C和程序集之间的链接错误
我正在编译一个c文件foo.c：C和程序集之间的链接错误,c,gcc,assembly,linker,C,Gcc,Assembly,Linker,我正在编译一个c文件foo.c： #include <stdlib.h> extern void *memcpy_optimized(void* __restrict, void* __restrict, size_t); void foo() { [blah blah blah] memcpy_optimized((void *)a, (void *)b, 123); } 这两个文件都可以使用：gcc$ ，必须在汇编中使用代码< >代码>优化的。我之所以这
#include <stdlib.h>
extern void *memcpy_optimized(void* __restrict, void* __restrict, size_t);
void foo() {
[blah blah blah]
memcpy_optimized((void *)a, (void *)b, 123);
}
foo.c:(.text+0x380): undefined reference to `memcpy_optimized(void*, void *, unsigned int)'
readelf -a obj/memcpy_optimized.o
ELF Header:
Magic: 7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
Class: ELF32
Data: 2's complement, little endian
Version: 1 (current)
OS/ABI: UNIX - System V
ABI Version: 0
Type: REL (Relocatable file)
Machine: ARM
Version: 0x1
Entry point address: 0x0
Start of program headers: 0 (bytes into file)
Start of section headers: 436 (bytes into file)
Flags: 0x5000000, Version5 EABI
Size of this header: 52 (bytes)
Size of program headers: 0 (bytes)
Number of program headers: 0
Size of section headers: 40 (bytes)
Number of section headers: 11
Section header string table index: 8
Section Headers:
[Nr] Name Type Addr Off Size ES Flg Lk Inf Al
[ 0] NULL 00000000 000000 000000 00 0 0 0
[ 1] .text PROGBITS 00000000 000040 0000f0 00 AX 0 0 16
[ 2] .data PROGBITS 00000000 000130 000000 00 WA 0 0 1
[ 3] .bss NOBITS 00000000 000130 000000 00 WA 0 0 1
[ 4] .ARM.extab PROGBITS 00000000 000130 000000 00 A 0 0 1
[ 5] .ARM.exidx ARM_EXIDX 00000000 000130 000008 00 AL 1 0 4
[ 6] .rel.ARM.exidx REL 00000000 00044c 000010 08 9 5 4
[ 7] .ARM.attributes ARM_ATTRIBUTES 00000000 000138 000023 00 0 0 1
[ 8] .shstrtab STRTAB 00000000 00015b 000056 00 0 0 1
[ 9] .symtab SYMTAB 00000000 00036c 0000b0 10 10 9 4
[10] .strtab STRTAB 00000000 00041c 00002f 00 0 0 1
Key to Flags:
W (write), A (alloc), X (execute), M (merge), S (strings)
I (info), L (link order), G (group), T (TLS), E (exclude), x (unknown)
O (extra OS processing required) o (OS specific), p (processor specific)
There are no section groups in this file.
There are no program headers in this file.
Relocation section '.rel.ARM.exidx' at offset 0x44c contains 2 entries:
Offset Info Type Sym.Value Sym. Name
00000000 0000012a R_ARM_PREL31 00000000 .text
00000000 00000a00 R_ARM_NONE 00000000 __aeabi_unwind_cpp_pr0
Unwind table index '.ARM.exidx' at offset 0x130 contains 1 entries:
0x0 <memcpy_optimized>: 0x80b0b0b0
Compact model 0
0xb0 finish
0xb0 finish
0xb0 finish
Symbol table '.symtab' contains 11 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 00000000 0 NOTYPE LOCAL DEFAULT UND
1: 00000000 0 SECTION LOCAL DEFAULT 1
2: 00000000 0 SECTION LOCAL DEFAULT 2
3: 00000000 0 SECTION LOCAL DEFAULT 3
4: 00000000 0 NOTYPE LOCAL DEFAULT 1 $a
5: 00000000 0 SECTION LOCAL DEFAULT 4
6: 00000000 0 SECTION LOCAL DEFAULT 5
7: 00000000 0 NOTYPE LOCAL DEFAULT 5 $d
8: 00000000 0 SECTION LOCAL DEFAULT 7
9: 00000000 0 FUNC GLOBAL DEFAULT 1 memcpy_optimized
10: 00000000 0 NOTYPE GLOBAL DEFAULT UND __aeabi_unwind_cpp_pr0
No version information found in this file.
