[Lldb-commits] [lldb] bf0cda9 - [lldb][COFF] Rewrite ParseSymtab to list both export and symbol tables
Martin Storsjö via lldb-commits
lldb-commits at lists.llvm.org
Wed Sep 28 02:58:15 PDT 2022
Author: Alvin Wong
Date: 2022-09-28T12:57:10+03:00
New Revision: bf0cda9ed2783a34efed3fc9804d784f7d1df242
URL: https://github.com/llvm/llvm-project/commit/bf0cda9ed2783a34efed3fc9804d784f7d1df242
DIFF: https://github.com/llvm/llvm-project/commit/bf0cda9ed2783a34efed3fc9804d784f7d1df242.diff
LOG: [lldb][COFF] Rewrite ParseSymtab to list both export and symbol tables
This reimplements `ObjectFilePECOFF::ParseSymtab` to replace the manual
data extraction with what `COFFObjectFile` already provides. Also use
`SymTab::AddSymbol` instead of resizing the SymTab then assigning each
elements afterwards.
Previously, ParseSymTab loads symbols from both the COFF symbol table
and the export table, but if there are any entries in the export table,
it overwrites all the symbols already loaded from the COFF symbol table.
Due to the change to use AddSymbols, this no longer happens, and so the
SymTab now contains all symbols from both tables as expected.
The export symbols are now ordered by ordinal, instead of by the name
table order.
In its current state, it is possible for symbols in the COFF symbol
table to be duplicated by those in the export table. This behaviour will
be modified in a separate change.
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D134196
Added:
lldb/test/Shell/ObjectFile/PECOFF/symbols-export-table.yaml
Modified:
lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp
lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.h
llvm/include/llvm/Object/COFF.h
Removed:
################################################################################
diff --git a/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp b/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp
index 5e7a921a2ec0a..3890e8b997fdc 100644
--- a/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp
+++ b/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.cpp
@@ -30,11 +30,12 @@
#include "lldb/Utility/StreamString.h"
#include "lldb/Utility/Timer.h"
#include "lldb/Utility/UUID.h"
-#include "llvm/BinaryFormat/COFF.h"
+#include "llvm/BinaryFormat/COFF.h"
#include "llvm/Object/COFFImportFile.h"
#include "llvm/Support/CRC.h"
#include "llvm/Support/Error.h"
+#include "llvm/Support/FormatAdapters.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/MemoryBuffer.h"
@@ -760,131 +761,93 @@ llvm::StringRef ObjectFilePECOFF::GetSectionName(const section_header_t §) {
void ObjectFilePECOFF::ParseSymtab(Symtab &symtab) {
SectionList *sect_list = GetSectionList();
- const uint32_t num_syms = m_coff_header.nsyms;
- if (m_file && num_syms > 0 && m_coff_header.symoff > 0) {
- const uint32_t symbol_size = 18;
- const size_t symbol_data_size = num_syms * symbol_size;
- // Include the 4-byte string table size at the end of the symbols
- DataExtractor symtab_data =
- ReadImageData(m_coff_header.symoff, symbol_data_size + 4);
- lldb::offset_t offset = symbol_data_size;
- const uint32_t strtab_size = symtab_data.GetU32(&offset);
- if (strtab_size > 0) {
- DataExtractor strtab_data = ReadImageData(
- m_coff_header.symoff + symbol_data_size, strtab_size);
-
- offset = 0;
- std::string symbol_name;
- Symbol *symbols = symtab.Resize(num_syms);
- for (uint32_t i = 0; i < num_syms; ++i) {
- coff_symbol_t symbol;
- const uint32_t symbol_offset = offset;
