[PATCH] D14922: [ELF/AArch64] Factor out overflow check into a separate function.

[Igor Kudrin via llvm-commits]

ikudrin created this revision.
ikudrin added reviewers: ruiu, davide.
ikudrin added a subscriber: llvm-commits.
ikudrin added a project: lld.
Herald added subscribers: rengolin, aemerson.

This patch mainly extracts overflow checks for AArch64 relocations into a separate function.

In addition, it corrects checks for R_AARCH64_PREL16 and R_AARCH64_PREL32 relocations.

http://reviews.llvm.org/D14922

Files:
  ELF/Target.cpp

Index: ELF/Target.cpp
===================================================================
--- ELF/Target.cpp
+++ ELF/Target.cpp
@@ -703,18 +703,22 @@
   return Expr & (~static_cast<uint64_t>(0xFFF));
 }
 
+template <unsigned N> static void checkOutOfRange(int64_t X, uint32_t Type) {
+  if (!isInt<N>(X))
+    error("Relocation " + getELFRelocationTypeName(EM_AARCH64, Type) +
+          " out of range");
+}
+
 void AArch64TargetInfo::relocateOne(uint8_t *Loc, uint8_t *BufEnd,
                                     uint32_t Type, uint64_t P,
                                     uint64_t SA) const {
   switch (Type) {
   case R_AARCH64_ABS16:
-    if (!isInt<16>(SA))
-      error("Relocation R_AARCH64_ABS16 out of range");
+    checkOutOfRange<16>(SA, Type);
     write16le(Loc, SA);
     break;
   case R_AARCH64_ABS32:
-    if (!isInt<32>(SA))
-      error("Relocation R_AARCH64_ABS32 out of range");
+    checkOutOfRange<32>(SA, Type);
     write32le(Loc, SA);
     break;
   case R_AARCH64_ABS64:
@@ -731,30 +735,21 @@
     break;
   case R_AARCH64_ADR_PREL_LO21: {
     uint64_t X = SA - P;
-    if (!isInt<21>(X))
-      error("Relocation R_AARCH64_ADR_PREL_LO21 out of range");
+    checkOutOfRange<21>(X, Type);
     updateAArch64Adr(Loc, X & 0x1FFFFF);
     break;
   }
   case R_AARCH64_ADR_GOT_PAGE:
   case R_AARCH64_ADR_PREL_PG_HI21: {
     uint64_t X = getAArch64Page(SA) - getAArch64Page(P);
-    if (!isInt<33>(X)) {
-      if (Type == R_AARCH64_ADR_GOT_PAGE)
-        error("Relocation R_AARCH64_ADR_GOT_PAGE out of range");
-      error("Relocation R_AARCH64_ADR_PREL_PG_HI21 out of range");
-    }
+    checkOutOfRange<33>(X, Type);
     updateAArch64Adr(Loc, (X >> 12) & 0x1FFFFF); // X[32:12]
     break;
   }
   case R_AARCH64_JUMP26:
   case R_AARCH64_CALL26: {
     uint64_t X = SA - P;
-    if (!isInt<28>(X)) {
-      if (Type == R_AARCH64_JUMP26)
-        error("Relocation R_AARCH64_JUMP26 out of range");
-      error("Relocation R_AARCH64_CALL26 out of range");
-    }
+    checkOutOfRange<28>(X, Type);
     or32le(Loc, (X & 0x0FFFFFFC) >> 2);
     break;
   }
@@ -777,13 +772,11 @@
     or32le(Loc, (SA & 0xFFF) << 10);
     break;
   case R_AARCH64_PREL16:
-    if (!isInt<16>(SA))
-      error("Relocation R_AARCH64_PREL16 out of range");
+    checkOutOfRange<16>(SA - P, Type);
     write16le(Loc, SA - P);
     break;
   case R_AARCH64_PREL32:
-    if (!isInt<32>(SA))
-      error("Relocation R_AARCH64_PREL32 out of range");
+    checkOutOfRange<32>(SA - P, Type);
     write32le(Loc, SA - P);
     break;
   case R_AARCH64_PREL64:


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