From: Justin Bogner <mail@justinbogner.com>
Date: Tue, 29 Aug 2017 00:11:05 +0000 (+0000)
Subject: [sanitizer-coverage] Mark the guard and 8-bit counter arrays as used
X-Git-Tag: android-x86-7.1-r4~11717
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=347f51897e158ae64f4856833cdf2db756bdc97e;p=android-x86%2Fexternal-llvm.git

[sanitizer-coverage] Mark the guard and 8-bit counter arrays as used

In r311742 we marked the PCs array as used so it wouldn't be dead
stripped, but left the guard and 8-bit counters arrays alone since
these are referenced by the coverage instrumentation. This doesn't
quite work if we want the indices of the PCs array to match the other
arrays though, since elements can still end up being dead and
disappear.

Instead, we mark all three of these arrays as used so that they'll be
consistent with one another.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311959 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Instrumentation/SanitizerCoverage.cpp b/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
index ffe35f57db7..0f2e7772c76 100644
--- a/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
+++ b/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
@@ -566,23 +566,30 @@ SanitizerCoverageModule::CreatePCArray(Function &F,
       ConstantArray::get(ArrayType::get(IntptrPtrTy, N * 2), PCs));
   PCArray->setConstant(true);
 
-  // We don't reference the PCs array in any of our runtime functions, so we
-  // need to prevent it from being dead stripped.
-  appendToUsed(*F.getParent(), {PCArray});
-
   return PCArray;
 }
 
 void SanitizerCoverageModule::CreateFunctionLocalArrays(
     Function &F, ArrayRef<BasicBlock *> AllBlocks) {
-  if (Options.TracePCGuard)
+  SmallVector<GlobalValue *, 3> LocalArrays;
+  if (Options.TracePCGuard) {
     FunctionGuardArray = CreateFunctionLocalArrayInSection(
         AllBlocks.size(), F, Int32Ty, SanCovGuardsSectionName);
-  if (Options.Inline8bitCounters)
+    LocalArrays.push_back(FunctionGuardArray);
+  }
+  if (Options.Inline8bitCounters) {
     Function8bitCounterArray = CreateFunctionLocalArrayInSection(
         AllBlocks.size(), F, Int8Ty, SanCovCountersSectionName);
-  if (Options.PCTable)
+    LocalArrays.push_back(Function8bitCounterArray);
+  }
+  if (Options.PCTable) {
     FunctionPCsArray = CreatePCArray(F, AllBlocks);
+    LocalArrays.push_back(FunctionPCsArray);
+  }
+
+  // We don't reference these arrays directly in any of our runtime functions,
+  // so we need to prevent them from being dead stripped.
+  appendToUsed(*F.getParent(), LocalArrays);
 }
 
 bool SanitizerCoverageModule::InjectCoverage(Function &F,