[ctxprof][nfc] Share the definition of FunctionData between compiler-rt and llvm

compiler-rt/lib/ctx_profile/CtxInstrContextNode.h

@@ -113,6 +113,24 @@ class ContextNode final {
   uint64_t entrycount() const { return counters()[0]; }
 };
 
+/// The internal structure of FunctionData. This makes sure that changes to
+/// the fields of FunctionData either get automatically captured on the llvm
+/// side, or force a manual corresponding update.
+///
+/// The macro arguments (see CtxInstrProfiling.h for example):
+///
+/// PTRDECL is a macro taking 2 parameters: a type and the name of the field.
+/// The field is a pointer of that type;
+///
+/// VOLATILE_PTRDECL is the same as above, but for volatile pointers;
+///
+/// MUTEXDECL takes one parameter, the name of a field that is a mutex.
+#define CTXPROF_FUNCTION_DATA(PTRDECL, VOLATILE_PTRDECL, MUTEXDECL)            \
+  PTRDECL(FunctionData, Next)                                                  \
+  VOLATILE_PTRDECL(ContextRoot, CtxRoot)                                       \
+  VOLATILE_PTRDECL(ContextNode, FlatCtx)                                       \
+  MUTEXDECL(Mutex)
+
 /// Abstraction for the parameter passed to `__llvm_ctx_profile_fetch`.
 /// `startContextSection` is called before any context roots are sent for
 /// writing. Then one or more `writeContextual` calls are made; finally,

compiler-rt/lib/ctx_profile/CtxInstrProfiling.h

@@ -142,17 +142,19 @@ struct ContextRoot {
 // The current design trades off a bit of overhead at the first time a function
 // is encountered *for flat profiling* for avoiding size penalties.
 struct FunctionData {
+#define _PTRDECL(T, N) T *N = nullptr;
+#define _VOLATILE_PTRDECL(T, N) T *volatile N = nullptr;
+#define _MUTEXDECL(N) ::__sanitizer::SpinMutex N;
+  CTXPROF_FUNCTION_DATA(_PTRDECL, _VOLATILE_PTRDECL, _MUTEXDECL)
+#undef _PTRDECL
+#undef _VOLATILE_PTRDECL
+#undef _MUTEXDECL
+
   // Constructor for test only - since this is expected to be
   // initialized by the compiler.
-  FunctionData() { Mutex.Init(); }
-
-  FunctionData *Next = nullptr;
-  ContextRoot *volatile CtxRoot = nullptr;
-  ContextNode *volatile FlatCtx = nullptr;
-
+  FunctionData() = default;
   ContextRoot *getOrAllocateContextRoot();
 
-  ::__sanitizer::StaticSpinMutex Mutex;
   // If (unlikely) StaticSpinMutex internals change, we need to modify the LLVM
   // instrumentation lowering side because it is responsible for allocating and
   // zero-initializing ContextRoots.

llvm/include/llvm/ProfileData/CtxInstrContextNode.h

@@ -113,6 +113,24 @@ class ContextNode final {
   uint64_t entrycount() const { return counters()[0]; }
 };
 
+/// The internal structure of FunctionData. This makes sure that changes to
+/// the fields of FunctionData either get automatically captured on the llvm
+/// side, or force a manual corresponding update.
+///
+/// The macro arguments (see CtxInstrProfiling.h for example):
+///
+/// PTRDECL is a macro taking 2 parameters: a type and the name of the field.
+/// The field is a pointer of that type;
+///
+/// VOLATILE_PTRDECL is the same as above, but for volatile pointers;
+///
+/// MUTEXDECL takes one parameter, the name of a field that is a mutex.
+#define CTXPROF_FUNCTION_DATA(PTRDECL, VOLATILE_PTRDECL, MUTEXDECL)            \
+  PTRDECL(FunctionData, Next)                                                  \
+  VOLATILE_PTRDECL(ContextRoot, CtxRoot)                                       \
+  VOLATILE_PTRDECL(ContextNode, FlatCtx)                                       \
+  MUTEXDECL(Mutex)
+
 /// Abstraction for the parameter passed to `__llvm_ctx_profile_fetch`.
 /// `startContextSection` is called before any context roots are sent for
 /// writing. Then one or more `writeContextual` calls are made; finally,

llvm/lib/Transforms/Instrumentation/PGOCtxProfLowering.cpp

@@ -18,6 +18,7 @@
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/PassManager.h"
+#include "llvm/ProfileData/CtxInstrContextNode.h"
 #include "llvm/ProfileData/InstrProf.h"
 #include "llvm/Support/CommandLine.h"
 #include <utility>
@@ -113,13 +114,16 @@ CtxInstrumentationLowerer::CtxInstrumentationLowerer(Module &M,
   auto *I32Ty = Type::getInt32Ty(M.getContext());
   auto *I64Ty = Type::getInt64Ty(M.getContext());
 
-  FunctionDataTy =
-      StructType::get(M.getContext(), {
-                                          PointerTy,          /*Next*/
-                                          PointerTy,          /*CtxRoot*/
-                                          PointerTy,          /*FlatCtx*/
-                                          SanitizerMutexType, /*Mutex*/
-                                      });
+#define _PTRDECL(_, __) PointerTy,
+#define _VOLATILE_PTRDECL(_, __) PointerTy,
+#define _MUTEXDECL(_) SanitizerMutexType,
+
+  FunctionDataTy = StructType::get(
+      M.getContext(),
+      {CTXPROF_FUNCTION_DATA(_PTRDECL, _VOLATILE_PTRDECL, _MUTEXDECL)});
+#undef _PTRDECL
+#undef _VOLATILE_PTRDECL
+#undef _MUTEXDECL
 
   // The Context header.
   ContextNodeTy = StructType::get(M.getContext(), {