[llvm] r307625 - [PM/ThinLTO] Fix PR33536, a bug where the ThinLTO bitcode writer was

[Chandler Carruth via llvm-commits]

Author: chandlerc
Date: Mon Jul 10 22:39:20 2017
New Revision: 307625

URL: http://llvm.org/viewvc/llvm-project?rev=307625&view=rev
Log:
[PM/ThinLTO] Fix PR33536, a bug where the ThinLTO bitcode writer was
querying for analysis results on a function declaration rather than
a definition.

The only reason this worked previously is by chance -- because the way
we got alias analysis results with the legacy PM, we happened to not
compute a dominator tree and so we happened to not hit an assert even
though it didn't make any real sense. Now we bail out before trying to
compute alias analysis so that we don't hit these asserts.

Added:
    llvm/trunk/test/Transforms/ThinLTOBitcodeWriter/pr33536.ll
Modified:
    llvm/trunk/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp

Modified: llvm/trunk/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp?rev=307625&r1=307624&r2=307625&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp Mon Jul 10 22:39:20 2017
@@ -271,7 +271,8 @@ void splitAndWriteThinLTOBitcode(
           if (!ArgT || ArgT->getBitWidth() > 64)
             return;
         }
-        if (computeFunctionBodyMemoryAccess(*F, AARGetter(*F)) == MAK_ReadNone)
+        if (!F->isDeclaration() &&
+            computeFunctionBodyMemoryAccess(*F, AARGetter(*F)) == MAK_ReadNone)
           EligibleVirtualFns.insert(F);
       });
     }

Added: llvm/trunk/test/Transforms/ThinLTOBitcodeWriter/pr33536.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/ThinLTOBitcodeWriter/pr33536.ll?rev=307625&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/ThinLTOBitcodeWriter/pr33536.ll (added)
+++ llvm/trunk/test/Transforms/ThinLTOBitcodeWriter/pr33536.ll Mon Jul 10 22:39:20 2017
@@ -0,0 +1,37 @@
+; Test for a bug specific to the new pass manager where we may build a domtree
+; to make more precise AA queries for functions.
+;
+; RUN: opt -aa-pipeline=default -passes='no-op-module' -debug-pass-manager -thinlto-bc -o %t %s
+; RUN: llvm-modextract -b -n 0 -o - %t | llvm-dis | FileCheck --check-prefix=M0 %s
+; RUN: llvm-modextract -b -n 1 -o - %t | llvm-dis | FileCheck --check-prefix=M1 %s
+
+target triple = "x86_64-unknown-linux-gnu"
+
+%struct.hoge = type { %struct.widget }
+%struct.widget = type { i32 (...)** }
+
+; M0: @global = local_unnamed_addr global
+; M1-NOT: @global
+ at global = local_unnamed_addr global %struct.hoge { %struct.widget { i32 (...)** bitcast (i8** getelementptr inbounds ({ [3 x i8*] }, { [3 x i8*] }* @global.1, i32 0, inrange i32 0, i32 2) to i32 (...)**) } }, align 8
+
+; M0: @global.1 = external unnamed_addr constant
+; M1: @global.1 = linkonce_odr unnamed_addr constant
+ at global.1 = linkonce_odr unnamed_addr constant { [3 x i8*] } { [3 x i8*] [i8* null, i8* bitcast ({ i8*, i8* }* @global.4 to i8*), i8* bitcast (i32 (%struct.widget*)* @quux to i8*)] }, align 8, !type !0
+
+; M0: @global.2 = external global
+; M1-NOT: @global.2
+ at global.2 = external global i8*
+
+; M0: @global.3 = linkonce_odr constant
+; M1-NOT: @global.3
+ at global.3 = linkonce_odr constant [22 x i8] c"zzzzzzzzzzzzzzzzzzzzz\00"
+
+; M0: @global.4 = linkonce_odr constant
+; M1: @global.4 = external constant
+ at global.4 = linkonce_odr constant { i8*, i8* }{ i8* bitcast (i8** getelementptr inbounds (i8*, i8** @global.2, i64 2) to i8*), i8* getelementptr inbounds ([22 x i8], [22 x i8]* @global.3, i32 0, i32 0) }
+
+ at llvm.global_ctors = appending global [0 x { i32, void ()*, i8* }] zeroinitializer
+
+declare i32 @quux(%struct.widget*) unnamed_addr
+
+!0 = !{i64 16, !"yyyyyyyyyyyyyyyyyyyyyyyyy"}