[Lldb-commits] [lldb] 2b2f2f6 - Revert "[LLDB] Recognize `std::noop_coroutine()` in `std::coroutine_handle` pretty printer"

Jason Molenda via lldb-commits lldb-commits at lists.llvm.org
Fri Nov 25 12:32:38 PST 2022


Author: Jason Molenda
Date: 2022-11-25T12:32:33-08:00
New Revision: 2b2f2f66141d52dc0d3082ddd12805d36872a189

URL: https://github.com/llvm/llvm-project/commit/2b2f2f66141d52dc0d3082ddd12805d36872a189
DIFF: https://github.com/llvm/llvm-project/commit/2b2f2f66141d52dc0d3082ddd12805d36872a189.diff

LOG: Revert "[LLDB] Recognize `std::noop_coroutine()` in `std::coroutine_handle` pretty printer"

This reverts commit 4346318f5c700f4e85f866610fb8328fc429319b.

This test case is failing on macOS, reverting until it can be
looked at more closely to unblock the macOS CI bots.

```
  File "/Volumes/work/llvm/llvm-project/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/coroutine_handle/TestCoroutineHandle.py", line 121, in test_libcpp
    self.do_test(USE_LIBCPP)
  File "/Volumes/work/llvm/llvm-project/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/coroutine_handle/TestCoroutineHandle.py", line 45, in do_test
    self.expect_expr("noop_hdl",
  File "/Volumes/work/llvm/llvm-project/lldb/packages/Python/lldbsuite/test/lldbtest.py", line 2441, in expect_expr
    value_check.check_value(self, eval_result, str(eval_result))
  File "/Volumes/work/llvm/llvm-project/lldb/packages/Python/lldbsuite/test/lldbtest.py", line 306, in check_value
    test_base.assertEqual(self.expect_summary, val.GetSummary(),
AssertionError: 'noop_coroutine' != 'coro frame = 0x100004058'
- noop_coroutine+ coro frame = 0x100004058 : (std::coroutine_handle<void>) $1 = coro frame = 0x100004058 {
  resume = 0x0000000100003344 (a.out`___lldb_unnamed_symbol223)
  destroy = 0x0000000100003344 (a.out`___lldb_unnamed_symbol223)
}
Checking SBValue: (std::coroutine_handle<void>) $1 = coro frame = 0x100004058 {
  resume = 0x0000000100003344 (a.out`___lldb_unnamed_symbol223)
  destroy = 0x0000000100003344 (a.out`___lldb_unnamed_symbol223)
}
```

Those lldb_unnamed_symbols are synthetic names that ObjectFileMachO
adds to the symbol table, most often seen with stripped binaries,
based off of the function start addresses for all the functions -
if a function has no symbol name, lldb adds one of these names.
This change was originally landed via https://reviews.llvm.org/D132624

Added: 
    

Modified: 
    lldb/source/Plugins/Language/CPlusPlus/Coroutines.cpp
    lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/coroutine_handle/TestCoroutineHandle.py
    lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/coroutine_handle/main.cpp

Removed: 
    


################################################################################
diff  --git a/lldb/source/Plugins/Language/CPlusPlus/Coroutines.cpp b/lldb/source/Plugins/Language/CPlusPlus/Coroutines.cpp
index aa6a6ef7e56ae..bd9ff99db67b8 100644
--- a/lldb/source/Plugins/Language/CPlusPlus/Coroutines.cpp
+++ b/lldb/source/Plugins/Language/CPlusPlus/Coroutines.cpp
@@ -35,7 +35,7 @@ static ValueObjectSP GetCoroFramePtrFromHandle(ValueObject &valobj) {
   return ptr_sp;
 }
 
-static Function *ExtractFunction(ValueObjectSP &frame_ptr_sp, int offset) {
+static Function *ExtractDestroyFunction(ValueObjectSP &frame_ptr_sp) {
   lldb::TargetSP target_sp = frame_ptr_sp->GetTargetSP();
   lldb::ProcessSP process_sp = frame_ptr_sp->GetProcessSP();
   auto ptr_size = process_sp->GetAddressByteSize();
@@ -47,64 +47,24 @@ static Function *ExtractFunction(ValueObjectSP &frame_ptr_sp, int offset) {
   lldbassert(addr_type == AddressType::eAddressTypeLoad);
 
