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author | 2023-04-03 11:16:17 +0200 | |
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committer | 2023-04-03 11:16:17 +0200 | |
commit | 57dc742c76d7876a2457594715a7b5bc2c9a92bd (patch) | |
tree | 76be1ec744face5bf4f617d4c9fca084707e4268 /vendor/github.com/cilium/ebpf/btf/format.go | |
parent | [bugfix/frontend] Preload css styles (#1638) (diff) | |
download | gotosocial-57dc742c76d7876a2457594715a7b5bc2c9a92bd.tar.xz |
[chore]: Bump github.com/KimMachineGun/automemlimit from 0.2.4 to 0.2.5 (#1666)
Bumps [github.com/KimMachineGun/automemlimit](https://github.com/KimMachineGun/automemlimit) from 0.2.4 to 0.2.5.
- [Release notes](https://github.com/KimMachineGun/automemlimit/releases)
- [Commits](https://github.com/KimMachineGun/automemlimit/compare/v0.2.4...v0.2.5)
---
updated-dependencies:
- dependency-name: github.com/KimMachineGun/automemlimit
dependency-type: direct:production
update-type: version-update:semver-patch
...
Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Diffstat (limited to 'vendor/github.com/cilium/ebpf/btf/format.go')
-rw-r--r-- | vendor/github.com/cilium/ebpf/btf/format.go | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/vendor/github.com/cilium/ebpf/btf/format.go b/vendor/github.com/cilium/ebpf/btf/format.go new file mode 100644 index 000000000..e7688a2a6 --- /dev/null +++ b/vendor/github.com/cilium/ebpf/btf/format.go @@ -0,0 +1,319 @@ +package btf + +import ( + "errors" + "fmt" + "strings" +) + +var errNestedTooDeep = errors.New("nested too deep") + +// GoFormatter converts a Type to Go syntax. +// +// A zero GoFormatter is valid to use. +type GoFormatter struct { + w strings.Builder + + // Types present in this map are referred to using the given name if they + // are encountered when outputting another type. + Names map[Type]string + + // Identifier is called for each field of struct-like types. By default the + // field name is used as is. + Identifier func(string) string + + // EnumIdentifier is called for each element of an enum. By default the + // name of the enum type is concatenated with Identifier(element). + EnumIdentifier func(name, element string) string +} + +// TypeDeclaration generates a Go type declaration for a BTF type. +func (gf *GoFormatter) TypeDeclaration(name string, typ Type) (string, error) { + gf.w.Reset() + if err := gf.writeTypeDecl(name, typ); err != nil { + return "", err + } + return gf.w.String(), nil +} + +func (gf *GoFormatter) identifier(s string) string { + if gf.Identifier != nil { + return gf.Identifier(s) + } + + return s +} + +func (gf *GoFormatter) enumIdentifier(name, element string) string { + if gf.EnumIdentifier != nil { + return gf.EnumIdentifier(name, element) + } + + return name + gf.identifier(element) +} + +// writeTypeDecl outputs a declaration of the given type. +// +// It encodes https://golang.org/ref/spec#Type_declarations: +// +// type foo struct { bar uint32; } +// type bar int32 +func (gf *GoFormatter) writeTypeDecl(name string, typ Type) error { + if name == "" { + return fmt.Errorf("need a name for type %s", typ) + } + + switch v := skipQualifiers(typ).(type) { + case *Enum: + fmt.Fprintf(&gf.w, "type %s ", name) + switch v.Size { + case 1: + gf.w.WriteString("int8") + case 2: + gf.w.WriteString("int16") + case 4: + gf.w.WriteString("int32") + case 8: + gf.w.WriteString("int64") + default: + return fmt.Errorf("%s: invalid enum size %d", typ, v.Size) + } + + if len(v.Values) == 0 { + return nil + } + + gf.w.WriteString("; const ( ") + for _, ev := range v.Values { + id := gf.enumIdentifier(name, ev.Name) + fmt.Fprintf(&gf.w, "%s %s = %d; ", id, name, ev.Value) + } + gf.w.WriteString(")") + + return nil + + default: + fmt.Fprintf(&gf.w, "type %s ", name) + return gf.writeTypeLit(v, 0) + } +} + +// writeType outputs the name of a named type or a literal describing the type. +// +// It encodes https://golang.org/ref/spec#Types. +// +// foo (if foo is a named type) +// uint32 +func (gf *GoFormatter) writeType(typ Type, depth int) error { + typ = skipQualifiers(typ) + + name := gf.Names[typ] + if name != "" { + gf.w.WriteString(name) + return nil + } + + return gf.writeTypeLit(typ, depth) +} + +// writeTypeLit outputs a literal describing the type. +// +// The function ignores named types. +// +// It encodes https://golang.org/ref/spec#TypeLit. +// +// struct { bar uint32; } +// uint32 +func (gf *GoFormatter) writeTypeLit(typ Type, depth int) error { + depth++ + if depth > maxTypeDepth { + return errNestedTooDeep + } + + var err error + switch v := skipQualifiers(typ).