Vendor import of stripped lld trunk r366426 (just before the release_90vendor/lld/lld-trunk-r366426

branch point):

https://llvm.org/svn/llvm-project/lld/trunk@366426

1 files changed, 379 insertions, 28 deletions

diff --git a/ELF/Arch/PPC.cpp b/ELF/Arch/PPC.cpp
index 767378067341..46c5891e4f8a 100644
--- a/ELF/Arch/PPC.cpp
+++ b/ELF/Arch/PPC.cpp
@@ -1,13 +1,14 @@
 //===- PPC.cpp ------------------------------------------------------------===//
 //
-//                             The LLVM Linker
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
+#include "OutputSections.h"
 #include "Symbols.h"
+#include "SyntheticSections.h"
 #include "Target.h"
 #include "lld/Common/ErrorHandler.h"
 #include "llvm/Support/Endian.h"
@@ -22,60 +23,410 @@ namespace {
 class PPC final : public TargetInfo {
 public:
   PPC();
-  void relocateOne(uint8_t *Loc, RelType Type, uint64_t Val) const override;
-  RelExpr getRelExpr(RelType Type, const Symbol &S,
-                     const uint8_t *Loc) const override;
+  RelExpr getRelExpr(RelType type, const Symbol &s,
+                     const uint8_t *loc) const override;
+  RelType getDynRel(RelType type) const override;
+  void writeGotHeader(uint8_t *buf) const override;
+  void writePltHeader(uint8_t *buf) const override {
+    llvm_unreachable("should call writePPC32GlinkSection() instead");
+  }
+  void writePlt(uint8_t *buf, uint64_t gotPltEntryAddr, uint64_t pltEntryAddr,
+    int32_t index, unsigned relOff) const override {
+    llvm_unreachable("should call writePPC32GlinkSection() instead");
+  }
+  void writeGotPlt(uint8_t *buf, const Symbol &s) const override;
+  bool needsThunk(RelExpr expr, RelType relocType, const InputFile *file,
+                  uint64_t branchAddr, const Symbol &s) const override;
+  uint32_t getThunkSectionSpacing() const override;
+  bool inBranchRange(RelType type, uint64_t src, uint64_t dst) const override;
+  void relocateOne(uint8_t *loc, RelType type, uint64_t val) const override;
+  RelExpr adjustRelaxExpr(RelType type, const uint8_t *data,
+                          RelExpr expr) const override;
+  int getTlsGdRelaxSkip(RelType type) const override;
+  void relaxTlsGdToIe(uint8_t *loc, RelType type, uint64_t val) const override;
+  void relaxTlsGdToLe(uint8_t *loc, RelType type, uint64_t val) const override;
+  void relaxTlsLdToLe(uint8_t *loc, RelType type, uint64_t val) const override;
+  void relaxTlsIeToLe(uint8_t *loc, RelType type, uint64_t val) const override;
 };
 } // namespace
 
+static uint16_t lo(uint32_t v) { return v; }
+static uint16_t ha(uint32_t v) { return (v + 0x8000) >> 16; }
+
+static uint32_t readFromHalf16(const uint8_t *loc) {
+  return read32(config->isLE ? loc : loc - 2);
+}
+
+static void writeFromHalf16(uint8_t *loc, uint32_t insn) {
+  write32(config->isLE ? loc : loc - 2, insn);
+}
+
+void elf::writePPC32GlinkSection(uint8_t *buf, size_t numEntries) {
+  // On PPC Secure PLT ABI, bl foo@plt jumps to a call stub, which loads an
+  // absolute address from a specific .plt slot (usually called .got.plt on
+  // other targets) and jumps there.
+  //
+  // a) With immediate binding (BIND_NOW), the .plt entry is resolved at load
+  // time. The .glink section is not used.
+  // b) With lazy binding, the .plt entry points to a `b PLTresolve`
+  // instruction in .glink, filled in by PPC::writeGotPlt().
+
+  // Write N `b PLTresolve` first.
+  for (size_t i = 0; i != numEntries; ++i)
+    write32(buf + 4 * i, 0x48000000 | 4 * (numEntries - i));
+  buf += 4 * numEntries;
+
+  // Then write PLTresolve(), which has two forms: PIC and non-PIC. PLTresolve()
+  // computes the PLT index (by computing the distance from the landing b to
+  // itself) and calls _dl_runtime_resolve() (in glibc).
