[PowerPC] Fix missing GOT indirect variant kind

The function MCSymbolRefExpr::getVariantKindForName was missing the entry for
VK_PPC_GOT_PCREL. This patch adds the missing entry.

Differential Revision: https://reviews.llvm.org/D79015

llvm/lib/MC/MCExpr.cpp

@@ -435,6 +435,7 @@ MCSymbolRefExpr::getVariantKindForName(StringRef Name) {
     .Case("got@tlsld@l", VK_PPC_GOT_TLSLD_LO)
     .Case("got@tlsld@h", VK_PPC_GOT_TLSLD_HI)
     .Case("got@tlsld@ha", VK_PPC_GOT_TLSLD_HA)
+    .Case("got@pcrel", VK_PPC_GOT_PCREL)
     .Case("notoc", VK_PPC_NOTOC)
     .Case("gdgot", VK_Hexagon_GD_GOT)
     .Case("gdplt", VK_Hexagon_GD_PLT)

llvm/test/MC/PowerPC/future-reloc.s

@@ -0,0 +1,53 @@
+# RUN: llvm-mc -triple=powerpc64le-unknown-unknown -filetype=obj %s 2>&1 | \
+# RUN: FileCheck %s -check-prefix=MC
+# RUN: llvm-mc -triple=powerpc64le-unknown-unknown -filetype=obj %s | \
+# RUN: llvm-readobj -r | FileCheck %s -check-prefix=READOBJ
+
+# This test checks that on Power PC we can correctly convert @pcrel and
+# @got@pcrel into R_PPC64_PCREL34 and R_PPC64_GOT_PCREL34.
+
+# MC-NOT:    error: invalid variant
+
+# READOBJ:        0x0 R_PPC64_PCREL34 locvalue 0x0
+# READOBJ-NEXT:   0x20 R_PPC64_GOT_PCREL34 evalue 0x0
+
+	.text
+	.abiversion 2
+	.globl	local                   # -- Begin function local
+	.p2align	4
+	.type	local,@function
+local:                                  # @local
+.Llocal$local:
+.Lfunc_begin0:
+# %bb.0:                                # %entry
+	plwa 3, locvalue@PCREL(0), 1
+	blr
+	.long	0
+	.quad	0
+.Lfunc_end0:
+	.size	local, .Lfunc_end0-.Lfunc_begin0
+                                        # -- End function
+	.globl	external                # -- Begin function external
+	.p2align	4
+	.type	external,@function
+external:                               # @external
+.Lexternal$local:
+.Lfunc_begin1:
+# %bb.0:                                # %entry
+	pld 3, evalue@got@pcrel(0), 1
+	lwa 3, 0(3)
+	blr
+	.long	0
+	.quad	0
+.Lfunc_end1:
+	.size	external, .Lfunc_end1-.Lfunc_begin1
+                                        # -- End function
+	.type	locvalue,@object        # @locvalue
+	.section	.bss,"aw",@nobits
+	.globl	locvalue
+	.p2align	2
+locvalue:
+.Llocvalue$local:
+	.long	0                       # 0x0
+	.size	locvalue, 4
+