Implement symbol table for functions

This commit is contained in:
Eugen Wissner 2022-06-11 22:52:13 +02:00
parent f5c4a27a6d
commit 3f1492947c
Signed by: belka
GPG Key ID: A27FDC1E8EE902C0
5 changed files with 371 additions and 218 deletions

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@ -26,7 +26,7 @@ rule(/build\/riscv\/[^\/\.]+$/ => ->(file) { test_for_out(file, '.o') }) do |t|
'/opt/riscv/riscv32-unknown-elf/lib/crt0.o',
'/opt/riscv/lib/gcc/riscv32-unknown-elf/11.1.0/crtbegin.o',
t.source,
'--start-group', '-lc', '-lgloss', '--end-group',
'--start-group', '-lgcc', '-lc', '-lgloss', '--end-group',
'/opt/riscv/lib/gcc/riscv32-unknown-elf/11.1.0/crtend.o'
end

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@ -7,6 +7,7 @@ import elna.extended;
import elna.riscv;
import elna.lexer;
import elna.parser;
import elna.result;
import std.algorithm;
import std.sumtype;
import std.typecons;
@ -55,9 +56,27 @@ int generate(string inFile, ref String outputFilename) @nogc
{
return 1;
}
auto programText = writeNext(ir);
auto elf = Elf(move(handle));
elf.addCode("main", programText);
auto program = writeNext(ir);
auto elf = Elf!ELFCLASS32(move(handle));
auto readOnlyData = Array!ubyte(cast(const(ubyte)[]) "%d".ptr[0 .. 3]); // With \0.
Array!Relocation relocationData;
foreach (ref reference; program.symbols)
{
Relocation relocationEntry;
relocationEntry.symbol = reference;
relocationEntry.typeInformation = R_RISCV_CALL;
relocationEntry.hasEntry = true;
relocationData.insertBack(relocationEntry);
relocationEntry.typeInformation = R_RISCV_RELAX;
relocationEntry.hasEntry = false;
relocationData.insertBack(relocationEntry);
}
elf.addReadOnlyData(readOnlyData);
elf.addCode(program.name, program.text, relocationData);
elf.finish();

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@ -1,12 +1,13 @@
module elna.elf;
import elna.extended;
import elna.result;
import std.algorithm;
import tanya.container.array;
import tanya.container.string;
/// Unsigned program address.
alias Elf64_Addr = ulong*;
alias Elf64_Addr = ulong;
/// Unsigned file offset.
alias Elf64_Off = ulong;
/// Unsigned medium integer.
@ -336,7 +337,7 @@ auto ELF64_R_TYPE(I)(I i)
return i & 0xffffffffL;
}
auto ELF64_R_INFO(S, T)(S s, t)
Elf64_Word ELF64_R_INFO(S)(S s, ubyte t)
{
return (s << 32) + (t & 0xffffffffL);
}
@ -356,7 +357,7 @@ ubyte ELF32_ST_INFO(ubyte b, ubyte t) @nogc nothrow pure @safe
return cast(ubyte) ((b << 4) + (t & 0xf));
}
T ELF32_R_SYMT(I)(I i)
auto ELF32_R_SYMT(I)(I i)
{
return i >> 8;
}
@ -366,9 +367,9 @@ ubyte ELF32_R_TYPE(I)(I i)
return cast(ubyte) i;
}
auto ELF32_R_INFO(S, T)(S s, T t)
Elf32_Word ELF32_R_INFO(S)(S s, ubyte t)
{
return (s << 8) + cast(ubyte) t;
return cast(Elf32_Word) ((s << 8) + t);
}
enum : uint
@ -407,153 +408,6 @@ enum : uint
STT_HIPROC = 15,
}
Elf64_Ehdr makeFileHeader(Elf64_Off sectionHeaderOffset,
Elf64_Half sectionHeaderCount,
Elf64_Half stringIndex) @nogc
{
Elf64_Ehdr header;
// Magic number.
header.e_ident[0] = '\x7f';
header.e_ident[1] = 'E';
header.e_ident[2] = 'L';
header.e_ident[3] = 'F';
// File class.
header.e_ident[4] = ELFCLASS64;
// Data encoding.
header.e_ident[5] = ELFDATA2LSB;
// Version.
header.e_ident[6] = EV_CURRENT;
// OS/ABI identification.
header.e_ident[7] = EI_OSABI.ELFOSABI_SYSV;
// ABI version.
