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-rw-r--r--pkg/lang/compiler/compiler.go53
-rw-r--r--pkg/lang/compiler/compiler_test.go20
-rw-r--r--pkg/lang/compiler/scope/scope_chain.go24
-rw-r--r--pkg/lang/vm/exec.go10
-rw-r--r--pkg/lang/vm/text/decompiler.go2
-rw-r--r--pkg/lang/vm/vm.go5
-rw-r--r--pkg/lang/vm/vm_test.go5
7 files changed, 102 insertions, 17 deletions
diff --git a/pkg/lang/compiler/compiler.go b/pkg/lang/compiler/compiler.go
index 4167088..e446dd6 100644
--- a/pkg/lang/compiler/compiler.go
+++ b/pkg/lang/compiler/compiler.go
@@ -96,8 +96,8 @@ func (comp *Compiler) compileStmt(t *code.Builder, stmt ast.Stmt) error {
case ast.StmtKindThrow:
panic("throw statements not implemented")
case ast.StmtKindExpr:
- expr := stmt.Value.(ast.StmtExpr).Value
- err = comp.compileExpr(t, expr)
+ exprStmt := stmt.Value.(ast.StmtExpr)
+ err = comp.compileExprStmt(t, exprStmt)
default:
panic(fmt.Errorf("unknown statement kind: %d", stmt.Kind))
}
@@ -139,7 +139,8 @@ func (comp *Compiler) compileFnDeclStmt(t *code.Builder, fnDeclStmt ast.StmtFnDe
return err
}
- comp.scopes.Exit()
+ // Function declaration scopes do not pollute stack
+ _ = comp.scopes.Exit()
comp.funcs = append(comp.funcs, &functionTarget)
@@ -175,6 +176,8 @@ func (comp *Compiler) compileIfStmt(t *code.Builder, ifStmt ast.StmtIf) error {
// preventing other CondNodes from running. This is missing from the last CondNode.
// Example: `jmp @end`
+ comp.scopes.Enter()
+
// First we create all the markers we'll need for the if statement
parentMarker := comp.scopes.CreateAnonymousFunctionSubUnit()
@@ -226,6 +229,8 @@ func (comp *Compiler) compileIfStmt(t *code.Builder, ifStmt ast.StmtIf) error {
t.PutMarker(endMarker)
+ comp.exitScopeAndCleanStack(t)
+
return nil
}
@@ -251,18 +256,24 @@ func (comp *Compiler) compileForCondStmt(t *code.Builder, forCondStmt ast.StmtFo
t.AppendMarkerReference(endMarker)
}
+ // Inner scope, dropped on every iteration
+ comp.scopes.Enter()
+
// Do block
if err := comp.compileBlockNode(t, forCondStmt.Do); err != nil {
return err
}
+ // Drop inner scope
+ comp.exitScopeAndCleanStack(t)
+
// Repeat jump
t.AppendOp(code.OpJmp)
t.AppendMarkerReference(repeatMarker)
t.PutMarker(endMarker)
- comp.scopes.Exit()
+ comp.exitScopeAndCleanStack(t)
return nil
}
@@ -302,6 +313,7 @@ func (comp *Compiler) compileForInStmt(t *code.Builder, forInStmt ast.StmtForIn)
// @end:
// halt
+ // Upper scope houses all internal loop locals, which are dropped when the loop ends.
endMarker, repeatMarker := comp.scopes.EnterLoop()
// Preparation
@@ -364,18 +376,25 @@ func (comp *Compiler) compileForInStmt(t *code.Builder, forInStmt ast.StmtForIn)
t.AppendOp(code.OpSetLocal)
t.AppendInt(int64(iLocal))
+ // Inner scope, dropped every loop iteration.
