[Lldb-commits] [lldb] [LLDB][NFC] Added the interface DWARFUnitInterface to break dependencies and reduce lldb-server size (PR #131645)
Dmitry Vasilyev via lldb-commits
lldb-commits at lists.llvm.org
Mon Mar 17 10:01:58 PDT 2025
https://github.com/slydiman created https://github.com/llvm/llvm-project/pull/131645
This patch addresses the issue #129543.
After this patch DWARFExpression does not call DWARFUnit directly and does not depend on lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp and a lot of clang code.
After this patch the size of lldb-server binary (Linux Aarch64) is reduced from 42MB to 13MB with LLVM 20.0.0
and from 47MB to 17MB with LLVM 21.0.0.
>From 464460db7550673bac788ad11e3ed4d45946cd71 Mon Sep 17 00:00:00 2001
From: Dmitry Vasilyev <dvassiliev at accesssoftek.com>
Date: Mon, 17 Mar 2025 19:13:20 +0400
Subject: [PATCH] [LLDB][NFC] Added the interface DWARFUnitInterface to break
dependencies and reduce lldb-server size
This patch addresses the issue #129543.
After this patch DWARFExpression does not call DWARFUnit directly and does not depend on lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp and a lot of clang code.
After this patch the size of lldb-server binary (Linux Aarch64)
is reduced from 42MB to 13MB with LLVM 20.0.0
and from 47MB to 17MB with LLVM 21.0.0.
---
.../include/lldb/Expression/DWARFExpression.h | 23 ++++----
lldb/source/Expression/DWARFExpression.cpp | 55 ++++++-------------
.../SymbolFile/DWARF/DWARFFormValue.cpp | 6 +-
.../Plugins/SymbolFile/DWARF/DWARFUnit.cpp | 39 ++++++++++---
.../Plugins/SymbolFile/DWARF/DWARFUnit.h | 50 +++++++++++++----
5 files changed, 101 insertions(+), 72 deletions(-)
diff --git a/lldb/include/lldb/Expression/DWARFExpression.h b/lldb/include/lldb/Expression/DWARFExpression.h
index 2c1e717ee32eb..cf4098f2acc51 100644
--- a/lldb/include/lldb/Expression/DWARFExpression.h
+++ b/lldb/include/lldb/Expression/DWARFExpression.h
@@ -23,7 +23,7 @@ namespace lldb_private {
namespace plugin {
namespace dwarf {
-class DWARFUnit;
+class DWARFUnitInterface;
} // namespace dwarf
} // namespace plugin
@@ -65,20 +65,20 @@ class DWARFExpression {
/// \return
/// The address specified by the operation, if the operation exists, or
/// an llvm::Error otherwise.
- llvm::Expected<lldb::addr_t>
- GetLocation_DW_OP_addr(const plugin::dwarf::DWARFUnit *dwarf_cu) const;
+ llvm::Expected<lldb::addr_t> GetLocation_DW_OP_addr(
+ const plugin::dwarf::DWARFUnitInterface *dwarf_cu) const;
- bool Update_DW_OP_addr(const plugin::dwarf::DWARFUnit *dwarf_cu,
+ bool Update_DW_OP_addr(const plugin::dwarf::DWARFUnitInterface *dwarf_cu,
lldb::addr_t file_addr);
void UpdateValue(uint64_t const_value, lldb::offset_t const_value_byte_size,
uint8_t addr_byte_size);
- bool
- ContainsThreadLocalStorage(const plugin::dwarf::DWARFUnit *dwarf_cu) const;
+ bool ContainsThreadLocalStorage(
+ const plugin::dwarf::DWARFUnitInterface *dwarf_cu) const;
bool LinkThreadLocalStorage(
- const plugin::dwarf::DWARFUnit *dwarf_cu,
+ const plugin::dwarf::DWARFUnitInterface *dwarf_cu,
std::function<lldb::addr_t(lldb::addr_t file_addr)> const
&link_address_callback);
@@ -132,13 +132,14 @@ class DWARFExpression {
static llvm::Expected<Value>
Evaluate(ExecutionContext *exe_ctx, RegisterContext *reg_ctx,
