[llvm] [llvm][AsmPrinter] Call graph section format. (PR #159866)

[Prabhu Rajasekaran via llvm-commits]

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@@ -1685,58 +1685,56 @@ void AsmPrinter::emitCallGraphSection(const MachineFunction &MF,
   OutStreamer->pushSection();
   OutStreamer->switchSection(FuncCGSection);
 
-  // Emit format version number.
-  OutStreamer->emitInt64(CallGraphSectionFormatVersion::V_0);
-
-  // Emit function's self information, which is composed of:
-  //  1) FunctionEntryPc
-  //  2) FunctionKind: Whether the function is indirect target, and if so,
-  //     whether its type id is known.
-  //  3) FunctionTypeId: Emit only when the function is an indirect target
-  //     and its type id is known.
-
-  // Emit function entry pc.
-  const MCSymbol *FunctionSymbol = getFunctionBegin();
-  OutStreamer->emitSymbolValue(FunctionSymbol, TM.getProgramPointerSize());
-
-  // If this function has external linkage or has its address taken and
-  // it is not a callback, then anything could call it.
-  const Function &F = MF.getFunction();
-  bool IsIndirectTarget =
-      !F.hasLocalLinkage() || F.hasAddressTaken(nullptr,
-                                                /*IgnoreCallbackUses=*/true,
-                                                /*IgnoreAssumeLikeCalls=*/true,
-                                                /*IgnoreLLVMUsed=*/false);
-
-  // FIXME: FunctionKind takes a few values but emitted as a 64-bit value.
-  // Can be optimized to occupy 2 bits instead.
-  // Emit function kind, and type id if available.
-  if (!IsIndirectTarget) {
-    OutStreamer->emitInt64(
-        static_cast<uint64_t>(FunctionKind::NOT_INDIRECT_TARGET));
-  } else {
+  auto EmitFunctionKindAndTypeId = [&]() {
+    const Function &F = MF.getFunction();
+    // If this function has external linkage or has its address taken and
+    // it is not a callback, then anything could call it.
+    bool IsIndirectTarget = !F.hasLocalLinkage() ||
+                            F.hasAddressTaken(nullptr,
+                                              /*IgnoreCallbackUses=*/true,
+                                              /*IgnoreAssumeLikeCalls=*/true,
+                                              /*IgnoreLLVMUsed=*/false);
----------------
Prabhuk wrote:

Thank you. However this feedback was useful in identifying a missing regression test. I've added a test that tests if a internal linkage, address taken function has its Type ID emitted correctly in the callgraph section. This new test does this for a callback function to make sure it is handled correctly. PTAL.

https://github.com/llvm/llvm-project/pull/159866