+  uint32_t got = in.got->getVA();
+  uint32_t glink = in.plt->getVA(); // VA of .glink
+  const uint8_t *end = buf + 64;
+  if (config->isPic) {
+    uint32_t afterBcl = in.plt->getSize() - target->pltHeaderSize + 12;
+    uint32_t gotBcl = got + 4 - (glink + afterBcl);
+    write32(buf + 0, 0x3d6b0000 | ha(afterBcl));  // addis r11,r11,1f-glink@ha
+    write32(buf + 4, 0x7c0802a6);                 // mflr r0
+    write32(buf + 8, 0x429f0005);                 // bcl 20,30,.+4
+    write32(buf + 12, 0x396b0000 | lo(afterBcl)); // 1: addi r11,r11,1b-.glink@l
+    write32(buf + 16, 0x7d8802a6);                // mflr r12
+    write32(buf + 20, 0x7c0803a6);                // mtlr r0
+    write32(buf + 24, 0x7d6c5850);                // sub r11,r11,r12
+    write32(buf + 28, 0x3d8c0000 | ha(gotBcl));   // addis 12,12,GOT+4-1b@ha
+    if (ha(gotBcl) == ha(gotBcl + 4)) {
+      write32(buf + 32, 0x800c0000 | lo(gotBcl)); // lwz r0,r12,GOT+4-1b@l(r12)
+      write32(buf + 36,
+              0x818c0000 | lo(gotBcl + 4));       // lwz r12,r12,GOT+8-1b@l(r12)
+    } else {
+      write32(buf + 32, 0x840c0000 | lo(gotBcl)); // lwzu r0,r12,GOT+4-1b@l(r12)
+      write32(buf + 36, 0x818c0000 | 4);          // lwz r12,r12,4(r12)
+    }
+    write32(buf + 40, 0x7c0903a6);                // mtctr 0
+    write32(buf + 44, 0x7c0b5a14);                // add r0,11,11
+    write32(buf + 48, 0x7d605a14);                // add r11,0,11
+    write32(buf + 52, 0x4e800420);                // bctr
+    buf += 56;
+  } else {
+    write32(buf + 0, 0x3d800000 | ha(got + 4));   // lis     r12,GOT+4@ha
+    write32(buf + 4, 0x3d6b0000 | ha(-glink));    // addis   r11,r11,-Glink@ha
+    if (ha(got + 4) == ha(got + 8))
+      write32(buf + 8, 0x800c0000 | lo(got + 4)); // lwz r0,GOT+4@l(r12)
+    else
+      write32(buf + 8, 0x840c0000 | lo(got + 4)); // lwzu r0,GOT+4@l(r12)
+    write32(buf + 12, 0x396b0000 | lo(-glink));   // addi    r11,r11,-Glink@l
+    write32(buf + 16, 0x7c0903a6);                // mtctr   r0
+    write32(buf + 20, 0x7c0b5a14);                // add     r0,r11,r11
+    if (ha(got + 4) == ha(got + 8))
+      write32(buf + 24, 0x818c0000 | lo(got + 8)); // lwz r12,GOT+8@ha(r12)
+    else
+      write32(buf + 24, 0x818c0000 | 4);          // lwz r12,4(r12)
+    write32(buf + 28, 0x7d605a14);                // add     r11,r0,r11
+    write32(buf + 32, 0x4e800420);                // bctr
+    buf += 36;
+  }
+
+  // Pad with nop. They should not be executed.
+  for (; buf < end; buf += 4)
+    write32(buf, 0x60000000);
+}
+
 PPC::PPC() {
-  NoneRel = R_PPC_NONE;
-  GotBaseSymOff = 0x8000;
-  GotBaseSymInGotPlt = false;
+  gotRel = R_PPC_GLOB_DAT;
+  noneRel = R_PPC_NONE;
+  pltRel = R_PPC_JMP_SLOT;
+  relativeRel = R_PPC_RELATIVE;
+  iRelativeRel = R_PPC_IRELATIVE;
+  symbolicRel = R_PPC_ADDR32;
+  gotBaseSymInGotPlt = false;
+  gotHeaderEntriesNum = 3;
+  gotPltHeaderEntriesNum = 0;
+  pltHeaderSize = 64; // size of PLTresolve in .glink
+  pltEntrySize = 4;
+
+  needsThunks = true;
+
+  tlsModuleIndexRel = R_PPC_DTPMOD32;
+  tlsOffsetRel = R_PPC_DTPREL32;
+  tlsGotRel = R_PPC_TPREL32;
+
+  defaultMaxPageSize = 65536;
+  defaultImageBase = 0x10000000;
+
+  write32(trapInstr.data(), 0x7fe00008);
+}
+
+void PPC::writeGotHeader(uint8_t *buf) const {
+  // _GLOBAL_OFFSET_TABLE_[0] = _DYNAMIC
+  // glibc stores _dl_runtime_resolve in _GLOBAL_OFFSET_TABLE_[1],
+  // link_map in _GLOBAL_OFFSET_TABLE_[2].