lldb::ModuleSP module_sp, const DataExtractor &opcodes,
- const plugin::dwarf::DWARFUnit *dwarf_cu,
+ const plugin::dwarf::DWARFUnitInterface *dwarf_cu,
const lldb::RegisterKind reg_set, const Value *initial_value_ptr,
const Value *object_address_ptr);
- static bool ParseDWARFLocationList(const plugin::dwarf::DWARFUnit *dwarf_cu,
- const DataExtractor &data,
- DWARFExpressionList *loc_list);
+ static bool
+ ParseDWARFLocationList(const plugin::dwarf::DWARFUnitInterface *dwarf_cu,
+ const DataExtractor &data,
+ DWARFExpressionList *loc_list);
bool GetExpressionData(DataExtractor &data) const {
data = m_data;
diff --git a/lldb/source/Expression/DWARFExpression.cpp b/lldb/source/Expression/DWARFExpression.cpp
index f48f3ab9307dd..41fbca59db60f 100644
--- a/lldb/source/Expression/DWARFExpression.cpp
+++ b/lldb/source/Expression/DWARFExpression.cpp
@@ -133,7 +133,7 @@ static llvm::Error ReadRegisterValueAsScalar(RegisterContext *reg_ctx,
static lldb::offset_t GetOpcodeDataSize(const DataExtractor &data,
const lldb::offset_t data_offset,
const LocationAtom op,
- const DWARFUnit *dwarf_cu) {
+ const DWARFUnitInterface *dwarf_cu) {
lldb::offset_t offset = data_offset;
switch (op) {
// Only used in LLVM metadata.
@@ -362,7 +362,8 @@ static lldb::offset_t GetOpcodeDataSize(const DataExtractor &data,
// + LEB128
{
data.Skip_LEB128(&offset);
- return DWARFUnit::GetAddressByteSize(dwarf_cu) + offset - data_offset;
+ return DWARFUnitInterface::GetAddressByteSize(dwarf_cu) + offset -
+ data_offset;
}
case DW_OP_GNU_entry_value:
@@ -393,8 +394,8 @@ static lldb::offset_t GetOpcodeDataSize(const DataExtractor &data,
return LLDB_INVALID_OFFSET;
}
-llvm::Expected<lldb::addr_t>
-DWARFExpression::GetLocation_DW_OP_addr(const DWARFUnit *dwarf_cu) const {
+llvm::Expected<lldb::addr_t> DWARFExpression::GetLocation_DW_OP_addr(
+ const DWARFUnitInterface *dwarf_cu) const {
lldb::offset_t offset = 0;
while (m_data.ValidOffset(offset)) {
const LocationAtom op = static_cast<LocationAtom>(m_data.GetU8(&offset));
@@ -422,7 +423,7 @@ DWARFExpression::GetLocation_DW_OP_addr(const DWARFUnit *dwarf_cu) const {
return LLDB_INVALID_ADDRESS;
}
-bool DWARFExpression::Update_DW_OP_addr(const DWARFUnit *dwarf_cu,
+bool DWARFExpression::Update_DW_OP_addr(const DWARFUnitInterface *dwarf_cu,
lldb::addr_t file_addr) {
lldb::offset_t offset = 0;
while (m_data.ValidOffset(offset)) {
@@ -481,7 +482,7 @@ bool DWARFExpression::Update_DW_OP_addr(const DWARFUnit *dwarf_cu,
}
bool DWARFExpression::ContainsThreadLocalStorage(
- const DWARFUnit *dwarf_cu) const {
+ const DWARFUnitInterface *dwarf_cu) const {
lldb::offset_t offset = 0;
while (m_data.ValidOffset(offset)) {
const LocationAtom op = static_cast<LocationAtom>(m_data.GetU8(&offset));
@@ -497,7 +498,7 @@ bool DWARFExpression::ContainsThreadLocalStorage(
return false;
}
bool DWARFExpression::LinkThreadLocalStorage(
- const DWARFUnit *dwarf_cu,
+ const DWARFUnitInterface *dwarf_cu,
std::function<lldb::addr_t(lldb::addr_t file_addr)> const
&link_address_callback) {
const uint32_t addr_byte_size = m_data.GetAddressByteSize();
@@ -783,7 +784,8 @@ enum LocationDescriptionKind {
/* Composite*/
};
/// Adjust value's ValueType according to the kind of location description.
