compileFunc: prevent compiling multiple times

cl/compile.go

@@ -169,7 +169,7 @@ func (p *context) compileMethods(pkg llssa.Package, typ types.Type) {
 	for i, n := 0, mthds.Len(); i < n; i++ {
 		mthd := mthds.At(i)
 		if ssaMthd := prog.MethodValue(mthd); ssaMthd != nil {
-			p.compileFunc(pkg, mthd.Obj().Pkg(), ssaMthd, false)
+			p.compileFunc(pkg, mthd.Obj().Pkg(), ssaMthd)
 		}
 	}
 }
@@ -200,48 +200,46 @@ func makeClosureCtx(pkg *types.Package, vars []*ssa.FreeVar) *types.Var {
 	return types.NewParam(token.NoPos, pkg, "__llgo_ctx", t)
 }
 
-func (p *context) compileFunc(pkg llssa.Package, pkgTypes *types.Package, f *ssa.Function, closure bool) llssa.Function {
+func (p *context) compileFunc(pkg llssa.Package, pkgTypes *types.Package, f *ssa.Function) llssa.Function {
+	name, ftype := p.funcName(pkgTypes, f, true)
+	if ftype != goFunc {
+		return nil
+	}
+	fn := pkg.FuncOf(name)
+	if fn != nil && fn.HasBody() {
+		return fn
+	}
+
 	var sig = f.Signature
-	var name string
-	var ftype int
-	var hasCtx bool
-	if closure {
-		name, ftype = funcName(pkgTypes, f), goFunc
+	var hasCtx = len(f.FreeVars) > 0
+	if hasCtx {
 		if debugInstr {
 			log.Println("==> NewClosure", name, "type:", sig)
 		}
-		if vars := f.FreeVars; len(vars) > 0 {
-			ctx := makeClosureCtx(pkgTypes, vars)
-			sig, hasCtx = llssa.FuncAddCtx(ctx, sig), true
-		}
+		ctx := makeClosureCtx(pkgTypes, f.FreeVars)
+		sig = llssa.FuncAddCtx(ctx, sig)
 	} else {
-		name, ftype = p.funcName(pkgTypes, f, true)
-		switch ftype {
-		case ignoredFunc, llgoInstr: // llgo extended instructions
-			return nil
-		}
 		if debugInstr {
 			log.Println("==> NewFunc", name, "type:", sig.Recv(), sig)
 		}
 	}
-	fn := pkg.NewFuncEx(name, sig, llssa.Background(ftype), hasCtx)
+	if fn == nil {
+		fn = pkg.NewFuncEx(name, sig, llssa.Background(ftype), hasCtx)
+	}
+	if nblk := len(f.Blocks); nblk > 0 {
+		fn.MakeBlocks(nblk) // to set fn.HasBody() = true
 		p.inits = append(p.inits, func() {
 			p.fn = fn
 			defer func() {
 				p.fn = nil
 			}()
 			p.phis = nil
-		nblk := len(f.Blocks)
-		if nblk == 0 { // external function
-			return
-		}
 			if debugGoSSA {
 				f.WriteTo(os.Stderr)
 			}
 			if debugInstr {
 				log.Println("==> FuncBody", name)
 			}
-		fn.MakeBlocks(nblk)
 			b := fn.NewBuilder()
 			p.bvals = make(map[ssa.Value]llssa.Expr)
 			for i, block := range f.Blocks {
@@ -251,9 +249,38 @@ func (p *context) compileFunc(pkg llssa.Package, pkgTypes *types.Package, f *ssa
 				phi()
 			}
 		})
+	}
 	return fn
 }
 
