[XRay][clang] Add flag to choose instrumentation bundles

Summary:
This change addresses http://llvm.org/PR36926 by allowing users to pick
which instrumentation bundles to use, when instrumenting with XRay. In
particular, the flag `-fxray-instrumentation-bundle=` has four valid
values:

- `all`: the default, emits all instrumentation kinds
- `none`: equivalent to -fnoxray-instrument
- `function`: emits the entry/exit instrumentation
- `custom`: emits the custom event instrumentation

These can be combined either as comma-separated values, or as
repeated flag values.

Reviewers: echristo, kpw, eizan, pelikan

Reviewed By: pelikan

Subscribers: mgorny, cfe-commits

Differential Revision: https://reviews.llvm.org/D44970

llvm-svn: 329985

3 files changed, 14 insertions, 3 deletions

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 73b95d981f4..4baa5aff72e 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -3341,6 +3341,11 @@ RValue CodeGenFunction::EmitBuiltinExpr(const FunctionDecl *FD,
   case Builtin::BI__xray_customevent: {
     if (!ShouldXRayInstrumentFunction())
       return RValue::getIgnored();
+
+    if (!CGM.getCodeGenOpts().XRayInstrumentationBundle.has(
+            XRayInstrKind::Custom))
+      return RValue::getIgnored();
+
     if (const auto *XRayAttr = CurFuncDecl->getAttr<XRayInstrumentAttr>())
       if (XRayAttr->neverXRayInstrument() && !AlwaysEmitXRayCustomEvents())
         return RValue::getIgnored();
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index 57b1c4b4db1..5367c2addec 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -468,7 +468,10 @@ bool CodeGenFunction::ShouldXRayInstrumentFunction() const {
 /// AlwaysEmitXRayCustomEvents - Return true if we should emit IR for calls to
 /// the __xray_customevent(...) builin calls, when doing XRay instrumentation.
 bool CodeGenFunction::AlwaysEmitXRayCustomEvents() const {
-  return CGM.getCodeGenOpts().XRayAlwaysEmitCustomEvents;
+  return CGM.getCodeGenOpts().XRayInstrumentFunctions &&
+         (CGM.getCodeGenOpts().XRayAlwaysEmitCustomEvents ||
+          CGM.getCodeGenOpts().XRayInstrumentationBundle.Mask ==
+              XRayInstrKind::Custom);
 }
 
 llvm::Constant *
@@ -900,7 +903,9 @@ void CodeGenFunction::StartFunction(GlobalDecl GD,
   }
 
   // Apply xray attributes to the function (as a string, for now)
-  bool InstrumentXray = ShouldXRayInstrumentFunction();
+  bool InstrumentXray = ShouldXRayInstrumentFunction() &&
+                        CGM.getCodeGenOpts().XRayInstrumentationBundle.has(
+                            XRayInstrKind::Function);
   if (D && InstrumentXray) {
     if (const auto *XRayAttr = D->getAttr<XRayInstrumentAttr>()) {
       if (XRayAttr->alwaysXRayInstrument())
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index c3de87021f5..701412f4f10 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1846,9 +1846,10 @@ bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
                                    StringRef Category) const {
   if (!LangOpts.XRayInstrument)
     return false;
+
   const auto &XRayFilter = getContext().getXRayFilter();
   using ImbueAttr = XRayFunctionFilter::ImbueAttribute;
-  auto Attr = XRayFunctionFilter::ImbueAttribute::NONE;
+  auto Attr = ImbueAttr::NONE;
   if (Loc.isValid())
     Attr = XRayFilter.shouldImbueLocation(Loc, Category);
   if (Attr == ImbueAttr::NONE)