mirror of
https://github.com/golang/go
synced 2024-11-12 05:40:22 -07:00
Implement labels, goto, labeled break, and labeled continue.
Return checking is now done as a general flow check at the end of function compilation, since break and goto complicated the way I was doing return checking before. Goto-over-declaration checking is also done as a final flow check. Temporary variables used for effect extraction are now actually temporary. Otherwise "op=", "++", and "--" appear as declarations that cannot be jumped over. R=rsc APPROVED=rsc DELTA=421 (344 added, 38 deleted, 39 changed) OCL=32527 CL=32535
This commit is contained in:
Austin Clements
parent
6ccebe082f
commit
36ca5fde68
@ -44,7 +44,27 @@ func (a *compiler) compileFuncType(b *block, typ *ast.FuncType) *FuncDecl
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func (a *compiler) compileArrayLen(b *block, expr ast.Expr) (int64, bool)
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type label struct {
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name string;
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desc string;
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// The PC goto statements should jump to, or nil if this label
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// cannot be goto'd (such as an anonymous for loop label).
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gotoPC *uint;
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// The PC break statements should jump to, or nil if a break
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// statement is invalid.
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breakPC *uint;
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// The PC continue statements should jump to, or nil if a
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// continue statement is invalid.
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continuePC *uint;
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// The position where this label was resolved. If it has not
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// been resolved yet, an invalid position.
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resolved token.Position;
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// The position where this label was first jumped to.
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used token.Position;
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}
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type codeBuf struct
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type flowBuf struct
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type FuncType struct
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// A funcCompiler captures information used throughout the compilation
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// of a single function body.
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@ -55,22 +75,21 @@ type funcCompiler struct {
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// kinds of return statements are legal.
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outVarsNamed bool;
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*codeBuf;
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flow *flowBuf;
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labels map[string] *label;
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err bool;
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}
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func (a *funcCompiler) checkLabels()
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// A blockCompiler captures information used throughout the compilation
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// of a single block within a function.
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type blockCompiler struct {
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*funcCompiler;
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block *block;
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returned bool;
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// The PC break statements should jump to, or nil if a break
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// statement is invalid.
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breakPC *uint;
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// The PC continue statements should jump to, or nil if a
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// continue statement is invalid.
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continuePC *uint;
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// The label of this block, used for finding break and
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// continue labels.
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label *label;
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// The blockCompiler for the block enclosing this one, or nil
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// for a function-level block.
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parent *blockCompiler;
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@ -178,7 +178,7 @@ func (b *block) enterChild() *block
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func (b *block) exit()
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func (b *block) ChildScope() *Scope
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func (b *block) DefineVar(name string, t Type) *Variable
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func (b *block) DefineTemp(t Type) *Variable
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func (b *block) DefineSlot(t Type) *Variable
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func (b *block) DefineConst(name string, t Type, v Value) *Constant
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func (b *block) DefineType(name string, t Type) Type
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func (b *block) Lookup(name string) (level int, def Def)
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@ -1324,7 +1324,10 @@ func (a *compiler) compileExpr(b *block, expr ast.Expr, constant bool) *exprComp
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// extractEffect separates out any effects that the expression may
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// have, returning a function that will perform those effects and a
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// new exprCompiler that is guaranteed to be side-effect free. These
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// are the moral equivalents of "temp := &expr" and "*temp".
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// are the moral equivalents of "temp := &expr" and "*temp". Because
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// this creates a temporary variable, the caller should create a
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// temporary block for the compilation of this expression and the
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// evaluation of the results.
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//
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// Implementation limit: The expression must be addressable.
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func (a *exprCompiler) extractEffect() (func(f *Frame), *exprCompiler) {
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@ -1337,9 +1340,7 @@ func (a *exprCompiler) extractEffect() (func(f *Frame), *exprCompiler) {
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// Create temporary
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tempBlock := a.block;
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tempType := NewPtrType(a.t);
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// TODO(austin) These temporaries accumulate in the scope. We
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// could enter a temporary block, but the caller has to exit it.