(type) { + case *Int: + gf.writeIntLit(v) + + case *Enum: + gf.w.WriteString("int32") + + case *Typedef: + err = gf.writeType(v.Type, depth) + + case *Array: + fmt.Fprintf(&gf.w, "[%d]", v.Nelems) + err = gf.writeType(v.Type, depth) + + case *Struct: + err = gf.writeStructLit(v.Size, v.Members, depth) + + case *Union: + // Always choose the first member to represent the union in Go. + err = gf.writeStructLit(v.Size, v.Members[:1], depth) + + case *Datasec: + err = gf.writeDatasecLit(v, depth) + + default: + return fmt.Errorf("type %T: %w", v, ErrNotSupported) + } + + if err != nil { + return fmt.Errorf("%s: %w", typ, err) + } + + return nil +} + +func (gf *GoFormatter) writeIntLit(i *Int) { + // NB: Encoding.IsChar is ignored. + if i.Encoding.IsBool() && i.Size == 1 { + gf.w.WriteString("bool") + return + } + + bits := i.Size * 8 + if i.Encoding.IsSigned() { + fmt.Fprintf(&gf.w, "int%d", bits) + } else { + fmt.Fprintf(&gf.w, "uint%d", bits) + } +} + +func (gf *GoFormatter) writeStructLit(size uint32, members []Member, depth int) error { + gf.w.WriteString("struct { ") + + prevOffset := uint32(0) + skippedBitfield := false + for i, m := range members { + if m.BitfieldSize > 0 { + skippedBitfield = true + continue + } + + offset := m.Offset.Bytes() + if n := offset - prevOffset; skippedBitfield && n > 0 { + fmt.Fprintf(&gf.w, "_ [%d]byte /* unsupported bitfield */; ", n) + } else { + gf.writePadding(n) + } + + size, err := Sizeof(m.Type) + if err != nil { + return fmt.Errorf("field %d: %w", i, err) + } + prevOffset = offset + uint32(size) + + if err := gf.writeStructField(m, depth); err != nil { + return fmt.Errorf("field %d: %w", i, err) + } + } + + gf.writePadding(size - prevOffset) + gf.w.WriteString("}") + return nil +} + +func (gf *GoFormatter) writeStructField(m Member, depth int) error { + if m.BitfieldSize > 0 { + return fmt.Errorf("bitfields are not supported") + } + if m.Offset%8 != 0 { + return fmt.Errorf("unsupported offset %d", m.Offset) + } + + if m.Name == "" { + // Special case a nested anonymous union like + // struct foo { union { int bar; int baz }; } + // by replacing the whole union with its first member. + union, ok := m.Type.(*Union) + if !ok { + return fmt.Errorf("anonymous fields are not supported") + + } + + if len(union.Members) == 0 { + return errors.New("empty anonymous union") + } + + depth++ + if depth > maxTypeDepth { + return errNestedTooDeep + } + + m := union.Members[0] + size, err := Sizeof(m.Type) + if err != nil { + return err + } + + if err := gf.writeStructField(m, depth); err != nil { + return err + } + + gf.writePadding(union.Size - uint32(size)) + return nil + + } + + fmt.Fprintf(&gf.w, "%s ", gf.identifier(m.Name)) + + if err := gf.writeType(m.Type, depth); err != nil { + return err + } + + gf.w.WriteString("; ") + return nil +} + +func (gf *GoFormatter) writeDatasecLit(ds *Datasec, depth int) error { + gf.w.WriteString("struct { ") + + prevOffset := uint32(0) + for i, vsi := range ds.Vars { + v := vsi.Type.(*Var) + if v.Linkage != GlobalVar { + // Ignore static, extern, etc. for now. + continue + } + + if v.Name == "" { + return fmt.Errorf("variable %d: empty name", i) + } + + gf.writePadding(vsi.Offset - prevOffset) + prevOffset = vsi.Offset + vsi.Size + + fmt.Fprintf(&gf.w, "%s ", gf.identifier(v.Name)) + + if err := gf.writeType(v.Type, depth); err != nil { + return fmt.Errorf("variable %d: %w", i, err) + } + + gf.w.WriteString("; ") + } + + gf.writePadding(ds.Size - prevOffset) + gf.w.WriteString("}") + return nil +} + +func (gf *GoFormatter) writePadding(bytes uint32) { + if bytes > 0 { + fmt.Fprintf(&gf.w, "_ [%d]byte; ", bytes) + } +} + +func skipQualifiers(typ Type) Type { + result := typ + for depth := 0; depth <= maxTypeDepth; depth++ { + switch v := (result).(type) { + case qualifier: + result = v.qualify() + default: + return result + } + } + return &cycle{typ} +} |