- const char *symbol_name_cstr = nullptr;
- // If the first 4 bytes of the symbol string are zero, then they
- // are followed by a 4-byte string table offset. Else these
- // 8 bytes contain the symbol name
- if (symtab_data.GetU32(&offset) == 0) {
- // Long string that doesn't fit into the symbol table name, so
- // now we must read the 4 byte string table offset
- uint32_t strtab_offset = symtab_data.GetU32(&offset);
- symbol_name_cstr = strtab_data.PeekCStr(strtab_offset);
- symbol_name.assign(symbol_name_cstr);
- } else {
- // Short string that fits into the symbol table name which is 8
- // bytes
- offset += sizeof(symbol.name) - 4; // Skip remaining
- symbol_name_cstr = symtab_data.PeekCStr(symbol_offset);
- if (symbol_name_cstr == nullptr)
- break;
- symbol_name.assign(symbol_name_cstr, sizeof(symbol.name));
- }
- symbol.value = symtab_data.GetU32(&offset);
- symbol.sect = symtab_data.GetU16(&offset);
- symbol.type = symtab_data.GetU16(&offset);
- symbol.storage = symtab_data.GetU8(&offset);
- symbol.naux = symtab_data.GetU8(&offset);
- symbols[i].GetMangled().SetValue(ConstString(symbol_name.c_str()));
- if ((int16_t)symbol.sect >= 1) {
- Address symbol_addr(sect_list->FindSectionByID(symbol.sect),
- symbol.value);
- symbols[i].GetAddressRef() = symbol_addr;
- symbols[i].SetType(MapSymbolType(symbol.type));
- }
+ AppendFromExportTable(sect_list, symtab);
+ AppendFromCOFFSymbolTable(sect_list, symtab);
+}
- if (symbol.naux > 0) {
- i += symbol.naux;
- offset += symbol.naux * symbol_size;
- }
- }
+void ObjectFilePECOFF::AppendFromCOFFSymbolTable(SectionList *sect_list,
+ Symtab &symtab) {
+ const uint32_t num_syms = m_binary->getNumberOfSymbols();
+ if (num_syms == 0)
+ return;
+ // Check that this is not a bigobj; we do not support bigobj.
+ if (m_binary->getSymbolTableEntrySize() !=
+ sizeof(llvm::object::coff_symbol16))
+ return;
+
+ Log *log = GetLog(LLDBLog::Object);
+ symtab.Reserve(symtab.GetNumSymbols() + num_syms);
+ for (const auto &sym_ref : m_binary->symbols()) {
+ const auto coff_sym_ref = m_binary->getCOFFSymbol(sym_ref);
+ auto name_or_error = sym_ref.getName();
+ if (auto err = name_or_error.takeError()) {
+ LLDB_LOG(log,
+ "ObjectFilePECOFF::AppendFromCOFFSymbolTable - failed to get "
+ "symbol table entry name: {0}",
+ llvm::fmt_consume(std::move(err)));
+ continue;
+ }
+ const llvm::StringRef sym_name = *name_or_error;
+ Symbol symbol;
+ symbol.GetMangled().SetValue(ConstString(sym_name));
+ int16_t section_number =
+ static_cast<int16_t>(coff_sym_ref.getSectionNumber());
+ if (section_number >= 1) {
+ symbol.GetAddressRef() = Address(
+ sect_list->FindSectionByID(section_number), coff_sym_ref.getValue());
+ symbol.SetType(MapSymbolType(coff_sym_ref.getType()));
}
+ symtab.AddSymbol(symbol);
}
+}
- // Read export header
- if (coff_data_dir_export_table < m_coff_header_opt.data_dirs.size() &&
- m_coff_header_opt.data_dirs[coff_data_dir_export_table].vmsize > 0 &&
- m_coff_header_opt.data_dirs[coff_data_dir_export_table].vmaddr > 0) {
- export_directory_entry export_table;
- uint32_t data_start =
- m_coff_header_opt.data_dirs[coff_data_dir_export_table].vmaddr;
-
- DataExtractor symtab_data = ReadImageDataByRVA(
- data_start, m_coff_header_opt.data_dirs[0].vmsize);
- lldb::offset_t offset = 0;
+void ObjectFilePECOFF::AppendFromExportTable(SectionList *sect_list,
+ Symtab &symtab) {
+ const auto *export_table = m_binary->getExportTable();
+ if (!export_table)
+ return;
+ const uint32_t num_syms = export_table->AddressTableEntries;
