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[PAC][MC][AArch64] Fix error message for AUTH_ABS64 reloc with ILP32 #89563

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Merged
merged 1 commit into from
Apr 23, 2024
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[PAC][MC][AArch64] Fix error message for AUTH_ABS64 reloc with ILP32 #89563

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16 changes: 8 additions & 8 deletions llvm/lib/Target/AArch64/MCTargetDesc/AArch64ELFObjectWriter.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -211,18 +211,18 @@ unsigned AArch64ELFObjectWriter::getRelocType(MCContext &Ctx,
Target.getAccessVariant() == MCSymbolRefExpr::VK_GOTPCREL)
? ELF::R_AARCH64_GOTPCREL32
: R_CLS(ABS32);
case FK_Data_8:
case FK_Data_8: {
bool IsAuth = (RefKind == AArch64MCExpr::VK_AUTH ||
RefKind == AArch64MCExpr::VK_AUTHADDR);
if (IsILP32) {
Ctx.reportError(Fixup.getLoc(),
"ILP32 8 byte absolute data "
"relocation not supported (LP64 eqv: ABS64)");
Twine("ILP32 8 byte absolute data "
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8-byte absolute data relocation is not supported in ILP32?

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According to the spec, it's not - see no "ELF32 code" for R_<CLS>_ABS64 in the table here https://github.com/ARM-software/abi-aa/blob/main/aaelf64/aaelf64.rst#static-data-relocations

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Ok, I was suggesting a candidate diagnostic message

8-byte absolute data relocation is not supported in ILP32

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It looks like that error messages across the function use some convention, so it's probably better to stick with it (or change the messages everywhere at once)

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Also, I think we should get rid of these LP64 eqv: messages because of the maintenance burden and because they're not really helpful. If you're targeting ILP32 and writing assembly that triggers one of these messages then you're probably an expert who doesn't need help figuring out which relocation type to use, and knowing the LP64 equivalent wouldn't help you anyway because you'd need something that works on ILP32.

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#138625

"relocation not supported (LP64 eqv: ") +
(IsAuth ? "AUTH_ABS64" : "ABS64") + Twine(')'));
return ELF::R_AARCH64_NONE;
} else {
if (RefKind == AArch64MCExpr::VK_AUTH ||
RefKind == AArch64MCExpr::VK_AUTHADDR)
return ELF::R_AARCH64_AUTH_ABS64;
return ELF::R_AARCH64_ABS64;
}
return (IsAuth ? ELF::R_AARCH64_AUTH_ABS64 : ELF::R_AARCH64_ABS64);
}
case AArch64::fixup_aarch64_add_imm12:
if (RefKind == AArch64MCExpr::VK_DTPREL_HI12)
return R_CLS(TLSLD_ADD_DTPREL_HI12);
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8 changes: 8 additions & 0 deletions llvm/test/MC/AArch64/ilp32-diagnostics.s
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Expand Up @@ -8,6 +8,14 @@

.xword sym+16
// CHECK-ERROR: error: ILP32 8 byte absolute data relocation not supported (LP64 eqv: ABS64)
// CHECK-ERROR: ^

.xword sym@AUTH(da,42)
// CHECK-ERROR: error: ILP32 8 byte absolute data relocation not supported (LP64 eqv: AUTH_ABS64)
// CHECK-ERROR: ^

.xword sym@AUTH(da,42,addr)
// CHECK-ERROR: error: ILP32 8 byte absolute data relocation not supported (LP64 eqv: AUTH_ABS64)
// CHECK-ERROR: ^

movz x7, #:abs_g3:some_label
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