diff --git a/src/build/asm/Instructions.go b/src/build/asm/Instructions.go index 4c51e87..ced8cf5 100644 --- a/src/build/asm/Instructions.go +++ b/src/build/asm/Instructions.go @@ -22,8 +22,12 @@ func (a *Assembler) Call(name string) { // Return returns back to the caller. func (a *Assembler) Return() { - if len(a.Instructions) > 0 && a.Instructions[len(a.Instructions)-1].Mnemonic == RETURN { - return + if len(a.Instructions) > 0 { + lastMnemonic := a.Instructions[len(a.Instructions)-1].Mnemonic + + if lastMnemonic == RETURN || lastMnemonic == JUMP { + return + } } a.Instructions = append(a.Instructions, Instruction{Mnemonic: RETURN}) diff --git a/src/build/ast/Count.go b/src/build/ast/Count.go index b14482d..d15a29e 100644 --- a/src/build/ast/Count.go +++ b/src/build/ast/Count.go @@ -9,6 +9,10 @@ func Count(body AST, kind token.Kind, name string) int { for _, node := range body { switch node := node.(type) { case *Assign: + if node.Name.Kind == kind && node.Name.Text() == name { + count++ + } + count += node.Value.Count(kind, name) case *Call: @@ -18,7 +22,9 @@ func Count(body AST, kind token.Kind, name string) int { count += node.Value.Count(kind, name) case *Return: - count += node.Value.Count(kind, name) + if node.Value != nil { + count += node.Value.Count(kind, name) + } case *If: count += node.Condition.Count(kind, name) diff --git a/src/build/ast/Parse.go b/src/build/ast/Parse.go index eaaad01..eb55aec 100644 --- a/src/build/ast/Parse.go +++ b/src/build/ast/Parse.go @@ -30,6 +30,10 @@ func toASTNode(tokens token.List) (Node, error) { word := tokens[0].Text() if word == keyword.Return { + if len(tokens) == 1 { + return &Return{}, nil + } + value := expression.Parse(tokens[1:]) return &Return{Value: value}, nil } diff --git a/src/build/core/CompileCall.go b/src/build/core/CompileCall.go index f7b9dfb..9bb4f1f 100644 --- a/src/build/core/CompileCall.go +++ b/src/build/core/CompileCall.go @@ -51,6 +51,10 @@ func (f *Function) CompileCall(root *expression.Expression) error { f.Call(funcName) } + for _, register := range registers { + f.Scope().Free(register) + } + // Pop for i := len(f.cpu.General) - 1; i >= 0; i-- { register := f.cpu.General[i] diff --git a/src/build/core/CompileDefinition.go b/src/build/core/CompileDefinition.go index 6a481a9..e591efa 100644 --- a/src/build/core/CompileDefinition.go +++ b/src/build/core/CompileDefinition.go @@ -44,26 +44,35 @@ func (f *Function) AddVariable(variable *Variable) { f.Comment("%s = %s (%s, %d uses)", variable.Name, variable.Value, variable.Register, variable.Alive) } - f.Scope().variables[variable.Name] = variable - f.Scope().Reserve(variable.Register) - f.Scope().Use(variable.Register) + scope := f.Scope() + variable.Scope = scope + + scope.variables[variable.Name] = variable + scope.Reserve(variable.Register) + scope.Use(variable.Register) } func (f *Function) useVariable(variable *Variable) { - for _, scope := range f.scopes { + for i, scope := range f.scopes { + if scope.inLoop && variable.Scope != scope { + continue + } + local := scope.variables[variable.Name] - if local != nil { - local.Alive-- + if local == nil { + continue } + local.Alive-- + if local.Alive < 0 { panic("incorrect number of variable use calls") } if local.Alive == 0 { if config.Comments { - f.Comment("%s died (%s)", local.Name, local.Register) + f.Comment("%s died (%s) in scope %d", local.Name, local.Register, i) } scope.Free(local.Register) diff --git a/src/build/core/CompileLoop.go b/src/build/core/CompileLoop.go index 6a798e5..c8e8258 100644 --- a/src/build/core/CompileLoop.go +++ b/src/build/core/CompileLoop.go @@ -12,9 +12,10 @@ func (f *Function) CompileLoop(loop *ast.Loop) error { f.count.loop++ label := fmt.Sprintf("%s_loop_%d", f.Name, f.count.loop) f.AddLabel(label) - f.pushScope(loop.Body) + scope := f.pushScope(loop.Body) + scope.inLoop = true err := f.CompileAST(loop.Body) - f.popScope() f.Jump(asm.JUMP, label) + f.popScope() return err } diff --git a/src/build/core/Scope.go b/src/build/core/Scope.go index a88187b..4cfcaeb 100644 --- a/src/build/core/Scope.go +++ b/src/build/core/Scope.go @@ -2,6 +2,7 @@ package core import ( "git.akyoto.dev/cli/q/src/build/ast" + "git.akyoto.dev/cli/q/src/build/config" "git.akyoto.dev/cli/q/src/build/cpu" "git.akyoto.dev/cli/q/src/build/token" ) @@ -10,6 +11,7 @@ import ( type Scope struct { cpu.State variables map[string]*Variable + inLoop bool } // Scope returns the current scope. @@ -18,13 +20,14 @@ func (s *state) Scope() *Scope { } // pushScope pushes a new scope to the top of the stack. -func (s *state) pushScope(body ast.AST) { +func (f *Function) pushScope(body ast.AST) *Scope { scope := &Scope{} - if len(s.scopes) > 0 { - lastScope := s.scopes[len(s.scopes)-1] + if len(f.scopes) > 0 { + lastScope := f.scopes[len(f.scopes)-1] scope.State = lastScope.State scope.variables = make(map[string]*Variable, len(lastScope.variables)) + scope.inLoop = lastScope.inLoop for k, v := range lastScope.variables { count := ast.Count(body, token.Identifier, v.Name) @@ -44,10 +47,20 @@ func (s *state) pushScope(body ast.AST) { scope.variables = map[string]*Variable{} } - s.scopes = append(s.scopes, scope) + f.scopes = append(f.scopes, scope) + + if config.Comments { + f.Comment("scope %d start", len(f.scopes)) + } + + return scope } // popScope removes the scope at the top of the stack. -func (s *state) popScope() { - s.scopes = s.scopes[:len(s.scopes)-1] +func (f *Function) popScope() { + if config.Comments { + f.Comment("scope %d end", len(f.scopes)) + } + + f.scopes = f.scopes[:len(f.scopes)-1] } diff --git a/src/build/core/Variable.go b/src/build/core/Variable.go index b7dd6ad..4f31806 100644 --- a/src/build/core/Variable.go +++ b/src/build/core/Variable.go @@ -11,6 +11,7 @@ type Variable struct { Name string Register cpu.Register Alive int + Scope *Scope } // Variable returns the variable with the given name or `nil` if it doesn't exist. diff --git a/tests/programs/loop-lifetime.q b/tests/programs/loop-lifetime.q new file mode 100644 index 0000000..1262b7d --- /dev/null +++ b/tests/programs/loop-lifetime.q @@ -0,0 +1,17 @@ +main() { + n := 10 + x := 1 + + loop { + if n == 0 { + return + } + + f(x) + n -= 1 + } +} + +f(x) { + return x +} \ No newline at end of file diff --git a/tests/programs/loop.q b/tests/programs/loop.q new file mode 100644 index 0000000..c6456dc --- /dev/null +++ b/tests/programs/loop.q @@ -0,0 +1,11 @@ +main() { + n := 10 + + loop { + if n == 0 { + return + } + + n -= 1 + } +} \ No newline at end of file diff --git a/tests/programs_test.go b/tests/programs_test.go index 93dbd50..aa3a6d5 100644 --- a/tests/programs_test.go +++ b/tests/programs_test.go @@ -31,6 +31,8 @@ var programs = []struct { {"branch-or", "", 0}, {"branch-both", "", 0}, {"jump-near", "", 0}, + {"loop", "", 0}, + {"loop-lifetime", "", 0}, } func TestPrograms(t *testing.T) {