[LLDB] Update DIL to handle smart pointers; add more tests.

This updates the DIL implementation to handle smart pointers (accessing
field members and dereferencing) in the same way the current 'frame
variable' implementation does.  It also adds tests for handling smart pointers,
as well as some additional DIL tests.

Author: cmtice

lldb/source/ValueObject/DILEval.cpp

@@ -253,6 +253,12 @@ Interpreter::Visit(const UnaryOpNode *node) {
       rhs = dynamic_rhs;
 
     lldb::ValueObjectSP child_sp = rhs->Dereference(error);
+    if (!child_sp && m_use_synthetic) {
+      if (lldb::ValueObjectSP synth_obj_sp = rhs->GetSyntheticValue()) {
+        error.Clear();
+        child_sp = synth_obj_sp->Dereference(error);
+      }
+    }
     if (error.Fail())
       return llvm::make_error<DILDiagnosticError>(m_expr, error.AsCString(),
                                                   node->GetLocation());
@@ -280,6 +286,7 @@ Interpreter::Visit(const MemberOfNode *node) {
   auto base_or_err = Evaluate(node->GetBase());
   if (!base_or_err)
     return base_or_err;
+  bool expr_is_ptr = node->GetIsArrow();
   lldb::ValueObjectSP base = *base_or_err;
 
   // Perform some basic type & correctness checking.
@@ -319,11 +326,11 @@ Interpreter::Visit(const MemberOfNode *node) {
         return llvm::make_error<DILDiagnosticError>(
             m_expr, errMsg, node->GetLocation(), node->GetFieldName().size());
       }
+      expr_is_ptr = false;
     }
   }
 
   if (m_check_ptr_vs_member) {
-    bool expr_is_ptr = node->GetIsArrow();
     bool base_is_ptr = base->IsPointerType();
 
     if (expr_is_ptr != base_is_ptr) {

lldb/test/API/commands/frame/var-dil/basics/BitField/Makefile

@@ -0,0 +1,3 @@
+CXX_SOURCES := main.cpp
+
+include Makefile.rules

lldb/test/API/commands/frame/var-dil/basics/BitField/TestFrameVarDILBitField.py

@@ -0,0 +1,38 @@
+"""
+Make sure 'frame var' using DIL parser/evaluator works for bit fields.
+"""
+
+import lldb
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test.decorators import *
+from lldbsuite.test import lldbutil
+
+import os
+import shutil
+import time
+
+class TestFrameVarDILBitField(TestBase):
+    # If your test case doesn't stress debug info, then
+    # set this to true.  That way it won't be run once for
+    # each debug info format.
+    NO_DEBUG_INFO_TESTCASE = True
+
+    def test_frame_var(self):
+        self.build()
+        lldbutil.run_to_source_breakpoint(self, "Set a breakpoint here",
+                                          lldb.SBFileSpec("main.cpp"))
+
+        self.runCmd("settings set target.experimental.use-DIL true")
+        self.expect_var_path("bf.a", value="1023")
+        self.expect_var_path("bf.b", value="9")
+        self.expect_var_path("bf.c", value="false")
+        self.expect_var_path("bf.d", value="true")
+
+        self.expect_var_path("abf.a", value="1023")
+        self.expect_var_path("abf.b", value="'\\x0f'")
+        self.expect_var_path("abf.c", value="3")
+
+        # Perform an operation to ensure we actually read the value.
+        # Address-of is not allowed for bit-fields.
+        self.expect("frame variable '&bf.a'", error=True,
+                    substrs=["'bf.a' doesn't have a valid address"])

lldb/test/API/commands/frame/var-dil/basics/BitField/main.cpp

@@ -0,0 +1,44 @@
+#include <cstdint>
+
+int
+main(int argc, char **argv)
+{
+  enum BitFieldEnum : uint32_t { kZero, kOne };
+
+  struct BitFieldStruct {
+    uint16_t a : 10;
+    uint32_t b : 4;
+    bool c : 1;
+    bool d : 1;
+    int32_t e : 32;
+    uint32_t f : 32;
+    uint32_t g : 31;
+    uint64_t h : 31;
+    uint64_t i : 33;
+    BitFieldEnum j : 10;
+  };
+
+  BitFieldStruct bf;
+  bf.a = 0b1111111111;
+  bf.b = 0b1001;
+  bf.c = 0b0;
+  bf.d = 0b1;
+  bf.e = 0b1;
+  bf.f = 0b1;
+  bf.g = 0b1;
+  bf.h = 0b1;
+  bf.i = 0b1;
+  bf.j = BitFieldEnum::kOne;
+
+  struct AlignedBitFieldStruct {
+    uint16_t a : 10;
+    uint8_t b : 4;
+    unsigned char : 0;
+    uint16_t c : 2;
+  };
+
+  uint32_t data = ~0;
+  AlignedBitFieldStruct abf = (AlignedBitFieldStruct&)data;
+
+  return 0; // Set a breakpoint here
+}

lldb/test/API/commands/frame/var-dil/basics/Indirection/Makefile

@@ -0,0 +1,3 @@
+CXX_SOURCES := main.cpp
+
+include Makefile.rules

lldb/test/API/commands/frame/var-dil/basics/Indirection/TestFrameVarDILIndirection.py

