[AVR] Support .reloc directive

Reviewed By: benshi001

Differential Revision: https://reviews.llvm.org/D141176

diff --git a/llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.cpp b/llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.cpp
index da9ad49..cf87106 100644 (file)
--- a/llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.cpp
+++ b/llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.cpp
@@ -380,6 +380,8 @@ void AVRAsmBackend::applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
                                MutableArrayRef<char> Data, uint64_t Value,
                                bool IsResolved,
                                const MCSubtargetInfo *STI) const {
+  if (Fixup.getKind() >= FirstLiteralRelocationKind)
+    return;
   adjustFixupValue(Fixup, Target, Value, &Asm.getContext());
   if (Value == 0)
     return; // Doesn't change encoding.
@@ -404,6 +406,21 @@ void AVRAsmBackend::applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
   }
 }
 
+std::optional<MCFixupKind> AVRAsmBackend::getFixupKind(StringRef Name) const {
+  unsigned Type;
+  Type = llvm::StringSwitch<unsigned>(Name)
+#define ELF_RELOC(X, Y) .Case(#X, Y)
+#include "llvm/BinaryFormat/ELFRelocs/AVR.def"
+#undef ELF_RELOC
+             .Case("BFD_RELOC_NONE", ELF::R_AVR_NONE)
+             .Case("BFD_RELOC_16", ELF::R_AVR_16)
+             .Case("BFD_RELOC_32", ELF::R_AVR_32)
+             .Default(-1u);
+  if (Type != -1u)
+    return static_cast<MCFixupKind>(FirstLiteralRelocationKind + Type);
+  return std::nullopt;
+}
+
 MCFixupKindInfo const &AVRAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
   // NOTE: Many AVR fixups work on sets of non-contignous bits. We work around
   // this by saying that the fixup is the size of the entire instruction.
@@ -463,6 +480,11 @@ MCFixupKindInfo const &AVRAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
       {"fixup_port5", 3, 5, 0},
   };
 
+  // Fixup kinds from .reloc directive are like R_AVR_NONE. They do not require
+  // any extra processing.
+  if (Kind >= FirstLiteralRelocationKind)
+    return MCAsmBackend::getFixupKindInfo(FK_NONE);
+
   if (Kind < FirstTargetFixupKind)
     return MCAsmBackend::getFixupKindInfo(Kind);
 
@@ -488,7 +510,7 @@ bool AVRAsmBackend::shouldForceRelocation(const MCAssembler &Asm,
                                           const MCValue &Target) {
   switch ((unsigned)Fixup.getKind()) {
   default:
-    return false;
+    return Fixup.getKind() >= FirstLiteralRelocationKind;
   // Fixups which should always be recorded as relocations.
   case AVR::fixup_7_pcrel:
   case AVR::fixup_13_pcrel:

diff --git a/llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.h b/llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.h
index ea7fc30..c4cb595 100644 (file)
--- a/llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.h
+++ b/llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.h
@@ -42,6 +42,7 @@ public:
                   uint64_t Value, bool IsResolved,
                   const MCSubtargetInfo *STI) const override;
 
+  std::optional<MCFixupKind> getFixupKind(StringRef Name) const override;
   const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override;
 
   unsigned getNumFixupKinds() const override {

diff --git a/llvm/lib/Target/AVR/MCTargetDesc/AVRELFObjectWriter.cpp b/llvm/lib/Target/AVR/MCTargetDesc/AVRELFObjectWriter.cpp
index 850ddf0..d9a7a3a 100644 (file)
--- a/llvm/lib/Target/AVR/MCTargetDesc/AVRELFObjectWriter.cpp
+++ b/llvm/lib/Target/AVR/MCTargetDesc/AVRELFObjectWriter.cpp
@@ -37,6 +37,9 @@ AVRELFObjectWriter::AVRELFObjectWriter(uint8_t OSABI)
 unsigned AVRELFObjectWriter::getRelocType(MCContext &Ctx, const MCValue &Target,
                                           const MCFixup &Fixup,
                                           bool IsPCRel) const {
+  const unsigned Kind = Fixup.getTargetKind();
+  if (Kind >= FirstLiteralRelocationKind)
+    return Kind - FirstLiteralRelocationKind;
   MCSymbolRefExpr::VariantKind Modifier = Target.getAccessVariant();
   switch ((unsigned)Fixup.getKind()) {
   case FK_Data_1:

