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      1 // Copyright (c) 2014, Google Inc.
      2 //
      3 // Permission to use, copy, modify, and/or distribute this software for any
      4 // purpose with or without fee is hereby granted, provided that the above
      5 // copyright notice and this permission notice appear in all copies.
      6 //
      7 // THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
      8 // WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
      9 // MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
     10 // SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     11 // WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
     12 // OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
     13 // CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     14 
     15 // This package generates chacha_vec_arm.S from chacha_vec.c. Install the
     16 // arm-linux-gnueabihf-gcc compiler as described in BUILDING.md. Then:
     17 // `(cd crypto/chacha && go run chacha_vec_arm_generate.go)`.
     18 
     19 package main
     20 
     21 import (
     22 	"bufio"
     23 	"bytes"
     24 	"os"
     25 	"os/exec"
     26 	"strings"
     27 )
     28 
     29 const defaultCompiler = "/opt/gcc-linaro-4.9-2014.11-x86_64_arm-linux-gnueabihf/bin/arm-linux-gnueabihf-gcc"
     30 
     31 func main() {
     32 	compiler := defaultCompiler
     33 	if len(os.Args) > 1 {
     34 		compiler = os.Args[1]
     35 	}
     36 
     37 	args := []string{
     38 		"-O3",
     39 		"-mcpu=cortex-a8",
     40 		"-mfpu=neon",
     41 		"-fpic",
     42 		"-DASM_GEN",
     43 		"-I", "../../include",
     44 		"-S", "chacha_vec.c",
     45 		"-o", "-",
     46 	}
     47 
     48 	output, err := os.OpenFile("chacha_vec_arm.S", os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
     49 	if err != nil {
     50 		panic(err)
     51 	}
     52 	defer output.Close()
     53 
     54 	output.WriteString(preamble)
     55 	output.WriteString(compiler)
     56 	output.WriteString(" ")
     57 	output.WriteString(strings.Join(args, " "))
     58 	output.WriteString("\n\n#if !defined(OPENSSL_NO_ASM)\n")
     59 	output.WriteString("#if defined(__arm__)\n\n")
     60 
     61 	cmd := exec.Command(compiler, args...)
     62 	cmd.Stderr = os.Stderr
     63 	asm, err := cmd.StdoutPipe()
     64 	if err != nil {
     65 		panic(err)
     66 	}
     67 	if err := cmd.Start(); err != nil {
     68 		panic(err)
     69 	}
     70 
     71 	attr28 := []byte(".eabi_attribute 28,")
     72 	globalDirective := []byte(".global\t")
     73 	newLine := []byte("\n")
     74 	attr28Handled := false
     75 
     76 	scanner := bufio.NewScanner(asm)
     77 	for scanner.Scan() {
     78 		line := scanner.Bytes()
     79 
     80 		if bytes.Contains(line, attr28) {
     81 			output.WriteString(attr28Block)
     82 			attr28Handled = true
     83 			continue
     84 		}
     85 
     86 		output.Write(line)
     87 		output.Write(newLine)
     88 
     89 		if i := bytes.Index(line, globalDirective); i >= 0 {
     90 			output.Write(line[:i])
     91 			output.WriteString(".hidden\t")
     92 			output.Write(line[i+len(globalDirective):])
     93 			output.Write(newLine)
     94 		}
     95 	}
     96 
     97 	if err := scanner.Err(); err != nil {
     98 		panic(err)
     99 	}
    100 
    101 	if !attr28Handled {
    102 		panic("EABI attribute 28 not seen in processing")
    103 	}
    104 
    105 	if err := cmd.Wait(); err != nil {
    106 		panic(err)
    107 	}
    108 
    109 	output.WriteString(trailer)
    110 }
    111 
    112 const preamble = `# Copyright (c) 2014, Google Inc.
    113 #
    114 # Permission to use, copy, modify, and/or distribute this software for any
    115 # purpose with or without fee is hereby granted, provided that the above
    116 # copyright notice and this permission notice appear in all copies.
    117 #
    118 # THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    119 # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
    120 # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
    121 # SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    122 # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
    123 # OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
    124 # CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
    125 
    126 # This file contains a pre-compiled version of chacha_vec.c for ARM. This is
    127 # needed to support switching on NEON code at runtime. If the whole of OpenSSL
    128 # were to be compiled with the needed flags to build chacha_vec.c, then it
    129 # wouldn't be possible to run on non-NEON systems.
    130 #
    131 # This file was generated by chacha_vec_arm_generate.go using the following
    132 # compiler command:
    133 #
    134 #     `
    135 
    136 const attr28Block = `
    137 # EABI attribute 28 sets whether VFP register arguments were used to build this
    138 # file. If object files are inconsistent on this point, the linker will refuse
    139 # to link them. Thus we report whatever the compiler expects since we don't use
    140 # VFP arguments.
    141 
    142 #if defined(__ARM_PCS_VFP)
    143 	.eabi_attribute 28, 1
    144 #else
    145 	.eabi_attribute 28, 0
    146 #endif
    147 
    148 `
    149 
    150 const trailer = `
    151 #endif  /* __arm__ */
    152 #endif  /* !OPENSSL_NO_ASM */
    153 `
    154