[dev.typeparams] cmd/compile: clean up instantiation and dictionary naming

Separate generation of instantiation and dictionary name generation.

Add code to add subdictionaries to a dictionary. Not quite working
yet, as we need to trigger generation of the subdictionaries for methods.

Change-Id: I0d46053eba695b217630b06ef2f990f6a0b52d83
Reviewed-on: https://go-review.googlesource.com/c/go/+/331209
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>

3 files changed, 68 insertions, 60 deletions

diff --git a/src/cmd/compile/internal/noder/stencil.go b/src/cmd/compile/internal/noder/stencil.go
index 60d56c206f..49781ddc07 100644
--- a/src/cmd/compile/internal/noder/stencil.go
+++ b/src/cmd/compile/internal/noder/stencil.go
@@ -18,7 +18,6 @@ import (
 	"cmd/internal/src"
 	"fmt"
 	"go/constant"
-	"strings"
 )
 
 func assert(p bool) {
@@ -519,7 +518,7 @@ func (g *irgen) getInstantiation(nameNode *ir.Name, targs []*types.Type, isMeth
 			ir.Dump(fmt.Sprintf("\nstenciled %v", st), st)
 		}
 	}
-	return st, g.getDictionary(sym.Name, nameNode, targs)
+	return st, g.getDictionaryValue(nameNode, targs, isMeth)
 }
 
 // Struct containing info needed for doing the substitution as we create the
@@ -1017,31 +1016,21 @@ func deref(t *types.Type) *types.Type {
 	return t
 }
 
-// getDictionary returns the dictionary for the named instantiated function, which
-// is instantiated from generic function or method gf, with the type arguments targs.
-func (g *irgen) getDictionary(name string, gf *ir.Name, targs []*types.Type) ir.Node {
+// getDictionarySym returns the dictionary for the named generic function gf, which
+// is instantiated with the type arguments targs.
+func (g *irgen) getDictionarySym(gf *ir.Name, targs []*types.Type, isMeth bool) *types.Sym {
 	if len(targs) == 0 {
-		base.Fatalf("%s should have type arguments", name)
-	}
-
-	// The dictionary for this instantiation is named after the function
-	// and concrete types it is instantiated with.
-	// TODO: decouple this naming from the instantiation naming. The instantiation
-	// naming will be based on GC shapes, this naming must be fully stenciled.
-	if !strings.HasPrefix(name, ".inst.") {
-		base.Fatalf("%s should start in .inst.", name)
+		base.Fatalf("%s should have type arguments", gf.Sym().Name)
 	}
 
 	info := g.getGfInfo(gf)
 
-	name = ".dict." + name[6:]
-
 	// Get a symbol representing the dictionary.
-	sym := typecheck.Lookup(name)
+	sym := typecheck.MakeDictName(gf.Sym(), targs, isMeth)
 