header.e_ident[8] = 0;
// Size of e_ident[].
header.e_ident[15] = 0;
header.e_type = ET_REL;
header.e_machine = 0x3e; // EM_X86_64: AMD x86-64 architecture
header.e_version = EV_CURRENT;
header.e_entry = null;
header.e_phoff = 0;
header.e_shoff = sectionHeaderOffset;
header.e_flags = 0;
header.e_ehsize = Elf64_Ehdr.sizeof;
header.e_phentsize = 0;
header.e_phnum = 0;
header.e_shentsize = Elf64_Shdr.sizeof;
header.e_shnum = sectionHeaderCount;
header.e_shstrndx = stringIndex;
return header;
}
Elf64_Shdr makeTextHeader(Elf64_Off offset, Elf64_Xword size) @nogc
{
Elf64_Shdr table;
table.sh_name = 0x1b;
table.sh_type = SHT_PROGBITS;
table.sh_flags = SHF_EXECINSTR | SHF_ALLOC;
table.sh_addr = null;
table.sh_offset = offset;
table.sh_size = size;
table.sh_link = SHN_UNDEF;
table.sh_info = 0;
table.sh_addralign = 1;
table.sh_entsize = 0;
return table;
}
Elf64_Shdr makeSymtableHeader(Elf64_Off offset, Elf64_Xword size, Elf64_Word entriesCount) @nogc
{
Elf64_Shdr table;
table.sh_name = 0x01;
table.sh_type = SHT_SYMTAB;
table.sh_flags = 0;
table.sh_addr = null;
table.sh_offset = offset;
table.sh_size = size;
table.sh_link = 0x03; // String table used by entries in this section.
table.sh_info = entriesCount;
table.sh_addralign = 8;
table.sh_entsize = Elf64_Sym.sizeof;
return table;
}
Elf64_Shdr makeStringHeader(Elf64_Word stringIndex, Elf64_Off offset, Elf64_Xword size) @nogc
{
Elf64_Shdr table;
table.sh_name = stringIndex;
table.sh_type = SHT_STRTAB;
table.sh_flags = 0;
table.sh_addr = null;
table.sh_offset = offset;
table.sh_size = size;
table.sh_link = SHN_UNDEF;
table.sh_info = 0;
table.sh_addralign = 1;
table.sh_entsize = 0;
return table;
}
Elf64_Shdr makeInitialHeader() @nogc
{
Elf64_Shdr table;
table.sh_name = 0;
table.sh_type = SHT_NULL;
table.sh_flags = 0;
table.sh_addr = null;
table.sh_offset = 0;
table.sh_size = 0;
table.sh_link = SHN_UNDEF;
table.sh_info = 0;
table.sh_addralign = 0;
table.sh_entsize = 0;
return table;
}
Elf64_Sym makeInitialSymTable() @nogc
{
Elf64_Sym table;
table.st_name = 0;
table.st_info = 0;
table.st_other = 0;
table.st_shndx = 0;
table.st_value = null;
table.st_size = 0;
return table;
}
Elf64_Sym makeMainSymTable(Elf64_Half textIndex) @nogc
{
Elf64_Sym table;
table.st_name = 0x01;
table.st_info = ELF32_ST_INFO(STB_GLOBAL, STT_FUNC);
table.st_other = 0;
table.st_shndx = textIndex;
table.st_value = null;
table.st_size = 0;
return table;
}
/// Special Section Indices.
enum : ushort
{
@ -633,6 +487,105 @@ enum : Elf64_Half
ET_HIPROC = 0xFFFF,
}
enum : ubyte
{
R_RISCV_NONE = 0,
/// 32-bit relocation.
R_RISCV_32 = 1,
/// 64-bit relocation.
R_RISCV_64 = 2,
/// Relocation against a local symbol in a shared object.
R_RISCV_RELATIVE = 3,
/// Must be in executable; not allowed in shared library.
R_RISCV_COPY = 4,
/// Indicates the symbol associated with a PLT entry.
R_RISCV_JUMP_SLOT = 5,
R_RISCV_TLS_DTPMOD32 = 6,
R_RISCV_TLS_DTPMOD64 = 7,
R_RISCV_TLS_DTPREL32 = 8,
R_RISCV_TLS_DTPREL64 = 9,
R_RISCV_TLS_TPREL32 = 10,
R_RISCV_TLS_TPREL64 = 11,
/// 12-bit PC-relative branch offset.
