1 files changed, 11 insertions, 1 deletions
diff --git a/lld/lib/ReaderWriter/PECOFF/ReaderCOFF.cpp b/lld/lib/ReaderWriter/PECOFF/ReaderCOFF.cpp
index 77399225f1e..26d1e63f7da 100644
--- a/lld/lib/ReaderWriter/PECOFF/ReaderCOFF.cpp
+++ b/lld/lib/ReaderWriter/PECOFF/ReaderCOFF.cpp
@@ -92,10 +92,20 @@ DefinedAtom::ContentPermissions getPermissions(const coff_section *section) {
 DefinedAtom::Alignment getAlignment(const coff_section *section) {
   if (section->Characteristics & llvm::COFF::IMAGE_SCN_TYPE_NO_PAD)
     return DefinedAtom::Alignment(0);
+
   // Bit [20:24] contains section alignment information. We need to decrease
   // the value stored by 1 in order to get the real exponent (e.g, ALIGN_1BYTE
   // is 0x00100000, but the exponent should be 0)
-  int powerOf2 = ((section->Characteristics >> 20) & 0xf) - 1;
+  uint32_t charactersitcis = (section->Characteristics >> 20) & 0xf;
+
+  // If all bits are off, we treat it as if ALIGN_1BYTE was on. The PE/COFF spec
+  // does not say anything about this case, but CVTRES.EXE does not set any bit
+  // in characteristics[20:24], and its output is intended to be copied to .rsrc
+  // section with no padding, so I think doing this is the right thing.
+  if (charactersitcis == 0)
+    return DefinedAtom::Alignment(0);
+
+  uint32_t powerOf2 = charactersitcis - 1;
   return DefinedAtom::Alignment(powerOf2);
 }