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binary: adds custom section decoder (#877)

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Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>
This commit is contained in:
Takeshi Yoneda
2022-12-01 20:08:40 +09:00
committed by GitHub
parent 4adfa48eb0
commit 40e698e068
8 changed files with 99 additions and 18 deletions
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4
internal/integration_test/bench/codec_test.go
View File

@@ -89,7 +89,7 @@ func newExample() *wasm.Module {
func TestExampleUpToDate(t *testing.T) {
t.Run("binary.DecodeModule", func(t *testing.T) {
m, err := binary.DecodeModule(exampleWasm, api.CoreFeaturesV2, wasm.MemoryLimitPages, false)
m, err := binary.DecodeModule(exampleWasm, api.CoreFeaturesV2, wasm.MemoryLimitPages, false, false)
require.NoError(t, err)
require.Equal(t, example, m)
})
@@ -116,7 +116,7 @@ func BenchmarkCodec(b *testing.B) {
b.Run("binary.DecodeModule", func(b *testing.B) {
b.ReportAllocs()
for i := 0; i < b.N; i++ {
if _, err := binary.DecodeModule(exampleWasm, api.CoreFeaturesV2, wasm.MemoryLimitPages, false); err != nil {
if _, err := binary.DecodeModule(exampleWasm, api.CoreFeaturesV2, wasm.MemoryLimitPages, false, false); err != nil {
b.Fatal(err)
}
}

8
internal/integration_test/spectest/spectest.go
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@@ -325,7 +325,7 @@ var spectestWasm []byte
// See https://github.com/WebAssembly/spec/blob/wg-1.0/test/core/imports.wast
// See https://github.com/WebAssembly/spec/blob/wg-1.0/interpreter/script/js.ml#L13-L25
func addSpectestModule(t *testing.T, ctx context.Context, s *wasm.Store, ns *wasm.Namespace, enabledFeatures api.CoreFeatures) {
mod, err := binaryformat.DecodeModule(spectestWasm, api.CoreFeaturesV2, wasm.MemoryLimitPages, false)
mod, err := binaryformat.DecodeModule(spectestWasm, api.CoreFeaturesV2, wasm.MemoryLimitPages, false, false)
require.NoError(t, err)
// (global (export "global_i32") i32 (i32.const 666))
@@ -420,7 +420,7 @@ func Run(t *testing.T, testDataFS embed.FS, ctx context.Context, newEngine func(
case "module":
buf, err := testDataFS.ReadFile(testdataPath(c.Filename))
require.NoError(t, err, msg)
mod, err := binaryformat.DecodeModule(buf, enabledFeatures, wasm.MemoryLimitPages, false)
mod, err := binaryformat.DecodeModule(buf, enabledFeatures, wasm.MemoryLimitPages, false, false)
require.NoError(t, err, msg)
require.NoError(t, mod.Validate(enabledFeatures))
mod.AssignModuleID(buf)
@@ -561,7 +561,7 @@ func Run(t *testing.T, testDataFS embed.FS, ctx context.Context, newEngine func(
//
// In practice, such a module instance can be used for invoking functions without any issue. In addition, we have to
// retain functions after the expected "instantiation" failure, so in wazero we choose to not raise error in that case.
mod, err := binaryformat.DecodeModule(buf, s.EnabledFeatures, wasm.MemoryLimitPages, false)
mod, err := binaryformat.DecodeModule(buf, s.EnabledFeatures, wasm.MemoryLimitPages, false, false)
require.NoError(t, err, msg)
err = mod.Validate(s.EnabledFeatures)
@@ -590,7 +590,7 @@ func Run(t *testing.T, testDataFS embed.FS, ctx context.Context, newEngine func(
}
func requireInstantiationError(t *testing.T, ctx context.Context, s *wasm.Store, ns *wasm.Namespace, buf []byte, msg string) {
mod, err := binaryformat.DecodeModule(buf, s.EnabledFeatures, wasm.MemoryLimitPages, false)
mod, err := binaryformat.DecodeModule(buf, s.EnabledFeatures, wasm.MemoryLimitPages, false, false)
if err != nil {
return
}

