[PATCH][lld] ELF: Handle sh_addralign being set to zero

[Will Newton]

sh_addralign of zero is equivalent to sh_addralign of one, meaning
no alignment specified. Avoid calculating Log2 or modulus when
sh_addralign is zero as the results will not be useful.
---
 lib/ReaderWriter/ELF/Atoms.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/ReaderWriter/ELF/Atoms.h b/lib/ReaderWriter/ELF/Atoms.h
index 23fa3f8..1aed346 100644
--- a/lib/ReaderWriter/ELF/Atoms.h
+++ b/lib/ReaderWriter/ELF/Atoms.h
@@ -286,6 +286,9 @@ public:
     if ((_symbol->getType() == llvm::ELF::STT_COMMON) ||
         _symbol->st_shndx == llvm::ELF::SHN_COMMON) {
       return Alignment(llvm::Log2_64(_symbol->st_value));
+    } else if (_section->sh_addralign == 0) {
+      // sh_addralign of 0 means no alignment
+      return Alignment(0, _symbol->st_value);
     }
     return Alignment(llvm::Log2_64(_section->sh_addralign),
                      _symbol->st_value % _section->sh_addralign);
-- 
2.1.0