   Status error;
-  auto func_ptr_addr = frame_ptr_addr + offset * ptr_size;
-  lldb::addr_t func_addr =
-      process_sp->ReadPointerFromMemory(func_ptr_addr, error);
+  // The destroy pointer is the 2nd pointer inside the compiler-generated
+  // `pair<resumePtr,destroyPtr>`.
+  auto destroy_func_ptr_addr = frame_ptr_addr + ptr_size;
+  lldb::addr_t destroy_func_addr =
+      process_sp->ReadPointerFromMemory(destroy_func_ptr_addr, error);
   if (error.Fail())
     return nullptr;
 
-  Address func_address;
-  if (!target_sp->ResolveLoadAddress(func_addr, func_address))
+  Address destroy_func_address;
+  if (!target_sp->ResolveLoadAddress(destroy_func_addr, destroy_func_address))
     return nullptr;
 
-  return func_address.CalculateSymbolContextFunction();
-}
-
-static Function *ExtractResumeFunction(ValueObjectSP &frame_ptr_sp) {
-  return ExtractFunction(frame_ptr_sp, 0);
-}
-
-static Function *ExtractDestroyFunction(ValueObjectSP &frame_ptr_sp) {
-  return ExtractFunction(frame_ptr_sp, 1);
-}
-
-static bool IsNoopCoroFunction(Function *f) {
-  if (!f)
-    return false;
-
-  // clang's `__builtin_coro_noop` gets lowered to
-  // `_NoopCoro_ResumeDestroy`. This is used by libc++
-  // on clang.
-  auto mangledName = f->GetMangled().GetMangledName();
-  if (mangledName == "__NoopCoro_ResumeDestroy")
-    return true;
-
-  // libc++ uses the following name as a fallback on
-  // compilers without `__builtin_coro_noop`.
-  auto name = f->GetNameNoArguments();
-  static RegularExpression libcxxRegex(
-      "^std::coroutine_handle<std::noop_coroutine_promise>::"
-      "__noop_coroutine_frame_ty_::__dummy_resume_destroy_func$");
-  lldbassert(libcxxRegex.IsValid());
-  if (libcxxRegex.Execute(name.GetStringRef()))
-    return true;
-  static RegularExpression libcxxRegexAbiNS(
-      "^std::__[[:alnum:]]+::coroutine_handle<std::__[[:alnum:]]+::"
-      "noop_coroutine_promise>::__noop_coroutine_frame_ty_::"
-      "__dummy_resume_destroy_func$");
-  lldbassert(libcxxRegexAbiNS.IsValid());
-  if (libcxxRegexAbiNS.Execute(name.GetStringRef()))
-    return true;
-
-  // libstdc++ uses the following name on both gcc and clang.
-  static RegularExpression libstdcppRegex(
-      "^std::__[[:alnum:]]+::coroutine_handle<std::__[[:alnum:]]+::"
-      "noop_coroutine_promise>::__frame::__dummy_resume_destroy$");
-  lldbassert(libstdcppRegex.IsValid());
-  if (libstdcppRegex.Execute(name.GetStringRef()))
-    return true;
+  Function *destroy_func =
+      destroy_func_address.CalculateSymbolContextFunction();
+  if (!destroy_func)
+    return nullptr;
 