22
internal/wasm/binary/custom.go Normal file
View File

@@ -0,0 +1,22 @@
package binary
import (
"bytes"
"github.com/tetratelabs/wazero/internal/wasm"
)
// decodeCustomSection deserializes the data **not** associated with the "name" key in SectionIDCustom.
//
// See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#custom-section%E2%91%A0
func decodeCustomSection(r *bytes.Reader, name string, limit uint64) (result *wasm.CustomSection, err error) {
buf := make([]byte, limit)
_, err = r.Read(buf)
result = &wasm.CustomSection{
Name: name,
Data: buf,
}
return
}

12
internal/wasm/binary/decoder.go
View File

@@ -17,7 +17,8 @@ func DecodeModule(
binary []byte,
enabledFeatures api.CoreFeatures,
memoryLimitPages uint32,
memoryCapacityFromMax bool,
memoryCapacityFromMax,
storeCustomSections bool,
) (*wasm.Module, error) {
r := bytes.NewReader(binary)
@@ -66,17 +67,22 @@ func DecodeModule(
break
}
// Now, either decode the NameSection or skip an unsupported one
// Now, either decode the NameSection or CustomSection
limit := sectionSize - nameSize
if name == "name" {
m.NameSection, err = decodeNameSection(r, uint64(limit))
} else if storeCustomSections {
custom, err := decodeCustomSection(r, name, uint64(limit))
if err != nil {
return nil, fmt.Errorf("failed to read custom section name[%s]: %w", name, err)
}
m.CustomSections = append(m.CustomSections, custom)
} else {
// Note: Not Seek because it doesn't err when given an offset past EOF. Rather, it leads to undefined state.
if _, err = io.CopyN(io.Discard, r, int64(limit)); err != nil {
return nil, fmt.Errorf("failed to skip name[%s]: %w", name, err)
}
}
case wasm.SectionIDType:
m.TypeSection, err = decodeTypeSection(enabledFeatures, r)
case wasm.SectionIDImport:

51
internal/wasm/binary/decoder_test.go
View File

@@ -81,7 +81,7 @@ func TestDecodeModule(t *testing.T) {
tc := tt
t.Run(tc.name, func(t *testing.T) {
m, e := DecodeModule(EncodeModule(tc.input), api.CoreFeaturesV1, wasm.MemoryLimitPages, false)
m, e := DecodeModule(EncodeModule(tc.input), api.CoreFeaturesV1, wasm.MemoryLimitPages, false, false)
require.NoError(t, e)
require.Equal(t, tc.input, m)
})
@@ -92,11 +92,28 @@ func TestDecodeModule(t *testing.T) {
wasm.SectionIDCustom, 0xf, // 15 bytes in this section
0x04, 'm', 'e', 'm', 'e',
1, 2, 3, 4, 5, 6, 7, 8, 9, 0)
m, e := DecodeModule(input, api.CoreFeaturesV1, wasm.MemoryLimitPages, false)
m, e := DecodeModule(input, api.CoreFeaturesV1, wasm.MemoryLimitPages, false, false)
require.NoError(t, e)
require.Equal(t, &wasm.Module{}, m)
})
t.Run("reads custom sections", func(t *testing.T) {
input := append(append(Magic, version...),
wasm.SectionIDCustom, 0xf, // 15 bytes in this section
0x04, 'm', 'e', 'm', 'e',
1, 2, 3, 4, 5, 6, 7, 8, 9, 0)
m, e := DecodeModule(input, api.CoreFeaturesV2, wasm.MemoryLimitPages, false, true)
require.NoError(t, e)
require.Equal(t, &wasm.Module{
CustomSections: []*wasm.CustomSection{
{
Name: "meme",
Data: []byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 0},
},
},
}, m)
})
t.Run("skips custom section, but not name", func(t *testing.T) {
input := append(append(Magic, version...),
wasm.SectionIDCustom, 0xf, // 15 bytes in this section
@@ -107,14 +124,38 @@ func TestDecodeModule(t *testing.T) {
subsectionIDModuleName, 0x07, // 7 bytes in this subsection
0x06, // the Module name simple is 6 bytes long
's', 'i', 'm', 'p', 'l', 'e')
m, e := DecodeModule(input, api.CoreFeaturesV1, wasm.MemoryLimitPages, false)
m, e := DecodeModule(input, api.CoreFeaturesV1, wasm.MemoryLimitPages, false, false)
require.NoError(t, e)
require.Equal(t, &wasm.Module{NameSection: &wasm.NameSection{ModuleName: "simple"}}, m)
})
t.Run("read custom sections and name separately", func(t *testing.T) {
input := append(append(Magic, version...),
wasm.SectionIDCustom, 0xf, // 15 bytes in this section
0x04, 'm', 'e', 'm', 'e',
1, 2, 3, 4, 5, 6, 7, 8, 9, 0,
wasm.SectionIDCustom, 0x0e, // 14 bytes in this section
0x04, 'n', 'a', 'm', 'e',
subsectionIDModuleName, 0x07, // 7 bytes in this subsection
0x06, // the Module name simple is 6 bytes long
's', 'i', 'm', 'p', 'l', 'e')
m, e := DecodeModule(input, api.CoreFeaturesV2, wasm.MemoryLimitPages, false, true)
require.NoError(t, e)
require.Equal(t, &wasm.Module{
NameSection: &wasm.NameSection{ModuleName: "simple"},
CustomSections: []*wasm.CustomSection{
{
Name: "meme",
Data: []byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 0},
},
},
}, m)
})
t.Run("data count section disabled", func(t *testing.T) {
input := append(append(Magic, version...),
wasm.SectionIDDataCount, 1, 0)
_, e := DecodeModule(input, api.CoreFeaturesV1, wasm.MemoryLimitPages, false)
_, e := DecodeModule(input, api.CoreFeaturesV1, wasm.MemoryLimitPages, false, false)
require.EqualError(t, e, `data count section not supported as feature "bulk-memory-operations" is disabled`)
})
}
@@ -164,7 +205,7 @@ func TestDecodeModule_Errors(t *testing.T) {
tc := tt
t.Run(tc.name, func(t *testing.T) {
_, e := DecodeModule(tc.input, api.CoreFeaturesV1, wasm.MemoryLimitPages, false)
_, e := DecodeModule(tc.input, api.CoreFeaturesV1, wasm.MemoryLimitPages, false, false)
require.EqualError(t, e, tc.expectedErr)
})
}

