[Driver] Use -push-/-pop-state and -as-needed for libc++ on Fuchsia

This avoids introducing unnecessary DT_NEEDED entries when using
C++ driver for linking C code or C++ code that doesn't use C++
standard library.

Differential Revision: https://reviews.llvm.org/D53854

llvm-svn: 346064

1 files changed, 5 insertions, 4 deletions

diff --git a/clang/lib/Driver/ToolChains/Fuchsia.cpp b/clang/lib/Driver/ToolChains/Fuchsia.cpp
index 94441fce7cd..f788f91d5d8 100644
--- a/clang/lib/Driver/ToolChains/Fuchsia.cpp
+++ b/clang/lib/Driver/ToolChains/Fuchsia.cpp
@@ -122,13 +122,14 @@ void fuchsia::Linker::ConstructJob(Compilation &C, const JobAction &JA,
       if (ToolChain.ShouldLinkCXXStdlib(Args)) {
         bool OnlyLibstdcxxStatic = Args.hasArg(options::OPT_static_libstdcxx) &&
                                    !Args.hasArg(options::OPT_static);
+        CmdArgs.push_back("--push-state");
+        CmdArgs.push_back("--as-needed");
         if (OnlyLibstdcxxStatic)
-          CmdArgs.push_back("-Bstatic");
+          CmdArgs.push_back("-static");
         ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
-        if (OnlyLibstdcxxStatic)
-          CmdArgs.push_back("-Bdynamic");
+        CmdArgs.push_back("-lm");
+        CmdArgs.push_back("--pop-state");
       }
-      CmdArgs.push_back("-lm");
     }
 
     AddRunTimeLibs(ToolChain, D, CmdArgs, Args);