+ if (num_syms == 0)
+ return;
- // Read export_table header
- export_table.characteristics = symtab_data.GetU32(&offset);
- export_table.time_date_stamp = symtab_data.GetU32(&offset);
- export_table.major_version = symtab_data.GetU16(&offset);
- export_table.minor_version = symtab_data.GetU16(&offset);
- export_table.name = symtab_data.GetU32(&offset);
- export_table.base = symtab_data.GetU32(&offset);
- export_table.number_of_functions = symtab_data.GetU32(&offset);
- export_table.number_of_names = symtab_data.GetU32(&offset);
- export_table.address_of_functions = symtab_data.GetU32(&offset);
- export_table.address_of_names = symtab_data.GetU32(&offset);
- export_table.address_of_name_ordinals = symtab_data.GetU32(&offset);
-
- bool has_ordinal = export_table.address_of_name_ordinals != 0;
-
- lldb::offset_t name_offset = export_table.address_of_names - data_start;
- lldb::offset_t name_ordinal_offset =
- export_table.address_of_name_ordinals - data_start;
-
- Symbol *symbols = symtab.Resize(export_table.number_of_names);
-
- std::string symbol_name;
-
- // Read each export table entry
- for (size_t i = 0; i < export_table.number_of_names; ++i) {
- uint32_t name_ordinal =
- has_ordinal ? symtab_data.GetU16(&name_ordinal_offset) : i;
- uint32_t name_address = symtab_data.GetU32(&name_offset);
-
- const char *symbol_name_cstr =
- symtab_data.PeekCStr(name_address - data_start);
- symbol_name.assign(symbol_name_cstr);
-
- lldb::offset_t function_offset = export_table.address_of_functions -
- data_start +
- sizeof(uint32_t) * name_ordinal;
- uint32_t function_rva = symtab_data.GetU32(&function_offset);
-
- Address symbol_addr(m_coff_header_opt.image_base + function_rva,
- sect_list);
- symbols[i].GetMangled().SetValue(ConstString(symbol_name.c_str()));
- symbols[i].GetAddressRef() = symbol_addr;
- symbols[i].SetType(lldb::eSymbolTypeCode);
- symbols[i].SetDebug(true);
+ Log *log = GetLog(LLDBLog::Object);
+ symtab.Reserve(symtab.GetNumSymbols() + num_syms);
+ // Read each export table entry, ordered by ordinal instead of by name.
+ for (const auto &entry : m_binary->export_directories()) {
+ llvm::StringRef sym_name;
+ if (auto err = entry.getSymbolName(sym_name)) {
+ LLDB_LOG(log,
+ "ObjectFilePECOFF::AppendFromExportTable - failed to get export "
+ "table entry name: {0}",
+ llvm::fmt_consume(std::move(err)));
+ continue;
+ }
+ Symbol symbol;
+ // Note: symbol name may be empty if it is only exported by ordinal.
+ symbol.GetMangled().SetValue(ConstString(sym_name));
+
+ uint32_t function_rva;
+ if (auto err = entry.getExportRVA(function_rva)) {
+ LLDB_LOG(log,
+ "ObjectFilePECOFF::AppendFromExportTable - failed to get "
+ "address of export entry '{0}': {1}",
+ sym_name, llvm::fmt_consume(std::move(err)));
+ continue;
}
+ symbol.GetAddressRef() =
+ Address(m_coff_header_opt.image_base + function_rva, sect_list);
+ symbol.SetType(lldb::eSymbolTypeCode);
+ symbol.SetDebug(true);
+ symtab.AddSymbol(symbol);
}
}
std::unique_ptr<CallFrameInfo> ObjectFilePECOFF::CreateCallFrameInfo() {
- if (coff_data_dir_exception_table >= m_coff_header_opt.data_dirs.size())
+ if (llvm::COFF::EXCEPTION_TABLE >= m_coff_header_opt.data_dirs.size())
return {};
data_directory data_dir_exception =
- m_coff_header_opt.data_dirs[coff_data_dir_exception_table];
+ m_coff_header_opt.data_dirs[llvm::COFF::EXCEPTION_TABLE];
if (!data_dir_exception.vmaddr)
return {};
