Fix (and improve) the support for C99 variable length array types
Clang recently improved its DWARF support for C VLA types. The DWARF
now looks like this:
0x00000051: DW_TAG_variable [4]
DW_AT_location( fbreg -32 )
DW_AT_name( "__vla_expr" )
DW_AT_type( {0x000000d3} ( long unsigned int ) )
DW_AT_artificial( true )
...
0x000000da: DW_TAG_array_type [10] *
DW_AT_type( {0x000000cc} ( int ) )
0x000000df: DW_TAG_subrange_type [11]
DW_AT_type( {0x000000e9} ( __ARRAY_SIZE_TYPE__ ) )
DW_AT_count( {0x00000051} )
Without this patch LLDB will naively interpret the DIE offset 0x51 as
the static size of the array, which is clearly wrong. This patch
extends ValueObject::GetNumChildren to query the dynamic properties of
incomplete array types.
See the testcase for an example:
4 int foo(int a) {
5 int vla[a];
6 for (int i = 0; i < a; ++i)
7 vla[i] = i;
8
-> 9 pause(); // break here
10 return vla[a-1];
11 }
(lldb) fr v vla
(int []) vla = ([0] = 0, [1] = 1, [2] = 2, [3] = 3)
(lldb) quit
rdar://problem/21814005
Differential Revision: https://reviews.llvm.org/D53530
llvm-svn: 346165
diff --git a/lldb/source/Plugins/Language/CPlusPlus/BlockPointer.cpp b/lldb/source/Plugins/Language/CPlusPlus/BlockPointer.cpp
index 82b7ac1..bb1a47c 100644
--- a/lldb/source/Plugins/Language/CPlusPlus/BlockPointer.cpp
+++ b/lldb/source/Plugins/Language/CPlusPlus/BlockPointer.cpp
@@ -89,7 +89,7 @@
size_t CalculateNumChildren() override {
const bool omit_empty_base_classes = false;
- return m_block_struct_type.GetNumChildren(omit_empty_base_classes);
+ return m_block_struct_type.GetNumChildren(omit_empty_base_classes, nullptr);
}
lldb::ValueObjectSP GetChildAtIndex(size_t idx) override {