+  write32(buf, mainPart->dynamic->getVA());
+}
+
+void PPC::writeGotPlt(uint8_t *buf, const Symbol &s) const {
+  // Address of the symbol resolver stub in .glink .
+  write32(buf, in.plt->getVA() + 4 * s.pltIndex);
+}
+
+bool PPC::needsThunk(RelExpr expr, RelType type, const InputFile *file,
+                     uint64_t branchAddr, const Symbol &s) const {
+  if (type != R_PPC_REL24 && type != R_PPC_PLTREL24)
+    return false;
+  if (s.isInPlt())
+    return true;
+  if (s.isUndefWeak())
+    return false;
+  return !(expr == R_PC && PPC::inBranchRange(type, branchAddr, s.getVA()));
 }
 
-RelExpr PPC::getRelExpr(RelType Type, const Symbol &S,
-                        const uint8_t *Loc) const {
-  switch (Type) {
+uint32_t PPC::getThunkSectionSpacing() const { return 0x2000000; }
+
+bool PPC::inBranchRange(RelType type, uint64_t src, uint64_t dst) const {
+  uint64_t offset = dst - src;
+  if (type == R_PPC_REL24 || type == R_PPC_PLTREL24)
+    return isInt<26>(offset);
+  llvm_unreachable("unsupported relocation type used in branch");
+}
+
+RelExpr PPC::getRelExpr(RelType type, const Symbol &s,
+                        const uint8_t *loc) const {
+  switch (type) {
+  case R_PPC_DTPREL16:
+  case R_PPC_DTPREL16_HA:
+  case R_PPC_DTPREL16_HI:
+  case R_PPC_DTPREL16_LO:
+  case R_PPC_DTPREL32:
+    return R_DTPREL;
   case R_PPC_REL14:
-  case R_PPC_REL24:
   case R_PPC_REL32:
+  case R_PPC_LOCAL24PC:
+  case R_PPC_REL16_LO:
+  case R_PPC_REL16_HI:
+  case R_PPC_REL16_HA:
     return R_PC;
-  case R_PPC_PLTREL24:
+  case R_PPC_GOT16:
+    return R_GOT_OFF;
+  case R_PPC_REL24:
     return R_PLT_PC;
+  case R_PPC_PLTREL24:
+    return R_PPC32_PLTREL;
+  case R_PPC_GOT_TLSGD16:
+    return R_TLSGD_GOT;
+  case R_PPC_GOT_TLSLD16:
+    return R_TLSLD_GOT;
+  case R_PPC_GOT_TPREL16:
+    return R_GOT_OFF;
+  case R_PPC_TLS:
+    return R_TLSIE_HINT;
+  case R_PPC_TLSGD:
+    return R_TLSDESC_CALL;
+  case R_PPC_TLSLD:
+    return R_TLSLD_HINT;
+  case R_PPC_TPREL16:
+  case R_PPC_TPREL16_HA:
+  case R_PPC_TPREL16_LO:
+  case R_PPC_TPREL16_HI:
+    return R_TLS;
   default:
     return R_ABS;
   }
 }
 
-void PPC::relocateOne(uint8_t *Loc, RelType Type, uint64_t Val) const {
-  switch (Type) {
+RelType PPC::getDynRel(RelType type) const {
+  if (type == R_PPC_ADDR32)
+    return type;
+  return R_PPC_NONE;
+}
+
+static std::pair<RelType, uint64_t> fromDTPREL(RelType type, uint64_t val) {
+  uint64_t dtpBiasedVal = val - 0x8000;
+  switch (type) {
+  case R_PPC_DTPREL16:
+    return {R_PPC64_ADDR16, dtpBiasedVal};
+  case R_PPC_DTPREL16_HA:
+    return {R_PPC_ADDR16_HA, dtpBiasedVal};
+  case R_PPC_DTPREL16_HI:
+    return {R_PPC_ADDR16_HI, dtpBiasedVal};
+  case R_PPC_DTPREL16_LO:
+    return {R_PPC_ADDR16_LO, dtpBiasedVal};
+  case R_PPC_DTPREL32:
+    return {R_PPC_ADDR32, dtpBiasedVal};