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temp := tempBlock.DefineTemp(tempType);
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temp := tempBlock.DefineSlot(tempType);
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tempIdx := temp.Index;
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// Generate "temp := &e"
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@ -51,14 +51,14 @@ func (b *block) DefineVar(name string, t Type) *Variable {
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if _, ok := b.defs[name]; ok {
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return nil;
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}
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v := b.DefineTemp(t);
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v := b.DefineSlot(t);
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if v != nil {
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b.defs[name] = v;
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}
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return v;
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}
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func (b *block) DefineTemp(t Type) *Variable {
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func (b *block) DefineSlot(t Type) *Variable {
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if b.inner != nil {
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log.Crash("Failed to exit child block before defining variable");
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}
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@ -15,6 +15,11 @@ import (
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"strconv";
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)
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const (
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returnPC = ^uint(0);
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badPC = ^uint(1);
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)
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/*
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* Statement compiler
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*/
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@ -22,6 +27,8 @@ import (
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type stmtCompiler struct {
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*blockCompiler;
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pos token.Position;
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// This statement's label, or nil if it is not labeled.
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stmtLabel *label;
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// err should be initialized to true before visiting and set
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// to false when the statement is compiled successfully. The
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// function invoking Visit should or this with
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@ -34,6 +41,183 @@ func (a *stmtCompiler) diag(format string, args ...) {
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a.diagAt(&a.pos, format, args);
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}
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/*
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* Flow checker
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*/
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type flowEnt struct {
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// Whether this flow entry is conditional. If true, flow can
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// continue to the next PC.
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cond bool;
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// True if this will terminate flow (e.g., a return statement).
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// cond must be false and jumps must be nil if this is true.
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term bool;
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// PC's that can be reached from this flow entry.
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jumps []*uint;
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// Whether this flow entry has been visited by reachesEnd.
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visited bool;
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}
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type flowBlock struct {
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// If this is a goto, the target label.
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target string;
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// The inner-most block containing definitions.
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block *block;
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// The numVars from each block leading to the root of the
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// scope, starting at block.
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numVars []int;
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}
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type flowBuf struct {
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cb *codeBuf;
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// ents is a map from PC's to flow entries. Any PC missing
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// from this map is assumed to reach only PC+1.
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ents map[uint] *flowEnt;
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// gotos is a map from goto positions to information on the
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// block at the point of the goto.
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gotos map[*token.Position] *flowBlock;
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// labels is a map from label name to information on the block
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// at the point of the label. labels are tracked by name,
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// since mutliple labels at the same PC can have different
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// blocks.
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labels map[string] *flowBlock;
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}
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func newFlowBuf(cb *codeBuf) *flowBuf {
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return &flowBuf{cb, make(map[uint] *flowEnt), make(map[*token.Position] *flowBlock), make(map[string] *flowBlock)};
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}
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// put creates a flow control point for the next PC in the code buffer.
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// This should be done before pushing the instruction into the code buffer.
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func (f *flowBuf) put(cond bool, term bool, jumps []*uint) {
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pc := f.cb.nextPC();
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if ent, ok := f.ents[pc]; ok {
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log.Crashf("Flow entry already exists at PC %d: %+v", pc, ent);
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}
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f.ents[pc] = &flowEnt{cond, term, jumps, false};
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}
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// putTerm creates a flow control point at the next PC that
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// unconditionally terminates execution.
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func (f *flowBuf) putTerm() {
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f.put(false, true, nil);
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}
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// put1 creates a flow control point at the next PC that jumps to one
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// PC and, if cond is true, can also continue to the PC following the
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// next PC.
