Define a maximum supported alignment value for load, store, and
alloca instructions (constrained by their internal encoding),
and add error checking for it. Fix an instcombine bug which
generated huge alignment values (null is infinitely aligned).
This fixes undefined behavior noticed by John Regehr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109643 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index 61b1ae5..e581a69 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -1154,6 +1154,8 @@
if (ParseUInt32(Alignment)) return true;
if (!isPowerOf2_32(Alignment))
return Error(AlignLoc, "alignment is not a power of two");
+ if (Alignment > MaximumAlignment)
+ return Error(AlignLoc, "huge alignments are not supported yet");
return false;
}
@@ -1176,6 +1178,7 @@
if (Lex.getKind() != lltok::kw_align)
return Error(Lex.getLoc(), "expected metadata or 'align'");
+ LocTy AlignLoc = Lex.getLoc();
if (ParseOptionalAlignment(Alignment)) return true;
}