-  return false;
+  return destroy_func;
 }
 
 static CompilerType InferPromiseType(Function &destroy_func) {
@@ -153,15 +113,9 @@ bool lldb_private::formatters::StdlibCoroutineHandleSummaryProvider(
 
   if (!ptr_sp->GetValueAsUnsigned(0)) {
     stream << "nullptr";
-    return true;
-  }
-  if (IsNoopCoroFunction(ExtractResumeFunction(ptr_sp)) &&
-      IsNoopCoroFunction(ExtractDestroyFunction(ptr_sp))) {
-    stream << "noop_coroutine";
-    return true;
+  } else {
+    stream.Printf("coro frame = 0x%" PRIx64, ptr_sp->GetValueAsUnsigned(0));
   }
-
-  stream.Printf("coro frame = 0x%" PRIx64, ptr_sp->GetValueAsUnsigned(0));
   return true;
 }
 
@@ -204,14 +158,6 @@ bool lldb_private::formatters::StdlibCoroutineHandleSyntheticFrontEnd::
   if (!ptr_sp)
     return false;
 
-  Function *resume_func = ExtractResumeFunction(ptr_sp);
-  Function *destroy_func = ExtractDestroyFunction(ptr_sp);
-
-  if (IsNoopCoroFunction(resume_func) && IsNoopCoroFunction(destroy_func)) {
-    // For `std::noop_coroutine()`, we don't want to display any child nodes.
-    return false;
-  }
-
   // Get the `promise_type` from the template argument
   CompilerType promise_type(
       valobj_sp->GetCompilerType().GetTypeTemplateArgument(0));
@@ -223,10 +169,12 @@ bool lldb_private::formatters::StdlibCoroutineHandleSyntheticFrontEnd::
   auto ast_ctx = ts.dyn_cast_or_null<TypeSystemClang>();
   if (!ast_ctx)
     return false;
-  if (promise_type.IsVoidType() && destroy_func) {
-    if (CompilerType inferred_type = InferPromiseType(*destroy_func)) {
-      // Copy the type over to the correct `TypeSystemClang` instance
-      promise_type = m_ast_importer->CopyType(*ast_ctx, inferred_type);
+  if (promise_type.IsVoidType()) {
+    if (Function *destroy_func = ExtractDestroyFunction(ptr_sp)) {
+      if (CompilerType inferred_type = InferPromiseType(*destroy_func)) {
+        // Copy the type over to the correct `TypeSystemClang` instance
+        promise_type = m_ast_importer->CopyType(*ast_ctx, inferred_type);
+      }
     }
   }
 

diff  --git a/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/coroutine_handle/TestCoroutineHandle.py b/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/coroutine_handle/TestCoroutineHandle.py
index d1b4d59de5f5f..44e5e6451c10d 100644
--- a/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/coroutine_handle/TestCoroutineHandle.py
+++ b/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/coroutine_handle/TestCoroutineHandle.py
@@ -38,13 +38,6 @@ def do_test(self, stdlib_type):
                     ValueCheck(name="current_value", value = "-1"),
                 ])
             ])
-        # We recognize and pretty-print `std::noop_coroutine`. We don't display
-        # any children as those are irrelevant for the noop coroutine.
-        # clang version < 16 did not yet write debug info for the noop coroutines.
-        if not (is_clang and self.expectedCompilerVersion(["<", "16"])):
-            self.expect_expr("noop_hdl",
-                result_summary="noop_coroutine",
-                result_children=[])
         if is_clang:
             # For a type-erased `coroutine_handle<>`, we can still devirtualize
             # the promise call and display the correctly typed promise.

diff  --git a/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/coroutine_handle/main.cpp b/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/coroutine_handle/main.cpp
index e34637f09f6ed..8cb81c3bc9f4c 100644
--- a/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/coroutine_handle/main.cpp
+++ b/lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/coroutine_handle/main.cpp
@@ -45,7 +45,6 @@ int main() {
   std::coroutine_handle<> type_erased_hdl = gen.hdl;
   std::coroutine_handle<int> incorrectly_typed_hdl =
       std::coroutine_handle<int>::from_address(gen.hdl.address());
-  std::coroutine_handle<> noop_hdl = std::noop_coroutine();
   gen.hdl.resume();                            // Break at initial_suspend
   gen.hdl.resume();                            // Break after co_yield
   empty_function_so_we_can_set_a_breakpoint(); // Break at final_suspend


        


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