[PATCH] D61973: [AArch64] Support .reloc *, R_AARCH64_NONE, *

[Fangrui Song via Phabricator via llvm-commits]

MaskRay created this revision.
MaskRay added reviewers: peter.smith, rprichard.
Herald added subscribers: llvm-commits, atanasyan, kristof.beyls, arichardson, javed.absar, sdardis.
Herald added a project: LLVM.

This can be used to create references among sections. When --gc-sections
is used, the referenced section will be retained if the origin section
is retained.

fixup_aarch64_NONE is similar to fixup_Mips_NONE.


Repository:
  rL LLVM

https://reviews.llvm.org/D61973

Files:
  lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
  lib/Target/AArch64/MCTargetDesc/AArch64ELFObjectWriter.cpp
  lib/Target/AArch64/MCTargetDesc/AArch64FixupKinds.h


Index: lib/Target/AArch64/MCTargetDesc/AArch64FixupKinds.h
===================================================================
--- lib/Target/AArch64/MCTargetDesc/AArch64FixupKinds.h
+++ lib/Target/AArch64/MCTargetDesc/AArch64FixupKinds.h
@@ -15,8 +15,11 @@
 namespace AArch64 {
 
 enum Fixups {
+  // Fixups resulting in R_AARCH64_NONE.
+  fixup_aarch64_NONE = FirstTargetFixupKind,
+
   // A 21-bit pc-relative immediate inserted into an ADR instruction.
-  fixup_aarch64_pcrel_adr_imm21 = FirstTargetFixupKind,
+  fixup_aarch64_pcrel_adr_imm21,
 
   // A 21-bit pc-relative immediate inserted into an ADRP instruction.
   fixup_aarch64_pcrel_adrp_imm21,
Index: lib/Target/AArch64/MCTargetDesc/AArch64ELFObjectWriter.cpp
===================================================================
--- lib/Target/AArch64/MCTargetDesc/AArch64ELFObjectWriter.cpp
+++ lib/Target/AArch64/MCTargetDesc/AArch64ELFObjectWriter.cpp
@@ -200,6 +200,8 @@
         return ELF::R_AARCH64_NONE;
       } else
         return ELF::R_AARCH64_ABS64;
+    case AArch64::fixup_aarch64_NONE:
+      return ELF::R_AARCH64_NONE;
     case AArch64::fixup_aarch64_add_imm12:
       if (RefKind == AArch64MCExpr::VK_DTPREL_HI12)
         return R_CLS(TLSLD_ADD_DTPREL_HI12);
Index: lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
===================================================================
--- lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
+++ lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
@@ -41,12 +41,15 @@
     return AArch64::NumTargetFixupKinds;
   }
 
+  Optional<MCFixupKind> getFixupKind(StringRef Name) const override;
+
   const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override {
     const static MCFixupKindInfo Infos[AArch64::NumTargetFixupKinds] = {
         // This table *must* be in the order that the fixup_* kinds are defined
         // in AArch64FixupKinds.h.
         //
         // Name                           Offset (bits) Size (bits)     Flags
+        {"fixup_aarch64_NONE", 0, 0, 0},
         {"fixup_aarch64_pcrel_adr_imm21", 0, 32, PCRelFlagVal},
         {"fixup_aarch64_pcrel_adrp_imm21", 0, 32, PCRelFlagVal},
         {"fixup_aarch64_add_imm12", 10, 12, 0},
@@ -103,6 +106,7 @@
   default:
     llvm_unreachable("Unknown fixup kind!");
 
+  case AArch64::fixup_aarch64_NONE:
   case AArch64::fixup_aarch64_tlsdesc_call:
     return 0;
 
@@ -304,6 +308,7 @@
     if (Value & 0x3)
       Ctx.reportError(Fixup.getLoc(), "fixup not sufficiently aligned");
     return (Value >> 2) & 0x3ffffff;
+  case AArch64::fixup_aarch64_NONE:
   case FK_Data_1:
   case FK_Data_2:
   case FK_Data_4:
@@ -314,6 +319,12 @@
   }
 }
 
+Optional<MCFixupKind> AArch64AsmBackend::getFixupKind(StringRef Name) const {
+  if (Name == "R_AARCH64_NONE")
+    return (MCFixupKind)AArch64::fixup_aarch64_NONE;
+  return MCAsmBackend::getFixupKind(Name);
+}
+
 /// getFixupKindContainereSizeInBytes - The number of bytes of the
 /// container involved in big endian or 0 if the item is little endian
 unsigned AArch64AsmBackend::getFixupKindContainereSizeInBytes(unsigned Kind) const {


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D61973.199713.patch
Type: text/x-patch
Size: 3110 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20190516/5345e5d3/attachment.bin>