diff options
| -rw-r--r-- | tools/go_marshal/gomarshal/generator.go | 4 | ||||
| -rw-r--r-- | tools/go_marshal/gomarshal/generator_interfaces_struct.go | 28 | ||||
| -rw-r--r-- | tools/go_marshal/marshal/marshal.go | 36 |
3 files changed, 34 insertions, 34 deletions
diff --git a/tools/go_marshal/gomarshal/generator.go b/tools/go_marshal/gomarshal/generator.go index 177013dbb..19bcd4e6a 100644 --- a/tools/go_marshal/gomarshal/generator.go +++ b/tools/go_marshal/gomarshal/generator.go @@ -413,13 +413,13 @@ func (g *Generator) Run() error { for _, t := range g.collectMarshallableTypes(a, fsets[i]) { impl := g.generateOne(t, fsets[i]) // Collect Marshallable types referenced by the generated code. - for ref, _ := range impl.ms { + for ref := range impl.ms { ms[ref] = struct{}{} } impls = append(impls, impl) // Collect imports referenced by the generated code and add them to // the list of imports we need to copy to the generated code. - for name, _ := range impl.is { + for name := range impl.is { if !g.imports.markUsed(name) { panic(fmt.Sprintf("Generated code for '%s' referenced a non-existent import with local name '%s'. Either go-marshal needs to add an import to the generated file, or a package in an input source file has a package name differ from the final component of its path, which go-marshal doesn't know how to detect; use an import alias to work around this limitation.", impl.typeName(), name)) } diff --git a/tools/go_marshal/gomarshal/generator_interfaces_struct.go b/tools/go_marshal/gomarshal/generator_interfaces_struct.go index 9cd3c9579..4b9cea08a 100644 --- a/tools/go_marshal/gomarshal/generator_interfaces_struct.go +++ b/tools/go_marshal/gomarshal/generator_interfaces_struct.go @@ -268,6 +268,10 @@ func (g *interfaceGenerator) emitMarshallableForStruct(st *ast.StructType) { g.emit("// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.\n") g.emit("func (%s *%s) MarshalUnsafe(dst []byte) {\n", g.r, g.typeName()) g.inIndent(func() { + fallback := func() { + g.emit("// Type %s doesn't have a packed layout in memory, fallback to MarshalBytes.\n", g.typeName()) + g.emit("%s.MarshalBytes(dst)\n", g.r) + } if thisPacked { g.recordUsedImport("safecopy") g.recordUsedImport("unsafe") @@ -277,16 +281,13 @@ func (g *interfaceGenerator) emitMarshallableForStruct(st *ast.StructType) { g.emit("safecopy.CopyIn(dst, unsafe.Pointer(%s))\n", g.r) }) g.emit("} else {\n") - g.inIndent(func() { - g.emit("%s.MarshalBytes(dst)\n", g.r) - }) + g.inIndent(fallback) g.emit("}\n") } else { g.emit("safecopy.CopyIn(dst, unsafe.Pointer(%s))\n", g.r) } } else { - g.emit("// Type %s doesn't have a packed layout in memory, fallback to MarshalBytes.\n", g.typeName()) - g.emit("%s.MarshalBytes(dst)\n", g.r) + fallback() } }) g.emit("}\n\n") @@ -294,6 +295,10 @@ func (g *interfaceGenerator) emitMarshallableForStruct(st *ast.StructType) { g.emit("// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.\n") g.emit("func (%s *%s) UnmarshalUnsafe(src []byte) {\n", g.r, g.typeName()) g.inIndent(func() { + fallback := func() { + g.emit("// Type %s doesn't have a packed layout in memory, fallback to UnmarshalBytes.\n", g.typeName()) + g.emit("%s.UnmarshalBytes(src)\n", g.r) + } if thisPacked { g.recordUsedImport("safecopy") g.recordUsedImport("unsafe") @@ -303,16 +308,13 @@ func (g *interfaceGenerator) emitMarshallableForStruct(st *ast.StructType) { g.emit("safecopy.CopyOut(unsafe.Pointer(%s), src)\n", g.r) }) g.emit("} else {\n") - g.inIndent(func() { - g.emit("%s.UnmarshalBytes(src)\n", g.r) - }) + g.inIndent(fallback) g.emit("}\n") } else { g.emit("safecopy.CopyOut(unsafe.Pointer(%s), src)\n", g.r) } } else { - g.emit("// Type %s doesn't have a packed layout in memory, fall back to UnmarshalBytes.\n", g.typeName()) - g.emit("%s.UnmarshalBytes(src)\n", g.r) + fallback() } }) g.emit("}\n\n") @@ -463,8 +465,10 @@ func (g *interfaceGenerator) emitMarshallableSliceForStruct(st *ast.StructType, }) g.emit("}\n\n") - g.emit("// Handle any final partial object.