diff --git a/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.h b/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.h
index ca1a61735879a..f29da9773d9c3 100644
--- a/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.h
+++ b/lldb/source/Plugins/ObjectFile/PECOFF/ObjectFilePECOFF.h
@@ -225,12 +225,6 @@ class ObjectFilePECOFF : public lldb_private::ObjectFile {
data_dirs; // will contain num_data_dir_entries entries
} coff_opt_header_t;
- enum coff_data_dir_type {
- coff_data_dir_export_table = 0,
- coff_data_dir_import_table = 1,
- coff_data_dir_exception_table = 3
- };
-
typedef struct section_header {
char name[8] = {};
uint32_t vmsize = 0; // Virtual Size
@@ -244,29 +238,6 @@ class ObjectFilePECOFF : public lldb_private::ObjectFile {
uint32_t flags = 0;
} section_header_t;
- typedef struct coff_symbol {
- char name[8] = {};
- uint32_t value = 0;
- uint16_t sect = 0;
- uint16_t type = 0;
- uint8_t storage = 0;
- uint8_t naux = 0;
- } coff_symbol_t;
-
- typedef struct export_directory_entry {
- uint32_t characteristics = 0;
- uint32_t time_date_stamp = 0;
- uint16_t major_version = 0;
- uint16_t minor_version = 0;
- uint32_t name = 0;
- uint32_t base = 0;
- uint32_t number_of_functions = 0;
- uint32_t number_of_names = 0;
- uint32_t address_of_functions = 0;
- uint32_t address_of_names = 0;
- uint32_t address_of_name_ordinals = 0;
- } export_directory_entry;
-
static bool ParseDOSHeader(lldb_private::DataExtractor &data,
dos_header_t &dos_header);
static bool ParseCOFFHeader(lldb_private::DataExtractor &data,
@@ -297,6 +268,10 @@ class ObjectFilePECOFF : public lldb_private::ObjectFile {
private:
bool CreateBinary();
+ void AppendFromCOFFSymbolTable(lldb_private::SectionList *sect_list,
+ lldb_private::Symtab &symtab);
+ void AppendFromExportTable(lldb_private::SectionList *sect_list,
+ lldb_private::Symtab &symtab);
dos_header_t m_dos_header;
coff_header_t m_coff_header;
diff --git a/lldb/test/Shell/ObjectFile/PECOFF/symbols-export-table.yaml b/lldb/test/Shell/ObjectFile/PECOFF/symbols-export-table.yaml
new file mode 100644
index 0000000000000..e0298fdf797cf
--- /dev/null
+++ b/lldb/test/Shell/ObjectFile/PECOFF/symbols-export-table.yaml
@@ -0,0 +1,109 @@
+# RUN: yaml2obj %s -o %t
+# RUN: lldb-test symbols %t | FileCheck %s
+
+# Checks that the symtab contains both symbols from the export table and the
+# COFF symbol table.
+
+# CHECK: UserID DSX Type File Address/Value {{.*}} Size Flags Name
+# CHECK-NEXT: ------
+# CHECK-NEXT: 4294967295 D Code 0x0000000180001020 0x{{[0-9a-f]+}} 0x{{[0-9a-f]+}} exportFnAlias
+# CHECK-NEXT: 4294967295 D Code 0x0000000180001010 0x{{[0-9a-f]+}} 0x{{[0-9a-f]+}} exportFunc
+# CHECK-NEXT: 4294967295 D Code 0x0000000180003000 0x{{[0-9a-f]+}} 0x{{[0-9a-f]+}} exportInt
+# CHECK-NEXT: 4294967295 D Code 0x0000000180003004 0x{{[0-9a-f]+}} 0x{{[0-9a-f]+}} exportIntAlias
+# CHECK-NEXT: 4294967295 Code 0x0000000180001000 0x{{[0-9a-f]+}} 0x{{[0-9a-f]+}} entry
+# CHECK-NEXT: 4294967295 Code 0x0000000180001010 0x{{[0-9a-f]+}} 0x{{[0-9a-f]+}} exportFunc
+# CHECK-NEXT: 4294967295 Code 0x0000000180001020 0x{{[0-9a-f]+}} 0x{{[0-9a-f]+}} aliasFunc
+# CHECK-NEXT: 4294967295 Invalid 0x0000000180003000 0x{{[0-9a-f]+}} 0x{{[0-9a-f]+}} exportInt
+# CHECK-NEXT: 4294967295 Invalid 0x0000000180003004 0x{{[0-9a-f]+}} 0x{{[0-9a-f]+}} aliasInt
+# CHECK-NEXT: 4294967295 Invalid 0x0000000180003008 0x{{[0-9a-f]+}} 0x{{[0-9a-f]+}} internalInt
+# CHECK-EMPTY:
+
+# Test file generated with:
+# clang -O2 --target=x86_64-windows-msvc test.c -nostdlib -c -o test.obj