+ comp.scopes.Enter()
+
// Do block
if err := comp.compileBlockNode(t, forInStmt.Do); err != nil {
return err
}
+ // Drop inner scope
+ comp.exitScopeAndCleanStack(t)
+
// Repeat jump
t.AppendOp(code.OpJmp)
t.AppendMarkerReference(repeatMarker)
t.PutMarker(endMarker)
- comp.scopes.Exit()
+ // Drop upper scope
+ comp.exitScopeAndCleanStack(t)
return nil
}
@@ -424,6 +443,23 @@ func (comp *Compiler) compileBreakStmt(t *code.Builder, breakStmt ast.StmtBreak)
return nil
}
+func (comp *Compiler) compileExprStmt(t *code.Builder, exprStmt ast.StmtExpr) error {
+ if err := comp.compileExpr(t, exprStmt.Value); err != nil {
+ return err
+ }
+
+ isAssignment := exprStmt.Value.Kind == ast.ExprKindBinary &&
+ exprStmt.Value.Value.(ast.ExprBinary).Op == ast.BinOpAssign
+
+ // If the expression is not assignment, we need to drop the junk value.
+ if !isAssignment {
+ t.AppendOp(code.OpDrop)
+ t.AppendInt(1)
+ }
+
+ return nil
+}
+
func (comp *Compiler) compileExpr(t *code.Builder, expr ast.Expr) error {
switch expr.Kind {
case ast.ExprKindBinary:
@@ -676,3 +712,10 @@ func (comp *Compiler) compileBlockNode(t *code.Builder, block ast.BlockNode) err
return nil
}
+
+func (comp *Compiler) exitScopeAndCleanStack(t *code.Builder) {
+ if stackSpace := comp.scopes.Exit(); stackSpace != 0 {
+ t.AppendOp(code.OpDrop)
+ t.AppendInt(int64(stackSpace))
+ }
+}
diff --git a/pkg/lang/compiler/compiler_test.go b/pkg/lang/compiler/compiler_test.go
index 7741ca9..b8a6264 100644
--- a/pkg/lang/compiler/compiler_test.go
+++ b/pkg/lang/compiler/compiler_test.go
@@ -21,6 +21,7 @@ func TestSimpleAddExpr(t *testing.T) {
push_int 1
push_int 2
add
+ drop 1
halt
`
@@ -44,6 +45,7 @@ func TestOperationOrder(t *testing.T) {
sub
push_int 4
add
+ drop 1
halt
`
@@ -78,6 +80,8 @@ func TestNestedExpr(t *testing.T) {
add
sub
+ drop 1
+
halt
`
@@ -141,15 +145,12 @@ func TestArrayLit(t *testing.T) {
func TestIf(t *testing.T) {
src := `
- ":("
if 1 <= 5 {
"hello " + "world"
}
`
expected := `
- push_string ":("
-
push_int 1
push_int 5
lte
@@ -160,6 +161,8 @@ func TestIf(t *testing.T) {
push_string "world"
add
+ drop 1
+
@end:
halt
`
@@ -183,16 +186,19 @@ func TestIfElifElse(t *testing.T) {
jf @elif
push_int 1
+ drop 1
jmp @end
@elif:
push_true
jf @else
push_int 2
+ drop 1
jmp @end
@else:
push_int 3
+ drop 1
@end:
halt
@@ -215,12 +221,14 @@ func TestIfNoElse(t *testing.T) {
jf @elif
push_int 1
+ drop 1
jmp @end
@elif:
push_true
jf @end
push_int 2
+ drop 1
@end:
halt
@@ -248,10 +256,12 @@ func TestNestedIfs(t *testing.T) {
jf @else
push_int 1
+ drop 1
jmp @end
@else:
push_int 2
+ drop 1
@end:
halt
@@ -279,6 +289,7 @@ func TestForCond(t *testing.T) {
jf @inner_end
push_int 1
+ drop 1
jmp @inner_start
@inner_end:
@@ -410,9 +421,11 @@ func TestForIn(t *testing.T) {
push_string "say"
get_local 2
call 1
+ drop 1
jmp @check
@end:
+ drop 3
halt
`
@@ -456,6 +469,7 @@ func TestFunctionArgs(t *testing.T) {
push_int 4
push_int 5
call 2
+ drop 1
halt
@add:
diff --git a/pkg/lang/compiler/scope/scope_chain.go b/pkg/lang/compiler/scope/scope_chain.go
index 4d5bbcf..d0108ee 100644
--- a/pkg/lang/compiler/scope/scope_chain.go
