folly/Foreach.h: avoid shadowing warnings

Summary:
Fix warnings exposed by gcc's -Wshadow-compatible-local.
Don't use a hard-coded names that would cause shadowing with each nested use of this macro.

This avoids errors like the following:

  folly/Foreach.h:94:18: error: declaration of 'FOR_EACH_privateCount' shadows a previous local [-Werror=shadow-compatible-local]
  folly/Foreach.h:91:12: error: shadowed declaration is here [-Werror=shadow-compatible-local]

Reviewed By: yfeldblum

Differential Revision: D4656783

fbshipit-source-id: d7cd820fb04ccd78242f7487e2b219dc300709b6

diff --git a/folly/Foreach.h b/folly/Foreach.h
index 77ef80ccbc04c2029ccd79dc706596fd01ccacde..5cc075c7e6aeeeeeb4a476a091da42bfa72e734a 100644 (file)
--- a/folly/Foreach.h
+++ b/folly/Foreach.h
@@ -88,13 +88,13 @@
  * }
  */
 #define FOR_EACH_ENUMERATE(count, i, c)                                \
-  if (bool FOR_EACH_state1 = false) {} else                            \
+  if (bool _FE_ANON(s1_) = false) {} else                            \
     for (auto && FOR_EACH_state2 = (c);                                \
-         !FOR_EACH_state1; FOR_EACH_state1 = true)                     \
-      if (size_t FOR_EACH_privateCount = 0) {} else                    \
-        if (const size_t& count = FOR_EACH_privateCount) {} else       \
+         !_FE_ANON(s1_); _FE_ANON(s1_) = true)                     \
+      if (size_t _FE_ANON(n1_) = 0) {} else                            \
+        if (const size_t& count = _FE_ANON(n1_)) {} else               \
           for (auto i = FOR_EACH_state2.begin();                       \
-               i != FOR_EACH_state2.end(); ++FOR_EACH_privateCount, ++i)
+               i != FOR_EACH_state2.end(); ++_FE_ANON(n1_), ++i)
 
 /**
  * Similar to FOR_EACH, but gives the user the key and value for each entry in