R_RISCV_BRANCH = 16,
/// 20-bit PC-relative jump offset.
R_RISCV_JAL = 17,
/// 32-bit PC-relative function call, macros `call`, `tail`.
R_RISCV_CALL = 18,
/// 32-bit PC-relative function call, macros `call`, `tail` (PIC).
R_RISCV_CALL_PLT = 19,
/// High 20 bits of 32-bit PC-relative GOT access, `%got_pcrel_hi(symbol)`.
R_RISCV_GOT_HI20 = 20,
/// High 20 bits of 32-bit PC-relative TLS IE GOT access, macro `la.tls.ie`.
R_RISCV_TLS_GOT_HI20 = 21,
/// High 20 bits of 32-bit PC-relative TLS GD GOT reference, macro `la.tls.gd`.
R_RISCV_TLS_GD_HI20 = 22,
/// High 20 bits of 32-bit PC-relative reference, `%pcrel_hi(symbol)`.
R_RISCV_PCREL_HI20 = 23,
/// Low 12 bits of a 32-bit PC-relative, `%pcrel_lo(address of %pcrel_hi)`, the addend must be 0.
R_RISCV_PCREL_LO12_I = 24,
/// Low 12 bits of a 32-bit PC-relative, `%pcrel_lo(address of %pcrel_hi)`, the addend must be 0.
R_RISCV_PCREL_LO12_S = 25,
/// High 20 bits of 32-bit absolute address, `%hi(symbol)`.
R_RISCV_HI20 = 26,
/// Low 12 bits of 32-bit absolute address, `%lo(symbol)`.
R_RISCV_LO12_I = 27,
/// Low 12 bits of 32-bit absolute address, `%lo(symbol)`.
R_RISCV_LO12_S = 28,
/// High 20 bits of TLS LE thread pointer offset, `%tprel_hi(symbol)`.
R_RISCV_TPREL_HI20 = 29,
/// Low 12 bits of TLS LE thread pointer offset, `%tprel_lo(symbol)`.
R_RISCV_TPREL_LO12_I = 30,
/// Low 12 bits of TLS LE thread pointer offset, `%tprel_lo(symbol)`.
R_RISCV_TPREL_LO12_S = 31,
/// TLS LE thread pointer usage, `%tprel_add(symbol)`.
R_RISCV_TPREL_ADD = 32,
/// 8-bit label addition.
R_RISCV_ADD8 = 33,
/// 16-bit label addition.
R_RISCV_ADD16 = 34,
/// 32-bit label addition.
R_RISCV_ADD32 = 35,
/// 64-bit label addition.
R_RISCV_ADD64 = 36,
/// 8-bit label subtraction.
R_RISCV_SUB8 = 37,
/// 16-bit label subtraction.
R_RISCV_SUB16 = 38,
/// 32-bit label subtraction.
R_RISCV_SUB32 = 39,
/// 64-bit label subtraction.
R_RISCV_SUB64 = 40,
/// GNU {Cpp} vtable hierarchy.
R_RISCV_GNU_VTINHERIT = 41,
/// GNU {Cpp} vtable member usage.
R_RISCV_GNU_VTENTRY = 42,
/// Alignment statement.
R_RISCV_ALIGN = 43,
/// 8-bit PC-relative branch offset.
R_RISCV_RVC_BRANCH = 44,
/// 11-bit PC-relative jump offset.
R_RISCV_RVC_JUMP = 45,
/// High 6 bits of 18-bit absolute address.
R_RISCV_RVC_LUI = 46,
/// Instruction can be relaxed, paired with a normal relocation at the same address.
R_RISCV_RELAX = 51,
/// Local label subtraction.
R_RISCV_SUB6 = 52,
/// Local label assignment.
R_RISCV_SET6 = 53,
/// Local label assignment.
R_RISCV_SET8 = 54,
/// Local label assignment.
R_RISCV_SET16 = 55,
/// Local label assignment.
R_RISCV_SET32 = 56,
/// 32-bit PC relative.
R_RISCV_32_PCREL = 57,
/// Relocation against a local ifunc symbol in a shared object.
