[XRay][clang] Consolidate runtime and link-time flag processing (NFC)

[dberris]

Summary

This change fixes http://llvm.org/PR36985 to define a single place in
CommonArgs.{h,cpp} where XRay runtime flags and link-time dependencies
are processed for all toolchains that support XRay instrumentation. This
is a refactoring of the same functionality spread across multiple
toolchain definitions.

[devnexen]

Do the unit tests have same outcome with these changes ? Otherwise, appreciate the simplification.

[dberris]

In D45243#1056549, @devnexen wrote:

Do the unit tests have same outcome with these changes ? Otherwise, appreciate the simplification.

Yes, locally, ninja check-all on Linux works just fine for me. No idea whether this will be the case for the buildbots, but that's easy enough to address when I get LGTM for the patch (and it lands, preferably daytime in Sydney).

[devnexen]

That's good enough for me the changes look neat. We ll see what others think.

[dberris]

• fixup: Rebase, and re-do OpenBSD specific changes

clang/include/clang/Driver/XRayArgs.h

class XRayArgs {
   int InstructionThreshold = 200;
   bool XRayAlwaysEmitCustomEvents = false;
 
 public:
   /// Parses the XRay arguments from an argument list.
   XRayArgs(const ToolChain &TC, const llvm::opt::ArgList &Args);
   void addArgs(const ToolChain &TC, const llvm::opt::ArgList &Args,
                llvm::opt::ArgStringList &CmdArgs, types::ID InputType) const;
+
+  bool needsXRayRt() const { return XRayInstrument; }
 };
 
 } // namespace driver
 } // namespace clang
 
 #endif // LLVM_CLANG_DRIVER_XRAYARGS_H

clang/lib/Driver/ToolChains/CommonArgs.h

 void claimNoWarnArgs(const llvm::opt::ArgList &Args);
 
 bool addSanitizerRuntimes(const ToolChain &TC, const llvm::opt::ArgList &Args,
                           llvm::opt::ArgStringList &CmdArgs);
 
 void linkSanitizerRuntimeDeps(const ToolChain &TC,
                               llvm::opt::ArgStringList &CmdArgs);
 
+bool addXRayRuntime(const ToolChain &TC, const llvm::opt::ArgList &Args,
+                    llvm::opt::ArgStringList &CmdArgs);
+
+void linkXRayRuntimeDeps(const ToolChain &TC,
+                         llvm::opt::ArgStringList &CmdArgs);
+
 void AddRunTimeLibs(const ToolChain &TC, const Driver &D,
                     llvm::opt::ArgStringList &CmdArgs,
                     const llvm::opt::ArgList &Args);
 
 void AddOpenMPLinkerScript(const ToolChain &TC, Compilation &C,
                            const InputInfo &Output,
                            const InputInfoList &Inputs,
                            const llvm::opt::ArgList &Args,

clang/lib/Driver/ToolChains/CommonArgs.cpp

 #include "clang/Driver/Compilation.h"
 #include "clang/Driver/Driver.h"
 #include "clang/Driver/DriverDiagnostic.h"
 #include "clang/Driver/Job.h"
 #include "clang/Driver/Options.h"
 #include "clang/Driver/SanitizerArgs.h"
 #include "clang/Driver/ToolChain.h"
 #include "clang/Driver/Util.h"
+#include "clang/Driver/XRayArgs.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/Option/Arg.h"
 #include "llvm/Option/ArgList.h"
 #include "llvm/Option/Option.h"
bool tools::addSanitizerRuntimes(const ToolChain &TC, const ArgList &Args,
 
   const SanitizerArgs &SanArgs = TC.getSanitizerArgs();
   if (SanArgs.hasCrossDsoCfi() && !AddExportDynamic)
     CmdArgs.push_back("-export-dynamic-symbol=__cfi_check");
 
   return !StaticRuntimes.empty() || !NonWholeStaticRuntimes.empty();
 }
 
+bool tools::addXRayRuntime(const ToolChain&TC, const ArgList &Args, ArgStringList &CmdArgs) {
+  if (Args.hasArg(options::OPT_shared))
+    return false;
+
+  if (TC.getXRayArgs().needsXRayRt()) {
+    CmdArgs.push_back("-whole-archive");
+    CmdArgs.push_back(TC.getCompilerRTArgString(Args, "xray", false));
+    CmdArgs.push_back("-no-whole-archive");
+    return true;
+  }
+
+  return false;
+}
+
+void tools::linkXRayRuntimeDeps(const ToolChain &TC, ArgStringList &CmdArgs) {
+  CmdArgs.push_back("--no-as-needed");
+  CmdArgs.push_back("-lpthread");
+  if (TC.getTriple().getOS() != llvm::Triple::OpenBSD)
+    CmdArgs.push_back("-lrt");
+  CmdArgs.push_back("-lm");
+
+  if (TC.getTriple().getOS() != llvm::Triple::FreeBSD &&
+      TC.getTriple().getOS() != llvm::Triple::NetBSD &&
+      TC.getTriple().getOS() != llvm::Triple::OpenBSD)
+    CmdArgs.push_back("-ldl");
+}
+
 bool tools::areOptimizationsEnabled(const ArgList &Args) {
   // Find the last -O arg and see if it is non-zero.
   if (Arg *A = Args.getLastArg(options::OPT_O_Group))
     return !A->getOption().matches(options::OPT_O0);
   // Defaults to -O0.
   return false;
 }
 

