diff options
Diffstat (limited to 'vendor/github.com/tetratelabs/wazero/internal/wasm/binary/value.go')
-rw-r--r-- | vendor/github.com/tetratelabs/wazero/internal/wasm/binary/value.go | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/vendor/github.com/tetratelabs/wazero/internal/wasm/binary/value.go b/vendor/github.com/tetratelabs/wazero/internal/wasm/binary/value.go new file mode 100644 index 000000000..755ee5ea3 --- /dev/null +++ b/vendor/github.com/tetratelabs/wazero/internal/wasm/binary/value.go @@ -0,0 +1,60 @@ +package binary + +import ( + "bytes" + "fmt" + "io" + "unicode/utf8" + "unsafe" + + "github.com/tetratelabs/wazero/internal/leb128" + "github.com/tetratelabs/wazero/internal/wasm" +) + +func decodeValueTypes(r *bytes.Reader, num uint32) ([]wasm.ValueType, error) { + if num == 0 { + return nil, nil + } + + ret := make([]wasm.ValueType, num) + _, err := io.ReadFull(r, ret) + if err != nil { + return nil, err + } + + for _, v := range ret { + switch v { + case wasm.ValueTypeI32, wasm.ValueTypeF32, wasm.ValueTypeI64, wasm.ValueTypeF64, + wasm.ValueTypeExternref, wasm.ValueTypeFuncref, wasm.ValueTypeV128: + default: + return nil, fmt.Errorf("invalid value type: %d", v) + } + } + return ret, nil +} + +// decodeUTF8 decodes a size prefixed string from the reader, returning it and the count of bytes read. +// contextFormat and contextArgs apply an error format when present +func decodeUTF8(r *bytes.Reader, contextFormat string, contextArgs ...interface{}) (string, uint32, error) { + size, sizeOfSize, err := leb128.DecodeUint32(r) + if err != nil { + return "", 0, fmt.Errorf("failed to read %s size: %w", fmt.Sprintf(contextFormat, contextArgs...), err) + } + + if size == 0 { + return "", uint32(sizeOfSize), nil + } + + buf := make([]byte, size) + if _, err = io.ReadFull(r, buf); err != nil { + return "", 0, fmt.Errorf("failed to read %s: %w", fmt.Sprintf(contextFormat, contextArgs...), err) + } + + if !utf8.Valid(buf) { + return "", 0, fmt.Errorf("%s is not valid UTF-8", fmt.Sprintf(contextFormat, contextArgs...)) + } + + // TODO: use unsafe.String after flooring Go 1.20. + ret := *(*string)(unsafe.Pointer(&buf)) + return ret, size + uint32(sizeOfSize), nil +} |