enable -flto=thin in clang-cl

Summary: This enables LTO to be used with the clang-cl frontend.

Reviewers: rnk, hans

Reviewed By: hans

Subscribers: pcc, cfe-commits, mehdi_amini, Prazek

Differential Revision: https://reviews.llvm.org/D30239

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@296373 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/DiagnosticDriverKinds.td b/include/clang/Basic/DiagnosticDriverKinds.td
index b92922e94da8f030471a875b9c95cf6326f1e7e6..b02599c8ae6c9b95eff81ba71d255006810d018c 100644 (file)
--- a/include/clang/Basic/DiagnosticDriverKinds.td
+++ b/include/clang/Basic/DiagnosticDriverKinds.td
@@ -133,6 +133,7 @@ def err_drv_invalid_gcc_output_type : Error<
     "invalid output type '%0' for use with gcc tool">;
 def err_drv_cc_print_options_failure : Error<
     "unable to open CC_PRINT_OPTIONS file: %0">;
+def err_drv_lto_without_lld : Error<"LTO requires -fuse-ld=lld">;
 def err_drv_preamble_format : Error<
     "incorrect format for -preamble-bytes=N,END">;
 def err_drv_conflicting_deployment_targets : Error<

diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
index 9aa5541751bf8c851c6f9124d7bdc4e24f53a644..9dd80c09184ce499680862565301d56d2ddcdaf4 100644 (file)
--- a/include/clang/Driver/Options.td
+++ b/include/clang/Driver/Options.td
@@ -957,7 +957,7 @@ def fxray_instruction_threshold_ :
 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=">, Flags<[CC1Option]>, Group<f_Group>,
+def flto_EQ : Joined<["-"], "flto=">, Flags<[CoreOption, CC1Option]>, Group<f_Group>,
   HelpText<"Set LTO mode to either 'full' or 'thin'">;
 def flto : Flag<["-"], "flto">, Flags<[CoreOption, CC1Option]>, Group<f_Group>,
   HelpText<"Enable LTO in 'full' mode">;

diff --git a/lib/Driver/Driver.cpp b/lib/Driver/Driver.cpp
index 6defb2041347c7f8998fd8a2a495ff56bd97a5f2..78e99d43ddb0807d11d67cda70fc624ba3bd8123 100644 (file)
--- a/lib/Driver/Driver.cpp
+++ b/lib/Driver/Driver.cpp
@@ -2353,8 +2353,12 @@ void Driver::BuildActions(Compilation &C, DerivedArgList &Args,
   Arg *FinalPhaseArg;
   phases::ID FinalPhase = getFinalPhase(Args, &FinalPhaseArg);
 
-  if (FinalPhase == phases::Link && Args.hasArg(options::OPT_emit_llvm)) {
-    Diag(clang::diag::err_drv_emit_llvm_link);
+  if (FinalPhase == phases::Link) {
+    if (Args.hasArg(options::OPT_emit_llvm))
+      Diag(clang::diag::err_drv_emit_llvm_link);
+    if (IsCLMode() && LTOMode != LTOK_None &&
+        !Args.getLastArgValue(options::OPT_fuse_ld_EQ).equals_lower("lld"))
+      Diag(clang::diag::err_drv_lto_without_lld);
   }
 
   // Reject -Z* at the top level, these options should never have been exposed

diff --git a/test/Driver/cl-options.c b/test/Driver/cl-options.c
index 232cdce1078e02cf9e2be85cd041fd0de2492947..c425e21dd7fb06ead5d0067e75433aa4980fb5a1 100644 (file)
--- a/test/Driver/cl-options.c
+++ b/test/Driver/cl-options.c
@@ -522,6 +522,15 @@
 
 // RUN: env CL="%s" _CL_="%s" not %clang --rsp-quoting=windows -c
 
+// RUN: %clang_cl -### /c -flto -- %s 2>&1 | FileCheck -check-prefix=LTO %s
+// LTO: -flto
+
+// RUN: %clang_cl -### /c -flto=thin -- %s 2>&1 | FileCheck -check-prefix=LTO-THIN %s
+// LTO-THIN: -flto=thin
+
+// RUN: %clang_cl -### -Fe%t.exe -entry:main -flto -- %s 2>&1 | FileCheck -check-prefix=LTO-WITHOUT-LLD %s
+// LTO-WITHOUT-LLD: LTO requires -fuse-ld=lld
+
 // Accept "core" clang options.
 // (/Zs is for syntax-only, -Werror makes it fail hard on unknown options)
 // RUN: %clang_cl \