avogelsgesang updated this revision to Diff 456055.
avogelsgesang added a comment.
disable tests on gcc
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D132624/new/
https://reviews.llvm.org/D132624
Files:
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
Index: lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/coroutine_handle/main.cpp
===================================================================
--- lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/coroutine_handle/main.cpp
+++ lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/coroutine_handle/main.cpp
@@ -43,6 +43,8 @@
bool is_supported = is_implementation_supported();
int_generator gen = my_generator_func();
std::coroutine_handle<> type_erased_hdl = gen.hdl;
+ std::coroutine_handle<int> incorrectly_typed_hdl =
+ std::coroutine_handle<int>::from_address(gen.hdl.address());
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
Index: 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/TestCoroutineHandle.py
+++ lldb/test/API/functionalities/data-formatter/data-formatter-stl/generic/coroutine_handle/TestCoroutineHandle.py
@@ -16,6 +16,7 @@
def do_test(self, stdlib_type):
"""Test std::coroutine_handle is displayed correctly."""
self.build(dictionary={stdlib_type: "1"})
+ is_clang = self.expectedCompiler(["clang"])
test_generator_func_ptr_re = re.compile(
r"^\(a.out`my_generator_func\(\) at main.cpp:[0-9]*\)$")
@@ -37,14 +38,31 @@
ValueCheck(name="current_value", value = "-1"),
])
])
- # For type-erased `coroutine_handle<>` we are missing the `promise`
- # but still show `resume` and `destroy`.
- self.expect_expr("type_erased_hdl",
- result_summary=re.compile("^coro frame = 0x[0-9a-f]*$"),
- result_children=[
- ValueCheck(name="resume", summary = test_generator_func_ptr_re),
- ValueCheck(name="destroy", summary = test_generator_func_ptr_re),
- ])
+ if is_clang:
+ # For a type-erased `coroutine_handle<>`, we can still devirtualize
+ # the promise call and display the correctly typed promise.
+ self.expect_expr("type_erased_hdl",
+ result_summary=re.compile("^coro frame = 0x[0-9a-f]*$"),
+ result_children=[
+ ValueCheck(name="resume", summary = test_generator_func_ptr_re),
+ ValueCheck(name="destroy", summary = test_generator_func_ptr_re),
+ ValueCheck(name="promise", children=[
+ ValueCheck(name="current_value", value = "-1"),
+ ])
+ ])
+ # For an incorrectly typed `coroutine_handle`, we use the user-supplied
+ # incorrect type instead of inferring the correct type. Strictly speaking,
+ # incorrectly typed coroutine handles are undefined behavior. However,
+ # it provides probably a better debugging experience if we display the
+ # promise as seen by the program instead of fixing this bug based on
+ # the available debug info.
+ self.expect_expr("incorrectly_typed_hdl",
+ result_summary=re.compile("^coro frame = 0x[0-9a-f]*$"),
+ result_children=[
+ ValueCheck(name="resume", summary = test_generator_func_ptr_re),
+ ValueCheck(name="destroy", summary = test_generator_func_ptr_re),
+ ValueCheck(name="promise", value="-1")
+ ])
# Run until after the `co_yield`
process = self.process()
@@ -73,6 +91,18 @@
ValueCheck(name="current_value", value = "42"),
])
])
+ if is_clang:
+ # Devirtualization still works, also at the final suspension point, despite
+ # the `resume` pointer being reset to a nullptr
+ self.expect_expr("type_erased_hdl",
+ result_summary=re.compile("^coro frame = 0x[0-9a-f]*$"),
+ result_children=[
+ ValueCheck(name="resume", value = "0x0000000000000000"),
