#54 add elf info method (#90)

This method provides info required to build ELF file accepted by gdb:
  - machine id
  - endianness
  - bit size

It also provides:
  - image base offset to rebase symbols to their original offsets
  - ELF flags (not mandatory)
  - program name

.gitignore

@@ -5,3 +5,6 @@ build/*
 *.gdb_history
 decomp2dbg/decompilers
 decomp2dbg/d2d.py
+decompilers/*/.gradle/
+decompilers/*/build/
+decompilers/*/dist/

decompilers/d2d_ghidra/src/main/java/decomp2dbg/D2DGhidraServerAPI.java

@@ -6,6 +6,9 @@
 
 import ghidra.app.decompiler.ClangLine;
 import ghidra.app.decompiler.PrettyPrinter;
+import ghidra.app.util.bin.MemoryByteProvider;
+import ghidra.app.util.bin.format.elf.ElfException;
+import ghidra.app.util.bin.format.elf.ElfHeader;
 import ghidra.program.model.listing.Function;
 import ghidra.program.model.symbol.Symbol;
 import ghidra.program.model.symbol.SymbolType;
@@ -323,4 +326,33 @@ public Map<String, Object> enums() {
 		this.server.plugin.enumCache = resp;
 		return resp;
 	}
+
+	public Map<String, Object> elf_info() {
+		if(!this.server.plugin.elfInfoCache.isEmpty())
+			return this.server.plugin.elfInfoCache;
+
+		Map<String, Object> elf_info = new HashMap<>();
+
+		var program = this.server.plugin.getCurrentProgram();
+		var provider = new MemoryByteProvider(program.getMemory(), program.getMinAddress());
+		ElfHeader header = null;
+		try {
+			header = new ElfHeader(provider, null);
+		}
+		catch (ElfException e) {
+			elf_info.put("error", e.toString());
+			return elf_info;
+		}
+
+		elf_info.put("flags", "0x" + Integer.toHexString(header.e_flags()));
+		elf_info.put("machine", (int) header.e_machine());
+		elf_info.put("is_big_endian", header.isBigEndian());
+		elf_info.put("is_32_bit", header.is32Bit());
+		elf_info.put("image_base", "0x" + Long.toHexString(program.getMinAddress().getOffset()));
+		elf_info.put("name", program.getName());
+		elf_info.put("error", "");
+
+		this.server.plugin.elfInfoCache = elf_info;
+		return elf_info;
+	}
 }

decompilers/d2d_ghidra/src/main/java/decomp2dbg/D2DPlugin.java

@@ -57,6 +57,7 @@ public class D2DPlugin extends ProgramPlugin implements DomainObjectListener {
 	public Map<String, Object> typeAliasCache;
 	public Map<String, Object> unionCache;
 	public Map<String, Object> enumCache;
+	public Map<String, Object> elfInfoCache;
 
 	public D2DPlugin(PluginTool tool) {
 		super(tool);
@@ -74,6 +75,7 @@ public D2DPlugin(PluginTool tool) {
 		typeAliasCache = new HashMap<>();
 		unionCache = new HashMap<>();
 		enumCache = new HashMap<>();
+		elfInfoCache = new HashMap<>();
 	}
 
 	@Override