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Diffstat (limited to 'src/main/java/com/seaofnodes/simple/codegen/ElfFile.java')
-rw-r--r--src/main/java/com/seaofnodes/simple/codegen/ElfFile.java382
1 files changed, 0 insertions, 382 deletions
diff --git a/src/main/java/com/seaofnodes/simple/codegen/ElfFile.java b/src/main/java/com/seaofnodes/simple/codegen/ElfFile.java
deleted file mode 100644
index b6267600..00000000
--- a/src/main/java/com/seaofnodes/simple/codegen/ElfFile.java
+++ /dev/null
@@ -1,382 +0,0 @@
-package com.seaofnodes.simple.codegen;
-
-import com.seaofnodes.simple.*;
-import com.seaofnodes.simple.codegen.Encoding.BAOS;
-import com.seaofnodes.simple.node.*;
-import com.seaofnodes.simple.type.*;
-import com.seaofnodes.simple.util.Ary;
-import java.io.*;
-import java.nio.ByteBuffer;
-import java.nio.ByteOrder;
-import java.util.HashMap;
-import java.util.Map;
-
-public class ElfFile {
-
- final CodeGen _code;
- Ary<Section> _sections = new Ary<>(Section.class);
-
- ElfFile( CodeGen code ) { _code = code; }
-
- public static int writeCString(DataSection strtab, String name) {
- // place name in the string table
- int pos = strtab._contents.size();
- byte[] name_bytes = name.getBytes();
- strtab._contents.write(name_bytes, 0, name_bytes.length);
- // the strings are null terminated
- strtab._contents.write(0);
- return pos;
- }
-
- public static void write4( ByteArrayOutputStream bits, int op ) {
- bits.write(op );
- bits.write(op>> 8);
- bits.write(op>>16);
- bits.write(op>>24);
- }
- public static void write8( ByteArrayOutputStream bits, long i64 ) {
- write4(bits, (int) i64 );
- write4(bits, (int)(i64>>32));
- }
-
- public static final int SYMBOL_SIZE = 4+1+1+2+8+8;
-
- public static final int SYM_BIND_LOCAL = 0;
- public static final int SYM_BIND_GLOBAL = 1;
- public static final int SYM_BIND_WEAK = 2;
-
- public static final int SYM_TYPE_NOTYPE = 0;
- public static final int SYM_TYPE_OBJECT = 1;
- public static final int SYM_TYPE_FUNC = 2;
- public static final int SYM_TYPE_SECTION = 3;
-
- public static class Symbol {
- String _name;
- int _name_pos;
-
- // index in the symbol table
- int _index;
-
- // which section is it in
- int _parent;
-
- // depends on the symbol type
- // TODO
- int _value, _size;
-
- // top 4bits are the "bind", bottom 4 are "type"
- int _info;
-
- // bind 1011
- // 00001111
- // 10110000
-
- Symbol(String name, int parent, int bind, int type) {
- _name = name;
- _parent = parent;
- _info = (bind << 4) | (type & 0xF);
- }
-
- void writeHeader(ByteBuffer out) {
- out.putInt(_name_pos); // name
- out.put((byte) _info); // info
- // default visibility
- out.put((byte) 0); // other
- out.putShort((short) _parent); // shndx
- out.putLong(_value); // value
- out.putLong(_size); // size
- }
- }
-
- public static final int SHF_WRITE = 1;
- public static final int SHF_ALLOC = 2;
- public static final int SHF_EXECINSTR = 4;
- public static final int SHF_STRINGS = 32;
- public static final int SHF_INFO_LINK = 64;
-
- public static final int SECTION_HDR_SIZE = 64;
- abstract public static class Section {
- String _name;
- int _index;
-
- int _type, _flags;
- int _link, _info;
-
- // where's the name in the string table
- int _name_pos;
- int _file_offset;
-
- Section(String name, int type) {
- _name = name;
- _type = type;
- }
-
- void writeHeader(ByteBuffer out) {
- out.putInt(_name_pos); // name
- out.putInt(_type); // type
- out.putLong(_flags); // flags
- out.putLong(0); // addr
- out.putLong(_file_offset); // offset
- out.putLong(size()); // size
- out.putInt(_link); // link
- out.putInt(_info); // info
- out.putLong(16); // addralign
- if (_type == 2) {