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func (f *flowBuf) put1(cond bool, jumpPC *uint) {
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f.put(cond, false, []*uint {jumpPC});
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}
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func newFlowBlock(target string, b *block) *flowBlock {
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// Find the inner-most block containing definitions
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for b.numVars == 0 && b.outer != nil && b.outer.scope == b.scope {
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b = b.outer;
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}
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// Count parents leading to the root of the scope
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n := 0;
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for bp := b; bp.scope == b.scope; bp = bp.outer {
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n++;
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}
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// Capture numVars from each block to the root of the scope
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numVars := make([]int, n);
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i := 0;
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for bp := b; i < n; bp = bp.outer {
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numVars[i] = bp.numVars;
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i++;
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}
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return &flowBlock{target, b, numVars};
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}
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// putGoto captures the block at a goto statement. This should be
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// called in addition to putting a flow control point.
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func (f *flowBuf) putGoto(pos token.Position, target string, b *block) {
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f.gotos[&pos] = newFlowBlock(target, b);
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}
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// putLabel captures the block at a label.
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func (f *flowBuf) putLabel(name string, b *block) {
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f.labels[name] = newFlowBlock("", b);
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}
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// reachesEnd returns true if the end of f's code buffer can be
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// reached from the given program counter. Error reporting is the
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// caller's responsibility.
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func (f *flowBuf) reachesEnd(pc uint) bool {
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endPC := f.cb.nextPC();
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if pc > endPC {
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log.Crashf("Reached bad PC %d past end PC %d", pc, endPC);
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}
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for ; pc < endPC; pc++ {
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ent, ok := f.ents[pc];
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if !ok {
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continue;
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}
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if ent.visited {
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return false;
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}
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ent.visited = true;
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if ent.term {
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return false;
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}
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// If anything can reach the end, we can reach the end
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// from pc.
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for _, j := range ent.jumps {
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if f.reachesEnd(*j) {
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return true;
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}
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}
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// If the jump was conditional, we can reach the next
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// PC, so try reaching the end from it.
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if ent.cond {
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continue;
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}
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return false;
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}
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return true;
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}
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// gotosObeyScopes returns true if no goto statement causes any
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// variables to come into scope that were not in scope at the point of
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// the goto. Reports any errors using the given compiler.
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func (f *flowBuf) gotosObeyScopes(a *compiler) bool {
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for pos, src := range f.gotos {
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tgt := f.labels[src.target];
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// The target block must be a parent of this block
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numVars := src.numVars;
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b := src.block;
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for len(numVars) > 0 && b != tgt.block {
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b = b.outer;
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numVars = numVars[1:len(numVars)];
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}
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if b != tgt.block {
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// We jumped into a deeper block
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a.diagAt(pos, "goto causes variables to come into scope");
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return false;
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}
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// There must be no variables in the target block that
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// did not exist at the jump
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tgtNumVars := tgt.numVars;
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for i := range numVars {
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if tgtNumVars[i] > numVars[i] {
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a.diagAt(pos, "goto causes variables to come into scope");
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return false;
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}
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}
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}
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return true;
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}
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/*
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* Statement visitors
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*/
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@ -51,7 +235,36 @@ func (a *stmtCompiler) DoEmptyStmt(s *ast.EmptyStmt) {
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}
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func (a *stmtCompiler) DoLabeledStmt(s *ast.LabeledStmt) {
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log.Crash("Not implemented");
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bad := false;
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// Define label
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l, ok := a.labels[s.Label.Value];
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if ok {
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if l.resolved.IsValid() {
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a.diag("label %s redefined; previous definition at line %d", s.Label.Value, l.resolved.Line);
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bad = true;
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}
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} else {
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pc := badPC;
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l = &label{name: s.Label.Value, gotoPC: &pc};
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a.labels[l.name] = l;
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}
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l.desc = "regular label";
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l.resolved = s.Pos();
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// Set goto PC
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*l.gotoPC = a.nextPC();
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// Define flow entry so we can check for jumps over declarations.
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a.flow.putLabel(l.name, a.block);
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// Compile the statement. Reuse our stmtCompiler for simplicity.
