the nested classes from
+        # other.cpp's CU.
+        warmup_result = frame.EvaluateExpression("b")
+        self.assertTrue(warmup_result.IsValid())
+        # Inspect fields of the nested classes. This will reuse the types that
+        # were parsed during the evaluation above. By accessing a chain of
+        # fields, we try to verify that all the DIEs, reused types and
+        # declaration contexts were wired properly into lldb's parser's state.
+        expr_result = frame.EvaluateExpression("a.y.oY_inner.oX_inner")
+        self.assertTrue(expr_result.IsValid())
+        self.assertEqual(expr_result.GetValue(), "42")
diff --git a/lldb/packages/Python/lldbsuite/test/lang/cpp/nested-class-other-compilation-unit/main.cpp b/lldb/packages/Python/lldbsuite/test/lang/cpp/nested-class-other-compilation-unit/main.cpp
new file mode 100644
index 00000000000..8a6e6ff81d2
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/lang/cpp/nested-class-other-compilation-unit/main.cpp
@@ -0,0 +1,22 @@
+#include "shared.h"
+
+struct WrapperA {
+  OuterY::Inner<unsigned int> y;
+};
+
+int main() {
+  // WrapperA refers to the Inner and Outer class DIEs from this CU.
+  WrapperA a;
+  // WrapperB refers to the Inner and Outer DIEs from the other.cpp CU.
+  // It is important that WrapperB is only forward-declared in shared.h.
+  WrapperB* b = foo();
+
+  // Evaluating 'b' here will parse other.cpp's DIEs for all
+  // the Inner and Outer classes from shared.h.
+  //
+  // Evaluating 'a' here will find and reuse the already-parsed
+  // versions of the Inner and Outer classes. In the associated test
+  // we make sure that we can still resolve all the types properly
+  // by evaluating 'a.y.oY_inner.oX_inner'.
+  return 0;  // break here
+}
diff --git a/lldb/packages/Python/lldbsuite/test/lang/cpp/nested-class-other-compilation-unit/other.cpp b/lldb/packages/Python/lldbsuite/test/lang/cpp/nested-class-other-compilation-unit/other.cpp
new file mode 100644
index 00000000000..71a9579c4e8
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/lang/cpp/nested-class-other-compilation-unit/other.cpp
@@ -0,0 +1,10 @@
+#include "shared.h"
+
+struct WrapperB {
+  OuterY y;
+  OuterX x;
+};
+
+WrapperB* foo() {
+  return new WrapperB();
+}
diff --git a/lldb/packages/Python/lldbsuite/test/lang/cpp/nested-class-other-compilation-unit/shared.h b/lldb/packages/Python/lldbsuite/test/lang/cpp/nested-class-other-compilation-unit/shared.h
new file mode 100644
index 00000000000..627f49ab79c
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/lang/cpp/nested-class-other-compilation-unit/shared.h
@@ -0,0 +1,17 @@
+struct OuterX {
+  template<typename T>
+  struct Inner {
+    int oX_inner = 42;
+  };
+};
+
+struct OuterY {
+  template<typename T>
+  struct Inner {
+    typename OuterX::Inner<T> oY_inner;
+  };
+};
+
+struct WrapperB;
+
+WrapperB* foo();