Implemented dependency tracking

src/asmc/call.go

@@ -1,6 +1,8 @@
 package asmc
 
 import (
+	"fmt"
+
 	"git.urbach.dev/cli/q/src/asm"
 	"git.urbach.dev/cli/q/src/x86"
 )
@@ -21,7 +23,7 @@ func (c *compiler) call(x asm.Instruction) {
 			destination, exists := c.codeLabels[data.Name]
 
 			if !exists {
-				panic("unknown jump label")
+				panic(fmt.Sprintf("unknown jump label %s", data.Name))
 			}
 
 			distance := destination - (pointer.Position + Address(pointer.Size))

src/asmc/jump.go

@@ -1,6 +1,8 @@
 package asmc
 
 import (
+	"fmt"
+
 	"git.urbach.dev/cli/q/src/asm"
 	"git.urbach.dev/cli/q/src/x86"
 )
@@ -36,7 +38,7 @@ func (c *compiler) jump(x asm.Instruction) {
 		destination, exists := c.codeLabels[label.Name]
 
 		if !exists {
-			panic("unknown jump label")
+			panic(fmt.Sprintf("unknown jump label %s", label.Name))
 		}
 
 		distance := destination - (pointer.Position + Address(pointer.Size))

src/compiler/Compile.go

@@ -82,6 +82,20 @@ func Compile(constants <-chan *core.Constant, files <-chan *fs.File, functions <
 		}
 	}
 
+	// Check for existence of `init`
+	init, exists := all.Functions["core.init"]
+
+	if !exists {
+		return result, errors.MissingInitFunction
+	}
+
+	// Check for existence of `main`
+	main, exists := all.Functions["main.main"]
+
+	if !exists {
+		return result, errors.MissingMainFunction
+	}
+
 	// Start parallel compilation
 	CompileFunctions(all.Functions)
 
@@ -104,20 +118,6 @@ func Compile(constants <-chan *core.Constant, files <-chan *fs.File, functions <
 		}
 	}
 
-	// Check for existence of `init`
-	init, exists := all.Functions["core.init"]
-
-	if !exists {
-		return result, errors.MissingInitFunction
-	}
-
-	// Check for existence of `main`
-	main, exists := all.Functions["main.main"]
-
-	if !exists {
-		return result, errors.MissingMainFunction
-	}
-
 	result.Init = init
 	result.Main = main
 	result.Functions = all.Functions

src/compiler/eachFunction.go

@@ -1,37 +1,20 @@
 package compiler
 
 import (
-	"git.urbach.dev/cli/q/src/asm"
 	"git.urbach.dev/cli/q/src/core"
 )
 
-// eachFunction recursively finds all the calls to external functions.
+// eachFunction recursively finds all the calls to other functions.
 // It avoids calling the same function twice with the help of a hashmap.
 func (r *Result) eachFunction(caller *core.Function, traversed map[*core.Function]bool, call func(*core.Function)) {
 	call(caller)
 	traversed[caller] = true
 
-	for _, x := range caller.Assembler.Instructions {
-		if x.Mnemonic != asm.CALL {
+	for _, function := range caller.Dependencies {
+		if traversed[function] {
 			continue
 		}
 
-		label, isLabel := x.Data.(*asm.Label)
-
-		if !isLabel {
-			continue
-		}
-
-		callee, exists := r.Functions[label.Name]
-
-		if !exists {
-			continue
-		}
-
-		if traversed[callee] {
-			continue
-		}
-
-		r.eachFunction(callee, traversed, call)
+		r.eachFunction(function, traversed, call)
 	}
 }

src/core/CompileCall.go

@@ -43,16 +43,7 @@ func (f *Function) CompileCall(root *expression.Expression) ([]types.Type, error
 
 	switch value := value.(type) {
 	case *eval.Label:
-		fn, exists := f.All.Functions[value.Label]
-
-		if !exists {
-			if value.Label == "main.main" && f.UniqueName == "core.init" {
-				f.Label(asm.CALL, "main.main")
-				return nil, nil
-			}
-
-			return nil, errors.New(&errors.UnknownIdentifier{Name: value.Label}, f.File, root.Children[0].Token.Position)
-		}
+		fn := f.All.Functions[value.Label]
 
 		if len(parameters) != len(fn.Input) {
 			return nil, errors.New(&errors.ParameterCountMismatch{Function: fn.Name, Count: len(parameters), ExpectedCount: len(fn.Input)}, f.File, root.Children[0].Token.End())