Attribute Section: aeabi
File Attributes
Tag_CPU_name: "7-A"
Tag_CPU_arch: v7
Tag_CPU_arch_profile: Application
Tag_ARM_ISA_use: Yes
Tag_THUMB_ISA_use: Thumb-2
Tag_FP_arch: VFPv3
Tag_Advanced_SIMD_arch: NEONv1
Tag_DIV_use: Not allowed
readelf-a obj/memcpy_optimized.o
ELF标头：
魔术：7f 45 4c 46 01 01 00 00
类别：ELF32
数据：2的补码，小尾端
版本：1（当前版本）
OS/ABI:UNIX-SystemV
ABI版本：0
类型：REL（可重定位文件）
机器：手臂
版本：0x1
入口点地址：0x0
程序头的开始：0（文件中的字节）
节头的开头：436（文件中的字节）
标志：0x5000000，版本5 EABI
此标头的大小：52（字节）
程序头的大小：0（字节）
程序头数：0
节标题的大小：40（字节）
节头数：11
节头字符串表索引：8
章节标题：
[Nr]名称类型地址尺寸ES Flg Lk Inf Al
[0]空0000000000000000000
[1].文本程序00000000 000040 0000F000 AX 0 16
[2]。数据程序00000000 000130 00000000 WA 0 1
[3].bss NOBITS 00000000 000130 00000000 WA 0 1
[4].ARM.extab程序位00000000 000130 00000000 A 0 1
[5].ARM.exidx ARM_exidx 00000000 000130 000008 00 AL 1 0 4
[6].rel.ARM.exidx rel 00000000 00044c 000010 08 9 5 4
[7].ARM.attributes ARM_attributes 00000000 000138 000023 00 0 1
[8].shstrtab STRTAB 00000000 00015b 000056 00 0 1
[9].symtab symtab 00000000 00036c 0000b0 10 10 9 4
[10] .strtab strtab 00000000 00041c 00002f 00 0 1
标志的关键点：
W（写入）、A（分配）、X（执行）、M（合并）、S（字符串）
I（信息）、L（链接顺序）、G（组）、T（TLS）、E（排除）、x（未知）
O（需要额外的操作系统处理）O（特定于操作系统），p（特定于处理器）
此文件中没有节组。
此文件中没有程序头。
偏移量0x44c处的重新定位节“.rel.ARM.exidx”包含2个条目：
偏移信息类型符号。值符号。名称
00000000 0000012 A R_ARM_PREL31 00000000。文本
00000000 00000 A00 R_臂_无00000000_aeabi_展开_cpp_pr0
在偏移量0x130处展开表索引“.ARM.exidx”包含1个条目：
0x0:0x80B0
紧凑型0
0xb0完成
0xb0完成
0xb0完成
符号表“.symtab”包含11个条目：
Num：值大小类型绑定到Ndx名称
0:00000000 0不键入本地默认值
1:00000000节本地默认值1
2:00000000节本地默认值2
3:00000000节本地默认值3
4:00000000不键入本地默认值1$a
5:00000000节本地默认值4
6:00000000节本地默认值5
7:00000000不键入本地默认值5$d
8:00000000节本地默认值7
9:00000000 FUNC全局默认值1内存优化
10:00000000不输入全局默认值和aeabi解卷cpp pr0
在此文件中找不到版本信息。
属性部分：aeabi
文件属性
标记CPU名称：“7-A”
标签：v7
Tag\u CPU\u arch\u配置文件：应用程序
Tag_ARM_ISA_用途：是
Tag_THUMB_ISA_用法：THUMB-2
标签FP拱门：VFPv3
Tag_Advanced_SIMD_arch:NEONv1
标记分区使用：不允许
extern void*readelf -a obj/memcpy_optimized.o
ELF Header:
Magic: 7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
Class: ELF32
Data: 2's complement, little endian
Version: 1 (current)
OS/ABI: UNIX - System V
ABI Version: 0
Type: REL (Relocatable file)
Machine: ARM
Version: 0x1
Entry point address: 0x0
Start of program headers: 0 (bytes into file)
Start of section headers: 436 (bytes into file)
Flags: 0x5000000, Version5 EABI
Size of this header: 52 (bytes)
