Added build result struct

src/build/Build.go

@@ -18,7 +18,7 @@ func New(files ...string) *Build {
 }
 
 // Run parses the input files and generates an executable file.
-func (build *Build) Run() (map[string]*Function, error) {
+func (build *Build) Run() (Result, error) {
 	functions, errors := scan(build.Files)
 	return compile(functions, errors)
 }

src/build/Finalize.go

@@ -1,36 +0,0 @@
-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 := entry()
-
-	main := functions["main"]
-	delete(functions, "main")
-	a.Merge(&main.Assembler)
-
-	for _, f := range functions {
-		a.Merge(&f.Assembler)
-	}
-
-	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.RegisterNumber(asm.MOVE, x64.SyscallRegisters[0], linux.Exit)
-	entry.RegisterNumber(asm.MOVE, x64.SyscallRegisters[1], 0)
-	entry.Syscall()
-	return entry
-}

src/build/Result.go

@@ -0,0 +1,42 @@
+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"
+)
+
+// Result contains all the compiled functions in a build.
+type Result struct {
+	Functions        map[string]*Function
+	instructionCount int
+}
+
+// Finalize generates the final machine code.
+func (r Result) Finalize() ([]byte, []byte) {
+	// This will be 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`.
+	final := asm.Assembler{
+		Instructions: make([]asm.Instruction, 0, r.instructionCount+4),
+	}
+
+	final.Call("main")
+	final.RegisterNumber(asm.MOVE, x64.SyscallRegisters[0], linux.Exit)
+	final.RegisterNumber(asm.MOVE, x64.SyscallRegisters[1], 0)
+	final.Syscall()
+
+	// Place the `main` function immediately after the entry point.
+	main := r.Functions["main"]
+	delete(r.Functions, "main")
+	final.Merge(&main.Assembler)
+
+	// Merge all the remaining functions.
+	for _, f := range r.Functions {
+		final.Merge(&f.Assembler)
+	}
+
+	code, data := final.Finalize()
+	return code, data
+}

src/build/asm/Assembler.go

@@ -11,13 +11,6 @@ type Assembler struct {
 	Instructions []Instruction
 }
 
-// New creates a new assembler.
-func New() *Assembler {
-	return &Assembler{
-		Instructions: make([]Instruction, 0, 8),
-	}
-}
-
 // Finalize generates the final machine code.
 func (a *Assembler) Finalize() ([]byte, []byte) {
 	code := make([]byte, 0, len(a.Instructions)*8)

src/build/compile.go

@@ -5,8 +5,10 @@ import (
 )
 
 // compile waits for the scan to finish and compiles all functions.
-func compile(functions <-chan *Function, errors <-chan error) (map[string]*Function, error) {
+func compile(functions <-chan *Function, errors <-chan error) (Result, error) {
-	allFunctions := map[string]*Function{}
+	result := Result{
+		Functions: map[string]*Function{},
+	}
 
 	for functions != nil || errors != nil {
 		select {
@@ -16,7 +18,7 @@ func compile(functions <-chan *Function, errors <-chan error) (map[string]*Funct
 				continue
 			}
 
-			return nil, err
+			return result, err
 
 		case function, ok := <-functions:
 			if !ok {
@@ -24,19 +26,21 @@ func compile(functions <-chan *Function, errors <-chan error) (map[string]*Funct
 				continue
 			}
 
-			allFunctions[function.Name] = function
+			result.Functions[function.Name] = function
 		}
 	}
 
-	compileFunctions(allFunctions)
+	compileFunctions(result.Functions)
 
-	for _, function := range allFunctions {
+	for _, function := range result.Functions {
 		if function.Error != nil {
-			return nil, function.Error
+			return result, function.Error
-		}
 		}
 
-	return allFunctions, nil
+		result.instructionCount += len(function.Assembler.Instructions)
+	}
+
+	return result, nil
 }
 
 // compileFunctions starts a goroutine for each function compilation and waits for completion.

src/build/scan.go

@@ -7,6 +7,7 @@ import (
 	"sync"
 
 	"git.akyoto.dev/cli/q/src/build/arch/x64"
+	"git.akyoto.dev/cli/q/src/build/asm"
 	"git.akyoto.dev/cli/q/src/build/cpu"
 	"git.akyoto.dev/cli/q/src/build/fs"
 	"git.akyoto.dev/cli/q/src/build/token"
@@ -231,6 +232,9 @@ func scanFile(path string, functions chan<- *Function) error {
 				Syscall: x64.SyscallRegisters,
 				Return:  x64.ReturnValueRegisters,
 			},
+			Assembler: asm.Assembler{
+				Instructions: make([]asm.Instruction, 0, 32),
+			},
 		}
 
 		nameStart = -1

src/cli/Build.go

@@ -43,7 +43,7 @@ func Build(args []string) int {
 	}
 
 	if config.Verbose {
-		for _, function := range result {
+		for _, function := range result.Functions {
 			function.PrintAsm()
 		}
 	}
@@ -53,7 +53,7 @@ func Build(args []string) int {
 	}
 
 	path := b.Executable()
-	code, data := build.Finalize(result)
+	code, data := result.Finalize()
 	err = build.Write(path, code, data)
 
 	if err != nil {