+# lld-link -debug:symtab -dll -out:test.dll -entry:entry -export:exportFnAlias=aliasFunc -export:exportIntAlias=aliasInt test.obj
+# test.c:
+# __declspec(dllexport) int exportInt;
+# int aliasInt;
+# int internalInt;
+# void entry(void) {}
+# __declspec(dllexport) void exportFunc(void) {}
+# void aliasFunc(void) {}
+
+--- !COFF
+OptionalHeader:
+ AddressOfEntryPoint: 4096
+ ImageBase: 6442450944
+ SectionAlignment: 4096
+ FileAlignment: 512
+ MajorOperatingSystemVersion: 6
+ MinorOperatingSystemVersion: 0
+ MajorImageVersion: 0
+ MinorImageVersion: 0
+ MajorSubsystemVersion: 6
+ MinorSubsystemVersion: 0
+ Subsystem: IMAGE_SUBSYSTEM_WINDOWS_GUI
+ DLLCharacteristics: [ IMAGE_DLL_CHARACTERISTICS_HIGH_ENTROPY_VA, IMAGE_DLL_CHARACTERISTICS_DYNAMIC_BASE, IMAGE_DLL_CHARACTERISTICS_NX_COMPAT ]
+ SizeOfStackReserve: 1048576
+ SizeOfStackCommit: 4096
+ SizeOfHeapReserve: 1048576
+ SizeOfHeapCommit: 4096
+ ExportTable:
+ RelativeVirtualAddress: 8192
+ Size: 156
+header:
+ Machine: IMAGE_FILE_MACHINE_AMD64
+ Characteristics: [ IMAGE_FILE_EXECUTABLE_IMAGE, IMAGE_FILE_LARGE_ADDRESS_AWARE, IMAGE_FILE_DLL ]
+sections:
+ - Name: .text
+ Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+ VirtualAddress: 4096
+ VirtualSize: 33
+ SectionData: C36666666666662E0F1F840000000000C36666666666662E0F1F840000000000C3
+ - Name: .rdata
+ Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_READ ]
+ VirtualAddress: 8192
+ VirtualSize: 156
+ SectionData: 0000000000000000000000002820000001000000040000000400000042200000522000006220000073796D626F6C732D6578706F7274732E632E746D702E646C6C00201000001010000000300000043000006A20000078200000832000008D20000000000100020003006578706F7274466E416C696173006578706F727446756E63006578706F7274496E74006578706F7274496E74416C69617300
+ - Name: .data
+ Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_READ, IMAGE_SCN_MEM_WRITE ]
+ VirtualAddress: 12288
+ VirtualSize: 12
+ SectionData: ''
+symbols:
+ - Name: entry
+ Value: 0
+ SectionNumber: 1
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_FUNCTION
+ StorageClass: IMAGE_SYM_CLASS_EXTERNAL
+ - Name: exportFunc
+ Value: 16
+ SectionNumber: 1
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_FUNCTION
+ StorageClass: IMAGE_SYM_CLASS_EXTERNAL
+ - Name: aliasFunc
+ Value: 32
+ SectionNumber: 1
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_FUNCTION
+ StorageClass: IMAGE_SYM_CLASS_EXTERNAL
+ - Name: exportInt
+ Value: 0
+ SectionNumber: 3
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_NULL
+ StorageClass: IMAGE_SYM_CLASS_EXTERNAL
+ - Name: aliasInt
+ Value: 4
+ SectionNumber: 3
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_NULL
+ StorageClass: IMAGE_SYM_CLASS_EXTERNAL
+ - Name: internalInt
+ Value: 8
+ SectionNumber: 3
+ SimpleType: IMAGE_SYM_TYPE_NULL
+ ComplexType: IMAGE_SYM_DTYPE_NULL
+ StorageClass: IMAGE_SYM_CLASS_EXTERNAL
+...
diff --git a/llvm/include/llvm/Object/COFF.h b/llvm/include/llvm/Object/COFF.h
index 7aa9eaf2287d0..8ad065d89c2a1 100644
--- a/llvm/include/llvm/Object/COFF.h
+++ b/llvm/include/llvm/Object/COFF.h
@@ -914,6 +914,10 @@ class COFFObjectFile : public ObjectFile {
uint32_t getStringTableSize() const { return StringTableSize; }
+ const export_directory_table_entry *getExportTable() const {
+ return ExportDirectory;
+ }
+
const coff_load_configuration32 *getLoadConfig32() const {
assert(!is64());
return reinterpret_cast<const coff_load_configuration32 *>(LoadConfig);
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