[llvm][lld] Pre-commit tests for RISCV TLSDESC symbols

Currently, we mistakenly mark the local labels used in RISC-V TLSDESC as
TLS symbols, when they should not be. This patch adds tests with the
current incorrect behavior, and subsequent patches will address the
issue.

Reviewers: MaskRay, topperc

Reviewed By: MaskRay

Pull Request: #85816

(cherry picked from commit f6f474c)

Author: ilovepi

lld/test/ELF/riscv-tlsdesc.s

@@ -29,6 +29,12 @@
 # RUN: ld.lld -e 0 -z now a.32.o c.32.so -o a.32.ie
 # RUN: llvm-objdump --no-show-raw-insn -M no-aliases -h -d a.32.ie | FileCheck %s --check-prefix=IE32
 
+# RUN: llvm-mc -triple=riscv64 -filetype=obj d.s -o d.64.o
+# RUN: not ld.lld -shared -soname=d.64.so -o d.64.so d.64.o 2>&1 | FileCheck %s --check-prefix=BADTLSLABEL
+
+# RUN: llvm-mc -triple=riscv32 -filetype=obj d.s -o d.32.o --defsym ELF32=1
+# RUN: not ld.lld -shared -soname=d.32.so -o d.32.so d.32.o 2>&1 | FileCheck %s --check-prefix=BADTLSLABEL
+
 # GD64-RELA:      .rela.dyn {
 # GD64-RELA-NEXT:   0x2408 R_RISCV_TLSDESC - 0x7FF
 # GD64-RELA-NEXT:   0x23E8 R_RISCV_TLSDESC a 0x0
@@ -150,6 +156,9 @@
 # IE32-NEXT:         lw      a0, 0x80(a0)
 # IE32-NEXT:         add     a0, a0, tp
 
+## FIXME This should not pass, but the code MC layer needs a fix to prevent this.
+# BADTLSLABEL: error: d.{{.*}}.o has an STT_TLS symbol but doesn't have an SHF_TLS section
+
 #--- a.s
 .macro load dst, src
 .ifdef ELF32
@@ -192,3 +201,19 @@ b:
 .tbss
 .globl c
 c: .zero 4
+
+#--- d.s
+.macro load dst, src
+.ifdef ELF32
+lw \dst, \src
+.else
+ld \dst, \src
+.endif
+.endm
+
+.Ltlsdesc_hi0:
+  auipc	a0, %tlsdesc_hi(foo)
+  load	a1, %tlsdesc_load_lo(.Ltlsdesc_hi0)(a0)
+  addi	a0, a0, %tlsdesc_add_lo(.Ltlsdesc_hi0)
+  jalr	t0, 0(a1), %tlsdesc_call(.Ltlsdesc_hi0)
+  add	a1, a0, tp

llvm/test/CodeGen/RISCV/tlsdesc-symbol.ll

@@ -0,0 +1,24 @@
+;; The test in this file do not appear in tls-models.ll because
+;; they are not auto-generated.
+; RUN: llc -mtriple=riscv64 -relocation-model=pic -enable-tlsdesc < %s \
+; RUN:     | llvm-mc -triple=riscv64 -filetype=obj -o - \
+; RUN:     | llvm-readelf --symbols - \
+; RUN:     | FileCheck %s
+
+; RUN: llc -mtriple=riscv32 -relocation-model=pic -enable-tlsdesc < %s \
+; RUN:     | llvm-mc -triple=riscv32 -filetype=obj -o - \
+; RUN:     | llvm-readelf --symbols - \
+; RUN:     | FileCheck %s
+
+; Check that TLS symbols are lowered correctly based on the specified
+; model. Make sure they're external to avoid them all being optimised to Local
+; Exec for the executable.
+
+@unspecified = external thread_local global i32
+
+define ptr @f1() nounwind {
+entry:
+  ret ptr @unspecified
+  ; CHECK: Symbol table '.symtab' contains 7 entries:
+  ; CHECK: TLS {{.*}} unspecified
+}