[elfabi] Prepare elfabi/ifs merging.

This change implements unified text stub format and command line
interface proposed in the elfabi/ifs merge plan.

Differential Revision: https://reviews.llvm.org/D99399

Author: zeroomega

llvm/include/llvm/BinaryFormat/ELF.h

@@ -19,8 +19,10 @@
 #ifndef LLVM_BINARYFORMAT_ELF_H
 #define LLVM_BINARYFORMAT_ELF_H
 
+#include "llvm/ADT/StringRef.h"
 #include <cstdint>
 #include <cstring>
+#include <string>
 
 namespace llvm {
 namespace ELF {
@@ -1673,6 +1675,12 @@ enum {
   ELFCOMPRESS_HIPROC = 0x7fffffff  // End of processor-specific.
 };
 
+/// Convert an architecture name into ELF's e_machine value.
+uint16_t convertArchNameToEMachine(StringRef Arch);
+
+/// Convert an ELF's e_machine value into an architecture name.
+StringRef convertEMachineToArchName(uint16_t EMachine);
+
 } // end namespace ELF
 } // end namespace llvm
 

llvm/include/llvm/InterfaceStub/ELFObjHandler.h

@@ -35,11 +35,10 @@ Expected<std::unique_ptr<ELFStub>> readELFFile(MemoryBufferRef Buf);
 ///
 /// @param FilePath File path for writing the ELF binary.
 /// @param Stub Source ELFStub to generate a binary ELF stub from.
-/// @param OutputFormat Target ELFType to write binary as.
 /// @param WriteIfChanged Whether or not to preserve timestamp if
 ///        the output stays the same.
 Error writeBinaryStub(StringRef FilePath, const ELFStub &Stub,
-                      ELFTarget OutputFormat, bool WriteIfChanged = false);
+                      bool WriteIfChanged = false);
 
 } // end namespace elfabi
 } // end namespace llvm

llvm/include/llvm/InterfaceStub/ELFStub.h

@@ -15,6 +15,7 @@
 #define LLVM_INTERFACESTUB_ELFSTUB_H
 
 #include "llvm/BinaryFormat/ELF.h"
+#include "llvm/Support/Error.h"
 #include "llvm/Support/VersionTuple.h"
 #include <set>
 #include <vector>
@@ -34,8 +35,25 @@ enum class ELFSymbolType {
   Unknown = 16,
 };
 
+enum class ELFEndiannessType {
+  Little = ELF::ELFDATA2LSB,
+  Big = ELF::ELFDATA2MSB,
+
+  // Endianness info is 1 bytes, 256 is safely out of rance.
+  Unknown = 256,
+};
+
+enum class ELFBitWidthType {
+  ELF32 = ELF::ELFCLASS32,
+  ELF64 = ELF::ELFCLASS64,
+
+  // Bit width info is 1 bytes, 256 is safely out of rance.
+  Unknown = 256,
+};
+
 struct ELFSymbol {
-  ELFSymbol(std::string SymbolName) : Name(SymbolName) {}
+  ELFSymbol() = default;
+  explicit ELFSymbol(std::string SymbolName) : Name(std::move(SymbolName)) {}
   std::string Name;
   uint64_t Size;
   ELFSymbolType Type;
@@ -45,21 +63,42 @@ struct ELFSymbol {
   bool operator<(const ELFSymbol &RHS) const { return Name < RHS.Name; }
 };
 
+struct IFSTarget {
+  Optional<std::string> Triple;
+  Optional<std::string> ObjectFormat;
+  Optional<ELFArch> Arch;
+  Optional<std::string> ArchString;
+  Optional<ELFEndiannessType> Endianness;
+  Optional<ELFBitWidthType> BitWidth;
+};
+
 // A cumulative representation of ELF stubs.
 // Both textual and binary stubs will read into and write from this object.
-class ELFStub {
+struct ELFStub {
   // TODO: Add support for symbol versioning.
-public:
   VersionTuple TbeVersion;
   Optional<std::string> SoName;
-  ELFArch Arch;
+  IFSTarget Target;
   std::vector<std::string> NeededLibs;
-  std::set<ELFSymbol> Symbols;
+  std::vector<ELFSymbol> Symbols;
 
   ELFStub() {}
   ELFStub(const ELFStub &Stub);
   ELFStub(ELFStub &&Stub);
 };
+
+// Create a alias class for ELFStub.
+// LLVM's YAML library does not allow mapping a class with 2 traits,
+// which prevents us using 'Target:' field with different definitions.
+// This class makes it possible to map a second traits so the same data
+// structure can be used for 2 different yaml schema.
+struct ELFStubTriple : ELFStub {
+  ELFStubTriple() {}
+  ELFStubTriple(const ELFStub &Stub);
+  ELFStubTriple(const ELFStubTriple &Stub);
+  ELFStubTriple(ELFStubTriple &&Stub);
+};
+
 } // end namespace elfabi
 } // end namespace llvm
 

llvm/include/llvm/InterfaceStub/TBEHandler.h

@@ -15,6 +15,7 @@
 #ifndef LLVM_INTERFACESTUB_TBEHANDLER_H
 #define LLVM_INTERFACESTUB_TBEHANDLER_H
 
+#include "ELFStub.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/VersionTuple.h"
 #include <memory>
@@ -27,7 +28,7 @@ class StringRef;
 
 namespace elfabi {
 
-class ELFStub;
+struct ELFStub;
 
 const VersionTuple TBEVersionCurrent(1, 0);
 
@@ -37,6 +38,22 @@ Expected<std::unique_ptr<ELFStub>> readTBEFromBuffer(StringRef Buf);
 /// Attempts to write an ELF interface file to a raw_ostream.
 Error writeTBEToOutputStream(raw_ostream &OS, const ELFStub &Stub);
 
+/// Override the target platform inforation in the text stub.
+Error overrideTBETarget(ELFStub &Stub, Optional<ELFArch> OverrideArch,
+                        Optional<ELFEndiannessType> OverrideEndianness,
+                        Optional<ELFBitWidthType> OverrideBitWidth,
+                        Optional<std::string> OverrideTriple);
+
+/// Validate the target platform inforation in the text stub.
+Error validateTBETarget(ELFStub &Stub, bool ParseTriple);
+
+/// Strips target platform information from the text stub.
+void stripTBETarget(ELFStub &Stub, bool StripTriple, bool StripArch,
+                    bool StripEndianness, bool StripBitWidth);
+
+/// Parse llvm triple string into a IFSTarget struct.
+IFSTarget parseTriple(StringRef TripleStr);
+
 } // end namespace elfabi
 } // end namespace llvm
 

llvm/lib/BinaryFormat/CMakeLists.txt

@@ -1,6 +1,7 @@
 add_llvm_component_library(LLVMBinaryFormat
   AMDGPUMetadataVerifier.cpp
   Dwarf.cpp
+  ELF.cpp
   MachO.cpp
   Magic.cpp
   Minidump.cpp