diff options
author | Rahat Mahmood <rahat@google.com> | 2020-09-29 12:32:32 -0700 |
---|---|---|
committer | gVisor bot <gvisor-bot@google.com> | 2020-09-29 12:34:30 -0700 |
commit | 44c7d550747a61baa6a85643de439fa45c2b9633 (patch) | |
tree | e64c757ab24cc12c3180f10651c460f0a026a513 /tools/go_marshal | |
parent | 7d64bc1fdf538869de5964475110a69580b481ad (diff) |
Support embedded fields in go-marshal.
PiperOrigin-RevId: 334437990
Diffstat (limited to 'tools/go_marshal')
-rw-r--r-- | tools/go_marshal/README.md | 15 | ||||
-rw-r--r-- | tools/go_marshal/gomarshal/generator_interfaces.go | 4 | ||||
-rw-r--r-- | tools/go_marshal/gomarshal/generator_interfaces_struct.go | 12 | ||||
-rw-r--r-- | tools/go_marshal/gomarshal/util.go | 20 | ||||
-rw-r--r-- | tools/go_marshal/test/test.go | 24 |
5 files changed, 60 insertions, 15 deletions
diff --git a/tools/go_marshal/README.md b/tools/go_marshal/README.md index 75e5c7888..d8045c295 100644 --- a/tools/go_marshal/README.md +++ b/tools/go_marshal/README.md @@ -113,3 +113,18 @@ The following are some guidelines for modifying the `go_marshal` tool: - No runtime reflection in the code generated for the marshallable interface. The entire point of the tool is to avoid runtime reflection. The generated tests may use reflection. + +## Debugging + +To enable debugging output from the go-marshal tool, use one of the following +options, depending on how go-marshal is being invoked: + +- Pass `--define gomarshal=verbose` to the bazel command. Note that this can + generate a lot of output depending on what's being compiled, as this will + enable debugging for all packages built by the command. + +- Set `marshal_debug = True` on the top-level `go_library` BUILD rule. + +- Set `debug = True` on the `go_marshal` BUILD rule. + +- Pass `-debug` to the go-marshal tool invocation. diff --git a/tools/go_marshal/gomarshal/generator_interfaces.go b/tools/go_marshal/gomarshal/generator_interfaces.go index cf76b5241..36447b86b 100644 --- a/tools/go_marshal/gomarshal/generator_interfaces.go +++ b/tools/go_marshal/gomarshal/generator_interfaces.go @@ -43,8 +43,8 @@ type interfaceGenerator struct { // of t's interfaces. ms map[string]struct{} - // as records embedded fields in t that are potentially not packed. The key - // is the accessor for the field. + // as records fields in t that are potentially not packed. The key is the + // accessor for the field. as map[string]struct{} } diff --git a/tools/go_marshal/gomarshal/generator_interfaces_struct.go b/tools/go_marshal/gomarshal/generator_interfaces_struct.go index 456662fab..fe76d3785 100644 --- a/tools/go_marshal/gomarshal/generator_interfaces_struct.go +++ b/tools/go_marshal/gomarshal/generator_interfaces_struct.go @@ -51,12 +51,6 @@ func (g *interfaceGenerator) areFieldsPackedExpression() (string, bool) { // later. func (g *interfaceGenerator) validateStruct(ts *ast.TypeSpec, st *ast.StructType) { forEachStructField(st, func(f *ast.Field) { - if len(f.Names) == 0 { - g.abortAt(f.Pos(), "Cannot marshal structs with embedded fields, give the field a name; use '_' for anonymous fields such as padding fields") - } - }) - - forEachStructField(st, func(f *ast.Field) { fieldDispatcher{ primitive: func(_, t *ast.Ident) { g.validatePrimitiveNewtype(t) @@ -101,7 +95,7 @@ func (g *interfaceGenerator) emitMarshallableForStruct(st *ast.StructType) { var dynamicSizeTerms []string forEachStructField(st, fieldDispatcher{ - primitive: func(n, t *ast.Ident) { + primitive: func(_, t *ast.Ident) { if size, dynamic := g.scalarSize(t); !dynamic { primitiveSize += size } else { @@ -109,13 +103,13 @@ func (g *interfaceGenerator) emitMarshallableForStruct(st *ast.StructType) { dynamicSizeTerms = append(dynamicSizeTerms, fmt.Sprintf("(*%s)(nil).SizeBytes()", t.Name)) } }, - selector: func(n, tX, tSel *ast.Ident) { + selector: func(_, tX, tSel *ast.Ident) { tName := fmt.Sprintf("%s.%s", tX.Name, tSel.Name) g.recordUsedImport(tX.Name) g.recordUsedMarshallable(tName) dynamicSizeTerms = append(dynamicSizeTerms, fmt.Sprintf("(*%s)(nil).SizeBytes()", tName)) }, - array: func(n *ast.Ident, a *ast.ArrayType, t *ast.Ident) { + array: func(_ *ast.Ident, a *ast.ArrayType, t *ast.Ident) { lenExpr := g.arrayLenExpr(a) if size, dynamic := g.scalarSize(t); !dynamic { dynamicSizeTerms = append(dynamicSizeTerms, fmt.Sprintf("%d*%s", size, lenExpr)) diff --git a/tools/go_marshal/gomarshal/util.go b/tools/go_marshal/gomarshal/util.go index d94314302..6a42691cd 100644 --- a/tools/go_marshal/gomarshal/util.go +++ b/tools/go_marshal/gomarshal/util.go @@ -79,7 +79,7 @@ type fieldDispatcher struct { } // Precondition: All dispatch callbacks that will be invoked must be -// provided. Embedded fields are not allowed, len(f.Names) >= 1. +// provided. func (fd fieldDispatcher) dispatch(f *ast.Field) { // Each field declaration may actually be multiple declarations of the same // type. For example, consider: @@ -88,12 +88,24 @@ func (fd fieldDispatcher) dispatch(f *ast.Field) { // x, y, z int // } // - // We invoke the call-backs once per such instance. Embedded fields are not - // allowed, and results in a panic. + // We invoke the call-backs once per such instance. + + // Handle embedded fields. Embedded fields have no names, but can be + // referenced by the type name. if len(f.Names) < 1 { - panic("Precondition not met: attempted to dispatch on embedded field") + switch v := f.Type.(type) { + case *ast.Ident: + fd.primitive(v, v) + case *ast.SelectorExpr: + fd.selector(v.Sel, v.X.(*ast.Ident), v.Sel) + default: + // Note: Arrays can't be embedded, which is handled here. + panic(fmt.Sprintf("Attempted to dispatch on embedded field of unsupported kind: %#v", f.Type)) + } + return } + // Non-embedded field. for _, name := range f.Names { switch v := f.Type.(type) { case *ast.Ident: diff --git a/tools/go_marshal/test/test.go b/tools/go_marshal/test/test.go index f75ca1b7f..d9e9f341b 100644 --- a/tools/go_marshal/test/test.go +++ b/tools/go_marshal/test/test.go @@ -174,3 +174,27 @@ type Type9 struct { x int64 y [sizeA]int32 } + +// Type10Embed is a test data type which is be embedded into another type. +// +// +marshal +type Type10Embed struct { + x int64 +} + +// Type10 is a test data type which contains an embedded struct. +// +// +marshal +type Type10 struct { + Type10Embed + y int64 +} + +// Type11 is a test data type which contains an embedded struct from an external +// package. +// +// +marshal +type Type11 struct { + ex.External + y int64 +} |