+  default:
+    return {type, val};
+  }
+}
+
+void PPC::relocateOne(uint8_t *loc, RelType type, uint64_t val) const {
+  RelType newType;
+  std::tie(newType, val) = fromDTPREL(type, val);
+  switch (newType) {
+  case R_PPC_ADDR16:
+    checkIntUInt(loc, val, 16, type);
+    write16(loc, val);
+    break;
+  case R_PPC_GOT16:
+  case R_PPC_GOT_TLSGD16:
+  case R_PPC_GOT_TLSLD16:
+  case R_PPC_GOT_TPREL16:
+  case R_PPC_TPREL16:
+    checkInt(loc, val, 16, type);
+    write16(loc, val);
+    break;
   case R_PPC_ADDR16_HA:
-    write16be(Loc, (Val + 0x8000) >> 16);
+  case R_PPC_DTPREL16_HA:
+  case R_PPC_GOT_TLSGD16_HA:
+  case R_PPC_GOT_TLSLD16_HA:
+  case R_PPC_GOT_TPREL16_HA:
+  case R_PPC_REL16_HA:
+  case R_PPC_TPREL16_HA:
+    write16(loc, ha(val));
     break;
   case R_PPC_ADDR16_HI:
-    write16be(Loc, Val >> 16);
+  case R_PPC_DTPREL16_HI:
+  case R_PPC_GOT_TLSGD16_HI:
+  case R_PPC_GOT_TLSLD16_HI:
+  case R_PPC_GOT_TPREL16_HI:
+  case R_PPC_REL16_HI:
+  case R_PPC_TPREL16_HI:
+    write16(loc, val >> 16);
     break;
   case R_PPC_ADDR16_LO:
-    write16be(Loc, Val);
+  case R_PPC_DTPREL16_LO:
+  case R_PPC_GOT_TLSGD16_LO:
+  case R_PPC_GOT_TLSLD16_LO:
+  case R_PPC_GOT_TPREL16_LO:
+  case R_PPC_REL16_LO:
+  case R_PPC_TPREL16_LO:
+    write16(loc, val);
     break;
   case R_PPC_ADDR32:
   case R_PPC_REL32:
-    write32be(Loc, Val);
+    write32(loc, val);
     break;
-  case R_PPC_REL14:
-    write32be(Loc, read32be(Loc) | (Val & 0xFFFC));
+  case R_PPC_REL14: {
+    uint32_t mask = 0x0000FFFC;
+    checkInt(loc, val, 16, type);
+    checkAlignment(loc, val, 4, type);
+    write32(loc, (read32(loc) & ~mask) | (val & mask));
     break;
-  case R_PPC_PLTREL24:
+  }
   case R_PPC_REL24:
-    write32be(Loc, read32be(Loc) | (Val & 0x3FFFFFC));
+  case R_PPC_LOCAL24PC:
+  case R_PPC_PLTREL24: {
+    uint32_t mask = 0x03FFFFFC;
+    checkInt(loc, val, 26, type);
+    checkAlignment(loc, val, 4, type);
+    write32(loc, (read32(loc) & ~mask) | (val & mask));
     break;
+  }
+  default:
+    error(getErrorLocation(loc) + "unrecognized relocation " + toString(type));
+  }
+}
+
+RelExpr PPC::adjustRelaxExpr(RelType type, const uint8_t *data,
+                             RelExpr expr) const {
+  if (expr == R_RELAX_TLS_GD_TO_IE)
+    return R_RELAX_TLS_GD_TO_IE_GOT_OFF;
+  if (expr == R_RELAX_TLS_LD_TO_LE)
+    return R_RELAX_TLS_LD_TO_LE_ABS;
+  return expr;
+}
+
+int PPC::getTlsGdRelaxSkip(RelType type) const {
+  // A __tls_get_addr call instruction is marked with 2 relocations:
+  //
+  //   R_PPC_TLSGD / R_PPC_TLSLD: marker relocation
+  //   R_PPC_REL24: __tls_get_addr
+  //
+  // After the relaxation we no longer call __tls_get_addr and should skip both
+  // relocations to not create a false dependence on __tls_get_addr being
+  // defined.
