[XRay][clang] Allow clang to build XRay instrumented binaries in OpenBSD

Summary:
This patch was originally reviewed in D45126. It enables clang to add
the XRay runtime and the link-time dependencies for XRay instrumentation
in OpenBSD.

Landing for devnexen.

Reviewers: brad, dberris

Subscribers: dberris, krytarowski, cfe-commits

Author: devnexen

Differential Revision: https://reviews.llvm.org/D45126

llvm-svn: 329183

1 files changed, 28 insertions, 0 deletions

diff --git a/clang/lib/Driver/ToolChains/OpenBSD.cpp b/clang/lib/Driver/ToolChains/OpenBSD.cpp
index c0f8eff6418..3a33432f3dc 100644
--- a/clang/lib/Driver/ToolChains/OpenBSD.cpp
+++ b/clang/lib/Driver/ToolChains/OpenBSD.cpp
@@ -22,6 +22,29 @@ using namespace clang::driver::toolchains;
 using namespace clang;
 using namespace llvm::opt;
 
+static bool addXRayRuntime(const ToolChain &TC, const ArgList &Args,
+                           ArgStringList &CmdArgs) {
+  if (Args.hasArg(options::OPT_shared))
+    return false;
+
+  if (Args.hasFlag(options::OPT_fxray_instrument,
+                   options::OPT_fnoxray_instrument, false)) {
+    CmdArgs.push_back("-whole-archive");
+    CmdArgs.push_back(TC.getCompilerRTArgString(Args, "xray", false));
+    CmdArgs.push_back("-no-whole-archive");
+    return true;
+  }
+
+  return false;
+}
+
+static void linkXRayRuntimeDeps(const ToolChain &TC, const ArgList &Args,
+                                ArgStringList &CmdArgs) {
+  CmdArgs.push_back("--no-as-needed");
+  CmdArgs.push_back("-lm");
+  CmdArgs.push_back("-lpthread");
+}
+
 void openbsd::Assembler::ConstructJob(Compilation &C, const JobAction &JA,
                                       const InputInfo &Output,
                                       const InputInfoList &Inputs,
@@ -180,6 +203,7 @@ void openbsd::Linker::ConstructJob(Compilation &C, const JobAction &JA,
                             options::OPT_Z_Flag, options::OPT_r});
 
   bool NeedsSanitizerDeps = addSanitizerRuntimes(ToolChain, Args, CmdArgs);
+  bool NeedsXRayDeps = addXRayRuntime(ToolChain, Args, CmdArgs);
   AddLinkerInputs(getToolChain(), Inputs, Args, CmdArgs, JA);
 
   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
@@ -195,6 +219,10 @@ void openbsd::Linker::ConstructJob(Compilation &C, const JobAction &JA,
       CmdArgs.push_back(ToolChain.getCompilerRTArgString(Args, "builtins", false));
       linkSanitizerRuntimeDeps(ToolChain, CmdArgs);
     }
+    if (NeedsXRayDeps) {
+      CmdArgs.push_back(ToolChain.getCompilerRTArgString(Args, "builtins", false));
+      linkXRayRuntimeDeps(ToolChain, Args, CmdArgs);
+    }
     // FIXME: For some reason GCC passes -lgcc before adding
     // the default system libraries. Just mimic this for now.
     CmdArgs.push_back("-lgcc");