这objdump 手册页给出以下示例输出objdump -t：
输出的格式取决于转储文件的格式，但有两种主要类型。一个看起来像这样：
[ 4](sec 3)(fl 0x00)(ty 0)(scl 3) (nx 1) 0x00000000 .bss [ 6](sec 1)(fl 0x00)(ty 0)(scl 2) (nx 0) 0x00000000 fred其中方括号内的数字是符号表中的条目号，sec 号是节号，fl 值是符号的标志位，ty 号是符号的类型，scl 号是符号的存储空间class 和 nx 值是与符号关联的辅助条目的数量。最后两个字段是符号的值及其名称。
所以scl意味着storage class，但它从未解释什么scl 3或scl 2实际意味着什么。
在哪里可以找到这些信息？
答案1
这些scl值定义在binutils-gdb/include/coff/internal.h:
/********************** STORAGE CLASSES **********************/
/* This used to be defined as -1, but now n_sclass is unsigned. */
#define C_EFCN 0xff /* physical end of function */
#define C_NULL 0
#define C_AUTO 1 /* automatic variable */
#define C_EXT 2 /* external symbol */
#define C_STAT 3 /* static */
#define C_REG 4 /* register variable */
#define C_EXTDEF 5 /* external definition */
#define C_LABEL 6 /* label */
#define C_ULABEL 7 /* undefined label */
#define C_MOS 8 /* member of structure */
#define C_ARG 9 /* function argument */
#define C_STRTAG 10 /* structure tag */
#define C_MOU 11 /* member of union */
#define C_UNTAG 12 /* union tag */
#define C_TPDEF 13 /* type definition */
#define C_USTATIC 14 /* undefined static */
#define C_ENTAG 15 /* enumeration tag */
#define C_MOE 16 /* member of enumeration */
#define C_REGPARM 17 /* register parameter */
#define C_FIELD 18 /* bit field */
#define C_AUTOARG 19 /* auto argument */
#define C_LASTENT 20 /* dummy entry (end of block) */
#define C_BLOCK 100 /* ".bb" or ".eb" */
#define C_FCN 101 /* ".bf" or ".ef" */
#define C_EOS 102 /* end of structure */
#define C_FILE 103 /* file name */
#define C_LINE 104 /* line # reformatted as symbol table entry */
#define C_ALIAS 105 /* duplicate tag */
#define C_HIDDEN 106 /* ext symbol in dmert public lib */
#define C_WEAKEXT 127 /* weak symbol -- GNU extension. */
/* New storage classes for TI COFF */
#define C_UEXT 19 /* Tentative external definition */
#define C_STATLAB 20 /* Static load time label */
#define C_EXTLAB 21 /* External load time label */
#define C_SYSTEM 23 /* System Wide variable */
/* New storage classes for WINDOWS_NT */
#define C_SECTION 104 /* section name */
#define C_NT_WEAK 105 /* weak external */
/* New storage classes for 80960 */
/* C_LEAFPROC is obsolete. Use C_LEAFEXT or C_LEAFSTAT */
#define C_LEAFPROC 108 /* Leaf procedure, "call" via BAL */
#define C_SCALL 107 /* Procedure reachable via system call */
#define C_LEAFEXT 108 /* External leaf */
#define C_LEAFSTAT 113 /* Static leaf */
#define C_OPTVAR 109 /* Optimized variable */
#define C_DEFINE 110 /* Preprocessor #define */
#define C_PRAGMA 111 /* Advice to compiler or linker */
#define C_SEGMENT 112 /* 80960 segment name */
/* New storage classes for RS/6000 */
#define C_HIDEXT 107 /* Un-named external symbol */
#define C_BINCL 108 /* Marks beginning of include file */
#define C_EINCL 109 /* Marks ending of include file */
#define C_AIX_WEAKEXT 111 /* AIX definition of C_WEAKEXT. */
#define C_DWARF 112 /* DWARF symbol */
所以scl 3意味着该变量是静态的，并且scl 2意味着它是外部的。