[ThinLTO] Do not assert when adding a module with a different but

compatible target triple

Currently, an assertion fails in ThinLTOCodeGenerator::addModule when
the target triple of the module being added doesn't match that of the
one stored in TMBuilder. This patch relaxes the constraint and makes
changes to allow target triples that only differ in their version
numbers on Apple platforms, similarly to what r228999 did.

rdar://problem/30133904

Differential Revision: https://reviews.llvm.org/D33291

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303326 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/ADT/Triple.h

@@ -252,6 +252,10 @@ public:
            ObjectFormat == Other.ObjectFormat;
   }
 
+  bool operator!=(const Triple &Other) const {
+    return !(*this == Other);
+  }
+
   /// @}
   /// @name Normalization
   /// @{
@@ -722,6 +726,12 @@ public:
   /// \returns true if the triple is little endian, false otherwise.
   bool isLittleEndian() const;
 
+  /// Test whether target triples are compatible.
+  bool isCompatibleWith(const Triple &Other) const;
+
+  /// Merge target triples.
+  std::string merge(const Triple &Other) const;
+
   /// @}
   /// @name Static helpers for IDs.
   /// @{

lib/LTO/ThinLTOCodeGenerator.cpp

@@ -505,29 +505,25 @@ static void initTMBuilder(TargetMachineBuilder &TMBuilder,
 
 void ThinLTOCodeGenerator::addModule(StringRef Identifier, StringRef Data) {
   ThinLTOBuffer Buffer(Data, Identifier);
-  if (Modules.empty()) {
-    // First module added, so initialize the triple and some options
-    LLVMContext Context;
-    StringRef TripleStr;
-    ErrorOr<std::string> TripleOrErr = expectedToErrorOrAndEmitErrors(
-        Context, getBitcodeTargetTriple(Buffer.getMemBuffer()));
-    if (TripleOrErr)
-      TripleStr = *TripleOrErr;
-    Triple TheTriple(TripleStr);
+  LLVMContext Context;
+  StringRef TripleStr;
+  ErrorOr<std::string> TripleOrErr = expectedToErrorOrAndEmitErrors(
+      Context, getBitcodeTargetTriple(Buffer.getMemBuffer()));
+
+  if (TripleOrErr)
+    TripleStr = *TripleOrErr;
+
+  Triple TheTriple(TripleStr);
+
+  if (Modules.empty())
     initTMBuilder(TMBuilder, Triple(TheTriple));
+  else if (TMBuilder.TheTriple != TheTriple) {
+    if (!TMBuilder.TheTriple.isCompatibleWith(TheTriple))
+      report_fatal_error("ThinLTO modules with incompatible triples not "
+                         "supported");
+    initTMBuilder(TMBuilder, Triple(TMBuilder.TheTriple.merge(TheTriple)));
   }
-#ifndef NDEBUG
-  else {
-    LLVMContext Context;
-    StringRef TripleStr;
-    ErrorOr<std::string> TripleOrErr = expectedToErrorOrAndEmitErrors(
-        Context, getBitcodeTargetTriple(Buffer.getMemBuffer()));
-    if (TripleOrErr)
-      TripleStr = *TripleOrErr;
-    assert(TMBuilder.TheTriple.str() == TripleStr &&
-           "ThinLTO modules with different triple not supported");
-  }
-#endif
+
   Modules.push_back(Buffer);
 }
 

lib/Linker/IRMover.cpp

@@ -1243,27 +1243,6 @@ Error IRLinker::linkModuleFlagsMetadata() {
   return Error::success();
 }
 
-// This function returns true if the triples match.
-static bool triplesMatch(const Triple &T0, const Triple &T1) {
-  // If vendor is apple, ignore the version number.
-  if (T0.getVendor() == Triple::Apple)
-    return T0.getArch() == T1.getArch() && T0.getSubArch() == T1.getSubArch() &&
-           T0.getVendor() == T1.getVendor() && T0.getOS() == T1.getOS();
-
-  return T0 == T1;
-}
-
-// This function returns the merged triple.
-static std::string mergeTriples(const Triple &SrcTriple,
-                                const Triple &DstTriple) {
-  // If vendor is apple, pick the triple with the larger version number.
-  if (SrcTriple.getVendor() == Triple::Apple)
-    if (DstTriple.isOSVersionLT(SrcTriple))
-      return SrcTriple.str();
-
-  return DstTriple.str();
-}
-
 Error IRLinker::run() {
   // Ensure metadata materialized before value mapping.
   if (SrcM->getMaterializer())
@@ -1289,14 +1268,15 @@ Error IRLinker::run() {
 
   Triple SrcTriple(SrcM->getTargetTriple()), DstTriple(DstM.getTargetTriple());
 
-  if (!SrcM->getTargetTriple().empty() && !triplesMatch(SrcTriple, DstTriple))
+  if (!SrcM->getTargetTriple().empty()&&
+      !SrcTriple.isCompatibleWith(DstTriple))
     emitWarning("Linking two modules of different target triples: " +
                 SrcM->getModuleIdentifier() + "' is '" +
                 SrcM->getTargetTriple() + "' whereas '" +
                 DstM.getModuleIdentifier() + "' is '" + DstM.getTargetTriple() +
                 "'\n");
 
-  DstM.setTargetTriple(mergeTriples(SrcTriple, DstTriple));
+  DstM.setTargetTriple(SrcTriple.merge(DstTriple));
 
   // Append the module inline asm string.
   if (!IsPerformingImport && !SrcM->getModuleInlineAsm().empty()) {

lib/Support/Triple.cpp

@@ -1472,6 +1472,24 @@ bool Triple::isLittleEndian() const {
   }
 }
 
+bool Triple::isCompatibleWith(const Triple &Other) const {
+  // If vendor is apple, ignore the version number.
+  if (getVendor() == Triple::Apple)
+    return getArch() == Other.getArch() && getSubArch() == Other.getSubArch() &&
+           getVendor() == Other.getVendor() && getOS() == Other.getOS();
+
+  return *this == Other;
+}
+
+std::string Triple::merge(const Triple &Other) const {
+  // If vendor is apple, pick the triple with the larger version number.
+  if (getVendor() == Triple::Apple)
+    if (Other.isOSVersionLT(*this))
+      return str();
+
+  return Other.str();
+}
+
 StringRef Triple::getARMCPUForArch(StringRef MArch) const {
   if (MArch.empty())
     MArch = getArchName();

test/ThinLTO/X86/Inputs/merge-triple.ll

@@ -0,0 +1 @@
+target triple = "x86_64-apple-macosx10.11.0"

test/ThinLTO/X86/merge-triple.ll

@@ -0,0 +1,10 @@
+; RUN: opt -module-summary %s -o %t1.bc
+; RUN: opt -module-summary %p/Inputs/merge-triple.ll -o %t2.bc
+; RUN: llvm-lto -thinlto-action=optimize %t1.bc %t2.bc
+; RUN: llvm-dis < %t1.bc.thinlto.imported.bc | FileCheck %s --check-prefix=CHECK1
+; RUN: llvm-dis < %t2.bc.thinlto.imported.bc | FileCheck %s --check-prefix=CHECK2
+
+target triple = "x86_64-apple-macosx10.12.0"
+
+; CHECK1: target triple = "x86_64-apple-macosx10.12.0"
+; CHECK2: target triple = "x86_64-apple-macosx10.11.0"