Size of program headers: 0 (bytes)
Number of program headers: 0
Size of section headers: 40 (bytes)
Number of section headers: 11
Section header string table index: 8
Section Headers:
[Nr] Name Type Addr Off Size ES Flg Lk Inf Al
[ 0] NULL 00000000 000000 000000 00 0 0 0
[ 1] .text PROGBITS 00000000 000040 0000f0 00 AX 0 0 16
[ 2] .data PROGBITS 00000000 000130 000000 00 WA 0 0 1
[ 3] .bss NOBITS 00000000 000130 000000 00 WA 0 0 1
[ 4] .ARM.extab PROGBITS 00000000 000130 000000 00 A 0 0 1
[ 5] .ARM.exidx ARM_EXIDX 00000000 000130 000008 00 AL 1 0 4
[ 6] .rel.ARM.exidx REL 00000000 00044c 000010 08 9 5 4
[ 7] .ARM.attributes ARM_ATTRIBUTES 00000000 000138 000023 00 0 0 1
[ 8] .shstrtab STRTAB 00000000 00015b 000056 00 0 0 1
[ 9] .symtab SYMTAB 00000000 00036c 0000b0 10 10 9 4
[10] .strtab STRTAB 00000000 00041c 00002f 00 0 0 1
Key to Flags:
W (write), A (alloc), X (execute), M (merge), S (strings)
I (info), L (link order), G (group), T (TLS), E (exclude), x (unknown)
O (extra OS processing required) o (OS specific), p (processor specific)
There are no section groups in this file.
There are no program headers in this file.
Relocation section '.rel.ARM.exidx' at offset 0x44c contains 2 entries:
Offset Info Type Sym.Value Sym. Name
00000000 0000012a R_ARM_PREL31 00000000 .text
00000000 00000a00 R_ARM_NONE 00000000 __aeabi_unwind_cpp_pr0
Unwind table index '.ARM.exidx' at offset 0x130 contains 1 entries:
0x0 <memcpy_optimized>: 0x80b0b0b0
Compact model 0
0xb0 finish
0xb0 finish
0xb0 finish
Symbol table '.symtab' contains 11 entries:
Num: Value Size Type Bind Vis Ndx Name
0: 00000000 0 NOTYPE LOCAL DEFAULT UND
1: 00000000 0 SECTION LOCAL DEFAULT 1
2: 00000000 0 SECTION LOCAL DEFAULT 2
3: 00000000 0 SECTION LOCAL DEFAULT 3
4: 00000000 0 NOTYPE LOCAL DEFAULT 1 $a
5: 00000000 0 SECTION LOCAL DEFAULT 4
6: 00000000 0 SECTION LOCAL DEFAULT 5
7: 00000000 0 NOTYPE LOCAL DEFAULT 5 $d
8: 00000000 0 SECTION LOCAL DEFAULT 7
9: 00000000 0 FUNC GLOBAL DEFAULT 1 memcpy_optimized
10: 00000000 0 NOTYPE GLOBAL DEFAULT UND __aeabi_unwind_cpp_pr0
No version information found in this file.
Attribute Section: aeabi
File Attributes
Tag_CPU_name: "7-A"
Tag_CPU_arch: v7
Tag_CPU_arch_profile: Application
Tag_ARM_ISA_use: Yes
Tag_THUMB_ISA_use: Thumb-2
Tag_FP_arch: VFPv3
Tag_Advanced_SIMD_arch: NEONv1
Tag_DIV_use: Not allowed