commit 2f63d549f1e1edd165392837aaa53f569f7fb88d
author Teresa Johnson <tejohnson@google.com> Fri Jan 24 12:24:18 2020 -0800
committer Teresa Johnson <tejohnson@google.com> Mon Jan 27 07:55:05 2020 -0800
tree 61db1979f4f195e45d48a2b3d9a28dc29ef7c744
parent bc3d900fa5fc537163b8556a6b59925231bc4d09

Restore "[LTO/WPD] Enable aggressive WPD under LTO option"

This restores 59733525d37cf9ad88b5021b33ecdbaf2e18911c (D71913), along
with bot fix 19c76989bb505c3117730c47df85fd3800ea2767.

The bot failure should be fixed by D73418, committed as
af954e441a5170a75687699d91d85e0692929d43.

I also added a fix for non-x86 bot failures by requiring x86 in new test
lld/test/ELF/lto/devirt_vcall_vis_public.ll.

clang/lib/CodeGen/CGVTables.cpp

diff --git a/clang/lib/CodeGen/CGVTables.cpp b/clang/lib/CodeGen/CGVTables.cpp
index cbc969a..403b9e2 100644
--- a/clang/lib/CodeGen/CGVTables.cpp
+++ b/clang/lib/CodeGen/CGVTables.cpp
@@ -1011,6 +1011,26 @@
   DeferredVTables.clear();
 }
 
+bool CodeGenModule::HasLTOVisibilityPublicStd(const CXXRecordDecl *RD) {
+  if (!getCodeGenOpts().LTOVisibilityPublicStd)
+    return false;
+
+  const DeclContext *DC = RD;
+  while (1) {
+    auto *D = cast<Decl>(DC);
+    DC = DC->getParent();
+    if (isa<TranslationUnitDecl>(DC->getRedeclContext())) {
+      if (auto *ND = dyn_cast<NamespaceDecl>(D))
+        if (const IdentifierInfo *II = ND->getIdentifier())
+          if (II->isStr("std") || II->isStr("stdext"))
+            return true;
+      break;
+    }
+  }
+
+  return false;
+}
+
 bool CodeGenModule::HasHiddenLTOVisibility(const CXXRecordDecl *RD) {
   LinkageInfo LV = RD->getLinkageAndVisibility();
   if (!isExternallyVisible(LV.getLinkage()))
@@ -1027,22 +1047,7 @@
       return false;
   }
 
-  if (getCodeGenOpts().LTOVisibilityPublicStd) {
-    const DeclContext *DC = RD;
-    while (1) {
-      auto *D = cast<Decl>(DC);
-      DC = DC->getParent();
-      if (isa<TranslationUnitDecl>(DC->getRedeclContext())) {
-        if (auto *ND = dyn_cast<NamespaceDecl>(D))
-          if (const IdentifierInfo *II = ND->getIdentifier())
-            if (II->isStr("std") || II->isStr("stdext"))
-              return false;
-        break;
-      }
-    }
-  }
-
-  return true;
+  return !HasLTOVisibilityPublicStd(RD);
 }
 
 llvm::GlobalObject::VCallVisibility