From: Davide Italiano <davide@freebsd.org>
Date: Sun, 23 Apr 2017 04:49:34 +0000 (+0000)
Subject: [ThinLTO/Summary] Rename anonymous globals as last action ...
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=49f1a751ecfa2932ac603fe058813bfe23d2dd10;p=llvm

[ThinLTO/Summary] Rename anonymous globals as last action ...

... in the per-TU -O0 pipeline.
The problem is that there could be passes registered using
`addExtensionsToPM()` introducing unnamed globals.
Asan is an example, but there may be others. Building cppcheck
with `-flto=thin` and `-fsanitize=address` triggers an assertion
while we're reading bitcode (in lib/LTO), as the BitcodeReader
assumes there are no unnamed globals (because the namer has run).
Unfortunately I wasn't able to find an easy way to test this.
I added a comment in the hope nobody moves this again.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301102 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/IPO/PassManagerBuilder.cpp b/lib/Transforms/IPO/PassManagerBuilder.cpp
index f11b58d1adc..2af8b6c473a 100644
--- a/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -414,11 +414,14 @@ void PassManagerBuilder::populateModulePassManager(
     else if (!GlobalExtensions->empty() || !Extensions.empty())
       MPM.add(createBarrierNoopPass());
 
+    addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
+
+    // Rename anon globals to be able to export them in the summary.
+    // This has to be done after we add the extensions to the pass manager
+    // as there could be passes (e.g. Adddress sanitizer) which introduce
+    // new unnamed globals.
     if (PrepareForThinLTO)
-      // Rename anon globals to be able to export them in the summary.
       MPM.add(createNameAnonGlobalPass());
-
-    addExtensionsToPM(EP_EnabledOnOptLevel0, MPM);
     return;
   }