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a.pos = s.Stmt.Pos();
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a.stmtLabel = l;
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s.Stmt.Visit(a);
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if bad {
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a.err = true;
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}
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}
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func (a *stmtCompiler) DoExprStmt(s *ast.ExprStmt) {
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@ -73,7 +286,11 @@ func (a *stmtCompiler) DoExprStmt(s *ast.ExprStmt) {
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}
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func (a *stmtCompiler) DoIncDecStmt(s *ast.IncDecStmt) {
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l := a.compileExpr(a.block, s.X, false);
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// Create temporary block for extractEffect
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bc := a.enterChild();
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defer bc.exit();
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l := a.compileExpr(bc.block, s.X, false);
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if l == nil {
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return;
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}
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@ -330,8 +547,12 @@ func (a *stmtCompiler) doAssignOp(s *ast.AssignStmt) {
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return;
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}
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l := a.compileExpr(a.block, s.Lhs[0], false);
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r := a.compileExpr(a.block, s.Rhs[0], false);
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// Create temporary block for extractEffect
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bc := a.enterChild();
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defer bc.exit();
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l := a.compileExpr(bc.block, s.Lhs[0], false);
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r := a.compileExpr(bc.block, s.Rhs[0], false);
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if l == nil || r == nil {
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return;
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}
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@ -387,13 +608,10 @@ func (a *stmtCompiler) DoReturnStmt(s *ast.ReturnStmt) {
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return;
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}
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// Supress return errors even if we fail to compile this
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// return statement.
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a.returned = true;
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if len(s.Results) == 0 && (len(a.fnType.Out) == 0 || a.outVarsNamed) {
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// Simple case. Simply exit from the function.
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a.push(func(v *vm) { v.pc = ^uint(0) });
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a.flow.putTerm();
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a.push(func(v *vm) { v.pc = returnPC });
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a.err = false;
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return;
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}
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@ -429,49 +647,68 @@ func (a *stmtCompiler) DoReturnStmt(s *ast.ReturnStmt) {
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// Compile
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start := len(a.fnType.In);
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nout := len(a.fnType.Out);
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a.flow.putTerm();
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a.push(func(v *vm) {
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assign(multiV(v.f.Vars[start:start+nout]), v.f);
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v.pc = ^uint(0);
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v.pc = returnPC;
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});
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a.err = false;
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}
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func (a *stmtCompiler) findLexicalLabel(name *ast.Ident, pred func(*label) bool, errOp, errCtx string) *label {
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bc := a.blockCompiler;
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for ; bc != nil; bc = bc.parent {
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if bc.label == nil {
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continue;
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}
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l := bc.label;
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if name == nil && pred(l) {
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return l;
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}
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if name != nil && l.name == name.Value {
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if !pred(l) {
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a.diag("cannot %s to %s %s", errOp, l.desc, l.name);
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return nil;
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}
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return l;
