diff options
| author | Martin Storsjo <martin@martin.st> | 2018-10-04 20:43:38 +0000 |
|---|---|---|
| committer | Martin Storsjo <martin@martin.st> | 2018-10-04 20:43:38 +0000 |
| commit | fea7ddb36e42bbb07faae66b771b52eaf88bfd0d (patch) | |
| tree | 0ecb772f973c61529eb6d2069e3a78120528c24f | |
| parent | a7fa70cb3e47668da003d5f1e5e9e64ceb4d5404 (diff) | |
[COFF] [X86] Don't use llvm_unreachable for unsupported relocation types
This can happen if assembling a reference to _GLOBAL_OFFSET_TABLE_.
While it doesn't make sense to try to assemble that for COFF,
the fact that we previously used llvm_unreachable meant that the code
had undefined behaviour if something tried to assemble that.
The configure script of libgmp would try to assemble such a snippet
(which should signal a failure). If llvm is built without assertions,
the undefined behaviour meant a (near) infinite loop.
Differential Revision: https://reviews.llvm.org/D52903
| -rw-r--r-- | llvm/lib/Target/X86/MCTargetDesc/X86WinCOFFObjectWriter.cpp | 6 | ||||
| -rw-r--r-- | llvm/test/MC/COFF/unsupported-relocations.s | 5 |
2 files changed, 9 insertions, 2 deletions
diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86WinCOFFObjectWriter.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86WinCOFFObjectWriter.cpp index a5e115e5ff4..2aec695b2db 100644 --- a/llvm/lib/Target/X86/MCTargetDesc/X86WinCOFFObjectWriter.cpp +++ b/llvm/lib/Target/X86/MCTargetDesc/X86WinCOFFObjectWriter.cpp @@ -79,7 +79,8 @@ unsigned X86WinCOFFObjectWriter::getRelocType(MCContext &Ctx, case FK_SecRel_4: return COFF::IMAGE_REL_AMD64_SECREL; default: - llvm_unreachable("unsupported relocation type"); + Ctx.reportError(Fixup.getLoc(), "unsupported relocation type"); + return COFF::IMAGE_REL_AMD64_ADDR32; } } else if (getMachine() == COFF::IMAGE_FILE_MACHINE_I386) { switch (FixupKind) { @@ -100,7 +101,8 @@ unsigned X86WinCOFFObjectWriter::getRelocType(MCContext &Ctx, case FK_SecRel_4: return COFF::IMAGE_REL_I386_SECREL; default: - llvm_unreachable("unsupported relocation type"); + Ctx.reportError(Fixup.getLoc(), "unsupported relocation type"); + return COFF::IMAGE_REL_I386_DIR32; } } else llvm_unreachable("Unsupported COFF machine type."); diff --git a/llvm/test/MC/COFF/unsupported-relocations.s b/llvm/test/MC/COFF/unsupported-relocations.s new file mode 100644 index 00000000000..5c17b0d45ff --- /dev/null +++ b/llvm/test/MC/COFF/unsupported-relocations.s @@ -0,0 +1,5 @@ +// RUN: not llvm-mc -filetype=obj -triple i386-pc-win32 %s 2>&1 | FileCheck %s +// RUN: not llvm-mc -filetype=obj -triple x86_64-pc-win32 %s 2>&1 | FileCheck %s +// CHECK: unsupported relocation type + .text + mov $_GLOBAL_OFFSET_TABLE_, %eax |