[PATCH] D65314: CodeGen: Don't follow aliases when extracting type info.

[Peter Collingbourne via Phabricator via llvm-commits]

This revision was automatically updated to reflect the committed changes.
pcc marked an inline comment as done.
Closed by commit rL367696: CodeGen: Don't follow aliases when extracting type info. (authored by pcc, committed by ).

Changed prior to commit:
  https://reviews.llvm.org/D65314?vs=211868&id=213085#toc

Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D65314/new/

https://reviews.llvm.org/D65314

Files:
  llvm/trunk/lib/CodeGen/Analysis.cpp
  llvm/trunk/test/CodeGen/X86/typeid-alias.ll


Index: llvm/trunk/lib/CodeGen/Analysis.cpp
===================================================================
--- llvm/trunk/lib/CodeGen/Analysis.cpp
+++ llvm/trunk/lib/CodeGen/Analysis.cpp
@@ -156,7 +156,7 @@
 
 /// ExtractTypeInfo - Returns the type info, possibly bitcast, encoded in V.
 GlobalValue *llvm::ExtractTypeInfo(Value *V) {
-  V = V->stripPointerCasts();
+  V = V->stripPointerCastsNoFollowAliases();
   GlobalValue *GV = dyn_cast<GlobalValue>(V);
   GlobalVariable *Var = dyn_cast<GlobalVariable>(V);
 
Index: llvm/trunk/test/CodeGen/X86/typeid-alias.ll
===================================================================
--- llvm/trunk/test/CodeGen/X86/typeid-alias.ll
+++ llvm/trunk/test/CodeGen/X86/typeid-alias.ll
@@ -0,0 +1,18 @@
+; Test that we don't crash in the case where the type info object is an
+; alias pointing to a non-zero offset within a global.
+
+; RUN: llc < %s | FileCheck %s
+
+target triple = "x86_64-unknown-linux-gnu"
+
+%struct.exception = type { i8, i8, i32, i8*, i8*, i32, i8* }
+ at g = global %struct.exception zeroinitializer
+ at a = alias %struct.exception, %struct.exception* inttoptr (i64 add (i64 ptrtoint (%struct.exception* @g to i64), i64 1297036692682702848) to %struct.exception*)
+
+define i32 @typeid() {
+  ; CHECK: movl $1, %eax
+  %eh_typeid = tail call i32 @llvm.eh.typeid.for( i8* getelementptr (%struct.exception, %struct.exception* @a, i32 0, i32 0))
+  ret i32 %eh_typeid
+}
+
+declare i32 @llvm.eh.typeid.for(i8*)


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