Implemented function calls

This commit is contained in:
Eduard Urbach 2024-06-18 16:42:56 +02:00
parent 086998a0c3
commit 76db8feee3
Signed by: akyoto
GPG Key ID: C874F672B1AF20C0
11 changed files with 114 additions and 62 deletions

View File

@ -1,8 +1,12 @@
main() {
hello()
}
hello() {
write := 1
stdout := 1
exit := 60
address := 4194305
length := 3
syscall(write, stdout, 4194305, 3)
syscall(exit, 0)
syscall(write, stdout, address, length)
}

View File

@ -1,12 +1,18 @@
package build
import (
"git.akyoto.dev/cli/q/src/build/arch/x64"
"git.akyoto.dev/cli/q/src/build/asm"
"git.akyoto.dev/cli/q/src/build/os/linux"
)
// Finalize generates the final machine code.
func Finalize(functions map[string]*Function) ([]byte, []byte) {
a := asm.New()
a := entry()
main := functions["main"]
delete(functions, "main")
a.Merge(&main.Assembler)
for _, f := range functions {
a.Merge(&f.Assembler)
@ -15,3 +21,16 @@ func Finalize(functions map[string]*Function) ([]byte, []byte) {
code, data := a.Finalize()
return code, data
}
// entry returns the entry point of the executable.
// The only job of the entry function is to call `main` and exit cleanly.
// The reason we call `main` instead of using `main` itself is to place
// a return address on the stack, which allows return statements in `main`.
func entry() *asm.Assembler {
entry := asm.New()
entry.Call("main")
entry.MoveRegisterNumber(x64.SyscallArgs[0], linux.Exit)
entry.MoveRegisterNumber(x64.SyscallArgs[1], 0)
entry.Syscall()
return entry
}

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@ -6,7 +6,6 @@ import (
"git.akyoto.dev/cli/q/src/build/arch/x64"
"git.akyoto.dev/cli/q/src/build/asm"
"git.akyoto.dev/cli/q/src/build/config"
"git.akyoto.dev/cli/q/src/build/expression"
"git.akyoto.dev/cli/q/src/build/fs"
"git.akyoto.dev/cli/q/src/build/token"
@ -27,11 +26,7 @@ type Function struct {
// Compile turns a function into machine code.
func (f *Function) Compile() {
if config.Verbose {
ansi.Bold.Println(f.Name)
ansi.Dim.Println("╭────────────────────────────────────────────────────────────")
}
f.Assembler.Label(f.Name)
start := 0
groupLevel := 0
@ -76,17 +71,11 @@ func (f *Function) Compile() {
}
f.Assembler.Return()
if config.Verbose {
ansi.Dim.Println("╰────────────────────────────────────────────────────────────")
f.PrintAsm()
}
}
// PrintAsm shows the assembly instructions.
func (f *Function) PrintAsm() {
fmt.Println()
ansi.Bold.Println(f.Name + ".asm")
ansi.Bold.Println(f.Name)
ansi.Dim.Println("╭────────────────────────────────────────────────────────────")
for _, x := range f.Assembler.Instructions {
@ -105,11 +94,6 @@ func (f *Function) PrintAsm() {
// CompileInstruction compiles a single instruction.
func (f *Function) CompileInstruction(line token.List) error {
if config.Verbose {
ansi.Dim.Print("│ ")
fmt.Println(line)
}
if len(line) == 0 {
return nil
}
@ -117,6 +101,12 @@ func (f *Function) CompileInstruction(line token.List) error {
if line[0].Kind == token.Keyword {
switch line[0].Text() {
case "return":
if len(line) > 1 {
value := expression.Parse(line[1:])
defer value.Close()
// TODO: Set the return value
}
f.Assembler.Return()
default:
@ -132,11 +122,7 @@ func (f *Function) CompileInstruction(line token.List) error {
defer expr.Close()
if config.Verbose {
ansi.Dim.Printf("│ %s\n", expr)
}
if expr.Token.Kind == token.Number || expr.Token.Kind == token.Identifier {
if expr.Token.Kind == token.Number || expr.Token.Kind == token.Identifier || expr.Token.Kind == token.String {
return errors.New(&errors.InvalidInstruction{Instruction: expr.Token.Text()}, f.File, expr.Token.Position)
}
@ -159,7 +145,8 @@ func (f *Function) CompileInstruction(line token.List) error {
return nil
}
if expr.Token.Text() == "λ" && expr.Children[0].Token.Text() == "syscall" {
if expr.Token.Text() == "λ" {
funcName := expr.Children[0].Token.Text()
parameters := expr.Children[1:]
for i, parameter := range parameters {
@ -189,7 +176,12 @@ func (f *Function) CompileInstruction(line token.List) error {
}
}
f.Assembler.Syscall()
if funcName == "syscall" {
f.Assembler.Syscall()
} else {
f.Assembler.Call(funcName)
}
return nil
}