diff --git a/llvm/test/MC/AVR/reloc-directive-err.s b/llvm/test/MC/AVR/reloc-directive-err.s
new file mode 100644 (file)
index 0000000..d660bde
--- /dev/null
+++ b/llvm/test/MC/AVR/reloc-directive-err.s
@@ -0,0 +1,10 @@
+# RUN: llvm-mc -triple=avr %s 2>&1 | FileCheck --check-prefix=PRINT %s
+# RUN: not llvm-mc -filetype=obj -triple=avr %s -o /dev/null 2>&1 | FileCheck %s
+
+# PRINT: .reloc 0, R_INVALID, 0
+# CHECK: {{.*}}.s:[[#@LINE+1]]:11: error: unknown relocation name
+.reloc 0, R_INVALID, 0
+
+# PRINT: .reloc 0, BFD_RELOC_64, 0
+# CHECK: {{.*}}.s:[[#@LINE+1]]:11: error: unknown relocation name
+.reloc 0, BFD_RELOC_64, 0

diff --git a/llvm/test/MC/AVR/reloc-directive.s b/llvm/test/MC/AVR/reloc-directive.s
new file mode 100644 (file)
index 0000000..6091317
--- /dev/null
+++ b/llvm/test/MC/AVR/reloc-directive.s
@@ -0,0 +1,43 @@
+# RUN: llvm-mc -triple=avr %s | FileCheck --check-prefix=PRINT %s
+# RUN: llvm-mc -filetype=obj -triple=avr %s | llvm-readobj -r - | FileCheck %s
+
+# PRINT:      .reloc 4, R_AVR_NONE, .data
+# PRINT-NEXT: .reloc 2, R_AVR_NONE, foo+4
+# PRINT-NEXT: .reloc 0, R_AVR_NONE, 8
+# PRINT:      .reloc 0, R_AVR_32, .data+2
+# PRINT-NEXT: .reloc 0, R_AVR_16, foo+3
+# PRINT:      .reloc 0, BFD_RELOC_NONE, 9
+# PRINT-NEXT: .reloc 0, BFD_RELOC_16, 9
+# PRINT-NEXT: .reloc 0, BFD_RELOC_32, 9
+
+# CHECK:      Section ({{.*}}) .rela.text {
+# CHECK-NEXT:   0x4 R_AVR_NONE .data 0x0
+# CHECK-NEXT:   0x2 R_AVR_NONE foo 0x4
+# CHECK-NEXT:   0x0 R_AVR_NONE - 0x8
+# CHECK-NEXT:   0x0 R_AVR_32 .data 0x2
+# CHECK-NEXT:   0x0 R_AVR_16 foo 0x3
+# CHECK-NEXT:   0x0 R_AVR_NONE - 0x9
+# CHECK-NEXT:   0x0 R_AVR_16 - 0x9
+# CHECK-NEXT:   0x0 R_AVR_32 - 0x9
+# CHECK-NEXT: }
+
+.text
+  ret
+  nop
+  nop
+  .reloc 4, R_AVR_NONE, .data
+  .reloc 2, R_AVR_NONE, foo+4
+  .reloc 0, R_AVR_NONE, 8
+
+  .reloc 0, R_AVR_32, .data+2
+  .reloc 0, R_AVR_16, foo+3
+
+  .reloc 0, BFD_RELOC_NONE, 9
+  .reloc 0, BFD_RELOC_16, 9
+  .reloc 0, BFD_RELOC_32, 9
+
+.data
+.globl foo
+foo:
+  .word 0
+  .word 0