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Revert "[lldb][DWARFASTParserClang] Fetch constant value from variabl…
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…e defintion if available (llvm#71004)"

This reverts commit ef3feba.

This caused an LLDB test failure on Linux for `lang/cpp/symbols/TestSymbols.test_dwo`:

```
make: Leaving directory '/home/worker/2.0.1/lldb-x86_64-debian/build/lldb-test-build.noindex/lang/cpp/symbols/TestSymbols.test_dwo'
runCmd: expression -- D::i
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.	HandleCommand(command = "expression -- D::i")
1.	<user expression 0>:1:4: current parser token 'i'
2.	<lldb wrapper prefix>:44:1: parsing function body '$__lldb_expr'
3.	<lldb wrapper prefix>:44:1: in compound statement ('{}')
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  _lldb.cpython-39-x86_64-linux-gnu.so 0x00007fbcfcb08b87
1  _lldb.cpython-39-x86_64-linux-gnu.so 0x00007fbcfcb067ae
2  _lldb.cpython-39-x86_64-linux-gnu.so 0x00007fbcfcb0923f
3  libpthread.so.0                      0x00007fbd07ab7140
```

And a failure in `TestCallStdStringFunction.py` on Linux aarch64:
```
--
Exit Code: -11

Command Output (stdout):
--
lldb version 18.0.0git (https://github.com/llvm/llvm-project.git revision ef3feba)
  clang revision ef3feba
  llvm revision ef3feba

--
Command Output (stderr):
--
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.      HandleCommand(command = "expression str")
1.      <lldb wrapper prefix>:45:34: current parser token ';'
2.      <lldb wrapper prefix>:44:1: parsing function body '$__lldb_expr'
3.      <lldb wrapper prefix>:44:1: in compound statement ('{}')
  #0 0x0000ffffb72a149c llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lib/python3.8/site-packages/lldb/_[lldb.cpython-38-aarch64-linux-gnu.so](http://lldb.cpython-38-aarch64-linux-gnu.so/)+0x58c749c)
  #1 0x0000ffffb729f458 llvm::sys::RunSignalHandlers() (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lib/python3.8/site-packages/lldb/_[lldb.cpython-38-aarch64-linux-gnu.so](http://lldb.cpython-38-aarch64-linux-gnu.so/)+0x58c5458)
  rust-lang#2 0x0000ffffb72a1bd0 SignalHandler(int) (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lib/python3.8/site-packages/lldb/_[lldb.cpython-38-aarch64-linux-gnu.so](http://lldb.cpython-38-aarch64-linux-gnu.so/)+0x58c7bd0)
  rust-lang#3 0x0000ffffbdd9e7dc (linux-vdso.so.1+0x7dc)
  rust-lang#4 0x0000ffffb71799d8 lldb_private::plugin::dwarf::SymbolFileDWARF::FindGlobalVariables(lldb_private::ConstString, lldb_private::CompilerDeclContext const&, unsigned int, lldb_private::VariableList&) (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lib/python3.8/site-packages/lldb/_[lldb.cpython-38-aarch64-linux-gnu.so](http://lldb.cpython-38-aarch64-linux-gnu.so/)+0x579f9d8)
  rust-lang#5 0x0000ffffb7197508 DWARFASTParserClang::FindConstantOnVariableDefinition(lldb_private::plugin::dwarf::DWARFDIE) (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lib/python3.8/site-packages/lldb/_[lldb.cpython-38-aarch64-linux-gnu.so](http://lldb.cpython-38-aarch64-linux-gnu.so/)+0x57bd508)
```
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Michael137 committed Nov 6, 2023
1 parent 947a32a commit 5f86b49
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Showing 5 changed files with 6 additions and 119 deletions.
63 changes: 1 addition & 62 deletions lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -31,7 +31,6 @@
#include "lldb/Symbol/SymbolFile.h"
#include "lldb/Symbol/TypeList.h"
#include "lldb/Symbol/TypeMap.h"
#include "lldb/Symbol/VariableList.h"
#include "lldb/Target/Language.h"
#include "lldb/Utility/LLDBAssert.h"
#include "lldb/Utility/Log.h"
Expand Down Expand Up @@ -134,54 +133,6 @@ static lldb::ModuleSP GetContainingClangModule(const DWARFDIE &die) {
return lldb::ModuleSP();
}

