From fb532b9a340958494a5346f2230d51653e8ed31e Mon Sep 17 00:00:00 2001
From: Peter Collingbourne <peter@pcc.me.uk>
Date: Wed, 24 Feb 2016 20:46:36 +0000
Subject: Add whole-program vtable optimization feature to Clang.

This patch introduces the -fwhole-program-vtables flag, which enables the
whole-program vtable optimization feature (D16795) in Clang.

Differential Revision: http://reviews.llvm.org/D16821

llvm-svn: 261767
---
 clang/lib/CodeGen/CGVTables.cpp | 35 ++++++++++++++++++++++++-----------
 1 file changed, 24 insertions(+), 11 deletions(-)

(limited to 'clang/lib/CodeGen/CGVTables.cpp')

diff --git a/clang/lib/CodeGen/CGVTables.cpp b/clang/lib/CodeGen/CGVTables.cpp
index e96a8120207..953053bd1c3 100644
--- a/clang/lib/CodeGen/CGVTables.cpp
+++ b/clang/lib/CodeGen/CGVTables.cpp
@@ -898,21 +898,34 @@ void CodeGenModule::EmitDeferredVTables() {
   DeferredVTables.clear();
 }
 
-bool CodeGenModule::IsCFIBlacklistedRecord(const CXXRecordDecl *RD) {
-  if (RD->hasAttr<UuidAttr>() &&
-      getContext().getSanitizerBlacklist().isBlacklistedType("attr:uuid"))
-    return true;
+bool CodeGenModule::NeedVTableBitSets() {
+  return getCodeGenOpts().WholeProgramVTables ||
+         getLangOpts().Sanitize.has(SanitizerKind::CFIVCall) ||
+         getLangOpts().Sanitize.has(SanitizerKind::CFINVCall) ||
+         getLangOpts().Sanitize.has(SanitizerKind::CFIDerivedCast) ||
+         getLangOpts().Sanitize.has(SanitizerKind::CFIUnrelatedCast);
+}
+
+bool CodeGenModule::IsBitSetBlacklistedRecord(const CXXRecordDecl *RD) {
+  std::string TypeName = RD->getQualifiedNameAsString();
+  auto isInBlacklist = [&](const SanitizerBlacklist &BL) {
+    if (RD->hasAttr<UuidAttr>() && BL.isBlacklistedType("attr:uuid"))
+      return true;
+
+    return BL.isBlacklistedType(TypeName);
+  };
 
-  return getContext().getSanitizerBlacklist().isBlacklistedType(
-      RD->getQualifiedNameAsString());
+  return isInBlacklist(WholeProgramVTablesBlacklist) ||
+         ((LangOpts.Sanitize.has(SanitizerKind::CFIVCall) ||
+           LangOpts.Sanitize.has(SanitizerKind::CFINVCall) ||
+           LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) ||
+           LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast)) &&
+          isInBlacklist(getContext().getSanitizerBlacklist()));
 }
 
 void CodeGenModule::EmitVTableBitSetEntries(llvm::GlobalVariable *VTable,
                                             const VTableLayout &VTLayout) {
-  if (!LangOpts.Sanitize.has(SanitizerKind::CFIVCall) &&
-      !LangOpts.Sanitize.has(SanitizerKind::CFINVCall) &&
-      !LangOpts.Sanitize.has(SanitizerKind::CFIDerivedCast) &&
-      !LangOpts.Sanitize.has(SanitizerKind::CFIUnrelatedCast))
+  if (!NeedVTableBitSets())
     return;
 
   CharUnits PointerWidth =
@@ -922,7 +935,7 @@ void CodeGenModule::EmitVTableBitSetEntries(llvm::GlobalVariable *VTable,
   std::vector<BSEntry> BitsetEntries;
   // Create a bit set entry for each address point.
   for (auto &&AP : VTLayout.getAddressPoints()) {
-    if (IsCFIBlacklistedRecord(AP.first.getBase()))
+    if (IsBitSetBlacklistedRecord(AP.first.getBase()))
       continue;
 
     BitsetEntries.push_back(std::make_pair(AP.first.getBase(), AP.second));
-- 
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