cmd/compile/internal/gc: cleanup FuncDecl noding

Collapse funcHeader into funcDecl.
Initialize pragmas earlier.
Move empty / non-empty body errors closer to fun.Body handling.
Switch some yyerror to yyerrorl.

Change-Id: I71fb7a3c0b77d656af560e4d88da894ba6183826
Reviewed-on: https://go-review.googlesource.com/38475
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

diff --git a/src/cmd/compile/internal/gc/noder.go b/src/cmd/compile/internal/gc/noder.go
index d20360381636cedcd4a75b2064e6380fc2f7efc2..0bddd6af394c8631f98d463f2f866cb10b5b8472 100644 (file)
--- a/src/cmd/compile/internal/gc/noder.go
+++ b/src/cmd/compile/internal/gc/noder.go
@@ -290,63 +290,21 @@ func (p *noder) declName(name *syntax.Name) *Node {
 }
 
 func (p *noder) funcDecl(fun *syntax.FuncDecl) *Node {
-       f := p.funcHeader(fun)
-       if f == nil {
-               return nil
-       }
-
-       var body []*Node
-       if fun.Body != nil {
-               body = p.stmts(fun.Body.List)
-               if body == nil {
-                       body = []*Node{p.nod(fun, OEMPTY, nil, nil)}
-               }
-       }
-
-       pragma := fun.Pragma
-
-       f.Nbody.Set(body)
-       f.SetNoescape(pragma&Noescape != 0)
-       if f.Noescape() && len(body) != 0 {
-               yyerror("can only use //go:noescape with external func implementations")
-       }
-       if pragma&Systemstack != 0 && pragma&Nosplit != 0 {
-               yyerror("go:nosplit and go:systemstack cannot be combined")
-       }
-       f.Func.Pragma = pragma
-       var rbrace src.Pos
-       if fun.Body != nil {
-               rbrace = fun.Body.Rbrace
-       }
-       lineno = Ctxt.PosTable.XPos(rbrace)
-       f.Func.Endlineno = lineno
-
-       funcbody(f)
-
-       if f.Nbody.Len() == 0 && (pure_go || strings.HasPrefix(f.Func.Nname.Sym.Name, "init.")) {
-               yyerrorl(f.Pos, "missing function body for %q", f.Func.Nname.Sym.Name)
-       }
-
-       return f
-}
-
-func (p *noder) funcHeader(fun *syntax.FuncDecl) *Node {
        name := p.name(fun.Name)
        t := p.signature(fun.Recv, fun.Type)
        f := p.nod(fun, ODCLFUNC, nil, nil)
 
        if fun.Recv == nil {
-               // FunctionName Signature
                if name.Name == "init" {
                        name = renameinit()
                        if t.List.Len() > 0 || t.Rlist.Len() > 0 {
-                               yyerror("func init must have no arguments and no return values")
+                               yyerrorl(f.Pos, "func init must have no arguments and no return values")
                        }
                }
 
                if localpkg.Name == "main" && name.Name == "main" {
                        if t.List.Len() > 0 || t.Rlist.Len() > 0 {
-                               yyerror("func main must have no arguments and no return values")
+                               yyerrorl(f.Pos, "func main must have no arguments and no return values")
                        }
                }
        } else {
@@ -356,13 +314,42 @@ func (p *noder) funcHeader(fun *syntax.FuncDecl) *Node {
 
        f.Func.Nname = newfuncname(name)
        f.Func.Nname.Name.Defn = f
-       f.Func.Nname.Name.Param.Ntype = t // TODO: check if nname already has an ntype
+       f.Func.Nname.Name.Param.Ntype = t
+
+       pragma := fun.Pragma
+       f.Func.Pragma = fun.Pragma
+       f.SetNoescape(pragma&Noescape != 0)
+       if pragma&Systemstack != 0 && pragma&Nosplit != 0 {
+               yyerrorl(f.Pos, "go:nosplit and go:systemstack cannot be combined")
+       }
 
        if fun.Recv == nil {
                declare(f.Func.Nname, PFUNC)
        }
 
        funchdr(f)
+
+       if fun.Body != nil {
+               if f.Noescape() {
+                       yyerrorl(f.Pos, "can only use //go:noescape with external func implementations")
+               }
+
+               body := p.stmts(fun.Body.List)
+               if body == nil {
+                       body = []*Node{p.nod(fun, OEMPTY, nil, nil)}
+               }
+               f.Nbody.Set(body)
+
+               lineno = Ctxt.PosTable.XPos(fun.Body.Rbrace)
+               f.Func.Endlineno = lineno
+       } else {
+               if pure_go || strings.HasPrefix(f.Func.Nname.Sym.Name, "init.") {
+                       yyerrorl(f.Pos, "missing function body for %q", f.Func.Nname.Sym.Name)
+               }
+       }
+
+       funcbody(f)
+
        return f
 }