+// funcOf returns a function by name and set ftype = goFunc, cFunc, etc.
+// or returns nil and set ftype = llgoCstr, llgoAlloca, llgoUnreachable, etc.
+func (p *context) funcOf(fn *ssa.Function) (ret llssa.Function, ftype int) {
+	pkgTypes := p.ensureLoaded(fn.Pkg.Pkg)
+	pkg := p.pkg
+	name, ftype := p.funcName(pkgTypes, fn, false)
+	if ftype == llgoInstr {
+		switch name {
+		case "cstr":
+			ftype = llgoCstr
+		case "advance":
+			ftype = llgoAdvance
+		case "alloca":
+			ftype = llgoAlloca
+		case "allocaCStr":
+			ftype = llgoAllocaCStr
+		case "unreachable":
+			ftype = llgoUnreachable
+		default:
+			panic("unknown llgo instruction: " + name)
+		}
+	} else if ret = pkg.FuncOf(name); ret == nil && len(fn.FreeVars) == 0 {
+		sig := fn.Signature
+		ret = pkg.NewFuncEx(name, sig, llssa.Background(ftype), false)
+	}
+	return
+}
+
 func (p *context) compileBlock(b llssa.Builder, block *ssa.BasicBlock, doInit bool) llssa.BasicBlock {
 	ret := p.fn.Block(block.Index)
 	b.SetBlock(ret)
@@ -618,14 +645,11 @@ func (p *context) compileValue(b llssa.Builder, v ssa.Value) llssa.Expr {
 			}
 		}
 	case *ssa.Function:
-		if v.Blocks != nil {
-			fn := p.compileFunc(p.pkg, p.goTyps, v, true)
+		if v.Pkg == p.goPkg { // function in this package
+			fn := p.compileFunc(p.pkg, p.goTyps, v)
 			return fn.Expr
 		}
-		fn, ftype := p.funcOf(v)
-		if ftype >= llgoInstrBase {
-			panic("can't use llgo instruction as a value")
-		}
+		fn, _ := p.funcOf(v)
 		return fn.Expr
 	case *ssa.Global:
 		g := p.varOf(v)
@@ -718,7 +742,7 @@ func NewPackage(prog llssa.Program, pkg *ssa.Package, files []*ast.File) (ret ll
 				// Do not try to build generic (non-instantiated) functions.
 				continue
 			}
-			ctx.compileFunc(ret, member.Pkg.Pkg, member, false)
+			ctx.compileFunc(ret, member.Pkg.Pkg, member)
 		case *ssa.Type:
 			ctx.compileType(ret, member)
 		case *ssa.Global:

cl/compile_test.go

@@ -29,7 +29,7 @@ func testCompile(t *testing.T, src, expected string) {
 }
 
 func TestFromTestrt(t *testing.T) {
-	cltest.FromDir(t, "intgen", "./_testrt", true)
+	cltest.FromDir(t, "", "./_testrt", true)
 }
 
 func TestFromTestdata(t *testing.T) {

cl/import.go

@@ -234,34 +234,6 @@ func (p *context) varName(pkg *types.Package, v *ssa.Global) (vName string, vtyp
 	return name, goVar
 }
 
-// funcOf returns a function by name and set ftype = goFunc, cFunc, etc.
-// or returns nil and set ftype = llgoCstr, llgoAlloca, llgoUnreachable, etc.
-func (p *context) funcOf(fn *ssa.Function) (ret llssa.Function, ftype int) {
-	pkgTypes := p.ensureLoaded(fn.Pkg.Pkg)
-	pkg := p.pkg
-	name, ftype := p.funcName(pkgTypes, fn, false)
-	if ftype == llgoInstr {
-		switch name {
-		case "cstr":
-			ftype = llgoCstr
-		case "advance":
-			ftype = llgoAdvance
-		case "alloca":
-			ftype = llgoAlloca
-		case "allocaCStr":
-			ftype = llgoAllocaCStr
-		case "unreachable":
-			ftype = llgoUnreachable
-		default:
-			panic("unknown llgo instruction: " + name)
-		}
-	} else if ret = pkg.FuncOf(name); ret == nil {
-		sig := fn.Signature
-		ret = pkg.NewFunc(name, sig, llssa.Background(ftype))
-	}
-	return
-}
-
 func (p *context) varOf(v *ssa.Global) (ret llssa.Global) {
 	pkgTypes := p.ensureLoaded(v.Pkg.Pkg)
 	pkg := p.pkg

ssa/decl.go

@@ -184,6 +184,11 @@ func (p Function) NewBuilder() Builder {
 	return &aBuilder{b, p, prog}
 }
 
+// HasBody reports whether the function has a body.
+func (p Function) HasBody() bool {
+	return len(p.blks) > 0
+}
+
 // MakeBody creates nblk basic blocks for the function, and creates
 // a new Builder associated to #0 block.
 func (p Function) MakeBody(nblk int) Builder {