+ ValueCheck(name="destroy", summary = test_generator_func_ptr_re),
+ ValueCheck(name="promise", children=[
+ ValueCheck(name="current_value", value = "42"),
+ ])
+ ])
@add_test_categories(["libstdcxx"])
def test_libstdcpp(self):
Index: lldb/source/Plugins/Language/CPlusPlus/Coroutines.cpp
===================================================================
--- lldb/source/Plugins/Language/CPlusPlus/Coroutines.cpp
+++ lldb/source/Plugins/Language/CPlusPlus/Coroutines.cpp
@@ -9,6 +9,8 @@
#include "Coroutines.h"
#include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
+#include "lldb/Symbol/Function.h"
+#include "lldb/Symbol/VariableList.h"
using namespace lldb;
using namespace lldb_private;
@@ -32,6 +34,57 @@
return ptr_sp;
}
+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();
+
+ AddressType addr_type;
+ lldb::addr_t frame_ptr_addr = frame_ptr_sp->GetPointerValue(&addr_type);
+ if (!frame_ptr_addr || frame_ptr_addr == LLDB_INVALID_ADDRESS)
+ return nullptr;
+ lldbassert(addr_type == AddressType::eAddressTypeLoad);
+
+ Status 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 destroy_func_address;
+ if (!target_sp->ResolveLoadAddress(destroy_func_addr, destroy_func_address))
+ return nullptr;
+
+ Function *destroy_func =
+ destroy_func_address.CalculateSymbolContextFunction();
+ if (!destroy_func)
+ return nullptr;
+
+ return destroy_func;
+}
+
+static CompilerType InferPromiseType(Function &destroy_func) {
+ SymbolContext sc;
+ Block &block = destroy_func.GetBlock(true);
+ auto variable_list = block.GetBlockVariableList(true);
+
+ // clang generates an artificial `__promise` variable inside the
+ // `destroy` function. Look for it.
+ auto promise_var = variable_list->FindVariable(ConstString("__promise"));
+ if (!promise_var)
+ return {};
+ if (!promise_var->IsArtificial())
+ return {};
+
+ Type *promise_type = promise_var->GetType();
+ if (!promise_type)
+ return {};
+ return promise_type->GetForwardCompilerType();
+}
+
static CompilerType GetCoroutineFrameType(TypeSystemClang &ast_ctx,
CompilerType promise_type) {
CompilerType void_type = ast_ctx.GetBasicType(lldb::eBasicTypeVoid);
@@ -58,7 +111,11 @@
if (!ptr_sp)
return false;
- stream.Printf("coro frame = 0x%" PRIx64, ptr_sp->GetValueAsUnsigned(0));
+ if (!ptr_sp->GetValueAsUnsigned(0)) {
+ stream << "nullptr";
+ } else {
+ stream.Printf("coro frame = 0x%" PRIx64, ptr_sp->GetValueAsUnsigned(0));
+ }
return true;
}
@@ -100,15 +157,26 @@
if (!ptr_sp)
return false;
- TypeSystemClang *ast_ctx = llvm::dyn_cast_or_null<TypeSystemClang>(
- valobj_sp->GetCompilerType().GetTypeSystem());
- if (!ast_ctx)
- return false;
-
+ // Get the `promise_type` from the template argument
CompilerType promise_type(
valobj_sp->GetCompilerType().GetTypeTemplateArgument(0));
if (!promise_type)
return false;
+
+ // Try to infer the promise_type if it was type-erased
+ if (promise_type.IsVoidType()) {
+ if (Function *destroy_func = ExtractDestroyFunction(ptr_sp)) {
+ if (CompilerType inferred_type = InferPromiseType(*destroy_func)) {
+ promise_type = inferred_type;
+ }
+ }
+ }
+
+ // Build the coroutine frame type
+ TypeSystemClang *ast_ctx = llvm::dyn_cast_or_null<TypeSystemClang>(
+ ptr_sp->GetCompilerType().GetTypeSystem());
+ if (!ast_ctx)
+ return {};
CompilerType coro_frame_type = GetCoroutineFrameType(*ast_ctx, promise_type);
m_frame_ptr_sp = ptr_sp->Cast(coro_frame_type.GetPointerType());
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