[ELF][MIPS] Allow .MIPS.abiflags larger than one Elf_Mips_ABIFlags struct

Older versions of BFD generate libraries with .MIPS.abiflags that only
concatenate the individual .MIPS.abiflags sections instead of merging.

Patch by Alexander Richardson.

Differential revision: https://reviews.llvm.org/D27770

llvm-svn: 290237

1 files changed, 7 insertions, 2 deletions

diff --git a/lld/ELF/SyntheticSections.cpp b/lld/ELF/SyntheticSections.cpp
index ea5e924e493..2dbe749029c 100644
--- a/lld/ELF/SyntheticSections.cpp
+++ b/lld/ELF/SyntheticSections.cpp
@@ -134,8 +134,13 @@ MipsAbiFlagsSection<ELFT> *MipsAbiFlagsSection<ELFT>::create() {
     Create = true;
 
     std::string Filename = toString(Sec->getFile());
-    if (Sec->Data.size() != sizeof(Elf_Mips_ABIFlags)) {
-      error(Filename + ": invalid size of .MIPS.abiflags section");
+    const size_t Size = Sec->Data.size();
+    // Older version of BFD (such as the default FreeBSD linker) concatenate
+    // .MIPS.abiflags instead of merging. To allow for this case (or potential
+    // zero padding) we ignore everything after the first Elf_Mips_ABIFlags
+    if (Size < sizeof(Elf_Mips_ABIFlags)) {
+      error(Filename + ": invalid size of .MIPS.abiflags section: got " +
+            Twine(Size) + " instead of " + Twine(sizeof(Elf_Mips_ABIFlags)));
       return nullptr;
     }
     auto *S = reinterpret_cast<const Elf_Mips_ABIFlags *>(Sec->Data.data());