[MC] Move EH DWARF encodings from MC to CodeGen, NFC
Summary:
The TType encoding, LSDA encoding, and personality encoding are all
passed explicitly by CodeGen to the assembler through .cfi_* directives,
so only the AsmPrinter needs to know about them.
The FDE CFI encoding however, controls the encoding of the label
implicitly created by the .cfi_startproc directive. That directive seems
to be special in that it doesn't take an encoding, so the assembler just
has to know how to encode one DSO-local label reference from .eh_frame
to .text.
As a result, it looks like MC will continue to have to know when the
large code model is in use. Perhaps we could invent a '.cfi_startproc
[large]' flag so that this knowledge doesn't need to pollute the
assembler.
Reviewers: davide, lliu0, JDevlieghere
Subscribers: hiraditya, fedor.sergeev, llvm-commits
Differential Revision: https://reviews.llvm.org/D50533
llvm-svn: 339397
diff --git a/llvm/lib/MC/MCObjectFileInfo.cpp b/llvm/lib/MC/MCObjectFileInfo.cpp
index b88d2d8..8f1ca4e 100644
--- a/llvm/lib/MC/MCObjectFileInfo.cpp
+++ b/llvm/lib/MC/MCObjectFileInfo.cpp
@@ -63,11 +63,7 @@
if (T.isWatchABI())
OmitDwarfIfHaveCompactUnwind = true;
- PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel
- | dwarf::DW_EH_PE_sdata4;
- LSDAEncoding = FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
- TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
- dwarf::DW_EH_PE_sdata4;
+ FDECFIEncoding = dwarf::DW_EH_PE_pcrel;
// .comm doesn't support alignment before Leopard.
if (T.isMacOSX() && T.isMacOSXVersionLT(10, 5))
@@ -311,161 +307,14 @@
case Triple::bpfeb:
FDECFIEncoding = dwarf::DW_EH_PE_sdata8;
break;
+ case Triple::hexagon:
+ FDECFIEncoding =
+ PositionIndependent ? dwarf::DW_EH_PE_pcrel : dwarf::DW_EH_PE_absptr;
default:
FDECFIEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
break;
}
- switch (T.getArch()) {
- case Triple::arm:
- case Triple::armeb:
- case Triple::thumb:
- case Triple::thumbeb:
- if (Ctx->getAsmInfo()->getExceptionHandlingType() == ExceptionHandling::ARM)
- break;
- // Fallthrough if not using EHABI
- LLVM_FALLTHROUGH;
- case Triple::ppc:
- case Triple::x86:
- PersonalityEncoding = PositionIndependent
- ? dwarf::DW_EH_PE_indirect |
- dwarf::DW_EH_PE_pcrel |
- dwarf::DW_EH_PE_sdata4
- : dwarf::DW_EH_PE_absptr;
- LSDAEncoding = PositionIndependent
- ? dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4
- : dwarf::DW_EH_PE_absptr;
- TTypeEncoding = PositionIndependent
- ? dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
- dwarf::DW_EH_PE_sdata4
- : dwarf::DW_EH_PE_absptr;
- break;
- case Triple::x86_64:
- if (PositionIndependent) {
- PersonalityEncoding =
- dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
- (Large ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4);
- LSDAEncoding = dwarf::DW_EH_PE_pcrel |
- (Large ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4);
- TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
- (Large ? dwarf::DW_EH_PE_sdata8 : dwarf::DW_EH_PE_sdata4);
- } else {
- PersonalityEncoding =
- Large ? dwarf::DW_EH_PE_absptr : dwarf::DW_EH_PE_udata4;
- LSDAEncoding = Large ? dwarf::DW_EH_PE_absptr : dwarf::DW_EH_PE_udata4;
- TTypeEncoding = Large ? dwarf::DW_EH_PE_absptr : dwarf::DW_EH_PE_udata4;
- }
- break;
- case Triple::hexagon:
- PersonalityEncoding = dwarf::DW_EH_PE_absptr;
- LSDAEncoding = dwarf::DW_EH_PE_absptr;
- FDECFIEncoding = dwarf::DW_EH_PE_absptr;
- TTypeEncoding = dwarf::DW_EH_PE_absptr;
- if (PositionIndependent) {
- PersonalityEncoding |= dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel;
- LSDAEncoding |= dwarf::DW_EH_PE_pcrel;
- FDECFIEncoding |= dwarf::DW_EH_PE_pcrel;
- TTypeEncoding |= dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel;
- }
- break;
- case Triple::aarch64:
- case Triple::aarch64_be:
- // The small model guarantees static code/data size < 4GB, but not where it
- // will be in memory. Most of these could end up >2GB away so even a signed
- // pc-relative 32-bit address is insufficient, theoretically.
