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/SymbolFile/NativePDB/SymbolFileNativePDB.cpp b/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
index 9125dab..676d2eb 100644
--- a/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
+++ b/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
@@ -1533,6 +1533,13 @@
return &*type_sp;
}
+llvm::Optional<SymbolFile::ArrayInfo>
+SymbolFileNativePDB::GetDynamicArrayInfoForUID(
+ lldb::user_id_t type_uid, const lldb_private::ExecutionContext *exe_ctx) {
+ return llvm::None;
+}
+
+
bool SymbolFileNativePDB::CompleteType(CompilerType &compiler_type) {
// If this is not in our map, it's an error.
clang::TagDecl *tag_decl = m_clang->GetAsTagDecl(compiler_type);
diff --git a/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.h b/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.h
index 94fa580..fd842b9 100644
--- a/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.h
+++ b/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.h
@@ -113,6 +113,10 @@
return 0;
}
Type *ResolveTypeUID(lldb::user_id_t type_uid) override;
+ llvm::Optional<ArrayInfo> GetDynamicArrayInfoForUID(
+ lldb::user_id_t type_uid,
+ const lldb_private::ExecutionContext *exe_ctx) override;
+
bool CompleteType(CompilerType &compiler_type) override;
uint32_t ResolveSymbolContext(const Address &so_addr,
lldb::SymbolContextItem resolve_scope,