- out.putLong(SYMBOL_SIZE);// entsize
- } else if (_type == 4) {
- out.putLong(24); // entsize
- } else {
- out.putLong(0); // entsize
- }
- }
-
- abstract void write(ByteBuffer out);
- abstract int size();
- }
-
- public static class SymbolSection extends Section {
- Ary<Symbol> _symbols = new Ary<>(Symbol.class);
- Ary<Symbol> _loc = new Ary<>(Symbol.class);
-
- SymbolSection(String name, int type) {
- super(name, type);
- }
-
- @Override
- void writeHeader(ByteBuffer out) {
- // points to string table section
- _link = 1;
-
- // number of non-local symbols
- _info = _loc.len() + 1;
-
- super.writeHeader(out);
- }
-
- void push(Symbol s) {
- if ((s._info >> 4) != SYM_BIND_LOCAL) {
- _symbols.push(s);
- } else {
- _loc.push(s);
- }
- }
-
- @Override
- void write(ByteBuffer out) {
- // Index 0 both designates the first entry in the table and serves as the undefined symbol index
- for( int i = 0; i < SYMBOL_SIZE/4; i++ ) {
- out.putInt(0);
- }
- // index is already set
- for( Symbol s : _loc ) {
- s.writeHeader(out);
- }
- for( Symbol s : _symbols ) {
- s.writeHeader(out);
- }
- }
-
- @Override
- int size() {
- return (1 + _symbols.len() + _loc.len()) * SYMBOL_SIZE;
- }
- }
-
- public static class DataSection extends Section {
- ByteArrayOutputStream _contents;
-
- DataSection(String name, int type) {
- super(name, type);
- _contents = new ByteArrayOutputStream();
- }
-
- DataSection(String name, int type, ByteArrayOutputStream contents) {
- super(name, type);
- _contents = contents;
- }
-
- @Override
- void write(ByteBuffer out) {
- out.put(_contents.toByteArray());
- }
-
- @Override
- int size() {
- return _contents.size();
- }
- }
-
- private void pushSection(Section s) {
- _sections.push(s);
- // ELF is effectively "1-based", due to the NULL section
- s._index = _sections._len;
- }
-
- /* creates function and stores where it starts*/
- private final HashMap<TypeFunPtr,Symbol> _funcs = new HashMap<>();
- private void encodeFunctions(SymbolSection symbols, DataSection text) {
- for( int i=0; i<_code._cfg._len; i++ ) {
- if( !(_code._cfg.at(i) instanceof FunNode fun) ) continue;
- // skip until the function ends
- while( !(_code._cfg.at(i) instanceof ReturnNode ret) )
- i++;
- int end = _code._encoding._opStart[ret._nid] + _code._encoding._opLen[ret._nid];
-
- if( fun._name==null ) continue; // Anonymous addresses are relocated within .text.
- Symbol func = new Symbol(fun._name, text._index, SYM_BIND_GLOBAL, SYM_TYPE_FUNC);
- func._value = _code._encoding._opStart[fun._nid];
- func._size = end - func._value;
- symbols.push(func);
- _funcs.put(fun.sig(), func);
- }
- }
-
- public void export(String fname) throws IOException {
- DataSection strtab = new DataSection(".strtab", 3 /* SHT_SYMTAB */);
- // first byte is reserved for an empty string
- strtab._contents.write(0);
- pushSection(strtab);
-
- // place all the symbols
- SymbolSection symbols = new SymbolSection(".symtab", 2 /* SHT_STRTAB */);
- pushSection(symbols);
-
- // zero flag by default
- // we've already constructed this entire section in the encoding phase
- DataSection text = new DataSection(".text", 1 /* SHT_PROGBITS */, _code._encoding._bits);
- text._flags = SHF_ALLOC | SHF_WRITE | SHF_EXECINSTR;
- pushSection(text);
-
- // Build and write constant pool
- BAOS cpool = new BAOS();
- Encoding enc = _code._encoding;
- enc.writeConstantPool(cpool,false);
- DataSection rdata = new DataSection(".rodata", 1 /* SHT_PROGBITS */, cpool);
- rdata._flags = SHF_ALLOC;
- pushSection(rdata);
-
- // populate function symbols
- encodeFunctions(symbols, text);
-
- int idx = 1;
- for( Section s : _sections ) {
- Symbol sym = new Symbol(s._name, idx++, SYM_BIND_LOCAL, SYM_TYPE_SECTION);
