[PATCH] If the user requested a zero-base-shadow sanitizer, infer -pie and -fPIC when appropriate.

[Peter Collingbourne]

================
Comment at: lib/Driver/ToolChains.cpp:2683
@@ -2680,1 +2682,3 @@
 
+bool Linux::isPICDefault() const {
+  return SanitizerHasZeroBaseShadow;
----------------
Evgeniy Stepanov wrote:
> This defaults to PIC even in cases where PIE would be enough. This may result in a performance hit "by default".
> Would you consider adding an isPIEDefault() method here?
> 
Done.


http://llvm-reviews.chandlerc.com/D502