Clang support for -flto=thin.

Summary:
Add clang support for -flto=thin option, which is used to set the
EmitFunctionSummary code gen option on compiles.

Add -flto=full as an alias to the existing -flto.

Add tests to check for proper overriding of -flto variants on the
command line, and convert grep tests to FileCheck.

Reviewers: dexonsmith, joker.eph

Subscribers: davidxl, cfe-commits

Differential Revision: http://reviews.llvm.org/D11908

llvm-svn: 250398

1 files changed, 14 insertions, 12 deletions

diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 56cbb90..a72e85e 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -1648,7 +1648,7 @@ static std::string getCPUName(const ArgList &Args, const llvm::Triple &T,
 }
 
 static void AddGoldPlugin(const ToolChain &ToolChain, const ArgList &Args,
-                          ArgStringList &CmdArgs) {
+                          ArgStringList &CmdArgs, bool IsThinLTO) {
   // Tell the linker to load the plugin. This has to come before AddLinkerInputs
   // as gold requires -plugin to come before any -plugin-opt that -Wl might
   // forward.
@@ -1664,6 +1664,8 @@ static void AddGoldPlugin(const ToolChain &ToolChain, const ArgList &Args,
   std::string CPU = getCPUName(Args, ToolChain.getTriple());
   if (!CPU.empty())
     CmdArgs.push_back(Args.MakeArgString(Twine("-plugin-opt=mcpu=") + CPU));
+
+  if (IsThinLTO) CmdArgs.push_back("-plugin-opt=thinlto");
 }
 
 /// This is a helper function for validating the optional refinement step
@@ -2845,6 +2847,7 @@ static VersionTuple getMSCompatibilityVersion(unsigned Version) {
 static void claimNoWarnArgs(const ArgList &Args) {
   // Don't warn about unused -f(no-)?lto.  This can happen when we're
   // preprocessing, precompiling or assembling.
+  Args.ClaimAllArgs(options::OPT_flto_EQ);
   Args.ClaimAllArgs(options::OPT_flto);
   Args.ClaimAllArgs(options::OPT_fno_lto);
 }
@@ -3272,10 +3275,6 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
   } else {
     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 ||
@@ -3306,6 +3305,9 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     // the use-list order, since serialization to bitcode is part of the flow.
     if (JA.getType() == types::TY_LLVM_BC)
       CmdArgs.push_back("-emit-llvm-uselists");
+
+    if (D.isUsingLTO())
+      Args.AddLastArg(CmdArgs, options::OPT_flto, options::OPT_flto_EQ);
   }
 
   // We normally speed up the clang process a bit by skipping destructors at
@@ -6456,8 +6458,8 @@ void cloudabi::Linker::ConstructJob(Compilation &C, const JobAction &JA,
                   {options::OPT_T_Group, options::OPT_e, options::OPT_s,
                    options::OPT_t, options::OPT_Z_Flag, options::OPT_r});
 
-  if (D.IsUsingLTO(Args))
-    AddGoldPlugin(ToolChain, Args, CmdArgs);
+  if (D.isUsingLTO())
+    AddGoldPlugin(ToolChain, Args, CmdArgs, D.getLTOMode() == LTOK_Thin);
 
   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs);
 
@@ -6600,7 +6602,7 @@ void darwin::Linker::AddLinkArgs(Compilation &C, const ArgList &Args,
                    options::OPT_fno_application_extension, false))
     CmdArgs.push_back("-application_extension");
 
-  if (D.IsUsingLTO(Args)) {
+  if (D.isUsingLTO()) {
     // If we are using LTO, then automatically create a temporary file path for
     // the linker to use, so that it's lifetime will extend past a possible
     // dsymutil step.
@@ -7602,8 +7604,8 @@ void freebsd::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   Args.AddAllArgs(CmdArgs, options::OPT_Z_Flag);
   Args.AddAllArgs(CmdArgs, options::OPT_r);
 
-  if (D.IsUsingLTO(Args))
-    AddGoldPlugin(ToolChain, Args, CmdArgs);
+  if (D.isUsingLTO())
+    AddGoldPlugin(ToolChain, Args, CmdArgs, D.getLTOMode() == LTOK_Thin);
 
   bool NeedsSanitizerDeps = addSanitizerRuntimes(ToolChain, Args, CmdArgs);
   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs);
@@ -8477,8 +8479,8 @@ void gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   for (const auto &Path : Paths)
     CmdArgs.push_back(Args.MakeArgString(StringRef("-L") + Path));
 
-  if (D.IsUsingLTO(Args))
-    AddGoldPlugin(ToolChain, Args, CmdArgs);
+  if (D.isUsingLTO())
+    AddGoldPlugin(ToolChain, Args, CmdArgs, D.getLTOMode() == LTOK_Thin);
 
   if (Args.hasArg(options::OPT_Z_Xlinker__no_demangle))
     CmdArgs.push_back("--no-demangle");