From: Mandeep Singh Grang <mgrang@codeaurora.org>
Date: Tue, 6 Jun 2017 00:36:09 +0000 (+0000)
Subject: [cmake] Enable reverse iteration by default through build macro
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=20350be310e85c72c3fca145ad02b054e73d42a1;p=llvm

[cmake] Enable reverse iteration by default through build macro

Summary:
Reverse iteration can be turned on, by default, by setting -DLLVM_REVERSE_ITERATION:BOOL=ON during cmake.
With this enabled, we can uncover lots of cases of non-determinism in codegen by simply running our tests (without any other change).
We can then setup a buildbot which will have this turned on by default. Initially, a lot of unit tests will fail in this configuration.
Once we start fixing non-determinism issues, we can gradually make this a blocker for patches.

Reviewers: davide, dblaikie, mehdi_amini, dberlin

Reviewed By: dblaikie

Subscribers: probinson, mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D33908

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304757 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/cmake/modules/HandleLLVMOptions.cmake b/cmake/modules/HandleLLVMOptions.cmake
index 3dd16d51f0b..d15933157d2 100644
--- a/cmake/modules/HandleLLVMOptions.cmake
+++ b/cmake/modules/HandleLLVMOptions.cmake
@@ -101,6 +101,10 @@ else()
   message(FATAL_ERROR "Unknown value for LLVM_ABI_BREAKING_CHECKS: \"${LLVM_ABI_BREAKING_CHECKS}\"!")
 endif()
 
+if( LLVM_REVERSE_ITERATION )
+  set( LLVM_ENABLE_REVERSE_ITERATION 1 )
+endif()
+
 if(WIN32)
   set(LLVM_HAVE_LINK_VERSION_SCRIPT 0)
   if(CYGWIN)
diff --git a/include/llvm/ADT/SmallPtrSet.h b/include/llvm/ADT/SmallPtrSet.h
index a0b380b237d..e326d3e35dc 100644
--- a/include/llvm/ADT/SmallPtrSet.h
+++ b/include/llvm/ADT/SmallPtrSet.h
@@ -31,8 +31,12 @@ namespace llvm {
 
 #if LLVM_ENABLE_ABI_BREAKING_CHECKS
 template <class T = void> struct ReverseIterate { static bool value; };
+#if LLVM_ENABLE_REVERSE_ITERATION
+template <class T> bool ReverseIterate<T>::value = true;
+#else
 template <class T> bool ReverseIterate<T>::value = false;
 #endif
+#endif
 
 /// SmallPtrSetImplBase - This is the common code shared among all the
 /// SmallPtrSet<>'s, which is almost everything.  SmallPtrSet has two modes, one
diff --git a/include/llvm/Config/abi-breaking.h.cmake b/include/llvm/Config/abi-breaking.h.cmake
index 4ce487b8f5f..7ae401e5b8a 100644
--- a/include/llvm/Config/abi-breaking.h.cmake
+++ b/include/llvm/Config/abi-breaking.h.cmake
@@ -15,6 +15,9 @@
 /* Define to enable checks that alter the LLVM C++ ABI */
 #cmakedefine01 LLVM_ENABLE_ABI_BREAKING_CHECKS
 
+/* Define to enable reverse iteration of unordered llvm containers */
+#cmakedefine01 LLVM_ENABLE_REVERSE_ITERATION
+
 /* Allow selectively disabling link-time mismatch checking so that header-only
    ADT content from LLVM can be used without linking libSupport. */
 #if !LLVM_DISABLE_ABI_BREAKING_CHECKS_ENFORCING