[llvm] r372573 - [FunctionAttrs] Enable nonnull arg propagation

[David Bolvansky via llvm-commits]

Author: xbolva00
Date: Mon Sep 23 02:58:02 2019
New Revision: 372573

URL: http://llvm.org/viewvc/llvm-project?rev=372573&view=rev
Log:
[FunctionAttrs] Enable nonnull arg propagation

Enable flag introduced in rL294998. Security concerns are no longer valid, since function signatures for mentioned libc functions has no nonnull attribute (Clang does not generate them? I see no nonnull attr in LLVM IR for these functions) and since rL372091 we carefully annotate the callsites where we know that size is static, non zero. So let's enable this flag again..



Modified:
    llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp

Modified: llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp?rev=372573&r1=372572&r2=372573&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/FunctionAttrs.cpp Mon Sep 23 02:58:02 2019
@@ -78,11 +78,8 @@ STATISTIC(NumNoRecurse, "Number of funct
 STATISTIC(NumNoUnwind, "Number of functions marked as nounwind");
 STATISTIC(NumNoFree, "Number of functions marked as nofree");
 
-// FIXME: This is disabled by default to avoid exposing security vulnerabilities
-// in C/C++ code compiled by clang:
-// http://lists.llvm.org/pipermail/cfe-dev/2017-January/052066.html
 static cl::opt<bool> EnableNonnullArgPropagation(
-    "enable-nonnull-arg-prop", cl::Hidden,
+    "enable-nonnull-arg-prop", cl::init(true), cl::Hidden,
     cl::desc("Try to propagate nonnull argument attributes from callsites to "
              "caller functions."));