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}
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}
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if name == nil {
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a.diag("%s outside %s", errOp, errCtx);
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} else {
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a.diag("%s label %s not defined", errOp, name.Value);
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}
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return nil;
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}
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func (a *stmtCompiler) DoBranchStmt(s *ast.BranchStmt) {
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var pc *uint;
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switch s.Tok {
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case token.BREAK:
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if s.Label != nil {
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log.Crash("break with label not implemented");
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l := a.findLexicalLabel(s.Label, func(l *label) bool { return l.breakPC != nil }, "break", "for loop, switch, or select");
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if l == nil {
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return;
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}
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bc := a.blockCompiler;
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for ; bc != nil; bc = bc.parent {
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if bc.breakPC != nil {
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pc := bc.breakPC;
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a.push(func(v *vm) { v.pc = *pc });
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a.err = false;
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return;
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}
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}
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a.diag("break outside for loop, switch, or select");
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pc = l.breakPC;
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case token.CONTINUE:
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if s.Label != nil {
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log.Crash("continue with label not implemented");
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l := a.findLexicalLabel(s.Label, func(l *label) bool { return l.continuePC != nil }, "continue", "for loop");
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if l == nil {
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return;
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}
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bc := a.blockCompiler;
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for ; bc != nil; bc = bc.parent {
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if bc.continuePC != nil {
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pc := bc.continuePC;
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a.push(func(v *vm) { v.pc = *pc });
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a.err = false;
|
||||
return;
|
||||
}
|
||||
}
|
||||
a.diag("continue outside for loop");
|
||||
pc = l.continuePC;
|
||||
|
||||
case token.GOTO:
|
||||
log.Crash("goto not implemented");
|
||||
l, ok := a.labels[s.Label.Value];
|
||||
if !ok {
|
||||
pc := badPC;
|
||||
l = &label{name: s.Label.Value, desc: "unresolved label", gotoPC: &pc, used: s.Pos()};
|
||||
a.labels[l.name] = l;
|
||||
}
|
||||
|
||||
pc = l.gotoPC;
|
||||
a.flow.putGoto(s.Pos(), l.name, a.block);
|
||||
|
||||
case token.FALLTHROUGH:
|
||||
log.Crash("fallthrough not implemented");
|
||||
@ -479,6 +716,10 @@ func (a *stmtCompiler) DoBranchStmt(s *ast.BranchStmt) {
|
||||
default:
|
||||
log.Crash("Unexpected branch token %v", s.Tok);
|
||||
}
|
||||
|
||||
a.flow.put1(false, pc);
|
||||
a.push(func(v *vm) { v.pc = *pc });
|
||||
a.err = false;
|
||||
}
|
||||
|
||||
func (a *stmtCompiler) DoBlockStmt(s *ast.BlockStmt) {
|
||||
@ -486,7 +727,6 @@ func (a *stmtCompiler) DoBlockStmt(s *ast.BlockStmt) {
|
||||
bc.compileStmts(s);
|
||||
bc.exit();
|
||||
|
||||
a.returned = a.returned || bc.returned;
|
||||
a.err = false;
|
||||
}
|
||||
|
||||
@ -509,7 +749,8 @@ func (a *stmtCompiler) DoIfStmt(s *ast.IfStmt) {
|
||||
bc.compileStmt(s.Init);
|
||||
}
|
||||
|
||||
var elsePC, endPC uint;
|
||||
elsePC := badPC;
|
||||
endPC := badPC;
|
||||
|
||||
// Compile condition, if any. If there is no condition, we
|
||||
// fall through to the body.
|
||||
@ -524,6 +765,7 @@ func (a *stmtCompiler) DoIfStmt(s *ast.IfStmt) {
|
||||
bad = true;
|
||||
default:
|
||||
eval := e.asBool();
|
||||
a.flow.put1(true, &elsePC);
|
||||
a.push(func(v *vm) {
|
||||
if !eval(v.f) {
|
||||
v.pc = elsePC;
|
||||
@ -540,15 +782,12 @@ func (a *stmtCompiler) DoIfStmt(s *ast.IfStmt) {
|
||||
// Compile else
|
||||
if s.Else != nil {
|
||||
// Skip over else if we executed the body
|
||||
a.flow.put1(false, &endPC);
|
||||
a.push(func(v *vm) {
|
||||
v.pc = endPC;
|
||||
});
|
||||
elsePC = a.nextPC();
|
||||
bc.compileStmt(s.Else);
|
||||
|
||||
if body.returned && bc.returned {
|
||||
a.returned = true;
|
||||
}
|
||||
} else {
|
||||
elsePC = a.nextPC();
|
||||
}
|
||||
@ -593,17 +832,27 @@ func (a *stmtCompiler) DoForStmt(s *ast.ForStmt) {
|
||||
bc.compileStmt(s.Init);
|
||||
}
|
||||
|
||||
var bodyPC, postPC, checkPC, endPC uint;
|
||||
bodyPC := badPC;
|
||||
postPC := badPC;
|
||||
checkPC := badPC;
|
||||
endPC := badPC;
|
||||
|
||||
// Jump to condition check. We generate slightly less code by
|
||||
// placing the condition check after the body.
