blob b78d96e0 (1242B) - Raw
1 // REQUIRES: x86 2 // RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o 3 // RUN: ld.lld %t.o -shared -o %t.so 4 // RUN: llvm-readelf -S %t.so | FileCheck %s -check-prefix=SECTION 5 // RUN: llvm-objdump -d %t.so | FileCheck %s 6 7 // SECTION: .dynamic DYNAMIC 0000000000003000 8 // SECTION: .got PROGBITS 0000000000003070 003070 000000 9 10 // All the _GLOBAL_OFFSET_TABLE_ occurrences below refer to the address 11 // of GOT base, not the address of the symbol _GLOBAL_OFFSET_TABLE_. These 12 // instructions are special and produce GOT base relative relocations. We 13 // currently use .got end as the GOT base, which is not equal to 14 // the address of the special symbol _GLOBAL_OFFSET_TABLE_. 15 16 // The assembly is generated by 17 // gcc -O2 -S -mcmodel=medium -fPIC a.c 18 // This computes the pc-relative address (runtime address) of _DYNAMIC. 19 // 20 // extern long _DYNAMIC[] __attribute__((visibility("hidden"))); 21 // long* dynamic() { return _DYNAMIC; } 22 23 // 0x3070 (.got end) - 0x1007 = 8297 24 // 0x3000 (_DYNAMIC) - 0x3070 (.got end) = -112 25 // CHECK: 1000: {{.*}} leaq 8297(%rip), %rdx 26 // CHECK-NEXT: 1007: {{.*}} movabsq $-112, %rax 27 .global dynamic 28 dynamic: 29 leaq _GLOBAL_OFFSET_TABLE_(%rip), %rdx 30 movabsq $_DYNAMIC@GOTOFF, %rax 31 addq %rdx, %rax 32 ret