\n") - g.emit("if length < size*count && length%size != 0 {\n") + g.emit("// Handle any final partial object. buf is guaranteed to be long enough for the\n") + g.emit("// final element, but may not contain valid data for the entire range. This may\n") + g.emit("// result in unmarshalling zero values for some parts of the object.\n") + g.emit("if length%size != 0 {\n") g.inIndent(func() { g.emit("idx := limit\n") g.emit("dst[idx].UnmarshalBytes(buf[size*idx:size*(idx+1)])\n") diff --git a/tools/go_marshal/marshal/marshal.go b/tools/go_marshal/marshal/marshal.go index cb2166252..85b196f08 100644 --- a/tools/go_marshal/marshal/marshal.go +++ b/tools/go_marshal/marshal/marshal.go @@ -58,18 +58,12 @@ type Marshallable interface { // likely make use of the type of these fields). SizeBytes() int - // MarshalBytes serializes a copy of a type to dst. dst may be smaller than - // SizeBytes(), which results in a part of the struct being marshalled. Note - // that this may have unexpected results for non-packed types, as implicit - // padding needs to be taken into account when reasoning about how much of - // the type is serialized. + // MarshalBytes serializes a copy of a type to dst. + // Precondition: dst must be at least SizeBytes() in length. MarshalBytes(dst []byte) - // UnmarshalBytes deserializes a type from src. src may be smaller than - // SizeBytes(), which results in a partially deserialized struct. Note that - // this may have unexpected results for non-packed types, as implicit - // padding needs to be taken into account when reasoning about how much of - // the type is deserialized. + // UnmarshalBytes deserializes a type from src. + // Precondition: src must be at least SizeBytes() in length. UnmarshalBytes(src []byte) // Packed returns true if the marshalled size of the type is the same as the @@ -89,8 +83,8 @@ type Marshallable interface { // representation to the dst buffer. This is only safe to do when the type // has no implicit padding, see Marshallable.Packed. When Packed would // return false, MarshalUnsafe should fall back to the safer but slower - // MarshalBytes. dst may be smaller than SizeBytes(), see comment for - // MarshalBytes for implications. + // MarshalBytes. + // Precondition: dst must be at least SizeBytes() in length. MarshalUnsafe(dst []byte) // UnmarshalUnsafe deserializes a type by directly copying to the underlying @@ -99,8 +93,8 @@ type Marshallable interface { // This allows much faster unmarshalling of types which have no implicit // padding, see Marshallable.Packed. When Packed would return false, // UnmarshalUnsafe should fall back to the safer but slower unmarshal - // mechanism implemented in UnmarshalBytes. src may be smaller than - // SizeBytes(), see comment for UnmarshalBytes for implications. + // mechanism implemented in UnmarshalBytes. + // Precondition: src must be at least SizeBytes() in length. UnmarshalUnsafe(src []byte) // CopyIn deserializes a Marshallable type from a task's memory. This may @@ -149,14 +143,16 @@ type Marshallable interface { // // Generates four additional functions for marshalling slices of Foos like this: // -// // MarshalUnsafeFooSlice is like Foo.MarshalUnsafe, buf for a []Foo. It's -// // more efficient that repeatedly calling calling Foo.MarshalUnsafe over a -// // []Foo in a loop. +// // MarshalUnsafeFooSlice is like Foo.MarshalUnsafe, buf for a []Foo. It +// // might be more efficient that repeatedly calling Foo.MarshalUnsafe +// // over a []Foo in a loop if the type is Packed. +// // Preconditions: dst must be at least len(src)*Foo.SizeBytes() in length. // func MarshalUnsafeFooSlice(src []Foo, dst []byte) (int, error) { ... } // -// // UnmarshalUnsafeFooSlice is like Foo.UnmarshalUnsafe, buf for a []Foo. It's -// // more efficient that repeatedly calling calling Foo.UnmarshalUnsafe over a -// // []Foo in a loop. +// // UnmarshalUnsafeFooSlice is like Foo.UnmarshalUnsafe, buf for a []Foo. It +// // might be more efficient that repeatedly calling Foo.UnmarshalUnsafe +// // over a []Foo in a loop if the type is Packed. +// // Preconditions: src must be at least len(dst)*Foo.SizeBytes() in length. // func UnmarshalUnsafeFooSlice(dst []Foo, src []byte) (int, error) { ... } // // // CopyFooSliceIn copies in a slice of Foo objects from the task's memory. |