[PDB] Parse UDT symbols and pointers to members (combined patch)

Summary:
In this patch I've tried to combine the best ideas from D49368 and D49410,
so it implements following:

- Completion of UDTs from a PDB with a filling of a layout info;
- Pointers to members;
- Fixes the bug relating to a virtual base offset reading from `vbtable`.
  The offset was treated as an unsigned, but it can be a negative sometimes.
- Support of MSInheritance attribute

Reviewers: asmith, zturner, rnk, labath, clayborg, lldb-commits

Reviewed By: zturner

Subscribers: aleksandr.urakov, stella.stamenova, JDevlieghere, lldb-commits

Differential Revision: https://reviews.llvm.org/D49980

llvm-svn: 339649

4 files changed, 199 insertions, 0 deletions

diff --git a/lldb/lit/SymbolFile/PDB/Inputs/ClassLayoutTest.cpp b/lldb/lit/SymbolFile/PDB/Inputs/ClassLayoutTest.cpp
new file mode 100644
index 00000000000..3c4b005cdf1
--- /dev/null
+++ b/lldb/lit/SymbolFile/PDB/Inputs/ClassLayoutTest.cpp
@@ -0,0 +1,111 @@
+// To avoid linking MSVC specific libs, we don't test virtual/override methods
+// that needs vftable support in this file.
+
+// Enum.
+enum Enum { RED, GREEN, BLUE };
+Enum EnumVar;
+
+// Union.
+union Union {
+  short Row;
+  unsigned short Col;
+  int Line : 16; // Test named bitfield.
+  short : 8;     // Unnamed bitfield symbol won't be generated in PDB.
+  long Table;
+};
+Union UnionVar;
+
+// Struct.
+struct Struct;
+typedef Struct StructTypedef;
+
+struct Struct {
+  bool A;
+  unsigned char UCharVar;
+  unsigned int UIntVar;
+  long long LongLongVar;
+  Enum EnumVar; // Test struct has UDT member.
+  int array[10];
+};
+struct Struct StructVar;
+
+struct _List; // Forward declaration.
+struct Complex {
+  struct _List *array[90];
+  struct { // Test unnamed struct. MSVC treats it as `int x`
+    int x;
+  };
+  union { // Test unnamed union. MSVC treats it as `int a; float b;`
+    int a;
+    float b;
+  };
+};
+struct Complex c;
+
+struct _List { // Test doubly linked list.
+  struct _List *current;
+  struct _List *previous;
+  struct _List *next;
+};
+struct _List ListVar;
+
+typedef struct {
+  int a;
+} UnnamedStruct; // Test unnamed typedef-ed struct.
+UnnamedStruct UnnanmedVar;
+
+// Class.
+namespace MemberTest {
+class Base {
+public:
+  Base() {}
+  ~Base() {}
+
+public:
+  int Get() { return 0; }
+
+protected:
+  int a;
+};
+class Friend {
+public:
+  int f() { return 3; }
+};
+class Class : public Base { // Test base class.
+  friend Friend;
+  static int m_static; // Test static member variable.
+public:
+  Class() : m_public(), m_private(), m_protected() {}
+  explicit Class(int a) { m_public = a; } // Test first reference of m_public.
+  ~Class() {}
+
+  static int StaticMemberFunc(int a, ...) {
+    return 1;
+  } // Test static member function.
+  int Get() { return 1; }
+  int f(Friend c) { return c.f(); }
+  inline bool operator==(const Class &rhs) const // Test operator.
+  {
+    return (m_public == rhs.m_public);
+  }
+
+public:
+  int m_public;
+  struct Struct m_struct;
+
+private:
+  Union m_union;
+  int m_private;
+
+protected:
+  friend class Friend;
+  int m_protected;
+};
+} // namespace MemberTest
+
+int main() {
+  MemberTest::Base B1;
+  B1.Get();
+  MemberTest::Class::StaticMemberFunc(1, 10, 2);
+  return 0;
+}
diff --git a/lldb/lit/SymbolFile/PDB/Inputs/PointerTypeTest.cpp b/lldb/lit/SymbolFile/PDB/Inputs/PointerTypeTest.cpp
new file mode 100644
index 00000000000..6612c30f00d
--- /dev/null
+++ b/lldb/lit/SymbolFile/PDB/Inputs/PointerTypeTest.cpp
@@ -0,0 +1,23 @@
+int main() {
+  // Test pointer to array.
+  int array[2][4];
+  int(*array_pointer)[2][4] = &array;
+
+  struct ST {
+    int a;
+    int f(int x) { return 1; }
+  };
+
+  ST s = {10};
+
+  // Test pointer to a local.
+  int *p_int = &s.a;
+
+  // Test pointer to data member.
+  int ST::*p_member_field = &ST::a;
+
+  // Test pointer to member function.
+  int (ST::*p_member_method)(int) = &ST::f;
+
+  return 0;
+}
diff --git a/lldb/lit/SymbolFile/PDB/Inputs/UdtLayoutTest.cpp b/lldb/lit/SymbolFile/PDB/Inputs/UdtLayoutTest.cpp
new file mode 100644
index 00000000000..59a4fc585d7
--- /dev/null
+++ b/lldb/lit/SymbolFile/PDB/Inputs/UdtLayoutTest.cpp
@@ -0,0 +1,61 @@
+struct A {
+  explicit A(int u) { _u._u3 = u; }
+  A(const A &) = default;
+  virtual ~A() = default;
+
+private:
+  union U {
+    char _u1;
+    short _u2;
+    int _u3;
+  };
+
+  A::U _u;
+};
+
+#pragma pack(push, 1)
+template <int I> struct B : public virtual A {
+  B(char a, unsigned short b, int c) : A(a + b + c), _a(a), _b(b), _c(c) {}
+
+private:
+  char _a;
+  unsigned short : 3;
+  unsigned short _b : 6;
+  unsigned short : 4;
+  int _c;
+};
+#pragma pack(pop)
+
+#pragma pack(push, 16)
+class C : private virtual B<0>, public virtual B<1>, private B<2>, public B<3> {
+public:
+  C(char x, char y, char z)
+      : A(x - y + z), B<0>(x, y, z), B<1>(x * 2, y * 2, z * 2),
+        B<2>(x * 3, y * 3, z * 3), B<3>(x * 4, y * 4, z * 4), _x(x * 5),
+        _y(y * 5), _z(z * 5) {}
+
+  static int abc;
+
+private:
+  int _x;
+  short _y;
+  char _z;
+};
+int C::abc = 123;
+#pragma pack(pop)
+
+class List {
+public:
+  List() = default;
+  List(List *p, List *n, C v) : Prev(p), Next(n), Value(v) {}
+
+private:
+  List *Prev = nullptr;
+  List *Next = nullptr;
+  C Value{1, 2, 3};
+};
+
+int main() {
+  List ls[16];
+  return 0;
+}
diff --git a/lldb/lit/SymbolFile/PDB/Inputs/UdtLayoutTest.script b/lldb/lit/SymbolFile/PDB/Inputs/UdtLayoutTest.script
new file mode 100644
index 00000000000..91de55f4ade
--- /dev/null
+++ b/lldb/lit/SymbolFile/PDB/Inputs/UdtLayoutTest.script
@@ -0,0 +1,4 @@
+breakpoint set --file UdtLayoutTest.cpp --line 60
+run
+target variable
+frame variable