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hanchenye-llvm-project/lld/test/ELF/undef-with-plt-addr.s

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Use the plt entry as the address of some symbols. This is the function equivalent of a copy relocation. Since functions are expected to change sizes, we cannot use copy relocations. In situations where one would be needed, what is done instead is: * Create a plt entry * Output an undefined symbol whose addr is the plt entry. The dynamic linker makes sure any shared library uses the plt entry as the function address. llvm-svn: 260224
2016-02-09 23:11:01 +08:00
// REQUIRES: x86
// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %p/Inputs/undef-with-plt-addr.s -o %t2.o
// RUN: ld.lld %t2.o -o %t2.so -shared
// RUN: ld.lld %t.o %t2.so -o %t3
Don't create dynamic relocations to ro segments. These would just crash at runtime. If we ever decide to support rw text segments this should make it easier to implement as there is now a single point where we notice the problem. I have tested this with a freebsd buildworld. It found a non pic assembly file being linked into a .so,. With that fixed, buildworld finished. llvm-svn: 268149
2016-04-30 09:15:17 +08:00
// RUN: llvm-readobj -t -s -r %t3 | FileCheck %s
Use the plt entry as the address of some symbols. This is the function equivalent of a copy relocation. Since functions are expected to change sizes, we cannot use copy relocations. In situations where one would be needed, what is done instead is: * Create a plt entry * Output an undefined symbol whose addr is the plt entry. The dynamic linker makes sure any shared library uses the plt entry as the function address. llvm-svn: 260224
2016-02-09 23:11:01 +08:00
.globl _start
_start:
movabsq $set_data, %rax
Don't create dynamic relocations to ro segments. These would just crash at runtime. If we ever decide to support rw text segments this should make it easier to implement as there is now a single point where we notice the problem. I have tested this with a freebsd buildworld. It found a non pic assembly file being linked into a .so,. With that fixed, buildworld finished. llvm-svn: 268149
2016-04-30 09:15:17 +08:00
.data
.quad foo
// Test that set_data has an address in the .plt, but foo is not
Use the plt entry as the address of some symbols. This is the function equivalent of a copy relocation. Since functions are expected to change sizes, we cannot use copy relocations. In situations where one would be needed, what is done instead is: * Create a plt entry * Output an undefined symbol whose addr is the plt entry. The dynamic linker makes sure any shared library uses the plt entry as the function address. llvm-svn: 260224
2016-02-09 23:11:01 +08:00
// CHECK: Name: .plt
// CHECK-NEXT: Type: SHT_PROGBITS
// CHECK-NEXT: Flags [
// CHECK-NEXT: SHF_ALLOC
// CHECK-NEXT: SHF_EXECINSTR
// CHECK-NEXT: ]
// CHECK-NEXT: Address: 0x11010
Don't create dynamic relocations to ro segments. These would just crash at runtime. If we ever decide to support rw text segments this should make it easier to implement as there is now a single point where we notice the problem. I have tested this with a freebsd buildworld. It found a non pic assembly file being linked into a .so,. With that fixed, buildworld finished. llvm-svn: 268149
2016-04-30 09:15:17 +08:00
// CHECK: Section ({{.*}}) .rela.dyn {
// CHECK-NEXT: 0x13000 R_X86_64_64 foo 0x0
// CHECK-NEXT: }
// CHECK-NEXT: Section ({{.*}}) .rela.plt {
// CHECK-NEXT: 0x13020 R_X86_64_JUMP_SLOT set_data 0x0
// CHECK-NEXT: }
// CHECK: Name: foo
// CHECK-NEXT: Value: 0x0
// CHECK-NEXT: Size: 0
// CHECK-NEXT: Binding: Global
// CHECK-NEXT: Type: Function
// CHECK-NEXT: Other: 0
// CHECK-NEXT: Section: Undefined
Use the plt entry as the address of some symbols. This is the function equivalent of a copy relocation. Since functions are expected to change sizes, we cannot use copy relocations. In situations where one would be needed, what is done instead is: * Create a plt entry * Output an undefined symbol whose addr is the plt entry. The dynamic linker makes sure any shared library uses the plt entry as the function address. llvm-svn: 260224
2016-02-09 23:11:01 +08:00
// CHECK: Name: set_data
// CHECK-NEXT: Value: 0x11020
Don't create dynamic relocations to ro segments. These would just crash at runtime. If we ever decide to support rw text segments this should make it easier to implement as there is now a single point where we notice the problem. I have tested this with a freebsd buildworld. It found a non pic assembly file being linked into a .so,. With that fixed, buildworld finished. llvm-svn: 268149
2016-04-30 09:15:17 +08:00
// CHECK-NEXT: Size: 0
// CHECK-NEXT: Binding: Global
// CHECK-NEXT: Type: Function
// CHECK-NEXT: Other: 0
// CHECK-NEXT: Section: Undefined