[ELF][RISCV][test] Test absolute/PC-relative/branch relocations to undefined weak symbols

# REQUIRES: riscv

# RUN: llvm-mc -filetype=obj -triple=riscv64 %s -o %t.o

# RUN: llvm-readobj -r %t.o | FileCheck --check-prefix=RELOC %s

# RUN: ld.lld -e absolute %t.o -o %t

# RUN: llvm-objdump -d --no-show-raw-insn %t | FileCheck --check-prefixes=CHECK,PC %s

# RUN: llvm-readelf -x .data %t | FileCheck --check-prefixes=HEX %s

# RUN: ld.lld -e absolute %t.o -o %t --export-dynamic

# RUN: llvm-objdump -d --no-show-raw-insn %t | FileCheck --check-prefixes=CHECK,PLT %s

# RUN: llvm-readelf -x .data %t | FileCheck --check-prefixes=HEX %s

.weak target

.global absolute, relative, branch

## Absolute relocations are resolved to 0.

# RELOC:      0x0 R_RISCV_HI20 target 0x1

# RELOC-NEXT: 0x4 R_RISCV_LO12_I target 0x1

# CHECK-LABEL: absolute:

# CHECK-NEXT:  lui t0, 0

# CHECK-NEXT:  addi t0, t0, 1

absolute:

  lui t0, %hi(target+1)

  addi t0, t0, %lo(target+1)

## Currently, PC-relative relocations are resolved to 0.

# RELOC-NEXT: 0x8 R_RISCV_PCREL_HI20 target 0x0

# RELOC-NEXT: 0xC R_RISCV_PCREL_LO12_I .Lpcrel_hi0 0x0

# RELOC-NEXT: 0x10 R_RISCV_PCREL_HI20 target 0x2

# RELOC-NEXT: 0x14 R_RISCV_PCREL_LO12_S .Lpcrel_hi1 0x0

## 1048559 should be -0x11.

# CHECK-LABEL: relative:

# CHECK-NEXT:  11{{...}}: auipc a1, 1048559

# PC-NEXT:     addi a1, a1, -352

# PLT-NEXT:    addi a1, a1, -792

# CHECK-LABEL: .Lpcrel_hi1:

# CHECK-NEXT:  11{{...}}: auipc t1, 1048559

# PC-NEXT:     sd a2, -358(t1)

# PLT-NEXT:    sd a2, -798(t1)

relative:

  la a1, target

  sd a2, target+2, t1

## Branch relocations

## If .dynsym does not exist, an undefined weak symbol is non-preemptible.

## Treat them as PC relative relocations.

# RELOC:      0x18 R_RISCV_CALL target 0x0

# RELOC-NEXT: 0x20 R_RISCV_JAL target 0x0

# PC-LABEL:    branch:

# PC-NEXT:     auipc ra, 1048559

# PC-NEXT:     jalr -368(ra)

## FIXME: llvm-objdump -d should print the address, instead of the offset.

# PC-NEXT:     j -70008

## If .dynsym exists, an undefined weak symbol is preemptible.

## We create a PLT entry and redirect the reference to it.

# PLT-LABEL:   branch:

# PLT-NEXT:    auipc ra, 0

# PLT-NEXT:    jalr 56(ra)

# PLT-NEXT:    j -70448

branch:

  call target

  jal x0, target

## Absolute relocations are resolved to 0.

# RELOC:      0x0 R_RISCV_64 target 0x3

# RELOC-NEXT: 0x8 R_RISCV_32 target 0x4

# HEX:      section '.data':

# HEX-NEXT: 03000000 00000000 04000000

.data

.p2align 3

.quad target+3

.long target+4

# PC-NOT:      .plt:

# PLT:         .plt: