Resubmit "Pass down the -flto option to the -cc1 job" (r239481)

The patch is the same except for the addition of a new test for the
issue that required reverting the dependent llvm commit.

--Original Commit Message--

Pass down the -flto option to the -cc1 job, and from there into the
CodeGenOptions and onto the PassManagerBuilder. This enables gating
the new EliminateAvailableExternally module pass on whether we are
preparing for LTO.

If we are preparing for LTO (e.g. a -flto -c compile), the new pass is not
included as we want to preserve available externally functions for possible
link time inlining.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@241467 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
index 6a75b7c2c1574be6b8492e9e80f2f5156c64b707..9855c7d54c13182f4e77a8b678e5274ea8f5e694 100644 (file)
--- a/include/clang/Driver/Options.td
+++ b/include/clang/Driver/Options.td
@@ -641,7 +641,7 @@ def flat__namespace : Flag<["-"], "flat_namespace">;
 def flax_vector_conversions : Flag<["-"], "flax-vector-conversions">, Group<f_Group>;
 def flimited_precision_EQ : Joined<["-"], "flimited-precision=">, Group<f_Group>;
 def flto_EQ : Joined<["-"], "flto=">, Group<clang_ignored_gcc_optimization_f_Group>;
-def flto : Flag<["-"], "flto">, Group<f_Group>;
+def flto : Flag<["-"], "flto">, Flags<[CC1Option]>, Group<f_Group>;
 def fno_lto : Flag<["-"], "fno-lto">, Group<f_Group>;
 def fmacro_backtrace_limit_EQ : Joined<["-"], "fmacro-backtrace-limit=">,
                                 Group<f_Group>, Flags<[DriverOption, CoreOption]>;

diff --git a/include/clang/Frontend/CodeGenOptions.def b/include/clang/Frontend/CodeGenOptions.def
index d34cf0cad1c90a58d3473d653766a4612ea13aa7..d52496d09511291521f2468b3ed8f02f8ae97e4d 100644 (file)
--- a/include/clang/Frontend/CodeGenOptions.def
+++ b/include/clang/Frontend/CodeGenOptions.def
@@ -67,6 +67,8 @@ CODEGENOPT(InstrumentFunctions , 1, 0) ///< Set when -finstrument-functions is
 CODEGENOPT(InstrumentForProfiling , 1, 0) ///< Set when -pg is enabled.
 CODEGENOPT(LessPreciseFPMAD  , 1, 0) ///< Enable less precise MAD instructions to
                                      ///< be generated.
+CODEGENOPT(PrepareForLTO     , 1, 0) ///< Set when -flto is enabled on the
+                                     ///< compile step.
 CODEGENOPT(MergeAllConstants , 1, 1) ///< Merge identical constants.
 CODEGENOPT(MergeFunctions    , 1, 0) ///< Set when -fmerge-functions is enabled.
 CODEGENOPT(MSVolatile        , 1, 0) ///< Set when /volatile:ms is enabled.

diff --git a/lib/CodeGen/BackendUtil.cpp b/lib/CodeGen/BackendUtil.cpp
index 0bccad0570da4373a97997ac2f31af434cf52672..5ff760ca874afe33e8a88444d0c289b0c1c5f921 100644 (file)
--- a/lib/CodeGen/BackendUtil.cpp
+++ b/lib/CodeGen/BackendUtil.cpp
@@ -292,6 +292,7 @@ void EmitAssemblyHelper::CreatePasses() {
   PMBuilder.DisableUnitAtATime = !CodeGenOpts.UnitAtATime;
   PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
   PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
+  PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
   PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
 
   PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index a2955dbb9e77347c3ace1649d95e67e8385eef90..3ea2b36cf52a5793e01d7366705ebd9c4961697b 100644 (file)
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -2805,6 +2805,10 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     assert((isa<CompileJobAction>(JA) || isa<BackendJobAction>(JA)) &&
            "Invalid action for clang tool.");
 
+    if (JA.getType() == types::TY_LTO_IR ||
+        JA.getType() == types::TY_LTO_BC) {
+      CmdArgs.push_back("-flto");
+    }
     if (JA.getType() == types::TY_Nothing) {
       CmdArgs.push_back("-fsyntax-only");
     } else if (JA.getType() == types::TY_LLVM_IR ||

diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index dd664ca652f0a203588adda7e8a5b66f96087fda..49823be0a008cf90b0d97478f99439131d3c1429 100644 (file)
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -508,6 +508,8 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
 
   Opts.MergeFunctions = Args.hasArg(OPT_fmerge_functions);
 
+  Opts.PrepareForLTO = Args.hasArg(OPT_flto);
+
   Opts.MSVolatile = Args.hasArg(OPT_fms_volatile);
 
   Opts.VectorizeBB = Args.hasArg(OPT_vectorize_slp_aggressive);

diff --git a/test/CodeGen/available-externally-hidden.cpp b/test/CodeGen/available-externally-hidden.cpp
new file mode 100644 (file)
index 0000000..dc13f26
--- /dev/null
+++ b/test/CodeGen/available-externally-hidden.cpp
@@ -0,0 +1,32 @@
+// RUN: %clang_cc1 -O2 -fvisibility hidden -std=c++11 -emit-llvm -o - -triple x86_64-apple-darwin10 %s | FileCheck %s
+
+// Ensure that available_externally functions eliminated at -O2 are now
+// declarations, and are not emitted as hidden with -fvisibility=hidden,
+// but rather with default visibility.
+struct Filter {
+  virtual void Foo();
+  int a;
+};
+
+class Message{};
+class Sender {
+ public:
+  virtual bool Send(Message* msg) = 0;
+
+ protected:
+  virtual ~Sender() {}
+};
+
+// CHECK: declare zeroext i1 @_ZThn16_N17SyncMessageFilter4SendEP7Message
+class SyncMessageFilter : public Filter, public Sender {
+ public:
+  bool Send(Message* message) override;
+};
+
+class TestSyncMessageFilter : public SyncMessageFilter {
+};
+
+int main() {
+TestSyncMessageFilter*  f = new TestSyncMessageFilter;
+  f->Send(new Message);
+}

diff --git a/test/CodeGen/available-externally-suppress.c b/test/CodeGen/available-externally-suppress.c
index 390d2017884a929e61fba46db68224ede01ae5c0..a25a28271277ddd8bd66aa542b5241832a8fb2d1 100644 (file)
--- a/test/CodeGen/available-externally-suppress.c
+++ b/test/CodeGen/available-externally-suppress.c
@@ -1,12 +1,18 @@
 // RUN: %clang_cc1 -emit-llvm -o - -triple x86_64-apple-darwin10 %s | FileCheck %s
+// RUN: %clang_cc1 -O2 -fno-inline -emit-llvm -o - -triple x86_64-apple-darwin10 %s | FileCheck %s
+// RUN: %clang_cc1 -flto -O2 -fno-inline -emit-llvm -o - -triple x86_64-apple-darwin10 %s | FileCheck %s -check-prefix=LTO
 
 // Ensure that we don't emit available_externally functions at -O0.
+// Also should not emit them at -O2, unless -flto is present in which case
+// we should preserve them for link-time inlining decisions.
 int x;
 
 inline void f0(int y) { x = y; }
 
 // CHECK-LABEL: define void @test()
 // CHECK: declare void @f0(i32)
+// LTO-LABEL: define void @test()
+// LTO: define available_externally void @f0
 void test() {
   f0(17);
 }
@@ -19,9 +25,13 @@ inline int __attribute__((always_inline)) f1(int x) {
 }
 
 // CHECK: @test1
+// LTO: @test1
 int test1(int x) {
   // CHECK: br i1
   // CHECK-NOT: call {{.*}} @f1
   // CHECK: ret i32
+  // LTO: br i1
+  // LTO-NOT: call {{.*}} @f1
+  // LTO: ret i32
   return f1(x);
 }