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[ELF][PPC64] Rename some PPC64 ELFv2 specific RelExpr from R_PPC_* to…
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… R_PPC64_*

The following abstract relocation types (RelExpr) are PPC64 ELFv2 ABI specific,
not used by PPC32. So rename them to prevent confusion when the PPC32 port is improved.

* R_PPC_CALL R_PPC_CALL_PLT:
  R_PPC_CALL_PLT represents R_PPC64_REL14 and R_PPC64_REL24.
  If the function is not preemptable, R_PPC_CALL_PLT can be optimized to R_PPC_CALL:
  the formula adjusts the symbol VA from the global entry point to the local entry point.
* R_PPC_TOC: represents R_PPC64_TOC.  We don't have a test. Add one to ppc64-relocs.s
  Rename it to R_PPC64_TOCBASE because `@tocbase` is the assembly form.

Reviewed By: ruiu

Differential Revision: https://reviews.llvm.org/D62800

llvm-svn: 362359
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MaskRay committed Jun 3, 2019
1 parent ea0c66b commit 8522d57
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Showing 5 changed files with 37 additions and 23 deletions.
4 changes: 2 additions & 2 deletions lld/ELF/Arch/PPC64.cpp
Expand Up @@ -545,10 +545,10 @@ RelExpr PPC64::getRelExpr(RelType Type, const Symbol &S,
case R_PPC64_TOC16_LO_DS:
return Config->TocOptimize ? R_PPC64_RELAX_TOC : R_GOTREL;
case R_PPC64_TOC:
return R_PPC_TOC;
return R_PPC64_TOCBASE;
case R_PPC64_REL14:
case R_PPC64_REL24:
return R_PPC_CALL_PLT;
return R_PPC64_CALL_PLT;
case R_PPC64_REL16_LO:
case R_PPC64_REL16_HA:
case R_PPC64_REL32:
Expand Down
8 changes: 4 additions & 4 deletions lld/ELF/InputSection.cpp
Expand Up @@ -717,9 +717,9 @@ static uint64_t getRelocTargetVA(const InputFile *File, RelType Type, int64_t A,
case R_PLT:
return Sym.getPltVA() + A;
case R_PLT_PC:
case R_PPC_CALL_PLT:
case R_PPC64_CALL_PLT:
return Sym.getPltVA() + A - P;
case R_PPC_CALL: {
case R_PPC64_CALL: {
uint64_t SymVA = Sym.getVA(A);
// If we have an undefined weak symbol, we might get here with a symbol
// address of zero. That could overflow, but the code must be unreachable,
Expand All @@ -735,7 +735,7 @@ static uint64_t getRelocTargetVA(const InputFile *File, RelType Type, int64_t A,
// branching to the local entry point.
return SymVA - P + getPPC64GlobalEntryToLocalEntryOffset(Sym.StOther);
}
case R_PPC_TOC:
case R_PPC64_TOCBASE:
return getPPC64TocBase() + A;
case R_RELAX_GOT_PC:
return Sym.getVA(A) - P;
Expand Down Expand Up @@ -922,7 +922,7 @@ void InputSectionBase::relocateAlloc(uint8_t *Buf, uint8_t *BufEnd) {
case R_RELAX_TLS_GD_TO_IE_GOTPLT:
Target->relaxTlsGdToIe(BufLoc, Type, TargetVA);
break;
case R_PPC_CALL:
case R_PPC64_CALL:
// If this is a call to __tls_get_addr, it may be part of a TLS
// sequence that has been relaxed and turned into a nop. In this
// case, we don't want to handle it as a call.
Expand Down
20 changes: 11 additions & 9 deletions lld/ELF/Relocations.cpp
Expand Up @@ -363,7 +363,7 @@ static bool isAbsoluteValue(const Symbol &Sym) {

// Returns true if Expr refers a PLT entry.
static bool needsPlt(RelExpr Expr) {
return oneof<R_PLT_PC, R_PPC_CALL_PLT, R_PLT>(Expr);
return oneof<R_PLT_PC, R_PPC64_CALL_PLT, R_PLT>(Expr);
}

// Returns true if Expr refers a GOT entry. Note that this function
Expand All @@ -378,8 +378,9 @@ static bool needsGot(RelExpr Expr) {
// True if this expression is of the form Sym - X, where X is a position in the
// file (PC, or GOT for example).
static bool isRelExpr(RelExpr Expr) {
return oneof<R_PC, R_GOTREL, R_GOTPLTREL, R_MIPS_GOTREL, R_PPC_CALL,
R_PPC64_RELAX_TOC, R_PPC_CALL_PLT, R_AARCH64_PAGE_PC, R_RELAX_GOT_PC>(Expr);
return oneof<R_PC, R_GOTREL, R_GOTPLTREL, R_MIPS_GOTREL, R_PPC64_CALL,
R_PPC64_CALL_PLT, R_PPC64_RELAX_TOC, R_AARCH64_PAGE_PC,
R_RELAX_GOT_PC>(Expr);
}