R_RISCV_IRELATIVE = 58
}
auto pad(ubyte elfClass)(size_t value) @nogc
{
static if (elfClass == ELFCLASS32)
@ -649,30 +602,76 @@ auto pad(ubyte elfClass)(size_t value) @nogc
}
}
struct Symbol
struct Elf(ubyte elfClass)
{
String name;
const(ubyte)[] text;
static if (elfClass == ELFCLASS32)
{
alias Addr = Elf32_Addr;
alias Off = Elf32_Off;
alias Half = Elf32_Half;
alias Word = Elf32_Word;
alias Sword = Elf32_Sword;
alias Xword = Elf32_Word;
alias Sxword = Elf32_Sword;
alias Ehdr = Elf32_Ehdr;
alias Shdr = Elf32_Shdr;
alias Rel = Elf32_Rel;
alias Rela = Elf32_Rela;
alias Sym = Elf32_Sym;
alias R_SYMT = ELF32_R_SYMT;
alias R_TYPE = ELF32_R_TYPE;
alias R_INFO = ELF32_R_INFO;
alias ST_BIND = ELF32_ST_BIND;
alias ST_TYPE = ELF32_ST_TYPE;
alias ST_INFO = ELF32_ST_INFO;
}
else static if (elfClass == ELFCLASS64)
{
alias Addr = Elf64_Addr;
alias Off = Elf64_Off;
alias Half = Elf64_Half;
alias Word = Elf64_Word;
alias Sword = Elf64_Sword;
alias Xword = Elf64_Xword;
alias Sxword = Elf64_Sxword;
alias Ehdr = Elf64_Ehdr;
alias Shdr = Elf64_Shdr;
alias Rel = Elf64_Rel;
alias Rela = Elf64_Rela;
alias Sym = Elf64_Sym;
alias R_SYMT = ELF64_R_SYMT;
alias R_TYPE = ELF64_R_TYPE;
alias R_INFO = ELF64_R_INFO;
alias ST_BIND = ELF64_ST_BIND;
alias ST_TYPE = ELF64_ST_TYPE;
alias ST_INFO = ELF64_ST_INFO;
}
else
{
static assert(false, "Invalid ELF class");
}
struct Elf
{
private Elf32_Ehdr fileHeader;
private Array!Elf32_Shdr sectionHeaders;
private Elf32_Off currentOffset = Elf32_Ehdr.sizeof;
private Array!Elf32_Sym symbols;
static immutable char[41] sections =
"\0.symtab\0.strtab\0.shstrtab\0.text\0.rodata\0";
static immutable char[52] sections =
"\0.symtab\0.strtab\0.shstrtab\0.text\0.rodata\0.rela.text\0";
private String strings;
private Elf32_Word lastLocalSymbol;
private Elf32_Word textSize;
private Word lastLocalSymbol;
private Word textSize;
private File output;
private Array!ubyte readOnly;
private Array!Rela relocations;
static Elf opCall(File output) @nogc
{
Elf elf = Elf.init;
elf.initializeFileHeader();
elf.initializeSectionHeaders();
elf.insertSymbols();
elf.output = move(output);
@ -687,7 +686,9 @@ struct Elf
void finish() @nogc
{
makeTextHeader();
initializeSymbolTable(cast(Elf32_Word) (this.sectionHeaders.length + 1));
makeRelaHeader(cast(Word) (this.sectionHeaders.length + 2), cast(Word) (this.sectionHeaders.length - 1));
makeRoDataHeader();
initializeSymbolTable(cast(Word) (this.sectionHeaders.length + 1));
foreach (symbol; this.symbols)
{
@ -711,12 +712,7 @@ struct Elf
output.write((cast(ubyte*) this.sectionHeaders.get)[0 .. Elf32_Shdr.sizeof * this.sectionHeaders.length]);
output.seek(0, File.Whence.set);
this.fileHeader.e_shoff = this.currentOffset;
this.fileHeader.e_shnum = cast(Elf32_Half) this.sectionHeaders.length;
// String table is the last one
this.fileHeader.e_shstrndx = cast(Elf32_Half) (this.sectionHeaders.length - 1);
output.write((cast(ubyte*) &this.fileHeader)[0 .. fileHeader.sizeof]);
this.initializeFileHeader();
}
private void insertSymbols() @nogc
@ -752,7 +748,7 @@ struct Elf
return table;
}
private void initializeSymbolTable(Elf32_Word stringTableIndex) @nogc
private void initializeSymbolTable(Word stringTableIndex) @nogc
{
Elf32_Shdr symbolTableHeader;
@ -771,24 +767,61 @@ struct Elf
this.sectionHeaders.insertBack(symbolTableHeader);
}
void addCode(string name, ref Array!ubyte text) @nogc
void addCode(ref String name, ref Array!ubyte text, Array!Relocation usedSymbols)
@nogc
{
this.output.write(text.get);
this.strings.insertBack("\0");
this.strings.insertBack(name[]);
