[PATCH] D103120: LTO: Export functions referenced by non-canonical CFI jump tables

[Nick Desaulniers via Phabricator via llvm-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rG2f9ba6aa8b6d: LTO: Export functions referenced by non-canonical CFI jump tables (authored by samitolvanen, committed by nickdesaulniers).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D103120/new/

https://reviews.llvm.org/D103120

Files:
  llvm/lib/LTO/LTO.cpp
  llvm/test/LTO/Resolution/X86/export-jumptable-noncanonical.ll


Index: llvm/test/LTO/Resolution/X86/export-jumptable-noncanonical.ll
===================================================================
--- /dev/null
+++ llvm/test/LTO/Resolution/X86/export-jumptable-noncanonical.ll
@@ -0,0 +1,35 @@
+; Test that we do not internalize functions that appear in the CFI jump table in
+; the full LTO object file; any such functions will be referenced by the jump
+; table.
+
+; RUN: opt -thinlto-bc -thinlto-split-lto-unit -o %t %s
+; RUN: llvm-lto2 run -o %t2 -r %t,f1,p -r %t,f2,p -r %t,_start,px %t -save-temps
+; RUN: llvm-dis %t2.1.2.internalize.bc -o - | FileCheck %s
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; CHECK: define void @f1()
+define void @f1() !type !0 {
+  ret void
+}
+
+; CHECK: define internal void @f2()
+define void @f2() !type !1 {
+  ret void
+}
+
+define i1 @_start(i1 %i) {
+  %1 = select i1 %i, void ()* @f1, void ()* @f2
+  %2 = bitcast void ()* %1 to i8*
+  %3 = call i1 @llvm.type.test(i8* %2, metadata !"typeid1")
+  ret i1 %3
+}
+
+declare i1 @llvm.type.test(i8*, metadata)
+
+!llvm.module.flags = !{!2}
+
+!0 = !{i64 0, !"typeid1"}
+!1 = !{i64 0, !"typeid2"}
+!2 = !{i32 4, !"CFI Canonical Jump Tables", i32 0}
Index: llvm/lib/LTO/LTO.cpp
===================================================================
--- llvm/lib/LTO/LTO.cpp
+++ llvm/lib/LTO/LTO.cpp
@@ -1480,6 +1480,9 @@
   for (auto &Def : ThinLTO.CombinedIndex.cfiFunctionDefs())
     ExportedGUIDs.insert(
         GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(Def)));
+  for (auto &Decl : ThinLTO.CombinedIndex.cfiFunctionDecls())
+    ExportedGUIDs.insert(
+        GlobalValue::getGUID(GlobalValue::dropLLVMManglingEscape(Decl)));
 
   auto isExported = [&](StringRef ModuleIdentifier, ValueInfo VI) {
     const auto &ExportList = ExportLists.find(ModuleIdentifier);


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