[clang] bb3111c - [clang][xray] Add xray attributes to functions without decls too

[Ian Levesque via cfe-commits]

Author: Ian Levesque
Date: 2020-04-01T00:02:39-04:00
New Revision: bb3111cbaf7b181bcda94415456a69b2a6b767ad

URL: https://github.com/llvm/llvm-project/commit/bb3111cbaf7b181bcda94415456a69b2a6b767ad
DIFF: https://github.com/llvm/llvm-project/commit/bb3111cbaf7b181bcda94415456a69b2a6b767ad.diff

LOG: [clang][xray] Add xray attributes to functions without decls too

Summary: This allows instrumenting things like global initializers

Reviewers: dberris, MaskRay, smeenai

Subscribers: cfe-commits, johnislarry

Tags: #clang

Differential Revision: https://reviews.llvm.org/D77191

Added: 
    clang/test/CodeGen/xray-global-init.cpp

Modified: 
    clang/lib/CodeGen/CodeGenFunction.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index 3393b1b3c5fb..618c9a046321 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -810,55 +810,54 @@ void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
           FD->getBody()->getStmtClass() == Stmt::CoroutineBodyStmtClass)
         SanOpts.Mask &= ~SanitizerKind::Null;
 
-  if (D) {
-    // Apply xray attributes to the function (as a string, for now)
-    if (const auto *XRayAttr = D->getAttr<XRayInstrumentAttr>()) {
-      if (CGM.getCodeGenOpts().XRayInstrumentationBundle.has(
-              XRayInstrKind::FunctionEntry) ||
-          CGM.getCodeGenOpts().XRayInstrumentationBundle.has(
-              XRayInstrKind::FunctionExit)) {
-        if (XRayAttr->alwaysXRayInstrument() && ShouldXRayInstrumentFunction())
-          Fn->addFnAttr("function-instrument", "xray-always");
-        if (XRayAttr->neverXRayInstrument())
-          Fn->addFnAttr("function-instrument", "xray-never");
-        if (const auto *LogArgs = D->getAttr<XRayLogArgsAttr>())
-          if (ShouldXRayInstrumentFunction())
-            Fn->addFnAttr("xray-log-args",
-                          llvm::utostr(LogArgs->getArgumentCount()));
-      }
-    } else {
-      if (ShouldXRayInstrumentFunction() && !CGM.imbueXRayAttrs(Fn, Loc))
-        Fn->addFnAttr(
-            "xray-instruction-threshold",
-            llvm::itostr(CGM.getCodeGenOpts().XRayInstructionThreshold));
+  // Apply xray attributes to the function (as a string, for now)
+  if (const auto *XRayAttr = D ? D->getAttr<XRayInstrumentAttr>() : nullptr) {
+    if (CGM.getCodeGenOpts().XRayInstrumentationBundle.has(
+            XRayInstrKind::FunctionEntry) ||
+        CGM.getCodeGenOpts().XRayInstrumentationBundle.has(
+            XRayInstrKind::FunctionExit)) {
+      if (XRayAttr->alwaysXRayInstrument() && ShouldXRayInstrumentFunction())
+        Fn->addFnAttr("function-instrument", "xray-always");
+      if (XRayAttr->neverXRayInstrument())
+        Fn->addFnAttr("function-instrument", "xray-never");
+      if (const auto *LogArgs = D->getAttr<XRayLogArgsAttr>())
+        if (ShouldXRayInstrumentFunction())
+          Fn->addFnAttr("xray-log-args",
+                        llvm::utostr(LogArgs->getArgumentCount()));
     }
+  } else {
+    if (ShouldXRayInstrumentFunction() && !CGM.imbueXRayAttrs(Fn, Loc))
+      Fn->addFnAttr(
+          "xray-instruction-threshold",
+          llvm::itostr(CGM.getCodeGenOpts().XRayInstructionThreshold));
+  }
 
-    if (ShouldXRayInstrumentFunction()) {
-      if (CGM.getCodeGenOpts().XRayIgnoreLoops)
-        Fn->addFnAttr("xray-ignore-loops");
+  if (ShouldXRayInstrumentFunction()) {
+    if (CGM.getCodeGenOpts().XRayIgnoreLoops)
+      Fn->addFnAttr("xray-ignore-loops");
 
-      if (!CGM.getCodeGenOpts().XRayInstrumentationBundle.has(
-              XRayInstrKind::FunctionExit))
-        Fn->addFnAttr("xray-skip-exit");
+    if (!CGM.getCodeGenOpts().XRayInstrumentationBundle.has(
+            XRayInstrKind::FunctionExit))
+      Fn->addFnAttr("xray-skip-exit");
 
-      if (!CGM.getCodeGenOpts().XRayInstrumentationBundle.has(
-              XRayInstrKind::FunctionEntry))
-        Fn->addFnAttr("xray-skip-entry");
-    }
+    if (!CGM.getCodeGenOpts().XRayInstrumentationBundle.has(
+            XRayInstrKind::FunctionEntry))
+      Fn->addFnAttr("xray-skip-entry");
+  }
 
-    unsigned Count, Offset;
-    if (const auto *Attr = D->getAttr<PatchableFunctionEntryAttr>()) {
-      Count = Attr->getCount();
-      Offset = Attr->getOffset();
-    } else {
-      Count = CGM.getCodeGenOpts().PatchableFunctionEntryCount;
-      Offset = CGM.getCodeGenOpts().PatchableFunctionEntryOffset;
-    }
-    if (Count && Offset <= Count) {
-      Fn->addFnAttr("patchable-function-entry", std::to_string(Count - Offset));
-      if (Offset)
-        Fn->addFnAttr("patchable-function-prefix", std::to_string(Offset));
-    }
+  unsigned Count, Offset;
+  if (const auto *Attr =
+          D ? D->getAttr<PatchableFunctionEntryAttr>() : nullptr) {
+    Count = Attr->getCount();
+    Offset = Attr->getOffset();
+  } else {
+    Count = CGM.getCodeGenOpts().PatchableFunctionEntryCount;
+    Offset = CGM.getCodeGenOpts().PatchableFunctionEntryOffset;
+  }
+  if (Count && Offset <= Count) {
+    Fn->addFnAttr("patchable-function-entry", std::to_string(Count - Offset));
+    if (Offset)
+      Fn->addFnAttr("patchable-function-prefix", std::to_string(Offset));
   }
 
   // Add no-jump-tables value.

diff  --git a/clang/test/CodeGen/xray-global-init.cpp b/clang/test/CodeGen/xray-global-init.cpp
new file mode 100644
index 000000000000..588be8a45a50
--- /dev/null
+++ b/clang/test/CodeGen/xray-global-init.cpp
@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -triple=x86_64-linux-gnu -emit-llvm -fxray-instrument -fxray-instruction-threshold=1 %s -o - \
+// RUN:   | FileCheck %s
+
+struct A {
+  A();
+  ~A();
+};
+
+A a;
+
+// Check that the xray-instruction-threshold was applied
+// CHECK: define internal void @_GLOBAL__sub_I_xray_global_init.cpp() [[NUX:#[0-9]+]] section ".text.startup" {
+// CHECK: attributes [[NUX]] = { noinline nounwind {{.*}}"xray-instruction-threshold"="1"{{.*}} }