diff options
Diffstat (limited to 'codegen/compiler.go')
| -rw-r--r-- | codegen/compiler.go | 75 |
1 files changed, 31 insertions, 44 deletions
diff --git a/codegen/compiler.go b/codegen/compiler.go index 6f41850..48d3d41 100644 --- a/codegen/compiler.go +++ b/codegen/compiler.go @@ -9,24 +9,32 @@ import ( ) type symbol struct { - index int // address of symbol in frame - local bool // if true address is relative to local frame, otherwise global + index int // address of symbol in frame + local bool // if true address is relative to local frame, otherwise global + node *parser.Node // symbol definition in AST } type Compiler struct { Code [][]int64 // produced code, to fill VM with Data []any // produced data, will be at the bottom of VM stack - Entry int + Entry int // offset in Code to start execution from (skip function defintions) - symbols map[string]symbol + symbols map[string]*symbol } -func NewCompiler() *Compiler { return &Compiler{symbols: map[string]symbol{}, Entry: -1} } +func NewCompiler() *Compiler { return &Compiler{symbols: map[string]*symbol{}, Entry: -1} } type nodedata struct { ipstart, ipend, fsp int // CFG and symbol node annotations } +type extNode struct { + *Compiler + *parser.Node + anc *parser.Node // node ancestor + rank int // node rank in ancestor's children +} + func (c *Compiler) CodeGen(node *parser.Node) (err error) { notes := map[*parser.Node]*nodedata{} // AST node annotations for CFG, symbols, ... scope := "" @@ -41,13 +49,13 @@ func (c *Compiler) CodeGen(node *parser.Node) (err error) { switch n.Kind { case parser.FuncDecl: fname := n.Child[0].Content() - c.AddSym(len(c.Code), scope+fname, false) + c.addSym(len(c.Code), scope+fname, false, n) scope = pushScope(scope, fname) frameNode = append(frameNode, n) fnote = notes[n] for j, child := range n.Child[1].Child { vname := child.Content() - c.AddSym(-j-2, scope+vname, true) + c.addSym(-j-2, scope+vname, true, child) fnote.fsp++ } @@ -61,27 +69,18 @@ func (c *Compiler) CodeGen(node *parser.Node) (err error) { }, func(n, a *parser.Node, k int) (ok bool) { // Node post-order processing callback. nd := notes[n] + x := extNode{c, n, a, k} switch n.Kind { case parser.AddOp: c.Emit(n, vm1.Add) case parser.CallExpr: - if c.isExternalSymbol(n.Child[0].Content()) { - // External call, using absolute addr in symtable - c.Emit(n, vm1.CallX, int64(len(n.Child[1].Child))) - break - } - // Internal call is always relative to instruction pointer. - i, ok := c.symInt(n.Child[0].Content()) - if !ok { - err = fmt.Errorf("invalid symbol %s", n.Child[0].Content()) - } - c.Emit(n, vm1.Call, int64(i-len(c.Code))) + err = postCallExpr(x) case parser.DefOp: // Define operation, global vars only. TODO: on local frame too - l := c.AddSym(nil, n.Child[0].Content(), false) + l := c.addSym(nil, n.Child[0].Content(), false, n) c.Emit(n, vm1.Assign, int64(l)) case parser.FuncDecl: @@ -98,7 +97,7 @@ func (c *Compiler) CodeGen(node *parser.Node) (err error) { c.Emit(n, vm1.Fdup, int64(s.index)) } else if a != nil && a.Kind == parser.AssignOp { c.Emit(n, vm1.Push, int64(s.index)) - } else if c.isExternalSymbol(ident) { + } else if _, ok := c.Data[s.index].(int); !ok { c.Emit(n, vm1.Dup, int64(s.index)) } } @@ -116,10 +115,8 @@ func (c *Compiler) CodeGen(node *parser.Node) (err error) { c.Emit(n, vm1.Push, v) case error: err = v - return false default: err = fmt.Errorf("type not supported: %T\n", v) - return false } case parser.ReturnStmt: @@ -141,6 +138,10 @@ func (c *Compiler) CodeGen(node *parser.Node) (err error) { c.Emit(n, vm1.Sub) } + if err != nil { + return false + } + // TODO: Fix this temporary hack to compute an entry point if c.Entry < 0 && len(scope) == 0 && n.Kind != parser.FuncDecl { c.Entry = len(c.Code) - 1 @@ -153,14 +154,16 @@ func (c *Compiler) CodeGen(node *parser.Node) (err error) { return } -func (c *Compiler) AddSym(v any, name string, local bool) int { +func (c *Compiler) AddSym(v any, name string) int { return c.addSym(v, name, false, nil) } + +func (c *Compiler) addSym(v any, name string, local bool, n *parser.Node) int { l := len(c.Data) if local { l = v.(int) } else { c.Data = append(c.Data, v) } - c.symbols[name] = symbol{index: l, local: local} + c.symbols[name] = &symbol{index: l, local: local, node: n} return l } @@ -171,25 +174,9 @@ func (c *Compiler) Emit(n *parser.Node, op ...int64) int { return l } -func (c *Compiler) isExternalSymbol(name string) bool { - s, ok := c.symbols[name] - if !ok { - return false - } - _, isInt := c.Data[s.index].(int) - return !isInt -} - -func (c *Compiler) symInt(name string) (int, bool) { - s, ok := c.symbols[name] - if !ok { - return 0, false - } - j, ok := c.Data[s.index].(int) - if !ok { - return 0, false - } - return j, true +func (c *Compiler) codeIndex(s *symbol) (i int, ok bool) { + i, ok = c.Data[s.index].(int) + return } func pushScope(scope, name string) string { @@ -206,7 +193,7 @@ func popScope(scope string) string { } // getSym searches for an existing symbol starting from the deepest scope. -func (c *Compiler) getSym(name, scope string) (sym symbol, sc string, ok bool) { +func (c *Compiler) getSym(name, scope string) (sym *symbol, sc string, ok bool) { for { if sym, ok = c.symbols[scope+name]; ok { return sym, scope, ok |