 	// Initialize the dictionary, if we haven't yet already.
 	if lsym := sym.Linksym(); len(lsym.P) == 0 {
-		infoPrint("Creating dictionary %v\n", name)
+		infoPrint("Creating dictionary %v\n", sym.Name)
 		off := 0
 		// Emit an entry for each targ (concrete type or gcshape).
 		for _, t := range targs {
@@ -1061,8 +1050,8 @@ func (g *irgen) getDictionary(name string, gf *ir.Name, targs []*types.Type) ir.
 			off = objw.SymPtr(lsym, off, s, 0)
 		}
 		// Emit an entry for each subdictionary (after substituting targs)
-		// TODO: actually emit symbol for the subdictionary entry
 		for _, n := range info.subDictCalls {
+			var sym *types.Sym
 			if n.Op() == ir.OCALL {
 				call := n.(*ir.CallExpr)
 				if call.X.Op() == ir.OXDOT {
@@ -1071,8 +1060,7 @@ func (g *irgen) getDictionary(name string, gf *ir.Name, targs []*types.Type) ir.
 					for i, t := range subtargs {
 						s2targs[i] = subst.Typ(t)
 					}
-					sym := typecheck.MakeInstName(ir.MethodSym(call.X.(*ir.SelectorExpr).X.Type(), call.X.(*ir.SelectorExpr).Sel), s2targs, true)
-					infoPrint(" - Subdict .dict.%v\n", sym.Name[6:])
+					sym = typecheck.MakeDictName(ir.MethodSym(call.X.(*ir.SelectorExpr).X.Type(), call.X.(*ir.SelectorExpr).Sel), s2targs, true)
 				} else {
 					inst := n.(*ir.CallExpr).X.(*ir.InstExpr)
 					var nameNode *ir.Name
@@ -1087,11 +1075,10 @@ func (g *irgen) getDictionary(name string, gf *ir.Name, targs []*types.Type) ir.
 					for i, t := range subtargs {
 						subtargs[i] = subst.Typ(t)
 					}
-					sym := typecheck.MakeInstName(nameNode.Sym(), subtargs, isMeth)
+					sym = g.getDictionarySym(nameNode, subtargs, isMeth)
 					// TODO: This can actually be a static
 					// main dictionary, if all of the subtargs
 					// are concrete types (!HasTParam)
-					infoPrint(" - Subdict .dict.%v\n", sym.Name[6:])
 				}
 			} else if n.Op() == ir.OFUNCINST {
 				inst := n.(*ir.InstExpr)
@@ -1100,11 +1087,10 @@ func (g *irgen) getDictionary(name string, gf *ir.Name, targs []*types.Type) ir.
 				for i, t := range subtargs {
 					subtargs[i] = subst.Typ(t)
 				}
-				sym := typecheck.MakeInstName(nameNode.Sym(), subtargs, false)
+				sym = g.getDictionarySym(nameNode, subtargs, false)
 				// TODO: This can actually be a static
 				// main dictionary, if all of the subtargs
 				// are concrete types (!HasTParam)
-				infoPrint(" - Subdict .dict.%v\n", sym.Name[6:])
 			} else if n.Op() == ir.OXDOT {
 				selExpr := n.(*ir.SelectorExpr)
 				subtargs := selExpr.X.Type().RParams()
@@ -1112,13 +1098,26 @@ func (g *irgen) getDictionary(name string, gf *ir.Name, targs []*types.Type) ir.
 				for i, t := range subtargs {
 					s2targs[i] = subst.Typ(t)
 				}
-				sym := typecheck.MakeInstName(ir.MethodSym(selExpr.X.Type(), selExpr.Sel), s2targs, true)
-				infoPrint(" - Subdict .dict.%v\n", sym.Name[6:])
+				sym = typecheck.MakeDictName(ir.MethodSym(selExpr.X.Type(), selExpr.Sel), s2targs, true)
+			}
+			// TODO: handle closure cases that need sub-dictionaries, get rid of conditional
+			if sym != nil {
+				// TODO: uncomment once we're sure all the
+				// subdictionaries are created correctly.
+				// Methods above aren't yet generating dictionaries recursively yet.
+				//off = objw.SymPtr(lsym, off, sym.Linksym(), 0)
+				infoPrint(" - Subdict %v\n", sym.Name)
 			}
-			// TODO: handle closure cases that need sub-dictionaries
 		}
 		objw.Global(lsym, int32(off), obj.DUPOK|obj.RODATA)
+
+		// Add any new, fully instantiated types seen during the substitution to g.instTypeList.
+		g.instTypeList = append(g.instTypeList, subst.InstTypeList...)
 	}
+	return sym
+}
+func (g *irgen) getDictionaryValue(gf *ir.Name, targs []*types.Type, isMeth bool) ir.Node {
+	sym := g.getDictionarySym(gf, targs, isMeth)
 
 	// Make a node referencing the dictionary symbol.
 	n := typecheck.NewName(sym)
diff --git a/src/cmd/compile/internal/reflectdata/reflect.go b/src/cmd/compile/internal/reflectdata/reflect.go
index 351aaab399..27522ca85e 100644
--- a/src/cmd/compile/internal/reflectdata/reflect.go
+++ b/src/cmd/compile/internal/reflectdata/reflect.go
@@ -1869,7 +1869,7 @@ func methodWrapper(rcvr *types.Type, method *types.Field, forItab bool) *obj.LSy
 			} else if !baseOrig.IsPtr() && method.Type.Recv().Type.IsPtr() {
 				baseOrig = types.NewPtr(baseOrig)
 			}
-			args = append(args, getDictionary(".inst."+ir.MethodSym(baseOrig, method.Sym).Name, targs)) // TODO: remove .inst.
+			args = append(args, getDictionary(ir.MethodSym(baseOrig, method.Sym), targs))
 			if indirect {
 				args = append(args, ir.NewStarExpr(base.Pos, dot.X))
 			} else if methodrcvr.IsPtr() && methodrcvr.Elem() == dot.X.Type() {
@@ -1971,28 +1971,16 @@ func MarkUsedIfaceMethod(n *ir.CallExpr) {
 
 // getDictionary returns the dictionary for the given named generic function
 // or method, with the given type arguments.
-// TODO: pass a reference to the generic function instead? We might need
-// that to look up protodictionaries.
-func getDictionary(name string, targs []*types.Type) ir.Node {
+func getDictionary(gf *types.Sym, targs []*types.Type) ir.Node {
 	if len(targs) == 0 {
-		base.Fatalf("%s should have type arguments", name)
+		base.Fatalf("%s should have type arguments", gf.Name)
 	}
 