-void UpdateValueTypeFromLocationDescription(Log *log, const DWARFUnit *dwarf_cu,
+void UpdateValueTypeFromLocationDescription(Log *log,
+ const DWARFUnitInterface *dwarf_cu,
LocationDescriptionKind kind,
Value *value = nullptr) {
// Note that this function is conflating DWARF expressions with
@@ -875,7 +877,7 @@ static Scalar DerefSizeExtractDataHelper(uint8_t *addr_bytes,
llvm::Expected<Value> DWARFExpression::Evaluate(
ExecutionContext *exe_ctx, RegisterContext *reg_ctx,
lldb::ModuleSP module_sp, const DataExtractor &opcodes,
- const DWARFUnit *dwarf_cu, const lldb::RegisterKind reg_kind,
+ const DWARFUnitInterface *dwarf_cu, const lldb::RegisterKind reg_kind,
const Value *initial_value_ptr, const Value *object_address_ptr) {
if (opcodes.GetByteSize() == 0)
@@ -2164,35 +2166,10 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
if (!bit_size)
return llvm::createStringError("unspecified architecture");
} else {
- // Retrieve the type DIE that the value is being converted to. This
- // offset is compile unit relative so we need to fix it up.
- const uint64_t abs_die_offset = die_offset + dwarf_cu->GetOffset();
- // FIXME: the constness has annoying ripple effects.
- DWARFDIE die = const_cast<DWARFUnit *>(dwarf_cu)->GetDIE(abs_die_offset);
- if (!die)
- return llvm::createStringError(
- "cannot resolve DW_OP_convert type DIE");
- uint64_t encoding =
- die.GetAttributeValueAsUnsigned(DW_AT_encoding, DW_ATE_hi_user);
- bit_size = die.GetAttributeValueAsUnsigned(DW_AT_byte_size, 0) * 8;
- if (!bit_size)
- bit_size = die.GetAttributeValueAsUnsigned(DW_AT_bit_size, 0);
- if (!bit_size)
- return llvm::createStringError(
- "unsupported type size in DW_OP_convert");
- switch (encoding) {
- case DW_ATE_signed:
- case DW_ATE_signed_char:
- sign = true;
- break;
- case DW_ATE_unsigned:
- case DW_ATE_unsigned_char:
- sign = false;
- break;
- default:
- return llvm::createStringError(
- "unsupported encoding in DW_OP_convert");
- }
+ if (llvm::Error err =
+ const_cast<DWARFUnitInterface *>(dwarf_cu)->GetBitSizeAndSign(
+ die_offset, bit_size, sign))
+ return err;
}
Scalar &top = stack.back().ResolveValue(exe_ctx);
top.TruncOrExtendTo(bit_size, sign);
@@ -2353,7 +2330,7 @@ llvm::Expected<Value> DWARFExpression::Evaluate(
}
bool DWARFExpression::ParseDWARFLocationList(
- const DWARFUnit *dwarf_cu, const DataExtractor &data,
+ const DWARFUnitInterface *dwarf_cu, const DataExtractor &data,
DWARFExpressionList *location_list) {
location_list->Clear();
std::unique_ptr<llvm::DWARFLocationTable> loctable_up =
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFFormValue.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFFormValue.cpp
index fd3d45cef4c5e..c2f4cc6a24af7 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFFormValue.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFFormValue.cpp
@@ -44,8 +44,8 @@ bool DWARFFormValue::ExtractValue(const DWARFDataExtractor &data,
switch (m_form) {
case DW_FORM_addr:
assert(m_unit);
- m_value.uval =
- data.GetMaxU64(offset_ptr, DWARFUnit::GetAddressByteSize(m_unit));
+ m_value.uval = data.GetMaxU64(
+ offset_ptr, DWARFUnitInterface::GetAddressByteSize(m_unit));
break;
case DW_FORM_block1:
m_value.uval = data.GetU8(offset_ptr);
@@ -242,7 +242,7 @@ bool DWARFFormValue::SkipValue(dw_form_t form,
// Compile unit address sized values
case DW_FORM_addr:
- *offset_ptr += DWARFUnit::GetAddressByteSize(unit);
+ *offset_ptr += DWARFUnitInterface::GetAddressByteSize(unit);
return true;
case DW_FORM_ref_addr:
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
index 1ceeef76f7cc3..168b134b84e2f 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
@@ -672,6 +672,37 @@ DWARFUnit::GetDIE(dw_offset_t die_offset) {
return DWARFDIE(); // Not found
}
+llvm::Error DWARFUnit::GetBitSizeAndSign(uint64_t die_offset,
+ uint64_t &bit_size, bool &sign) {
+ // Retrieve the type DIE that the value is being converted to. This
+ // offset is compile unit relative so we need to fix it up.
