[Lldb-commits] [lldb] e08d8e3 - [LLDB][PDB] Run UDT layout test with native PDB too (#159769)
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Tue Sep 23 02:34:52 PDT 2025
Author: nerix
Date: 2025-09-23T11:34:48+02:00
New Revision: e08d8e3d16d6994df5e42cee7c2672d2fe9cc46c
URL: https://github.com/llvm/llvm-project/commit/e08d8e3d16d6994df5e42cee7c2672d2fe9cc46c
DIFF: https://github.com/llvm/llvm-project/commit/e08d8e3d16d6994df5e42cee7c2672d2fe9cc46c.diff
LOG: [LLDB][PDB] Run UDT layout test with native PDB too (#159769)
This test was failing with the native plugin due to two reasons:
1. The static `C::abc` was printed as `(int) ::C::abc = 123`
2. The order of the base classes of [`C`
(`List::Value`)](https://github.com/llvm/llvm-project/blob/b7e4edca3d56ec87f719c202f5397b245595f7cc/lldb/test/Shell/SymbolFile/PDB/Inputs/UdtLayoutTest.cpp#L30)
is different between DIA and the native plugin. I don't know how the
order in the DIA plugin is determined - it prints `B<0>`, `B<1>`,
`B<2>`, `B<3>`, `A`. The native plugin follows the order of the bases in
memory and prints `B<2>`, `B<3>`, `A`, `B<0>`, `B<1>` (last three are
the virtual bases).
<details><summary>Class layout of C</summary>
```
class C size(88):
+---
0 | +--- (base class B<2>)
0 | | {vbptr}
8 | | _a
9. | | _b (bitstart=3,nbits=6)
11 | | _c
| +---
15 | +--- (base class B<3>)
15 | | {vbptr}
23 | | _a
24. | | _b (bitstart=3,nbits=6)
26 | | _c
| +---
| <alignment member> (size=2)
32 | _x
36 | _y
38 | _z
| <alignment member> (size=1)
| <alignment member> (size=2)
+---
+--- (virtual base A)
40 | {vfptr}
48 | U _u
| <alignment member> (size=4)
+---
+--- (virtual base B<0>)
56 | {vbptr}
64 | _a
65. | _b (bitstart=3,nbits=6)
67 | _c
+---
+--- (virtual base B<1>)
71 | {vbptr}
79 | _a
80. | _b (bitstart=3,nbits=6)
82 | _c
+---
```
</details>
I split the tests for the plugins for better readability.
Added:
lldb/test/Shell/SymbolFile/NativePDB/udt-layout.test
Modified:
lldb/test/Shell/SymbolFile/PDB/udt-layout.test
Removed:
################################################################################
diff --git a/lldb/test/Shell/SymbolFile/NativePDB/udt-layout.test b/lldb/test/Shell/SymbolFile/NativePDB/udt-layout.test
new file mode 100644
index 0000000000000..6e971541de60c
--- /dev/null
+++ b/lldb/test/Shell/SymbolFile/NativePDB/udt-layout.test
@@ -0,0 +1,129 @@
+# REQUIRES: target-windows
+
+# Test UDT layout reconstruction
+# RUN: split-file %s %t
+# RUN: %build --compiler=clang-cl -o %t.exe -- %t/main.cpp
+# RUN: %lldb -f %t.exe -s %t/commands.input 2>&1 | FileCheck %s
+
+#--- main.cpp
+
+// this is from the DIA plugin (UdtLayoutTest.cpp)
+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; // break here
+}
+
+#--- commands.input
+
+settings set target.max-children-depth 10
+br set -p "break here"
+run
+target variable
+frame variable
+quit
+
+# CHECK: (int) ::C::abc = 123
+
+# CHECK: (List[16]) ls = {
+# CHECK: [15] = {
+# CHECK-NEXT: Prev = nullptr
+# CHECK-NEXT: Next = nullptr
+# CHECK-NEXT: Value = {
+# CHECK-NEXT: B<2> = {
+# CHECK-NEXT: A = {
+# CHECK-NEXT: _u = (_u1 = '\x02', _u2 = 2, _u3 = 2)
+# CHECK-NEXT: }
+# CHECK-NEXT: _a = '\x03'
+# CHECK-NEXT: _b = 6
+# CHECK-NEXT: _c = 9
+# CHECK-NEXT: }
+# CHECK-NEXT: B<3> = {
+# CHECK-NEXT: A = {
+# CHECK-NEXT: _u = (_u1 = '\x02', _u2 = 2, _u3 = 2)
+# CHECK-NEXT: }
+# CHECK-NEXT: _a = '\x04'
+# CHECK-NEXT: _b = 8
+# CHECK-NEXT: _c = 12
+# CHECK-NEXT: }
+# CHECK-NEXT: A = {
+# CHECK-NEXT: _u = (_u1 = '\x02', _u2 = 2, _u3 = 2)
+# CHECK-NEXT: }
+# CHECK-NEXT: B<0> = {
+# CHECK-NEXT: A = {
+# CHECK-NEXT: _u = (_u1 = '\x02', _u2 = 2, _u3 = 2)
+# CHECK-NEXT: }
+# CHECK-NEXT: _a = '\x01'
+# CHECK-NEXT: _b = 2
+# CHECK-NEXT: _c = 3
+# CHECK-NEXT: }
+# CHECK-NEXT: B<1> = {
+# CHECK-NEXT: A = {
+# CHECK-NEXT: _u = (_u1 = '\x02', _u2 = 2, _u3 = 2)
+# CHECK-NEXT: }
+# CHECK-NEXT: _a = '\x02'
+# CHECK-NEXT: _b = 4
+# CHECK-NEXT: _c = 6
+# CHECK-NEXT: }
+# CHECK-NEXT: _x = 5
+# CHECK-NEXT: _y = 10
+# CHECK-NEXT: _z = '\x0f'
+# CHECK-NEXT: }
+# CHECK-NEXT: }
+# CHECK-NEXT: }
diff --git a/lldb/test/Shell/SymbolFile/PDB/udt-layout.test b/lldb/test/Shell/SymbolFile/PDB/udt-layout.test
index bc68539e25ec1..619646b3f12ba 100644
--- a/lldb/test/Shell/SymbolFile/PDB/udt-layout.test
+++ b/lldb/test/Shell/SymbolFile/PDB/udt-layout.test
@@ -1,4 +1,4 @@
-REQUIRES: target-windows, lld
+REQUIRES: target-windows, lld, diasdk
RUN: %build --compiler=clang-cl --output=%t.exe %S/Inputs/UdtLayoutTest.cpp
RUN: %lldb -b -s %S/Inputs/UdtLayoutTest.script -- %t.exe | FileCheck %s
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