IPO: Const correctness for summaries passed into passes.

Pass const qualified summaries into importers and unqualified summaries into
exporters. This lets us const-qualify the summary argument to thinBackend.

Differential Revision: https://reviews.llvm.org/D31230

llvm-svn: 298534

1 files changed, 12 insertions, 7 deletions

diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp
index 605a32d7331..dcf48e9837b 100644
--- a/llvm/lib/LTO/LTOBackend.cpp
+++ b/llvm/lib/LTO/LTOBackend.cpp
@@ -223,14 +223,16 @@ static void runNewPMCustomPasses(Module &Mod, TargetMachine *TM,
 }
 
 static void runOldPMPasses(Config &Conf, Module &Mod, TargetMachine *TM,
-                           bool IsThinLTO, ModuleSummaryIndex &CombinedIndex) {
+                           bool IsThinLTO, ModuleSummaryIndex *ExportSummary,
+                           const ModuleSummaryIndex *ImportSummary) {
   legacy::PassManager passes;
   passes.add(createTargetTransformInfoWrapperPass(TM->getTargetIRAnalysis()));
 
   PassManagerBuilder PMB;
   PMB.LibraryInfo = new TargetLibraryInfoImpl(Triple(TM->getTargetTriple()));
   PMB.Inliner = createFunctionInliningPass();
-  PMB.Summary = &CombinedIndex;
+  PMB.ExportSummary = ExportSummary;
+  PMB.ImportSummary = ImportSummary;
   // Unconditionally verify input since it is not verified before this
   // point and has unknown origin.
   PMB.VerifyInput = true;
@@ -247,7 +249,8 @@ static void runOldPMPasses(Config &Conf, Module &Mod, TargetMachine *TM,
 }
 
 bool opt(Config &Conf, TargetMachine *TM, unsigned Task, Module &Mod,
-         bool IsThinLTO, ModuleSummaryIndex &CombinedIndex) {
+         bool IsThinLTO, ModuleSummaryIndex *ExportSummary,
+         const ModuleSummaryIndex *ImportSummary) {
   // There's still no ThinLTO pipeline hooked up in the new pass manager,
   // once there is one, we can just remove this.
   if (LTOUseNewPM && IsThinLTO)
@@ -260,7 +263,7 @@ bool opt(Config &Conf, TargetMachine *TM, unsigned Task, Module &Mod,
   else if (LTOUseNewPM)
     runNewPMPasses(Mod, TM, Conf.OptLevel);
   else
-    runOldPMPasses(Conf, Mod, TM, IsThinLTO, CombinedIndex);
+    runOldPMPasses(Conf, Mod, TM, IsThinLTO, ExportSummary, ImportSummary);
   return !Conf.PostOptModuleHook || Conf.PostOptModuleHook(Task, Mod);
 }
 
@@ -383,7 +386,8 @@ Error lto::backend(Config &C, AddStreamFn AddStream,
   auto DiagnosticOutputFile = std::move(*DiagFileOrErr);
 
   if (!C.CodeGenOnly) {
-    if (!opt(C, TM.get(), 0, *Mod, /*IsThinLTO=*/false, CombinedIndex)) {
+    if (!opt(C, TM.get(), 0, *Mod, /*IsThinLTO=*/false,
+             /*ExportSummary=*/&CombinedIndex, /*ImportSummary=*/nullptr)) {
       finalizeOptimizationRemarks(std::move(DiagnosticOutputFile));
       return Error::success();
     }
@@ -400,7 +404,7 @@ Error lto::backend(Config &C, AddStreamFn AddStream,
 }
 
 Error lto::thinBackend(Config &Conf, unsigned Task, AddStreamFn AddStream,
-                       Module &Mod, ModuleSummaryIndex &CombinedIndex,
+                       Module &Mod, const ModuleSummaryIndex &CombinedIndex,
                        const FunctionImporter::ImportMapTy &ImportList,
                        const GVSummaryMapTy &DefinedGlobals,
                        MapVector<StringRef, BitcodeModule> &ModuleMap) {
@@ -452,7 +456,8 @@ Error lto::thinBackend(Config &Conf, unsigned Task, AddStreamFn AddStream,
   if (Conf.PostImportModuleHook && !Conf.PostImportModuleHook(Task, Mod))
     return Error::success();
 
-  if (!opt(Conf, TM.get(), Task, Mod, /*IsThinLTO=*/true, CombinedIndex))
+  if (!opt(Conf, TM.get(), Task, Mod, /*IsThinLTO=*/true,
+           /*ExportSummary=*/nullptr, /*ImportSummary=*/&CombinedIndex))
     return Error::success();
 
   codegen(Conf, TM.get(), AddStream, Task, Mod);