+ const uint64_t abs_die_offset = die_offset + GetOffset();
+ // FIXME: the constness has annoying ripple effects.
+ DWARFDIE die = GetDIE(abs_die_offset);
+ if (!die)
+ return llvm::createStringError("cannot resolve DW_OP_convert type DIE");
+ uint64_t encoding =
+ die.GetAttributeValueAsUnsigned(DW_AT_encoding, DW_ATE_hi_user);
+ bit_size = die.GetAttributeValueAsUnsigned(DW_AT_byte_size, 0) * 8;
+ if (!bit_size)
+ bit_size = die.GetAttributeValueAsUnsigned(DW_AT_bit_size, 0);
+ if (!bit_size)
+ return llvm::createStringError("unsupported type size in DW_OP_convert");
+ switch (encoding) {
+ case DW_ATE_signed:
+ case DW_ATE_signed_char:
+ sign = true;
+ break;
+ case DW_ATE_unsigned:
+ case DW_ATE_unsigned_char:
+ sign = false;
+ break;
+ default:
+ return llvm::createStringError("unsupported encoding in DW_OP_convert");
+ }
+ return llvm::Error::success();
+}
+
llvm::StringRef DWARFUnit::PeekDIEName(dw_offset_t die_offset) {
DWARFDebugInfoEntry die;
if (!die.Extract(GetData(), *this, &die_offset))
@@ -703,14 +734,6 @@ DWARFUnit &DWARFUnit::GetNonSkeletonUnit() {
return *this;
}
-uint8_t DWARFUnit::GetAddressByteSize(const DWARFUnit *cu) {
- if (cu)
- return cu->GetAddressByteSize();
- return DWARFUnit::GetDefaultAddressSize();
-}
-
-uint8_t DWARFUnit::GetDefaultAddressSize() { return 4; }
-
DWARFCompileUnit *DWARFUnit::GetSkeletonUnit() {
if (m_skeleton_unit.load() == nullptr && IsDWOUnit()) {
SymbolFileDWARFDwo *dwo =
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h
index ba142ae86fe0e..8d0bf51208108 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.h
@@ -38,7 +38,34 @@ enum DWARFProducer {
eProducerOther
};
-class DWARFUnit : public UserID {
+class DWARFUnitInterface {
+public:
+ DWARFUnitInterface() = default;
+ virtual ~DWARFUnitInterface() = default;
+
+ virtual SymbolFileDWARF &GetSymbolFileDWARF() const = 0;
+ virtual dw_addr_t ReadAddressFromDebugAddrSection(uint32_t index) const = 0;
+ virtual uint16_t GetVersion() const = 0;
+ virtual std::unique_ptr<llvm::DWARFLocationTable>
+ GetLocationTable(const DataExtractor &data) const = 0;
+ virtual dw_addr_t GetBaseAddress() const = 0;
+ virtual uint8_t GetAddressByteSize() const = 0;
+ virtual llvm::Error GetBitSizeAndSign(uint64_t die_offset, uint64_t &bit_size,
+ bool &sign) = 0;
+
+ static uint8_t GetAddressByteSize(const DWARFUnitInterface *cu) {
+ if (cu)
+ return cu->GetAddressByteSize();
+ return GetDefaultAddressSize();
+ }
+
+ static uint8_t GetDefaultAddressSize() { return 4; }
+
+ DWARFUnitInterface(const DWARFUnitInterface &) = delete;
+ DWARFUnitInterface &operator=(const DWARFUnitInterface &) = delete;
+};
+
+class DWARFUnit : public UserID, public DWARFUnitInterface {
using die_iterator_range =
llvm::iterator_range<DWARFDebugInfoEntry::collection::iterator>;
@@ -116,12 +143,14 @@ class DWARFUnit : public UserID {
size_t GetDebugInfoSize() const;
// Size of the CU data incl. header but without initial length.
