[llvm-objcopy][MachO] Rebuild the symbol/string table in the writer
Summary: Build the string table using StringTableBuilder, reassign symbol indices, and update symbol indices in relocations to allow adding/modifying/removing symbols from the object.
Reviewers: alexshap, rupprecht, jhenderson
Reviewed By: alexshap
Subscribers: mgorny, jakehehrlich, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63309
llvm-svn: 364000
diff --git a/llvm/tools/llvm-objcopy/MachO/Object.h b/llvm/tools/llvm-objcopy/MachO/Object.h
index 93b44a3..ed85fcb 100644
--- a/llvm/tools/llvm-objcopy/MachO/Object.h
+++ b/llvm/tools/llvm-objcopy/MachO/Object.h
@@ -12,6 +12,7 @@
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/BinaryFormat/MachO.h"
+#include "llvm/MC/StringTableBuilder.h"
#include "llvm/ObjectYAML/DWARFYAML.h"
#include "llvm/Support/YAMLTraits.h"
#include <cstdint>
@@ -33,6 +34,7 @@
uint32_t Reserved = 0;
};
+struct RelocationInfo;
struct Section {
std::string Sectname;
std::string Segname;
@@ -48,7 +50,7 @@
uint32_t Reserved3;
StringRef Content;
- std::vector<MachO::any_relocation_info> Relocations;
+ std::vector<RelocationInfo> Relocations;
MachO::SectionType getType() const {
return static_cast<MachO::SectionType>(Flags & MachO::SECTION_TYPE);
@@ -79,8 +81,11 @@
std::vector<Section> Sections;
};
-struct NListEntry {
- uint32_t n_strx;
+// A symbol information. Fields which starts with "n_" are same as them in the
+// nlist.
+struct SymbolEntry {
+ std::string Name;
+ uint32_t Index;
uint8_t n_type;
uint8_t n_sect;
uint16_t n_desc;
@@ -90,7 +95,9 @@
/// The location of the symbol table inside the binary is described by LC_SYMTAB
/// load command.
struct SymbolTable {
- std::vector<NListEntry> NameList;
+ std::vector<std::unique_ptr<SymbolEntry>> Symbols;
+
+ const SymbolEntry *getSymbolByIndex(uint32_t Index) const;
};
/// The location of the string table inside the binary is described by LC_SYMTAB
@@ -99,6 +106,13 @@
std::vector<std::string> Strings;
};
+struct RelocationInfo {
+ const SymbolEntry *Symbol;
+ // True if Info is a scattered_relocation_info.
+ bool Scattered;
+ MachO::any_relocation_info Info;
+};
+
/// The location of the rebase info inside the binary is described by
/// LC_DYLD_INFO load command. Dyld rebases an image whenever dyld loads it at
/// an address different from its preferred address. The rebase information is