src/core/CompileDelete.go

@@ -22,6 +22,8 @@ func (f *Function) CompileDelete(root *expression.Expression) error {
 	f.SaveRegister(f.CPU.Input[1])
 	f.RegisterRegister(asm.MOVE, f.CPU.Input[0], variable.Value.Register)
 	f.RegisterNumber(asm.MOVE, f.CPU.Input[1], variable.Value.Typ.(*types.Pointer).To.Size())
-	f.CallSafe(f.All.Functions["mem.free"], f.CPU.Input[:2])
+	free := f.All.Functions["mem.free"]
+	f.CallSafe(free, f.CPU.Input[:2])
+	f.Dependencies = append(f.Dependencies, free)
 	return nil
 }

src/core/CompileNew.go

@@ -45,6 +45,8 @@ func (f *Function) CompileNew(root *expression.Expression) (types.Type, error) {
 
 	f.SaveRegister(f.CPU.Input[0])
 	f.RegisterNumber(asm.MOVE, f.CPU.Input[0], typ.Size())
-	f.CallSafe(f.All.Functions["mem.alloc"], f.CPU.Input[:1])
+	alloc := f.All.Functions["mem.alloc"]
+	f.CallSafe(alloc, f.CPU.Input[:1])
+	f.Dependencies = append(f.Dependencies, alloc)
 	return &types.Pointer{To: typ}, nil
 }

src/core/EvaluateDot.go

@@ -42,7 +42,8 @@ func (f *Function) EvaluateDot(expr *expression.Expression) (eval.Value, error)
 		return value, nil
 	}
 
-	constant, isConst := f.All.Constants[f.Package+"."+leftText+"."+rightText]
+	label := fmt.Sprintf("%s.%s", leftText, rightText)
+	constant, isConst := f.All.Constants[f.Package+"."+label]
 
 	if isConst {
 		number, err := ToNumber(constant.Token, constant.File)
@@ -73,10 +74,18 @@ func (f *Function) EvaluateDot(expr *expression.Expression) (eval.Value, error)
 		}
 	}
 
-	value := &eval.Label{
-		Typ:   types.AnyPointer,
-		Label: fmt.Sprintf("%s.%s", leftText, rightText),
+	function, exists := f.All.Functions[label]
+
+	if exists {
+		f.Dependencies = append(f.Dependencies, function)
+
+		value := &eval.Label{
+			Typ:   types.AnyPointer,
+			Label: label,
+		}
+
+		return value, nil
 	}
 
-	return value, nil
+	return nil, errors.New(&errors.UnknownIdentifier{Name: label}, f.File, left.Token.Position)
 }

src/core/EvaluateToken.go

@@ -41,6 +41,8 @@ func (f *Function) EvaluateToken(t token.Token) (eval.Value, error) {
 		}
 
 		if function != nil {
+			f.Dependencies = append(f.Dependencies, function)
+
 			value := &eval.Label{
 				Typ:   types.AnyPointer,
 				Label: function.UniqueName,

src/core/Function.go

@@ -11,17 +11,18 @@ import (
 // Function represents the smallest unit of code.
 type Function struct {
 	register.Machine
-	Package     string
-	Name        string
-	UniqueName  string
-	All         *Environment
-	File        *fs.File
-	Body        token.List
-	Input       []*Parameter
-	Output      []*Parameter
-	OutputTypes []types.Type
-	DLLs        dll.List
-	Err         error
-	deferred    []func()
-	count       count
+	Package      string
+	Name         string
+	UniqueName   string
+	All          *Environment
+	File         *fs.File
+	Body         token.List
+	Input        []*Parameter
+	Output       []*Parameter
+	OutputTypes  []types.Type
+	Dependencies []*Function
+	DLLs         dll.List
+	Err          error
+	deferred     []func()
+	count        count
 }

tests/programs/function-pointer-field.q

@@ -1,4 +1,4 @@
-import core
+import sys
 
 struct Struct {
 	func *any
@@ -6,6 +6,11 @@ struct Struct {
 
 main() {
 	s := new(Struct)
-	s.func = core.exit
+	s.func = f
 	s.func()
+	sys.exit(1)
+}
+
+f() {
+	sys.exit(0)
 }

tests/programs/function-pointer.q

@@ -1,6 +1,13 @@
 import core
+import sys
 
 main() {
+	func := f
+	func()
+	sys.exit(1)
+}
+
+f() {
 	exit := core.exit
 	exit()
 }