-	// The dictionary for this instantiation is named after the function
-	// and concrete types it is instantiated with.
-	// TODO: decouple this naming from the instantiation naming. The instantiation
-	// naming will be based on GC shapes, this naming must be fully stenciled.
-	if !strings.HasPrefix(name, ".inst.") {
-		base.Fatalf("%s should start in .inst.", name)
-	}
-	name = ".dict." + name[6:]
-
-	// Get a symbol representing the dictionary.
-	sym := typecheck.Lookup(name)
+	sym := typecheck.MakeDictName(gf, targs, true)
 
 	// Initialize the dictionary, if we haven't yet already.
 	if lsym := sym.Linksym(); len(lsym.P) == 0 {
-		base.Fatalf("Dictionary should have alredy been generated: %v", sym)
+		base.Fatalf("Dictionary should have already been generated: %s.%s", sym.Pkg.Path, sym.Name)
 	}
 
 	// Make a node referencing the dictionary symbol.
diff --git a/src/cmd/compile/internal/typecheck/subr.go b/src/cmd/compile/internal/typecheck/subr.go
index fb6d660db5..db1faaf6f7 100644
--- a/src/cmd/compile/internal/typecheck/subr.go
+++ b/src/cmd/compile/internal/typecheck/subr.go
@@ -888,19 +888,10 @@ func TypesOf(x []ir.Node) []*types.Type {
 	return r
 }
 
-// MakeInstName makes the unique name for a stenciled generic function or method,
-// based on the name of the function fnsym and the targs. It replaces any
-// existing bracket type list in the name. makeInstName asserts that fnsym has
-// brackets in its name if and only if hasBrackets is true.
-//
-// Names of declared generic functions have no brackets originally, so hasBrackets
-// should be false. Names of generic methods already have brackets, since the new
-// type parameter is specified in the generic type of the receiver (e.g. func
-// (func (v *value[T]).set(...) { ... } has the original name (*value[T]).set.
-//
-// The standard naming is something like: 'genFn[int,bool]' for functions and
-// '(*genType[int,bool]).methodName' for methods
-func MakeInstName(fnsym *types.Sym, targs []*types.Type, hasBrackets bool) *types.Sym {
+// makeGenericName returns the name of the generic function instantiated
+// with the given types.
+// name is the name of the generic function or method.
+func makeGenericName(name string, targs []*types.Type, hasBrackets bool) string {
 	b := bytes.NewBufferString("")
 
 	// Determine if the type args are concrete types or new typeparams.
@@ -922,7 +913,6 @@ func MakeInstName(fnsym *types.Sym, targs []*types.Type, hasBrackets bool) *type
 		b.WriteString(".inst.")
 	}
 
-	name := fnsym.Name
 	i := strings.Index(name, "[")
 	assert(hasBrackets == (i >= 0))
 	if i >= 0 {
@@ -952,7 +942,38 @@ func MakeInstName(fnsym *types.Sym, targs []*types.Type, hasBrackets bool) *type
 	if strings.HasPrefix(b.String(), ".inst..inst.") {
 		panic(fmt.Sprintf("multiple .inst. prefix in %s", b.String()))
 	}
-	return fnsym.Pkg.Lookup(b.String())
+	return b.String()
+}
+
+// MakeInstName makes the unique name for a stenciled generic function or method,
+// based on the name of the function fnsym and the targs. It replaces any
+// existing bracket type list in the name. makeInstName asserts that fnsym has
+// brackets in its name if and only if hasBrackets is true.
+//
+// Names of declared generic functions have no brackets originally, so hasBrackets
+// should be false. Names of generic methods already have brackets, since the new
+// type parameter is specified in the generic type of the receiver (e.g. func
+// (func (v *value[T]).set(...) { ... } has the original name (*value[T]).set.
+//
+// The standard naming is something like: 'genFn[int,bool]' for functions and
+// '(*genType[int,bool]).methodName' for methods
+func MakeInstName(gf *types.Sym, targs []*types.Type, hasBrackets bool) *types.Sym {
+	return gf.Pkg.Lookup(makeGenericName(gf.Name, targs, hasBrackets))
+}
+
+func MakeDictName(gf *types.Sym, targs []*types.Type, hasBrackets bool) *types.Sym {
+	for _, targ := range targs {
+		if targ.HasTParam() {
+			fmt.Printf("FUNCTION %s\n", gf.Name)
+			for _, targ := range targs {
+				fmt.Printf("  PARAM %+v\n", targ)
+			}
+			panic("dictionary should always have concrete type args")
+		}
+	}
+	name := makeGenericName(gf.Name, targs, hasBrackets)
+	name = ".dict." + name[6:]
+	return gf.Pkg.Lookup(name)
 }
 
 func assert(p bool) {