dw_offset_t GetLength() const { return m_header.getLength(); }
- uint16_t GetVersion() const { return m_header.getVersion(); }
+ uint16_t GetVersion() const override { return m_header.getVersion(); }
const llvm::DWARFAbbreviationDeclarationSet *GetAbbreviations() const;
dw_offset_t GetAbbrevOffset() const;
- uint8_t GetAddressByteSize() const { return m_header.getAddressByteSize(); }
+ uint8_t GetAddressByteSize() const override {
+ return m_header.getAddressByteSize();
+ }
dw_addr_t GetAddrBase() const { return m_addr_base.value_or(0); }
- dw_addr_t GetBaseAddress() const { return m_base_addr; }
+ dw_addr_t GetBaseAddress() const override { return m_base_addr; }
dw_offset_t GetLineTableOffset();
dw_addr_t GetRangesBase() const { return m_ranges_base; }
dw_addr_t GetStrOffsetsBase() const { return m_str_offsets_base; }
@@ -131,7 +160,7 @@ class DWARFUnit : public UserID {
void SetStrOffsetsBase(dw_offset_t str_offsets_base);
virtual void BuildAddressRangeTable(DWARFDebugAranges *debug_aranges) = 0;
- dw_addr_t ReadAddressFromDebugAddrSection(uint32_t index) const;
+ dw_addr_t ReadAddressFromDebugAddrSection(uint32_t index) const override;
lldb::ByteOrder GetByteOrder() const;
@@ -145,6 +174,9 @@ class DWARFUnit : public UserID {
DWARFDIE GetDIE(dw_offset_t die_offset);
+ llvm::Error GetBitSizeAndSign(uint64_t die_offset, uint64_t &bit_size,
+ bool &sign) override;
+
/// Returns the AT_Name of the DIE at `die_offset`, if it exists, without
/// parsing the entire compile unit. An empty is string is returned upon
/// error or if the attribute is not present.
@@ -152,10 +184,6 @@ class DWARFUnit : public UserID {
DWARFUnit &GetNonSkeletonUnit();
- static uint8_t GetAddressByteSize(const DWARFUnit *cu);
-
- static uint8_t GetDefaultAddressSize();
-
lldb_private::CompileUnit *GetLLDBCompUnit() const { return m_lldb_cu; }
void SetLLDBCompUnit(lldb_private::CompileUnit *cu) { m_lldb_cu = cu; }
@@ -174,7 +202,7 @@ class DWARFUnit : public UserID {
bool Supports_unnamed_objc_bitfields();
- SymbolFileDWARF &GetSymbolFileDWARF() const { return m_dwarf; }
+ SymbolFileDWARF &GetSymbolFileDWARF() const override { return m_dwarf; }
DWARFProducer GetProducer();
@@ -237,7 +265,7 @@ class DWARFUnit : public UserID {
/// Return the location table for parsing the given location list data. The
/// format is chosen according to the unit type. Never returns null.
std::unique_ptr<llvm::DWARFLocationTable>
- GetLocationTable(const DataExtractor &data) const;
+ GetLocationTable(const DataExtractor &data) const override;
DWARFDataExtractor GetLocationData() const;
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