[Lldb-commits] [lldb] [lldb][test] Add test for no_unique_address when mixed with bitfields (PR #108155)

[Michael Buch via lldb-commits]

https://github.com/Michael137 updated https://github.com/llvm/llvm-project/pull/108155

>From ab898a3e176d0366fc15f6aad4b627d6e999753d Mon Sep 17 00:00:00 2001
From: Michael Buch <michaelbuch12 at gmail.com>
Date: Wed, 11 Sep 2024 01:15:21 +0100
Subject: [PATCH 1/4] [lldb][test] Add test for no_unique_address when mixed
 with bitfields

This is the root-cause for the LLDB failures that started
occurring after https://github.com/llvm/llvm-project/pull/105865.

The DWARFASTParserClang has logic to try derive unnamed bitfields
from DWARF offsets. In this case we treat `padding` as a 1-byte
size field that would overlap with `flag`, and decide we need to
introduce an unnamed bitfield into the AST, which is incorrect.
---
 .../no_unique_address-with-bitfields.cpp      | 30 +++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 lldb/test/Shell/SymbolFile/DWARF/no_unique_address-with-bitfields.cpp

diff --git a/lldb/test/Shell/SymbolFile/DWARF/no_unique_address-with-bitfields.cpp b/lldb/test/Shell/SymbolFile/DWARF/no_unique_address-with-bitfields.cpp
new file mode 100644
index 00000000000000..950bd9585baa22
--- /dev/null
+++ b/lldb/test/Shell/SymbolFile/DWARF/no_unique_address-with-bitfields.cpp
@@ -0,0 +1,30 @@
+// LLDB currently erroneously adds an unnamed bitfield
+// into the AST when a overlapping no_unique_address
+// field precedes a bitfield.
+
+// XFAIL: *
+
+// RUN: %clangxx_host -gdwarf -o %t %s
+// RUN: %lldb %t \
+// RUN:   -o "target var global" \
+// RUN:   -o "image dump ast" \
+// RUN:   -o exit | FileCheck %s
+
+// CHECK:      (lldb) image dump ast
+// CHECK-NEXT: CXXRecordDecl {{.*}} struct Foo definition
+// CHECK:      |-FieldDecl {{.*}} data 'char[5]'
+// CHECK-NEXT: |-FieldDecl {{.*}} padding 'Empty'
+// CHECK-NEXT: |-FieldDecl {{.*}} 'int'
+// CHECK-NEXT: | `-IntegerLiteral {{.*}} 'int' 8
+// CHECK-NEXT: `-FieldDecl {{.*}} sloc> mem 'unsigned long'
+// CHECK-NEXT:   `-IntegerLiteral {{.*}} 'int' 1
+
+struct Empty {};
+
+struct Foo {
+  char data[5];
+  [[no_unique_address]] Empty padding;
+  unsigned long flag : 1;
+};
+
+Foo global;

>From 3a8a1ecf16267d1304b1491803412702f258ce4c Mon Sep 17 00:00:00 2001
From: Michael Buch <michaelbuch12 at gmail.com>
Date: Wed, 11 Sep 2024 08:44:59 +0100
Subject: [PATCH 2/4] fixup! fix typo; don't link

---
 .../SymbolFile/DWARF/no_unique_address-with-bitfields.cpp     | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lldb/test/Shell/SymbolFile/DWARF/no_unique_address-with-bitfields.cpp b/lldb/test/Shell/SymbolFile/DWARF/no_unique_address-with-bitfields.cpp
index 950bd9585baa22..b26da25ac5d2fe 100644
--- a/lldb/test/Shell/SymbolFile/DWARF/no_unique_address-with-bitfields.cpp
+++ b/lldb/test/Shell/SymbolFile/DWARF/no_unique_address-with-bitfields.cpp
@@ -1,10 +1,10 @@
 // LLDB currently erroneously adds an unnamed bitfield
-// into the AST when a overlapping no_unique_address
+// into the AST when an overlapping no_unique_address
 // field precedes a bitfield.
 