- if (PositionIndependent) {
- PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
- dwarf::DW_EH_PE_sdata8;
- LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8;
- TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
- dwarf::DW_EH_PE_sdata8;
- } else {
- PersonalityEncoding = dwarf::DW_EH_PE_absptr;
- LSDAEncoding = dwarf::DW_EH_PE_absptr;
- TTypeEncoding = dwarf::DW_EH_PE_absptr;
- }
- break;
- case Triple::lanai:
- LSDAEncoding = dwarf::DW_EH_PE_absptr;
- PersonalityEncoding = dwarf::DW_EH_PE_absptr;
- TTypeEncoding = dwarf::DW_EH_PE_absptr;
- break;
- case Triple::mips:
- case Triple::mipsel:
- case Triple::mips64:
- case Triple::mips64el:
- // MIPS uses indirect pointer to refer personality functions and types, so
- // that the eh_frame section can be read-only. DW.ref.personality will be
- // generated for relocation.
- PersonalityEncoding = dwarf::DW_EH_PE_indirect;
- // FIXME: The N64 ABI probably ought to use DW_EH_PE_sdata8 but we can't
- // identify N64 from just a triple.
- TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
- dwarf::DW_EH_PE_sdata4;
- // We don't support PC-relative LSDA references in GAS so we use the default
- // DW_EH_PE_absptr for those.
-
- // FreeBSD must be explicit about the data size and using pcrel since it's
- // assembler/linker won't do the automatic conversion that the Linux tools
- // do.
- if (T.isOSFreeBSD()) {
- PersonalityEncoding |= dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
- LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
- }
- break;
- case Triple::ppc64:
- case Triple::ppc64le:
- PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
- dwarf::DW_EH_PE_udata8;
- LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8;
- TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
- dwarf::DW_EH_PE_udata8;
- break;
- case Triple::sparcel:
- case Triple::sparc:
- if (PositionIndependent) {
- LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
- PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
- dwarf::DW_EH_PE_sdata4;
- TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
- dwarf::DW_EH_PE_sdata4;
- } else {
- LSDAEncoding = dwarf::DW_EH_PE_absptr;
- PersonalityEncoding = dwarf::DW_EH_PE_absptr;
- TTypeEncoding = dwarf::DW_EH_PE_absptr;
- }
- break;
- case Triple::sparcv9:
- LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
- if (PositionIndependent) {
- PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
- dwarf::DW_EH_PE_sdata4;
- TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
- dwarf::DW_EH_PE_sdata4;
- } else {
- PersonalityEncoding = dwarf::DW_EH_PE_absptr;
- TTypeEncoding = dwarf::DW_EH_PE_absptr;
- }
- break;
- case Triple::systemz:
- // All currently-defined code models guarantee that 4-byte PC-relative
- // values will be in range.
- if (PositionIndependent) {
- PersonalityEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
- dwarf::DW_EH_PE_sdata4;
- LSDAEncoding = dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4;
- TTypeEncoding = dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |
- dwarf::DW_EH_PE_sdata4;
- } else {
- PersonalityEncoding = dwarf::DW_EH_PE_absptr;
- LSDAEncoding = dwarf::DW_EH_PE_absptr;
- TTypeEncoding = dwarf::DW_EH_PE_absptr;
- }
- break;
- default:
- break;
- }
-
unsigned EHSectionType = T.getArch() == Triple::x86_64
? ELF::SHT_X86_64_UNWIND
: ELF::SHT_PROGBITS;
@@ -908,8 +757,7 @@
SupportsCompactUnwindWithoutEHFrame = false;
OmitDwarfIfHaveCompactUnwind = false;
- PersonalityEncoding = LSDAEncoding = FDECFIEncoding = TTypeEncoding =
- dwarf::DW_EH_PE_absptr;
+ FDECFIEncoding = dwarf::DW_EH_PE_absptr;
CompactUnwindDwarfEHFrameOnly = 0;