Elf32_Sym symbol;
Sym symbol;
// Main function
symbol.st_name = 0x1; // Word
symbol.st_value = 0; // Addr
symbol.st_size = cast(Elf32_Word) text.length; // Word
symbol.st_info = ELF32_ST_INFO(STB_GLOBAL, STT_FUNC); // char
symbol.st_info = ST_INFO(STB_GLOBAL, STT_FUNC); // char
symbol.st_other = 0; // char
// .text header index, half word
symbol.st_shndx = cast(Elf32_Half) this.sectionHeaders.length;
this.symbols.insertBack(symbol);
this.textSize += text.length;
foreach (usedSymbol; usedSymbols)
{
Rela relocationEntry;
relocationEntry.r_offset = cast(Addr) usedSymbol.symbol.offset;
if (usedSymbol.hasEntry)
{
relocationEntry.r_info = ELF32_R_INFO(this.symbols.length, usedSymbol.typeInformation);
this.relocations.insertBack(relocationEntry);
}
else
{
relocationEntry.r_info = ELF32_R_INFO(0, usedSymbol.typeInformation);
this.relocations.insertBack(relocationEntry);
continue;
}
Sym usedSymbolEntry;
this.strings.insertBack("\0");
usedSymbolEntry.st_name = cast(Word) this.strings.length;
usedSymbolEntry.st_value = 0;
usedSymbolEntry.st_size = 0;
usedSymbolEntry.st_info = ST_INFO(STB_GLOBAL, STT_NOTYPE);
usedSymbolEntry.st_other = 0;
usedSymbolEntry.st_shndx = SHN_UNDEF;
this.strings.insertBack(usedSymbol.symbol.name[]);
this.strings.insertBack("\0");
this.symbols.insertBack(usedSymbolEntry);
}
}
void addReadOnlyData(ref Array!ubyte data) @nogc
{
this.readOnly.insertBack(data[]);
}
private void makeTextHeader() @nogc
@ -847,13 +880,59 @@ struct Elf
this.fileHeader.e_version = EV_CURRENT;
this.fileHeader.e_entry = 0;
this.fileHeader.e_phoff = 0;
// this.fileHeader.e_shoff = ?; (section header offset)
this.fileHeader.e_shoff = this.currentOffset;
this.fileHeader.e_flags = 0;
this.fileHeader.e_ehsize = Elf32_Ehdr.sizeof;
this.fileHeader.e_phentsize = 0;
this.fileHeader.e_phnum = 0;
this.fileHeader.e_shentsize = Elf32_Shdr.sizeof;
// this.fileHeader.e_shnum = ?; (section header count)
// this.fileHeader.e_shstrndx = ?; (string index)
this.fileHeader.e_shnum = cast(Elf32_Half) this.sectionHeaders.length;
// String table is the last one
this.fileHeader.e_shstrndx = cast(Elf32_Half) (this.sectionHeaders.length - 1);
output.seek(0, File.Whence.set);
output.write((cast(ubyte*) &this.fileHeader)[0 .. fileHeader.sizeof]);
}
private void makeRoDataHeader() @nogc
{
Shdr table;
table.sh_name = 0x21;
table.sh_type = SHT_PROGBITS;
table.sh_flags = SHF_ALLOC;
table.sh_addr = 0;
table.sh_offset = this.currentOffset;
table.sh_size = cast(Xword) this.readOnly.length;
table.sh_link = SHN_UNDEF;
table.sh_info = 0;
table.sh_addralign = 4;
table.sh_entsize = 0;
output.write(this.readOnly.get);
this.sectionHeaders.insertBack(table);
this.currentOffset += this.readOnly.length;
}
private void makeRelaHeader(Word symTableIndex, Word targetTableIndex) @nogc
{
Shdr table;
table.sh_name = 0x29;
table.sh_type = SHT_RELA;
table.sh_flags = this.relocations.length == 0 ? 0 : SHF_ALLOC;
table.sh_addr = 0;
table.sh_offset = this.currentOffset;
table.sh_size = cast(Word) (Rela.sizeof * this.relocations.length);
table.sh_link = symTableIndex;
table.sh_info = targetTableIndex;
table.sh_addralign = 4;
table.sh_entsize = Rela.sizeof;
this.output.write((cast(ubyte*) this.relocations.get)[0 .. Rela.sizeof * this.relocations.length]);
this.currentOffset += Rela.sizeof * this.relocations.length;
this.sectionHeaders.insertBack(table);
}
}

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@ -1,6 +1,8 @@
module elna.result;
import std.typecons;
import tanya.container.array;
import tanya.container.string;
/**
* Position in the source text.