View File

@ -4,7 +4,6 @@ import (
"encoding/binary"
"git.akyoto.dev/cli/q/src/build/arch/x64"
"git.akyoto.dev/cli/q/src/build/config"
)
// Assembler contains a list of instructions.
@ -23,19 +22,14 @@ func New() *Assembler {
func (a *Assembler) Finalize() ([]byte, []byte) {
code := make([]byte, 0, len(a.Instructions)*8)
data := make([]byte, 0, 16)
labels := map[string]Address{}
pointers := []Pointer{}
for _, x := range a.Instructions {
switch x.Mnemonic {
case MOVE:
code = x64.MoveRegNum32(code, uint8(x.Data.(*RegisterNumber).Register), uint32(x.Data.(*RegisterNumber).Number))
if x.Data.(*RegisterNumber).IsPointer {
pointers = append(pointers, Pointer{
Position: Address(len(code) - 4),
Address: Address(x.Data.(*RegisterNumber).Number),
})
}
regNum := x.Data.(*RegisterNumber)
code = x64.MoveRegNum32(code, uint8(regNum.Register), uint32(regNum.Number))
case RETURN:
code = x64.Return(code)
@ -43,17 +37,33 @@ func (a *Assembler) Finalize() ([]byte, []byte) {
case SYSCALL:
code = x64.Syscall(code)
case CALL:
code = x64.Call(code, 0x00_00_00_00)
label := x.Data.(*Label)
nextInstructionAddress := len(code)
pointers = append(pointers, Pointer{
Position: Address(len(code) - 4),
Resolve: func() Address {
destination := labels[label.Name]
distance := int32(destination) - int32(nextInstructionAddress)
return Address(distance)
},
})
case LABEL:
labels[x.Data.(*Label).Name] = Address(len(code))
default:
panic("Unknown mnemonic: " + x.Mnemonic.String())
}
}
dataStart := config.BaseAddress + config.CodeOffset + Address(len(code))
// dataStart := config.BaseAddress + config.CodeOffset + Address(len(code))
for _, pointer := range pointers {
slice := code[pointer.Position : pointer.Position+4]
address := dataStart + pointer.Address
binary.LittleEndian.PutUint32(slice, address)
binary.LittleEndian.PutUint32(slice, pointer.Resolve())
}
return code, data

View File

@ -7,21 +7,28 @@ func (a *Assembler) MoveRegisterNumber(reg cpu.Register, number uint64) {
a.Instructions = append(a.Instructions, Instruction{
Mnemonic: MOVE,
Data: &RegisterNumber{
Register: reg,
Number: number,
IsPointer: false,
Register: reg,
Number: number,
},
})
}
// MoveRegisterAddress moves an address into the given register.
func (a *Assembler) MoveRegisterAddress(reg cpu.Register, address Address) {
// Label adds a label at the current position.
func (a *Assembler) Label(name string) {
a.Instructions = append(a.Instructions, Instruction{
Mnemonic: MOVE,
Data: &RegisterNumber{
Register: reg,
Number: uint64(address),
IsPointer: true,
Mnemonic: LABEL,
Data: &Label{
Name: name,
},
})
}
// Call calls a function whose position is identified by a label.
func (a *Assembler) Call(name string) {
a.Instructions = append(a.Instructions, Instruction{
Mnemonic: CALL,
Data: &Label{
Name: name,
},
})
}

11
src/build/asm/Label.go Normal file
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@ -0,0 +1,11 @@
package asm
// Label represents a jump label.
type Label struct {
Name string
}
// String returns a human readable version.
func (data *Label) String() string {
return data.Name
}

View File

@ -7,6 +7,8 @@ const (
MOVE
RETURN
SYSCALL
LABEL
CALL
)
// String returns a human readable version.
@ -20,6 +22,12 @@ func (m Mnemonic) String() string {
case SYSCALL:
return "syscall"
case LABEL:
return "label"
case CALL:
return "call"
}
return "NONE"

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@ -5,8 +5,8 @@ type Address = uint32
// Pointer stores a relative memory address that we can later turn into an absolute one.
// Position: The machine code offset where the address was inserted.
// Address: The offset inside the section.
// Resolve: The function that will return the final address.
type Pointer struct {
Position uint32
Address uint32
Position Address
Resolve func() Address
}

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@ -8,9 +8,8 @@ import (
// RegisterNumber operates with a register and a number.
type RegisterNumber struct {
Register cpu.Register
Number uint64
IsPointer bool
Register cpu.Register
Number uint64
}
// String returns a human readable version.

View File

@ -42,6 +42,12 @@ func Build(args []string) int {
return 1
}
if config.Verbose {
for _, function := range result {
function.PrintAsm()
}
}
if !writeExecutable {
return 0
}

View File

@ -1,7 +1,3 @@
main() {
()
1+(2*3)
(1+2)
f(x)
(a+b)(c)
return 1+2*3
}