[Lldb-commits] [PATCH] D76808: Fix handling of bit-fields when there is a base class when parsing DWARF

[Shafik Yaghmour via Phabricator via lldb-commits]

shafik updated this revision to Diff 253147.
shafik marked 2 inline comments as done.
shafik added a comment.

Minor fixes


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D76808/new/

https://reviews.llvm.org/D76808

Files:
  lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
  lldb/test/API/lang/cpp/bitfields/TestCppBitfields.py
  lldb/test/API/lang/cpp/bitfields/main.cpp


Index: lldb/test/API/lang/cpp/bitfields/main.cpp
===================================================================
--- lldb/test/API/lang/cpp/bitfields/main.cpp
+++ lldb/test/API/lang/cpp/bitfields/main.cpp
@@ -60,6 +60,16 @@
     } 
   } clang_example;
 
+  class B {
+  public:
+    uint32_t b_a;
+  };
+
+  class D : public B {
+  public:
+    uint32_t d_a : 1;
+  } derived;
+
   lba.a = 2;
 
   lbb.a = 1;
@@ -76,6 +86,8 @@
   lbd.arr[2] = '\0';
   lbd.a = 5;
 
+  derived.b_a = 2;
+  derived.d_a = 1;
 
   return 0; // Set break point at this line.
 }
Index: lldb/test/API/lang/cpp/bitfields/TestCppBitfields.py
===================================================================
--- lldb/test/API/lang/cpp/bitfields/TestCppBitfields.py
+++ lldb/test/API/lang/cpp/bitfields/TestCppBitfields.py
@@ -103,3 +103,10 @@
                    '(uint64_t:1) k = 1',
                 ])
 
+        self.expect(
+            "frame variable --show-types derived",
+            VARIABLES_DISPLAYED_CORRECTLY,
+            substrs=[
+                '(uint32_t) b_a = 2',
+                '(uint32_t:1) d_a = 1',
+                ])
Index: lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
===================================================================
--- lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
+++ lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
@@ -2668,9 +2668,19 @@
               }
 
               // If we have a gap between the last_field_end and the current
-              // field we have an unnamed bit-field
+              // field we have an unnamed bit-field.
+              // If we have a base class, we assume there is no unnamed
+              // bit-field if this is the first field since the gap can be
+              // attributed to the members from the base class. This assumption
+              // is not correct if the first field of the derived class is
+              // indeed an unnamed bit-field. We currently do not have the
+              // machinary to track the offset of the last field of classes we
+              // have seen before, so we are not handling this case.
               if (this_field_info.bit_offset != last_field_end &&
-                  !(this_field_info.bit_offset < last_field_end)) {
+                  this_field_info.bit_offset > last_field_end &&
+                  !(last_field_info.bit_offset == 0 &&
+                    last_field_info.bit_size == 0 &&
+                    layout_info.base_offsets.size() != 0)) {
                 unnamed_field_info = FieldInfo{};
                 unnamed_field_info->bit_size =
                     this_field_info.bit_offset - last_field_end;


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