clang/lib/Driver/ToolChains/FreeBSD.cpp

void freebsd::Assembler::ConstructJob(Compilation &C, const JobAction &JA,
 
   for (const auto &II : Inputs)
     CmdArgs.push_back(II.getFilename());
 
   const char *Exec = Args.MakeArgString(getToolChain().GetProgramPath("as"));
   C.addCommand(llvm::make_unique<Command>(JA, *this, Exec, CmdArgs, Inputs));
 }
 
-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("-lrt");
-  CmdArgs.push_back("-lm");
-  CmdArgs.push_back("-lpthread");
-} 
-
 void freebsd::Linker::ConstructJob(Compilation &C, const JobAction &JA,
                                    const InputInfo &Output,
                                    const InputInfoList &Inputs,
                                    const ArgList &Args,
                                    const char *LinkingOutput) const {
   const toolchains::FreeBSD &ToolChain =
       static_cast<const toolchains::FreeBSD &>(getToolChain());
   const Driver &D = ToolChain.getDriver();
if (D.CCCIsCXX()) {
       if (Args.hasArg(options::OPT_pg))
         CmdArgs.push_back("-lm_p");
       else
         CmdArgs.push_back("-lm");
     }
     if (NeedsSanitizerDeps)
       linkSanitizerRuntimeDeps(ToolChain, CmdArgs);
     if (NeedsXRayDeps)
-      linkXRayRuntimeDeps(ToolChain, Args, CmdArgs);
+      linkXRayRuntimeDeps(ToolChain, CmdArgs);
     // FIXME: For some reason GCC passes -lgcc and -lgcc_s before adding
     // the default system libraries. Just mimic this for now.
     if (Args.hasArg(options::OPT_pg))
       CmdArgs.push_back("-lgcc_p");
     else
       CmdArgs.push_back("-lgcc");
     if (Args.hasArg(options::OPT_static)) {
       CmdArgs.push_back("-lgcc_eh");

clang/lib/Driver/ToolChains/Gnu.cpp

void tools::gcc::Compiler::RenderExtraToolArgs(const JobAction &JA,
   }
 }
 
 void tools::gcc::Linker::RenderExtraToolArgs(const JobAction &JA,
                                              ArgStringList &CmdArgs) const {
   // The types are (hopefully) good enough.
 }
 
-static bool addXRayRuntime(const ToolChain &TC, const ArgList &Args,
-                           ArgStringList &CmdArgs) {
-  // Do not add the XRay runtime to shared libraries.
-  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("-lpthread");
-  if (TC.getTriple().getOS() != llvm::Triple::OpenBSD)
-    CmdArgs.push_back("-lrt");
-  CmdArgs.push_back("-lm");
-
-  if (TC.getTriple().getOS() != llvm::Triple::FreeBSD &&
-      TC.getTriple().getOS() != llvm::Triple::NetBSD &&
-      TC.getTriple().getOS() != llvm::Triple::OpenBSD)
-    CmdArgs.push_back("-ldl");
-}
-
 static const char *getLDMOption(const llvm::Triple &T, const ArgList &Args) {
   switch (T.getArch()) {
   case llvm::Triple::x86:
     if (T.isOSIAMCU())
       return "elf_iamcu";
     return "elf_i386";
   case llvm::Triple::aarch64:
     return "aarch64linux";
if (!Args.hasArg(options::OPT_nostdlib)) {
     if (!Args.hasArg(options::OPT_nodefaultlibs)) {
       if (Args.hasArg(options::OPT_static))
         CmdArgs.push_back("--start-group");
 
       if (NeedsSanitizerDeps)
         linkSanitizerRuntimeDeps(ToolChain, CmdArgs);
 
       if (NeedsXRayDeps)
-        linkXRayRuntimeDeps(ToolChain, Args, CmdArgs);
+        linkXRayRuntimeDeps(ToolChain, CmdArgs);
 
       bool WantPthread = Args.hasArg(options::OPT_pthread) ||
                          Args.hasArg(options::OPT_pthreads);
 
       // FIXME: Only pass GompNeedsRT = true for platforms with libgomp that
       // require librt. Most modern Linux platforms do, but some may not.
       if (addOpenMPRuntime(CmdArgs, ToolChain, Args,
                            JA.isHostOffloading(Action::OFK_OpenMP),