@ -82,3 +84,23 @@ struct Result(T)
return error.isNull;
}
}
struct Reference
{
String name;
size_t offset;
}
struct Symbol
{
String name;
Array!ubyte text;
Array!Reference symbols;
}
struct Relocation
{
Reference symbol;
ubyte typeInformation;
bool hasEntry = true;
}

View File

@ -2,6 +2,7 @@ module elna.riscv;
import elna.extended;
import elna.ir;
import elna.result;
import std.algorithm;
import std.typecons;
import tanya.container.array;
@ -115,11 +116,16 @@ struct Instruction
{
private uint instruction;
ref Instruction i(BaseOpcode opcode, XRegister rd, Funct3 funct3, XRegister rs1, uint immediate)
this(BaseOpcode opcode) @nogc
{
this.instruction = opcode;
}
@disable this();
ref Instruction i(XRegister rd, Funct3 funct3, XRegister rs1, uint immediate)
return scope @nogc
{
this.instruction = opcode
| (rd << 7)
this.instruction |= (rd << 7)
| (funct3 << 12)
| (rs1 << 15)
| (immediate << 20);
@ -127,11 +133,10 @@ struct Instruction
return this;
}
ref Instruction s(BaseOpcode opcode, uint imm1, Funct3 funct3, XRegister rs1, XRegister rs2, uint imm2 = 0)
ref Instruction s(uint imm1, Funct3 funct3, XRegister rs1, XRegister rs2, uint imm2 = 0)
return scope @nogc
{
this.instruction = opcode
| (imm1 << 7)
this.instruction |= (imm1 << 7)
| (funct3 << 12)
| (rs1 << 15)
| (rs2 << 20)
@ -140,11 +145,10 @@ struct Instruction
return this;
}
ref Instruction r(BaseOpcode opcode, XRegister rd, Funct3 funct3, XRegister rs1, XRegister rs2, ubyte funct7 = 0)
ref Instruction r(XRegister rd, Funct3 funct3, XRegister rs1, XRegister rs2, ubyte funct7 = 0)
return scope @nogc
{
this.instruction = opcode
| (rd << 7)
this.instruction |= (rd << 7)
| (funct3 << 12)
| (rs1 << 15)
| (rs2 << 20)
@ -153,28 +157,51 @@ struct Instruction
return this;
}
ref Instruction u(XRegister rd, uint imm)
return scope @nogc
{
this.instruction |= (rd << 7) | (imm << 12);
return this;
}
ubyte[] encode() return scope @nogc
{
return (cast(ubyte*) (&this.instruction))[0 .. uint.sizeof];
}
}
Array!ubyte writeNext(Definition ast) @nogc
Symbol writeNext(Definition ast) @nogc
{
Array!Instruction instructions;
Array!Reference references;
// Prologue.
instructions.insertBack(
Instruction()
.i(BaseOpcode.opImm, XRegister.sp, Funct3.addi, XRegister.sp, cast(uint) -16)
Instruction(BaseOpcode.opImm)
.i(XRegister.sp, Funct3.addi, XRegister.sp, cast(uint) -32)
);
instructions.insertBack(
Instruction()
.s(BaseOpcode.store, 12, Funct3.sw, XRegister.sp, XRegister.s0)
Instruction(BaseOpcode.store)
.s(28, Funct3.sw, XRegister.sp, XRegister.s0)
);
instructions.insertBack(
Instruction()
.i(BaseOpcode.opImm, XRegister.s0, Funct3.addi, XRegister.sp, 16)
Instruction(BaseOpcode.store)
.s(24, Funct3.sw, XRegister.sp, XRegister.ra)
);
instructions.insertBack(
Instruction(BaseOpcode.opImm)
.i(XRegister.s0, Funct3.addi, XRegister.sp, 32)
);
// Code generation.
references.insertBack(Reference(String("putchar"), instructions.length * 4));
instructions.insertBack(
Instruction(BaseOpcode.auipc).u(XRegister.ra, 0)
);
instructions.insertBack(
Instruction(BaseOpcode.jalr)
.i(XRegister.ra, Funct3.jalr, XRegister.ra, 0)
);
int i = 1;
@ -185,8 +212,8 @@ Array!ubyte writeNext(Definition ast) @nogc
// Opcode of mov is “0xb8 + r”, where “r” is the register opcode.