+++ b/pkg/lang/compiler/scope/scope_chain.go
@@ -84,13 +84,29 @@ func (sc *ScopeChain) EnterLoop() (code.Marker, code.Marker) {
return breakMarker, continueMarker
}
-func (sc *ScopeChain) Exit() {
+func (sc *ScopeChain) Exit() int {
if sc.CurrentScopeID() == 0 {
- return
+ return 0
}
+ id := sc.CurrentScopeID()
+ stackSpace := len(sc.symbolScopes[id].variableSymbols)
- sc.symbolScopes[sc.CurrentScopeID()] = SymbolScope{}
- sc.symbolScopes = sc.symbolScopes[:sc.CurrentScopeID()]
+ sc.symbolScopes[id] = SymbolScope{}
+ sc.symbolScopes = sc.symbolScopes[:id]
+
+ if sc.CurrentLoop() != nil && sc.CurrentLoop().id == id {
+ lastLoopScope := len(sc.loopScopes) - 1
+ sc.loopScopes[lastLoopScope] = LoopScope{}
+ sc.loopScopes = sc.loopScopes[:lastLoopScope]
+ }
+
+ if sc.CurrentFunction().id == id {
+ lastFunctionScope := len(sc.functionScopes) - 1
+ sc.functionScopes[lastFunctionScope] = FunctionScope{}
+ sc.functionScopes = sc.functionScopes[:lastFunctionScope]
+ }
+
+ return stackSpace
}
func (sc *ScopeChain) Declare(name string) (int, bool) {
diff --git a/pkg/lang/vm/exec.go b/pkg/lang/vm/exec.go
index f92e486..3a1ce36 100644
--- a/pkg/lang/vm/exec.go
+++ b/pkg/lang/vm/exec.go
@@ -97,6 +97,16 @@ func (vm *VM) execPushType(name string) error {
return nil
}
+func (vm *VM) execDrop(dropAmount uint) error {
+ for i := 0; i < int(dropAmount); i++ {
+ if _, err := vm.popAndDrop(); err != nil {
+ return err
+ }
+ }
+
+ return nil
+}
+
func (vm *VM) execGetMember(name string) error {
parent, err := vm.stack.Pop()
if err != nil {
diff --git a/pkg/lang/vm/text/decompiler.go b/pkg/lang/vm/text/decompiler.go
index b3c8bb4..2b4e704 100644
--- a/pkg/lang/vm/text/decompiler.go
+++ b/pkg/lang/vm/text/decompiler.go
@@ -55,7 +55,6 @@ func (d *Decompiler) decompileInstruction(bc code.Raw) (string, code.Raw) {
code.OpPushNull,
code.OpPushArray,
code.OpPushObject,
- code.OpDrop,
code.OpAnchorType,
code.OpAdd,
code.OpSub,
@@ -75,6 +74,7 @@ func (d *Decompiler) decompileInstruction(bc code.Raw) (string, code.Raw) {
// Operations that take an int.
case code.OpPushInt,
+ code.OpDrop,
code.OpGetLocal,
code.OpSetLocal,
code.OpGetEnv,
diff --git a/pkg/lang/vm/vm.go b/pkg/lang/vm/vm.go
index ff9c28e..8b47915 100644
--- a/pkg/lang/vm/vm.go
+++ b/pkg/lang/vm/vm.go
@@ -116,7 +116,10 @@ func (vm *VM) step(op code.Op) (stepDecision, error) {
err = vm.execPushType(name)
case code.OpDrop:
- _, err = vm.stack.Pop()
+ dropAmount, advance := vm.code.GetUint(vm.pc)
+ vm.pc += advance
+
+ err = vm.execDrop(uint(dropAmount))
case code.OpGetGlobal:
panic("not implemented")
diff --git a/pkg/lang/vm/vm_test.go b/pkg/lang/vm/vm_test.go
index 7fe07dd..7e749a4 100644
--- a/pkg/lang/vm/vm_test.go
+++ b/pkg/lang/vm/vm_test.go
@@ -75,7 +75,7 @@ func TestFibonacci(t *testing.T) {
temp_arr_push
# Drop local 1, which was the length of the array, which we no longer need
- drop
+ drop 1
get_local 0
temp_arr_len
@@ -391,8 +391,7 @@ func TestPrimes(t *testing.T) {
add
set_local 0
- drop
- drop
+ drop 2
jmp @main_loop
@end:
generated by cgit v1.3.1 (git 2.54.0) at 2026-10-18 18:35:44 +0000