+  if (type == R_PPC_TLSGD || type == R_PPC_TLSLD)
+    return 2;
+  return 1;
+}
+
+void PPC::relaxTlsGdToIe(uint8_t *loc, RelType type, uint64_t val) const {
+  switch (type) {
+  case R_PPC_GOT_TLSGD16: {
+    // addi rT, rA, x@got@tlsgd --> lwz rT, x@got@tprel(rA)
+    uint32_t insn = readFromHalf16(loc);
+    writeFromHalf16(loc, 0x80000000 | (insn & 0x03ff0000));
+    relocateOne(loc, R_PPC_GOT_TPREL16, val);
+    break;
+  }
+  case R_PPC_TLSGD:
+    // bl __tls_get_addr(x@tldgd) --> add r3, r3, r2
+    write32(loc, 0x7c631214);
+    break;
+  default:
+    llvm_unreachable("unsupported relocation for TLS GD to IE relaxation");
+  }
+}
+
+void PPC::relaxTlsGdToLe(uint8_t *loc, RelType type, uint64_t val) const {
+  switch (type) {
+  case R_PPC_GOT_TLSGD16:
+    // addi r3, r31, x@got@tlsgd --> addis r3, r2, x@tprel@ha
+    writeFromHalf16(loc, 0x3c620000 | ha(val));
+    break;
+  case R_PPC_TLSGD:
+    // bl __tls_get_addr(x@tldgd) --> add r3, r3, x@tprel@l
+    write32(loc, 0x38630000 | lo(val));
+    break;
+  default:
+    llvm_unreachable("unsupported relocation for TLS GD to LE relaxation");
+  }
+}
+
+void PPC::relaxTlsLdToLe(uint8_t *loc, RelType type, uint64_t val) const {
+  switch (type) {
+  case R_PPC_GOT_TLSLD16:
+    // addi r3, rA, x@got@tlsgd --> addis r3, r2, 0
+    writeFromHalf16(loc, 0x3c620000);
+    break;
+  case R_PPC_TLSLD:
+    // r3+x@dtprel computes r3+x-0x8000, while we want it to compute r3+x@tprel
+    // = r3+x-0x7000, so add 4096 to r3.
+    // bl __tls_get_addr(x@tlsld) --> addi r3, r3, 4096
+    write32(loc, 0x38631000);
+    break;
+  case R_PPC_DTPREL16:
+  case R_PPC_DTPREL16_HA:
+  case R_PPC_DTPREL16_HI:
+  case R_PPC_DTPREL16_LO:
+    relocateOne(loc, type, val);
+    break;
+  default:
+    llvm_unreachable("unsupported relocation for TLS LD to LE relaxation");
+  }
+}
+
+void PPC::relaxTlsIeToLe(uint8_t *loc, RelType type, uint64_t val) const {
+  switch (type) {
+  case R_PPC_GOT_TPREL16: {
+    // lwz rT, x@got@tprel(rA) --> addis rT, r2, x@tprel@ha
+    uint32_t rt = readFromHalf16(loc) & 0x03e00000;
+    writeFromHalf16(loc, 0x3c020000 | rt | ha(val));
+    break;
+  }
+  case R_PPC_TLS: {
+    uint32_t insn = read32(loc);
+    if (insn >> 26 != 31)
+      error("unrecognized instruction for IE to LE R_PPC_TLS");
+    // addi rT, rT, x@tls --> addi rT, rT, x@tprel@l
+    uint32_t dFormOp = getPPCDFormOp((read32(loc) & 0x000007fe) >> 1);
+    if (dFormOp == 0)
+      error("unrecognized instruction for IE to LE R_PPC_TLS");
+    write32(loc, (dFormOp << 26) | (insn & 0x03ff0000) | lo(val));
+    break;
+  }
   default:
-    error(getErrorLocation(Loc) + "unrecognized reloc " + Twine(Type));
+    llvm_unreachable("unsupported relocation for TLS IE to LE relaxation");
   }
 }
 
 TargetInfo *elf::getPPCTargetInfo() {
-  static PPC Target;
-  return &Target;
+  static PPC target;
+  return &target;
 }