Make CompilerType::getBitSize() / getByteSize() return an optional result. NFC
The code in LLDB assumes that CompilerType and friends use the size 0
as a sentinel value to signal an error. This works for C++, where no
zero-sized type exists, but in many other programming languages
(including I believe C) types of size zero are possible and even
common. This is a particular pain point in swift-lldb, where extra
code exists to double-check that a type is *really* of size zero and
not an error at various locations.
To remedy this situation, this patch starts by converting
CompilerType::getBitSize() and getByteSize() to return an optional
result. To avoid wasting space, I hand-rolled my own optional data
type assuming that no type is larger than what fits into 63
bits. Follow-up patches would make similar changes to the ValueObject
hierarchy.
rdar://problem/47178964
Differential Revision: https://reviews.llvm.org/D56688
llvm-svn: 351214
diff --git a/lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp b/lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp
index 5a56068..af118a7 100644
--- a/lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp
+++ b/lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp
@@ -225,9 +225,14 @@
m_pair_ptr = nullptr;
return false;
}
- CompilerType pair_type(__i_->GetCompilerType().GetTypeTemplateArgument(0));
- std::string name; uint64_t bit_offset_ptr; uint32_t bitfield_bit_size_ptr; bool is_bitfield_ptr;
- pair_type = pair_type.GetFieldAtIndex(0, name, &bit_offset_ptr, &bitfield_bit_size_ptr, &is_bitfield_ptr);
+ CompilerType pair_type(
+ __i_->GetCompilerType().GetTypeTemplateArgument(0));
+ std::string name;
+ uint64_t bit_offset_ptr;
+ uint32_t bitfield_bit_size_ptr;
+ bool is_bitfield_ptr;
+ pair_type = pair_type.GetFieldAtIndex(
+ 0, name, &bit_offset_ptr, &bitfield_bit_size_ptr, &is_bitfield_ptr);
if (!pair_type) {
m_pair_ptr = nullptr;
return false;
@@ -235,27 +240,38 @@
auto addr(m_pair_ptr->GetValueAsUnsigned(LLDB_INVALID_ADDRESS));
m_pair_ptr = nullptr;
- if (addr && addr!=LLDB_INVALID_ADDRESS) {
- ClangASTContext *ast_ctx = llvm::dyn_cast_or_null<ClangASTContext>(pair_type.GetTypeSystem());
+ if (addr && addr != LLDB_INVALID_ADDRESS) {
+ ClangASTContext *ast_ctx =
+ llvm::dyn_cast_or_null<ClangASTContext>(pair_type.GetTypeSystem());
if (!ast_ctx)
return false;
- CompilerType tree_node_type = ast_ctx->CreateStructForIdentifier(ConstString(), {
- {"ptr0",ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()},
- {"ptr1",ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()},
- {"ptr2",ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()},
- {"cw",ast_ctx->GetBasicType(lldb::eBasicTypeBool)},
- {"payload",pair_type}
- });
- DataBufferSP buffer_sp(new DataBufferHeap(tree_node_type.GetByteSize(nullptr),0));
+ CompilerType tree_node_type = ast_ctx->CreateStructForIdentifier(
+ ConstString(),
+ {{"ptr0",
+ ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()},
+ {"ptr1",
+ ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()},
+ {"ptr2",
+ ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()},
+ {"cw", ast_ctx->GetBasicType(lldb::eBasicTypeBool)},
+ {"payload", pair_type}});
+ auto size = tree_node_type.GetByteSize(nullptr);
+ if (!size)
+ return false;
+ DataBufferSP buffer_sp(new DataBufferHeap(*size, 0));
ProcessSP process_sp(target_sp->GetProcessSP());
Status error;
- process_sp->ReadMemory(addr, buffer_sp->GetBytes(), buffer_sp->GetByteSize(), error);
+ process_sp->ReadMemory(addr, buffer_sp->GetBytes(),
+ buffer_sp->GetByteSize(), error);
if (error.Fail())
return false;
- DataExtractor extractor(buffer_sp, process_sp->GetByteOrder(), process_sp->GetAddressByteSize());
- auto pair_sp = CreateValueObjectFromData("pair", extractor, valobj_sp->GetExecutionContextRef(), tree_node_type);
+ DataExtractor extractor(buffer_sp, process_sp->GetByteOrder(),
+ process_sp->GetAddressByteSize());
+ auto pair_sp = CreateValueObjectFromData(
+ "pair", extractor, valobj_sp->GetExecutionContextRef(),
+ tree_node_type);
if (pair_sp)
- m_pair_sp = pair_sp->GetChildAtIndex(4,true);
+ m_pair_sp = pair_sp->GetChildAtIndex(4, true);
}
}
}
@@ -560,6 +576,8 @@
->GetScratchClangASTContext()
->GetBasicType(lldb::eBasicTypeWChar)
.GetByteSize(nullptr);
+ if (!wchar_t_size)
+ return false;
options.SetData(extractor);
options.SetStream(&stream);
@@ -568,7 +586,7 @@
options.SetSourceSize(size);
options.SetBinaryZeroIsTerminator(false);
- switch (wchar_t_size) {
+ switch (*wchar_t_size) {
case 1:
StringPrinter::ReadBufferAndDumpToStream<
lldb_private::formatters::StringPrinter::StringElementType::UTF8>(