[dev.cmdgo] all: merge master (5e6a7e9) into dev.cmdgo

Merge List:

+ 2021-08-26 5e6a7e9b86 embed: remove reference to global variables in docs
+ 2021-08-26 166b691b65 cmd/compile/internal/types2: remove need for instance (struct)
+ 2021-08-26 d6bdae33e9 cmd/compile/internal/types2: address some TODOs (cleanup)
+ 2021-08-26 770df2e18d crypto/tls: fix typo in PreferServerCipherSuites comment
+ 2021-08-26 a6ff433d6a cmd/go: pass -gcflags after other flags generated by the go command
+ 2021-08-25 4f2620285d cmd/compile/internal/types2: fix type set printing and add test
+ 2021-08-25 0ac64f6d70 cmd/compile/internal/types2: rename IsMethodSet to IsConstraint (cleanup)
+ 2021-08-25 4068fb6c21 cmd/compile: always accept 1.18 syntax but complain if not 1.18
+ 2021-08-25 bf0bc4122f go/types, types2: don't re-evaluate context string for each function argument (optimization)
+ 2021-08-25 4158e88f64 cmd/compile/internal/syntax: fix position of type parameter field
+ 2021-08-25 647bef6c59 go/types: implement NewTypeList and use it instead of composite literals
+ 2021-08-25 6cf1d5d0fa cmd/compile: generic SSA rules for simplifying 2 and 3 operand integer arithmetic expressions
+ 2021-08-25 5baf60d472 bytes, strings: optimize Trim for single byte cutsets
+ 2021-08-25 3d667671ad cmd/compile: fix function contains no TParam in generic function
+ 2021-08-25 4f2ebfe34b cmd/compile: allow embed into any byte slice type
+ 2021-08-25 d2f002cb39 time/format: avoid growslice in time.String()/time.GoString()
+ 2021-08-25 08d4cc20ca cmd/compile: fix stencil call expression.
+ 2021-08-25 099b819085 cmd/compile: fix CheckSize() calculation for -G=3 and stencils
+ 2021-08-25 e1fcf8857e test: add test that caused gofrontend compiler crash
+ 2021-08-25 d37b8dedf7 test: add test case that gofrontend miscompiled
+ 2021-08-25 41b99dab0f os/user: don't skip TestLookupGroup if supported
+ 2021-08-25 de1c934b97 cmd/compile: fix checkptr false positive for (*[Big]T)(ptr)[:n:n] pattern
+ 2021-08-24 54cdef1f10 reflect: add MapIter.SetKey and MapIter.SetValue
+ 2021-08-24 5d863f89fe cmd/compile: simplify bad conversion check

Change-Id: I29ab927f0e47f44d82f9307c642900f75f4f678f

1 files changed, 10 insertions, 14 deletions

diff --git a/src/cmd/compile/internal/noder/types.go b/src/cmd/compile/internal/noder/types.go
index 541ed68ef3..c9f7c2bbe4 100644
--- a/src/cmd/compile/internal/noder/types.go
+++ b/src/cmd/compile/internal/noder/types.go
@@ -30,21 +30,11 @@ func (g *irgen) pkg(pkg *types2.Package) *types.Pkg {
 // typ converts a types2.Type to a types.Type, including caching of previously
 // translated types.
 func (g *irgen) typ(typ types2.Type) *types.Type {
+	// Defer the CheckSize calls until we have fully-defined a
+	// (possibly-recursive) top-level type.
+	types.DeferCheckSize()
 	res := g.typ1(typ)
-
-	// Calculate the size for all concrete types seen by the frontend. The old
-	// typechecker calls CheckSize() a lot, and we want to eliminate calling
-	// it eventually, so we should do it here instead. We only call it for
-	// top-level types (i.e. we do it here rather in typ1), to make sure that
-	// recursive types have been fully constructed before we call CheckSize.
-	if res != nil && !res.IsUntyped() && !res.IsFuncArgStruct() && !res.HasTParam() {
-		types.CheckSize(res)
-		if res.IsPtr() {
-			// Pointers always have their size set, even though their element
-			// may not have its size set.
-			types.CheckSize(res.Elem())
-		}
-	}
+	types.ResumeCheckSize()
 	return res
 }
 
@@ -59,6 +49,12 @@ func (g *irgen) typ1(typ types2.Type) *types.Type {
 	res, ok := g.typs[typ]
 	if !ok {
 		res = g.typ0(typ)
+		// Calculate the size for all concrete types seen by the frontend.
+		// This is the replacement for the CheckSize() calls in the types1
+		// typechecker. These will be deferred until the top-level g.typ().
+		if res != nil && !res.IsUntyped() && !res.IsFuncArgStruct() && !res.HasTParam() {
+			types.CheckSize(res)
+		}
 		g.typs[typ] = res
 	}
 	return res