7
internal/wasm/counts.go
View File

@@ -41,16 +41,17 @@ func (m *Module) importCount(et ExternType) (res uint32) {
//
// For example...
// * SectionIDType returns the count of FunctionType
// * SectionIDCustom returns one if the NameSection is present
// * SectionIDCustom returns the count of CustomSections plus one if NameSection is present
// * SectionIDHostFunction returns the count of HostFunctionSection
// * SectionIDExport returns the count of unique export names
func (m *Module) SectionElementCount(sectionID SectionID) uint32 { // element as in vector elements!
switch sectionID {
case SectionIDCustom:
numCustomSections := uint32(len(m.CustomSections))
if m.NameSection != nil {
return 1
numCustomSections++
}
return 0
return numCustomSections
case SectionIDType:
return uint32(len(m.TypeSection))
case SectionIDImport:

11
internal/wasm/module.go
View File

@@ -154,6 +154,11 @@ type Module struct {
// See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#custom-section%E2%91%A0
NameSection *NameSection
// CustomSections are set when the SectionIDCustom other than "name" were successfully decoded from the binary format.
//
// See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#custom-section%E2%91%A0
CustomSections []*CustomSection
// validatedActiveElementSegments are built on Validate when
// SectionIDElement is non-empty and all inputs are valid.
//
@@ -877,6 +882,12 @@ type NameSection struct {
LocalNames IndirectNameMap
}
// CustomSection contains the name and raw data of a custom section.
type CustomSection struct {
Name string
Data []byte
}
// NameMap associates an index with any associated names.
//
// Note: Often the index namespace bridges multiple sections. For example, the function index namespace starts with any

2
runtime.go
View File

@@ -172,7 +172,7 @@ func (r *runtime) CompileModule(ctx context.Context, binary []byte) (CompiledMod
return nil, errors.New("invalid binary")
}
internal, err := binaryformat.DecodeModule(binary, r.enabledFeatures, r.memoryLimitPages, r.memoryCapacityFromMax)
internal, err := binaryformat.DecodeModule(binary, r.enabledFeatures, r.memoryLimitPages, r.memoryCapacityFromMax, false)
if err != nil {
return nil, err
} else if err = internal.Validate(r.enabledFeatures); err != nil {