code review 49970044: debug/plan9obj: implement parsing of Plan 9 a.out execu...

src/pkg/debug/plan9obj/plan9obj.go

 // Copyright 2014 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.
 
 /*
  * Plan 9 a.out constants and data structures
  */
 
 package plan9obj
 
@@ skipping 15 matching lines @@
 }
 
 // Plan 9 symbol table entries.
 type sym struct {
         value uint64
         typ   byte
         name  []byte
 }
 
 const (
-        hsize     = 4 * 8
-        HDR_MAGIC = 0x00008000 /* header expansion */

[rsc, 2014/01/22 21:32:07]

Please unexported all these constants until we know they are needed. Put a _ at
the beginning of each (_HDR_MAGIC, _A_MAGIC, ...)

+        hsize      = 4 * 8
+        _HDR_MAGIC = 0x00008000 /* header expansion */
 )
 
 func magic(f, b int) string {
         buf := new(bytes.Buffer)
         var i uint32 = uint32((f) | ((((4 * (b)) + 0) * (b)) + 7))
         binary.Write(buf, binary.BigEndian, i)
         return string(buf.Bytes())
 }
 
 var (
-        A_MAGIC = magic(0, 8)          /* 68020 (retired) */
-        I_MAGIC = magic(0, 11)         /* intel 386 */
-        J_MAGIC = magic(0, 12)         /* intel 960 (retired) */
-        K_MAGIC = magic(0, 13)         /* sparc */
-        V_MAGIC = magic(0, 16)         /* mips 3000 BE */
-        X_MAGIC = magic(0, 17)         /* att dsp 3210 (retired) */
-        M_MAGIC = magic(0, 18)         /* mips 4000 BE */
-        D_MAGIC = magic(0, 19)         /* amd 29000 (retired) */
-        E_MAGIC = magic(0, 20)         /* arm */
-        Q_MAGIC = magic(0, 21)         /* powerpc */
-        N_MAGIC = magic(0, 22)         /* mips 4000 LE */
-        L_MAGIC = magic(0, 23)         /* dec alpha (retired) */
-        P_MAGIC = magic(0, 24)         /* mips 3000 LE */
-        U_MAGIC = magic(0, 25)         /* sparc64 (retired) */
-        S_MAGIC = magic(HDR_MAGIC, 26) /* amd64 */
-        T_MAGIC = magic(HDR_MAGIC, 27) /* powerpc64 */
-        R_MAGIC = magic(HDR_MAGIC, 28) /* arm64 */
+        _A_MAGIC = magic(0, 8)           /* 68020 (retired) */
+        _I_MAGIC = magic(0, 11)          /* intel 386 */
+        _J_MAGIC = magic(0, 12)          /* intel 960 (retired) */
+        _K_MAGIC = magic(0, 13)          /* sparc */
+        _V_MAGIC = magic(0, 16)          /* mips 3000 BE */
+        _X_MAGIC = magic(0, 17)          /* att dsp 3210 (retired) */
+        _M_MAGIC = magic(0, 18)          /* mips 4000 BE */
+        _D_MAGIC = magic(0, 19)          /* amd 29000 (retired) */
+        _E_MAGIC = magic(0, 20)          /* arm */
+        _Q_MAGIC = magic(0, 21)          /* powerpc */
+        _N_MAGIC = magic(0, 22)          /* mips 4000 LE */
+        _L_MAGIC = magic(0, 23)          /* dec alpha (retired) */
+        _P_MAGIC = magic(0, 24)          /* mips 3000 LE */
+        _U_MAGIC = magic(0, 25)          /* sparc64 (retired) */
+        _S_MAGIC = magic(_HDR_MAGIC, 26) /* amd64 */
+        _T_MAGIC = magic(_HDR_MAGIC, 27) /* powerpc64 */
+        _R_MAGIC = magic(_HDR_MAGIC, 28) /* arm64 */
 )
 
 type ExecTable struct {
         Magic string
         Ptrsz int
         Hsize uint32
 }
 
 var exectab = []ExecTable{
-        {A_MAGIC, 4, hsize},
-        {I_MAGIC, 4, hsize},
-        {J_MAGIC, 4, hsize},
-        {K_MAGIC, 4, hsize},
-        {V_MAGIC, 4, hsize},
-        {X_MAGIC, 4, hsize},
-        {M_MAGIC, 4, hsize},
-        {D_MAGIC, 4, hsize},
-        {E_MAGIC, 4, hsize},
-        {Q_MAGIC, 4, hsize},
-        {N_MAGIC, 4, hsize},
-        {L_MAGIC, 4, hsize},
-        {P_MAGIC, 4, hsize},
-        {U_MAGIC, 4, hsize},
-        {S_MAGIC, 8, hsize + 8},
-        {T_MAGIC, 8, hsize + 8},
-        {R_MAGIC, 8, hsize + 8},
+        {_A_MAGIC, 4, hsize},
+        {_I_MAGIC, 4, hsize},
+        {_J_MAGIC, 4, hsize},
+        {_K_MAGIC, 4, hsize},
+        {_V_MAGIC, 4, hsize},
+        {_X_MAGIC, 4, hsize},
+        {_M_MAGIC, 4, hsize},
+        {_D_MAGIC, 4, hsize},
+        {_E_MAGIC, 4, hsize},
+        {_Q_MAGIC, 4, hsize},
+        {_N_MAGIC, 4, hsize},
+        {_L_MAGIC, 4, hsize},
+        {_P_MAGIC, 4, hsize},
+        {_U_MAGIC, 4, hsize},
+        {_S_MAGIC, 8, hsize + 8},
+        {_T_MAGIC, 8, hsize + 8},
+        {_R_MAGIC, 8, hsize + 8},
 }