- // we can reuse the same name pos from the actual section
- sym._name_pos = s._name_pos;
- sym._size = s.size();
- symbols.push(sym);
- }
-
- // calculate local index
- int num = 1;
- for( Symbol s : symbols._loc )
- s._index = num++;
- // extra space for .rela.text
- int start_global = num+1; // Add one to skip the final .rela.text local symbol
- for( Symbol a: symbols._symbols )
- a._index = start_global++;
-
- // create .text relocations
- DataSection text_rela = new DataSection(".rela.text", 4 /* SHT_RELA */);
- for( Node n : enc._externals.keySet()) {
- int nid = n._nid;
- String extern = enc._externals.get(n);
-
- Symbol sym = new Symbol(extern, 0, SYM_BIND_GLOBAL, SYM_TYPE_NOTYPE);
- sym._index = start_global++;
- symbols.push(sym);
-
- int offset = enc._opStart[nid] + enc._opLen[nid] - 4;
-
- // u64 offset
- write8(text_rela._contents, offset);
- // u64 info
- write8(text_rela._contents, ((long)sym._index << 32L) | 4L /* PLT32 */);
- // i64 addend
- write8(text_rela._contents, -4);
- }
-
- // Write relocations for the constant pool
- for( Encoding.Relo relo : enc._bigCons.values() ) {
- Symbol glob = new Symbol("CPOOL$"+start_global, rdata._index, SYM_BIND_GLOBAL, SYM_TYPE_FUNC);
- glob._value = relo._target;
- glob._size = relo._t.size();
- glob._index = start_global++;
- symbols.push(glob);
- write8(text_rela._contents, relo._opStart+relo._off);
- write8(text_rela._contents, ((long)glob._index << 32L) | relo._elf );
- write8(text_rela._contents, -4);
- }
-
- text_rela._flags = SHF_INFO_LINK;
- text_rela._link = 2;
- text_rela._info = text._index;
- pushSection(text_rela);
-
- // Final .rela.text symbol
- Symbol sym = new Symbol(text_rela._name, num++, SYM_BIND_LOCAL, SYM_TYPE_SECTION);
- sym._name_pos = text_rela._name_pos;
- sym._size = text_rela.size();
- symbols.push(sym);
-
- // populate string table
- for( Section s : _sections ) { s._name_pos = writeCString(strtab, s._name); }
- for( Symbol s : symbols._symbols ) { s._name_pos = writeCString(strtab, s._name); }
- for( Symbol s : symbols._loc ) { s._name_pos = writeCString(strtab, s._name); }
-
- int size = 64; // ELF header
- // size of all section data
- for( Section s : _sections ) {
- s._file_offset = size;
- size += s.size();
- }
- // headers go at the very end
- int shdr_offset = size;
- // there's a "null" section at the start of the section headers
- size += SECTION_HDR_SIZE*(1 + _sections.len());
-
- // System.out.printf("Hello %d, %d, %s\n", size, shdr_offset);
- ByteBuffer out = ByteBuffer.allocate(size);
- out.order(ByteOrder.LITTLE_ENDIAN);
-
- // ELF header
- out.put(new byte[]{ 0x7F, 'E', 'L', 'F', 2, 1, 1, 0 });
- out.put(new byte[8]);
- out.putShort((short)1 /* ET_REL */); // type
- out.putShort((short)62 /* AMD64 */); // machine
- out.putInt(1); // version
- out.putLong(0); // entry
- out.putLong(0); // phoff
- out.putLong(shdr_offset); // shoff
- out.putInt(0); // flags
- out.putShort((short)64); // ehsize
- out.putShort((short)0); // phentsize
- out.putShort((short)0); // phnum
- out.putShort((short)64); // shentsize
- out.putShort((short) (1 + _sections.len())); // shnum
- out.putShort((short)1); // shstrndx
-
- // raw section data
- for( Section s : _sections ) {
- s.write(out);
- }
-
- // "null" section
- for( int i = 0; i < 16; i++ ) {
- out.putInt(0);
- }
-
- for( Section s : _sections ) {
- s.writeHeader(out);
- }
- assert out.position() == size;
-
- File file = new File(fname);
- if( file.getParentFile()!=null )
- file.getParentFile().mkdirs();
- BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(file));
- bos.write(out.array());
- bos.close();
- }
-
-}
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