// Returns true if a given relocation can be computed at link-time.
Expand All @@ -398,7 +399,7 @@ static bool isStaticLinkTimeConstant(RelExpr E, RelType Type, const Symbol &Sym,
R_MIPS_GOT_LOCAL_PAGE, R_MIPS_GOTREL, R_MIPS_GOT_OFF,
R_MIPS_GOT_OFF32, R_MIPS_GOT_GP_PC, R_MIPS_TLSGD,
R_AARCH64_GOT_PAGE_PC, R_GOT_PC, R_GOTONLY_PC, R_GOTPLTONLY_PC,
R_PLT_PC, R_TLSGD_GOT, R_TLSGD_GOTPLT, R_TLSGD_PC, R_PPC_CALL_PLT,
R_PLT_PC, R_TLSGD_GOT, R_TLSGD_GOTPLT, R_TLSGD_PC, R_PPC64_CALL_PLT,
R_PPC64_RELAX_TOC, R_TLSDESC_CALL, R_TLSDESC_PC,
R_AARCH64_TLSDESC_PAGE, R_HINT, R_TLSLD_HINT, R_TLSIE_HINT>(E))
return true;
Expand Down Expand Up @@ -452,8 +453,8 @@ static bool isStaticLinkTimeConstant(RelExpr E, RelType Type, const Symbol &Sym,

static RelExpr toPlt(RelExpr Expr) {
switch (Expr) {
case R_PPC_CALL:
return R_PPC_CALL_PLT;
case R_PPC64_CALL:
return R_PPC64_CALL_PLT;
case R_PC:
return R_PLT_PC;
case R_ABS:
Expand All @@ -469,8 +470,8 @@ static RelExpr fromPlt(RelExpr Expr) {
switch (Expr) {
case R_PLT_PC:
return R_PC;
case R_PPC_CALL_PLT:
return R_PPC_CALL;
case R_PPC64_CALL_PLT:
return R_PPC64_CALL;
case R_PLT:
return R_ABS;
default:
Expand Down Expand Up @@ -1125,7 +1126,8 @@ static void scanReloc(InputSectionBase &Sec, OffsetGetter &GetOffset, RelTy *&I,
// The 4 types that relative GOTPLT are all x86 and x86-64 specific.
if (oneof<R_GOTPLTONLY_PC, R_GOTPLTREL, R_GOTPLT, R_TLSGD_GOTPLT>(Expr)) {
In.GotPlt->HasGotPltOffRel = true;
} else if (oneof<R_GOTONLY_PC, R_GOTREL, R_PPC_TOC, R_PPC64_RELAX_TOC>(Expr)) {
} else if (oneof<R_GOTONLY_PC, R_GOTREL, R_PPC64_TOCBASE, R_PPC64_RELAX_TOC>(
Expr)) {
In.Got->HasGotOffRel = true;
}

Expand Down
6 changes: 3 additions & 3 deletions lld/ELF/Relocations.h
Expand Up @@ -91,10 +91,10 @@ enum RelExpr {
R_MIPS_GOT_OFF32,
R_MIPS_TLSGD,
R_MIPS_TLSLD,
R_PPC_CALL,
R_PPC_CALL_PLT,
R_PPC_TOC,
R_PPC64_CALL,
R_PPC64_CALL_PLT,
R_PPC64_RELAX_TOC,
R_PPC64_TOCBASE,
R_RISCV_PC_INDIRECT,
};

Expand Down
22 changes: 17 additions & 5 deletions lld/test/ELF/ppc64-relocs.s
Expand Up @@ -2,12 +2,12 @@

# RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %s -o %t.o
# RUN: ld.lld --no-toc-optimize %t.o -o %t
# RUN: llvm-readelf -x .rodata -x .eh_frame %t | FileCheck %s --check-prefix=DATALE
# RUN: llvm-readelf -x .rodata -x .R_PPC64_TOC -x .eh_frame %t | FileCheck %s --check-prefix=DATALE
# RUN: llvm-objdump -d --no-show-raw-insn %t | FileCheck %s

# RUN: llvm-mc -filetype=obj -triple=powerpc64-unknown-linux %s -o %t.o
# RUN: ld.lld --no-toc-optimize %t.o -o %t
# RUN: llvm-readelf -x .rodata -x .eh_frame %t | FileCheck %s --check-prefix=DATABE
# RUN: llvm-readelf -x .rodata -x .R_PPC64_TOC -x .eh_frame %t | FileCheck %s --check-prefix=DATABE
# RUN: llvm-objdump -d --no-show-raw-insn %t | FileCheck %s

.text
Expand Down Expand Up @@ -139,14 +139,26 @@ _start:
__foo:
li 3,0

.section .R_PPC64_TOC,"a",@progbits
.quad .TOC.@tocbase

# SEC: .got PROGBITS 0000000010020000

## tocbase = .got+0x8000 = 0x10028000
# DATALE-LABEL: section '.R_PPC64_TOC':
# DATALE: 00800210 00000000

# DATABE-LABEL: section '.R_PPC64_TOC':
# DATABE: 00000000 10028000

# Check that the personality (relocated by R_PPC64_REL64) in the .eh_frame
# equals the address of __foo.
# 0x100001e2 + 0x76fe = 0x10010058
# 0x100001ea + 0xfe6e = 0x10010058
# DATALE: section '.eh_frame':
# DATALE: 0x100001e0 {{....}}76fe
# DATALE: 0x100001e8 {{....}}6efe

# DATABE: section '.eh_frame':
# DATABE: 0x100001e0 {{[0-9a-f]+ [0-9a-f]+}} fe76{{....}}
# DATABE: 0x100001e8 {{[0-9a-f]+ [0-9a-f]+}} fe6e{{....}}

# CHECK: __foo
# CHECK-NEXT: 10010058: li 3, 0

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