| // Copyright 2015 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // Package flags implements top-level flags and the usage message for the assembler. |
| package flags |
| |
| import ( |
| "cmd/internal/objabi" |
| "flag" |
| "fmt" |
| "os" |
| "path/filepath" |
| "strings" |
| ) |
| |
| var ( |
| Debug = flag.Bool("debug", false, "dump instructions as they are parsed") |
| OutputFile = flag.String("o", "", "output file; default foo.o for /a/b/c/foo.s as first argument") |
| PrintOut = flag.Bool("S", false, "print assembly and machine code") |
| TrimPath = flag.String("trimpath", "", "remove prefix from recorded source file paths") |
| Shared = flag.Bool("shared", false, "generate code that can be linked into a shared library") |
| Dynlink = flag.Bool("dynlink", false, "support references to Go symbols defined in other shared libraries") |
| AllErrors = flag.Bool("e", false, "no limit on number of errors reported") |
| SymABIs = flag.Bool("gensymabis", false, "write symbol ABI information to output file, don't assemble") |
| Importpath = flag.String("p", "", "set expected package import to path") |
| Spectre = flag.String("spectre", "", "enable spectre mitigations in `list` (all, ret)") |
| ) |
| |
| var ( |
| D MultiFlag |
| I MultiFlag |
| ) |
| |
| func init() { |
| flag.Var(&D, "D", "predefined symbol with optional simple value -D=identifier=value; can be set multiple times") |
| flag.Var(&I, "I", "include directory; can be set multiple times") |
| objabi.AddVersionFlag() // -V |
| } |
| |
| // MultiFlag allows setting a value multiple times to collect a list, as in -I=dir1 -I=dir2. |
| type MultiFlag []string |
| |
| func (m *MultiFlag) String() string { |
| if len(*m) == 0 { |
| return "" |
| } |
| return fmt.Sprint(*m) |
| } |
| |
| func (m *MultiFlag) Set(val string) error { |
| (*m) = append(*m, val) |
| return nil |
| } |
| |
| func Usage() { |
| fmt.Fprintf(os.Stderr, "usage: asm [options] file.s ...\n") |
| fmt.Fprintf(os.Stderr, "Flags:\n") |
| flag.PrintDefaults() |
| os.Exit(2) |
| } |
| |
| func Parse() { |
| flag.Usage = Usage |
| flag.Parse() |
| if flag.NArg() == 0 { |
| flag.Usage() |
| } |
| |
| // Flag refinement. |
| if *OutputFile == "" { |
| if flag.NArg() != 1 { |
| flag.Usage() |
| } |
| input := filepath.Base(flag.Arg(0)) |
| if strings.HasSuffix(input, ".s") { |
| input = input[:len(input)-2] |
| } |
| *OutputFile = fmt.Sprintf("%s.o", input) |
| } |
| } |