 // XFAIL: *
 
-// RUN: %clangxx_host -gdwarf -o %t %s
+// RUN: %clangxx_host -c -gdwarf -o %t %s
 // RUN: %lldb %t \
 // RUN:   -o "target var global" \
 // RUN:   -o "image dump ast" \

>From 2749ad639b9f1bcb75e41e44ee3e07e0f5d0848e Mon Sep 17 00:00:00 2001
From: Michael Buch <michaelbuch12 at gmail.com>
Date: Wed, 11 Sep 2024 08:46:35 +0100
Subject: [PATCH 3/4] fixup! fix AST expectation; no need for the XFAIL

---
 .../SymbolFile/DWARF/no_unique_address-with-bitfields.cpp   | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/lldb/test/Shell/SymbolFile/DWARF/no_unique_address-with-bitfields.cpp b/lldb/test/Shell/SymbolFile/DWARF/no_unique_address-with-bitfields.cpp
index b26da25ac5d2fe..4877a69006a8e9 100644
--- a/lldb/test/Shell/SymbolFile/DWARF/no_unique_address-with-bitfields.cpp
+++ b/lldb/test/Shell/SymbolFile/DWARF/no_unique_address-with-bitfields.cpp
@@ -2,8 +2,6 @@
 // into the AST when an overlapping no_unique_address
 // field precedes a bitfield.
 
-// XFAIL: *
-
 // RUN: %clangxx_host -c -gdwarf -o %t %s
 // RUN: %lldb %t \
 // RUN:   -o "target var global" \
@@ -11,12 +9,12 @@
 // RUN:   -o exit | FileCheck %s
 
 // CHECK:      (lldb) image dump ast
-// CHECK-NEXT: CXXRecordDecl {{.*}} struct Foo definition
+// CHECK:      CXXRecordDecl {{.*}} struct Foo definition
 // CHECK:      |-FieldDecl {{.*}} data 'char[5]'
 // CHECK-NEXT: |-FieldDecl {{.*}} padding 'Empty'
 // CHECK-NEXT: |-FieldDecl {{.*}} 'int'
 // CHECK-NEXT: | `-IntegerLiteral {{.*}} 'int' 8
-// CHECK-NEXT: `-FieldDecl {{.*}} sloc> mem 'unsigned long'
+// CHECK-NEXT: `-FieldDecl {{.*}} sloc> flag 'unsigned long'
 // CHECK-NEXT:   `-IntegerLiteral {{.*}} 'int' 1
 
 struct Empty {};

>From 735f59516c01e1b9af855d1d8121bd8b7e9a765a Mon Sep 17 00:00:00 2001
From: Michael Buch <michaelbuch12 at gmail.com>
Date: Wed, 11 Sep 2024 09:37:45 +0100
Subject: [PATCH 4/4] fixup! added triple

---
 .../Shell/SymbolFile/DWARF/no_unique_address-with-bitfields.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lldb/test/Shell/SymbolFile/DWARF/no_unique_address-with-bitfields.cpp b/lldb/test/Shell/SymbolFile/DWARF/no_unique_address-with-bitfields.cpp
index 4877a69006a8e9..1c9cc36a711b47 100644
--- a/lldb/test/Shell/SymbolFile/DWARF/no_unique_address-with-bitfields.cpp
+++ b/lldb/test/Shell/SymbolFile/DWARF/no_unique_address-with-bitfields.cpp
@@ -2,7 +2,7 @@
 // into the AST when an overlapping no_unique_address
 // field precedes a bitfield.
 
-// RUN: %clangxx_host -c -gdwarf -o %t %s
+// RUN: %clang --target=x86_64-apple-macosx -c -gdwarf -o %t %s
 // RUN: %lldb %t \
 // RUN:   -o "target var global" \
 // RUN:   -o "image dump ast" \