@@ -0,0 +1,36 @@
+"""
+Make sure 'frame var' using DIL parser/evaluator works for indirection.
+"""
+
+import lldb
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test.decorators import *
+from lldbsuite.test import lldbutil
+
+import os
+import shutil
+import time
+
+class TestFrameVarDILIndirection(TestBase):
+    # If your test case doesn't stress debug info, then
+    # set this to true.  That way it won't be run once for
+    # each debug info format.
+    NO_DEBUG_INFO_TESTCASE = True
+
+    def test_frame_var(self):
+        self.build()
+        lldbutil.run_to_source_breakpoint(self, "Set a breakpoint here",
+                                          lldb.SBFileSpec("main.cpp"))
+
+        self.runCmd("settings set target.experimental.use-DIL true")
+        self.expect_var_path("*p", value="1")
+        self.expect_var_path("p", type="int *")
+        self.expect_var_path("*my_p", value="1")
+        self.expect_var_path("my_p", type="myp")
+        self.expect_var_path("*my_pr", type="int *")
+        self.expect_var_path("my_pr", type="mypr")
+
+        self.expect("frame variable '*1'", error=True,
+                    substrs=["Unexpected token: <'1' (numeric_constant)>"])
+        self.expect("frame variable '*val'", error=True,
+                    substrs=["dereference failed: not a pointer, reference or array type: (int) val"])

lldb/test/API/commands/frame/var-dil/basics/Indirection/main.cpp

@@ -0,0 +1,14 @@
+int
+main(int argc, char **argv)
+{
+  int val = 1;
+  int* p = &val;
+
+  typedef int* myp;
+  myp my_p = &val;
+
+  typedef int*& mypr;
+  mypr my_pr = p;
+
+  return 0; // Set a breakpoint here
+}

lldb/test/API/commands/frame/var-dil/basics/PointerDereference/Makefile

@@ -0,0 +1,3 @@
+CXX_SOURCES := main.cpp
+
+include Makefile.rules

lldb/test/API/commands/frame/var-dil/basics/PointerDereference/TestFrameVarDILPointerDereference.py

@@ -0,0 +1,30 @@
+"""
+Test DIL pointer dereferencing.
+"""
+
+import lldb
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test.decorators import *
+from lldbsuite.test import lldbutil
+
+import os
+import shutil
+import time
+
+class TestFrameVarDILPointerDereference(TestBase):
+    NO_DEBUG_INFO_TESTCASE = True
+
+    def test_frame_var(self):
+        self.build()
+        lldbutil.run_to_source_breakpoint(
+            self, "Set a breakpoint here", lldb.SBFileSpec("main.cpp")
+        )
+
+        self.runCmd("settings set target.experimental.use-DIL true")
+        self.expect_var_path("*p_int0", value="0")
+        self.expect_var_path("*cp_int5", value="5")
+        self.expect_var_path("&pp_void0[2]", type="void **")
+        self.expect_var_path("**pp_int0", value="0")
+        self.expect_var_path("&**pp_int0", type="int *")
+        self.expect("frame variable '&p_void[0]'", error=True,
+                    substrs=["subscript of pointer to incomplete type 'void'"])

lldb/test/API/commands/frame/var-dil/basics/PointerDereference/main.cpp

@@ -0,0 +1,32 @@
+#include <cstddef>
+
+int main (int argc, char **argv) {
+    int* p_null = nullptr;
+  const char* p_char1 = "hello";
+
+  typedef const char* my_char_ptr;
+  my_char_ptr my_p_char1 = p_char1;
+
+  int offset = 5;
+  int array[10];
+  array[0] = 0;
+  array[offset] = offset;
+
+  int(&array_ref)[10] = array;
+
+  int* p_int0 = &array[0];
+  int** pp_int0 = &p_int0;
+  const int* cp_int0 = &array[0];
+  const int* cp_int5 = &array[offset];
+
+  typedef int* td_int_ptr_t;
+  td_int_ptr_t td_int_ptr0 = &array[0];
+
+  void* p_void = (void*)p_char1;
+  void** pp_void0 = &p_void;
+  void** pp_void1 = pp_void0 + 1;
+
+  std::nullptr_t std_nullptr_t = nullptr;
+
+  return 0; // Set a breakpoint here
+}