|
||||
a.flow.put1(false, &checkPC);
|
||||
a.push(func(v *vm) { v.pc = checkPC });
|
||||
|
||||
// Compile body
|
||||
bodyPC = a.nextPC();
|
||||
body := bc.enterChild();
|
||||
body.breakPC = &endPC;
|
||||
body.continuePC = &postPC;
|
||||
if a.stmtLabel != nil {
|
||||
body.label = a.stmtLabel;
|
||||
} else {
|
||||
body.label = &label{resolved: s.Pos()};
|
||||
}
|
||||
body.label.desc = "for loop";
|
||||
body.label.breakPC = &endPC;
|
||||
body.label.continuePC = &postPC;
|
||||
body.compileStmts(s.Body);
|
||||
body.exit();
|
||||
|
||||
@ -620,6 +869,7 @@ func (a *stmtCompiler) DoForStmt(s *ast.ForStmt) {
|
||||
checkPC = a.nextPC();
|
||||
if s.Cond == nil {
|
||||
// If the condition is absent, it is equivalent to true.
|
||||
a.flow.put1(false, &bodyPC);
|
||||
a.push(func(v *vm) { v.pc = bodyPC });
|
||||
} else {
|
||||
e := bc.compileExpr(bc.block, s.Cond, false);
|
||||
@ -631,6 +881,7 @@ func (a *stmtCompiler) DoForStmt(s *ast.ForStmt) {
|
||||
bad = true;
|
||||
default:
|
||||
eval := e.asBool();
|
||||
a.flow.put1(true, &bodyPC);
|
||||
a.push(func(v *vm) {
|
||||
if eval(v.f) {
|
||||
v.pc = bodyPC;
|
||||
@ -658,7 +909,7 @@ func (a *blockCompiler) compileStmt(s ast.Stmt) {
|
||||
if a.block.inner != nil {
|
||||
log.Crash("Child scope still entered");
|
||||
}
|
||||
sc := &stmtCompiler{a, s.Pos(), true};
|
||||
sc := &stmtCompiler{a, s.Pos(), nil, true};
|
||||
s.Visit(sc);
|
||||
if a.block.inner != nil {
|
||||
log.Crash("Forgot to exit child scope");
|
||||
@ -677,7 +928,6 @@ func (a *blockCompiler) enterChild() *blockCompiler {
|
||||
return &blockCompiler{
|
||||
funcCompiler: a.funcCompiler,
|
||||
block: block,
|
||||
returned: false,
|
||||
parent: a,
|
||||
};
|
||||
}
|
||||
@ -701,33 +951,36 @@ func (a *compiler) compileFunc(b *block, decl *FuncDecl, body *ast.BlockStmt) (f
|
||||
if decl.InNames[i] != nil {
|
||||
bodyScope.DefineVar(decl.InNames[i].Value, t);
|
||||
} else {
|
||||
// TODO(austin) Not technically a temp
|
||||
bodyScope.DefineTemp(t);
|
||||
bodyScope.DefineSlot(t);
|
||||
}
|
||||
}
|
||||
for i, t := range decl.Type.Out {
|
||||
if decl.OutNames[i] != nil {
|
||||
bodyScope.DefineVar(decl.OutNames[i].Value, t);
|
||||
} else {
|
||||
bodyScope.DefineTemp(t);
|
||||
bodyScope.DefineSlot(t);
|
||||
}
|
||||
}
|
||||
|
||||
// Create block context
|
||||
fc := &funcCompiler{a, decl.Type, false, newCodeBuf(), false};
|
||||
if len(decl.OutNames) > 0 && decl.OutNames[0] != nil {
|
||||
fc.outVarsNamed = true;
|
||||
}
|
||||
cb := newCodeBuf();
|
||||
fc := &funcCompiler{
|
||||
compiler: a,
|
||||
fnType: decl.Type,
|
||||
outVarsNamed: len(decl.OutNames) > 0 && decl.OutNames[0] != nil,
|
||||
codeBuf: cb,
|
||||
flow: newFlowBuf(cb),
|
||||
labels: make(map[string] *label),
|
||||
err: false,
|
||||
};
|
||||
bc := &blockCompiler{
|
||||
funcCompiler: fc,
|
||||
block: bodyScope.block,
|
||||
returned: false,
|
||||
};
|
||||
|
||||
// Compile body
|
||||
bc.compileStmts(body);
|
||||
|
||||
// TODO(austin) Check that all gotos were linked?