// Register opcode of %eax is 0.
instructions.insertBack(
Instruction() // movl $x, %eax; where $x is a number.
.i(BaseOpcode.opImm, XRegister.a0, Funct3.addi, XRegister.zero,
Instruction(BaseOpcode.opImm) // movl $x, %eax; where $x is a number.
.i(XRegister.a0, Funct3.addi, XRegister.zero,
(cast(Number) statement.subroutine.lhs).value)
);
}
@ -194,8 +221,8 @@ Array!ubyte writeNext(Definition ast) @nogc
{
// movl -x(%rbp), %eax; where x is a number.
instructions.insertBack(
Instruction()
.i(BaseOpcode.load, XRegister.a0, Funct3.lw, XRegister.sp,
Instruction(BaseOpcode.load)
.i(XRegister.a0, Funct3.lw, XRegister.sp,
cast(byte) (cast(Variable) statement.subroutine.lhs).counter * 4)
);
}
@ -204,8 +231,8 @@ Array!ubyte writeNext(Definition ast) @nogc
// Opcode of mov is “0xb8 + r”, where “r” is the register opcode.
// Register opcode of %ebx is 3.
instructions.insertBack(
Instruction() // movl $x, %ebx; where $x is a number.
.i(BaseOpcode.opImm, XRegister.t0, Funct3.addi, XRegister.zero,
Instruction(BaseOpcode.opImm) // movl $x, %ebx; where $x is a number.
.i(XRegister.t0, Funct3.addi, XRegister.zero,
(cast(Number) statement.subroutine.rhs).value)
);
}
@ -213,42 +240,48 @@ Array!ubyte writeNext(Definition ast) @nogc
{
// movl -x(%rbp), %ebx; where x is a number.
instructions.insertBack(
Instruction()
.i(BaseOpcode.load, XRegister.t0, Funct3.lw, XRegister.sp,
Instruction(BaseOpcode.load)
.i(XRegister.t0, Funct3.lw, XRegister.sp,
cast(byte) (cast(Variable) statement.subroutine.rhs).counter * 4)
);
}
// Calculate the result and assign it to a variable on the stack.
instructions.insertBack(
Instruction()
.r(BaseOpcode.op, XRegister.a0, Funct3.add, XRegister.a0, XRegister.t0)
Instruction(BaseOpcode.op)
.r(XRegister.a0, Funct3.add, XRegister.a0, XRegister.t0)
);
instructions.insertBack( // movl %eax, -x(%rbp); where x is a number.
Instruction()
.s(BaseOpcode.store, cast(uint) (i * 4), Funct3.sw, XRegister.sp, XRegister.a0)
Instruction(BaseOpcode.store)
.s(cast(uint) (i * 4), Funct3.sw, XRegister.sp, XRegister.a0)
);
++i;
}
// Prologue.
instructions.insertBack(
Instruction()
.i(BaseOpcode.load, XRegister.s0, Funct3.lw, XRegister.sp, 12)
Instruction(BaseOpcode.load)
.i(XRegister.s0, Funct3.lw, XRegister.sp, 28)
);
instructions.insertBack(
Instruction()
.i(BaseOpcode.opImm, XRegister.sp, Funct3.addi, XRegister.sp, 16)
Instruction(BaseOpcode.load)
.i(XRegister.ra, Funct3.lw, XRegister.sp, 24)
);
instructions.insertBack(
Instruction()
.i(BaseOpcode.jalr, XRegister.zero, Funct3.jalr, XRegister.ra, 0)
Instruction(BaseOpcode.opImm)
.i(XRegister.sp, Funct3.addi, XRegister.sp, 32)
);
instructions.insertBack(
Instruction(BaseOpcode.jalr)
.i(XRegister.zero, Funct3.jalr, XRegister.ra, 0)
);
Array!ubyte programText;
auto program = Symbol(String("main"));
program.symbols = move(references);
foreach (ref instruction; instructions)
{
programText.insertBack(instruction.encode);
program.text.insertBack(instruction.encode);
}
return programText;
return program;
}