|
||||
fc.checkLabels();
|
||||
|
||||
if fc.err {
|
||||
return nil;
|
||||
@ -735,7 +988,7 @@ func (a *compiler) compileFunc(b *block, decl *FuncDecl, body *ast.BlockStmt) (f
|
||||
|
||||
// Check that the body returned if necessary. We only check
|
||||
// this if there were no errors compiling the body.
|
||||
if len(decl.Type.Out) > 0 && !bc.returned {
|
||||
if len(decl.Type.Out) > 0 && fc.flow.reachesEnd(0) {
|
||||
// XXX(Spec) Not specified.
|
||||
a.diagAt(&body.Rbrace, "function ends without a return statement");
|
||||
return nil;
|
||||
@ -746,6 +999,30 @@ func (a *compiler) compileFunc(b *block, decl *FuncDecl, body *ast.BlockStmt) (f
|
||||
return func(f *Frame) Func { return &evalFunc{f, maxVars, code} };
|
||||
}
|
||||
|
||||
// Checks that labels were resolved and that all jumps obey scoping
|
||||
// rules. Reports an error and set fc.err if any check fails.
|
||||
func (a *funcCompiler) checkLabels() {
|
||||
bad := false;
|
||||
for _, l := range a.labels {
|
||||
if !l.resolved.IsValid() {
|
||||
a.diagAt(&l.used, "label %s not defined", l.name);
|
||||
bad = true;
|
||||
}
|
||||
}
|
||||
if bad {
|
||||
a.err = true;
|
||||
// Don't check scopes if we have unresolved labels
|
||||
return;
|
||||
}
|
||||
|
||||
// Executing the "goto" statement must not cause any variables
|
||||
// to come into scope that were not already in scope at the
|
||||
// point of the goto.
|
||||
if !a.flow.gotosObeyScopes(a.compiler) {
|
||||
a.err = true;
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Testing interface
|
||||
*/
|
||||
@ -761,16 +1038,25 @@ func (s *Stmt) Exec(f *Frame) {
|
||||
func CompileStmts(scope *Scope, stmts []ast.Stmt) (*Stmt, os.Error) {
|
||||
errors := scanner.NewErrorVector();
|
||||
cc := &compiler{errors};
|
||||
fc := &funcCompiler{cc, nil, false, newCodeBuf(), false};
|
||||
cb := newCodeBuf();
|
||||
fc := &funcCompiler{
|
||||
compiler: cc,
|
||||
fnType: nil,
|
||||
outVarsNamed: false,
|
||||
codeBuf: cb,
|
||||
flow: newFlowBuf(cb),
|
||||
labels: make(map[string] *label),
|
||||
err: false,
|
||||
};
|
||||
bc := &blockCompiler{
|
||||
funcCompiler: fc,
|
||||
block: scope.block,
|
||||
returned: false
|
||||
};
|
||||
out := make([]*Stmt, len(stmts));
|
||||
for i, stmt := range stmts {
|
||||
bc.compileStmt(stmt);
|
||||
}
|
||||
fc.checkLabels();
|
||||
if fc.err {
|
||||
return nil, errors.GetError(scanner.Sorted);
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user