std::optional<DWARFFormValue>
DWARFASTParserClang::FindConstantOnVariableDefinition(DWARFDIE die) {
assert(die.Tag() == llvm::dwarf::DW_TAG_member);

auto *dwarf = die.GetDWARF();
if (!dwarf)
return {};

ConstString name{die.GetName()};
if (!name)
return {};

auto *CU = die.GetCU();
if (!CU)
return {};

DWARFASTParser *dwarf_ast = dwarf->GetDWARFParser(*CU);
auto parent_decl_ctx = dwarf_ast->GetDeclContextContainingUIDFromDWARF(die);

// Make sure we populate the GetDieToVariable cache.
VariableList variables;
dwarf->FindGlobalVariables(name, parent_decl_ctx, UINT_MAX, variables);

// The cache contains the variable definition whose DW_AT_specification
// points to our declaration DIE. Look up that definition using our
// declaration.
auto const &die_to_var = dwarf->GetDIEToVariable();
auto it = die_to_var.find(die.GetDIE());
if (it == die_to_var.end())
return {};

auto var_sp = it->getSecond();
assert(var_sp != nullptr);

if (!var_sp->GetLocationIsConstantValueData())
return {};

auto def = dwarf->GetDIE(var_sp->GetID());
auto def_attrs = def.GetAttributes();
DWARFFormValue form_value;
if (!def_attrs.ExtractFormValueAtIndex(
def_attrs.FindAttributeIndex(llvm::dwarf::DW_AT_const_value),
form_value))
return {};

return form_value;
}

TypeSP DWARFASTParserClang::ParseTypeFromClangModule(const SymbolContext &sc,
const DWARFDIE &die,
Log *log) {
Expand Down Expand Up @@ -2955,21 +2906,9 @@ void DWARFASTParserClang::ParseSingleMember(

bool unused;
// TODO: Support float/double static members as well.
if (!ct.IsIntegerOrEnumerationType(unused))
if (!attrs.const_value_form || !ct.IsIntegerOrEnumerationType(unused))
return;

// Newer versions of Clang don't emit the DW_AT_const_value
// on the declaration of an inline static data member. Instead
// it's attached to the definition DIE. If that's the case,
// try and fetch it.
if (!attrs.const_value_form) {
auto maybe_form_value = FindConstantOnVariableDefinition(die);
if (!maybe_form_value)
return;

attrs.const_value_form = *maybe_form_value;
}

llvm::Expected<llvm::APInt> const_value_or_err =
ExtractIntFromFormValue(ct, *attrs.const_value_form);
if (!const_value_or_err) {
Expand Down
11 changes: 0 additions & 11 deletions lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.h
Original file line number Diff line number Diff line change
Expand Up @@ -373,17 +373,6 @@ class DWARFASTParserClang : public lldb_private::plugin::dwarf::DWARFASTParser {
lldb_private::CompilerType &class_clang_type,
const lldb::AccessType default_accesibility,
lldb_private::ClangASTImporter::LayoutInfo &layout_info);

/// Tries to find the definition DW_TAG_variable DIE of the the specified
/// DW_TAG_member 'die'. If such definition exists, returns the
/// DW_AT_const_value of that definition if available. Returns std::nullopt
/// otherwise.
///
/// In newer versions of clang, DW_AT_const_value attributes are not attached
/// to the declaration of a inline static data-member anymore, but rather on
/// its definition. This function is used to locate said constant.
std::optional<lldb_private::plugin::dwarf::DWARFFormValue>
FindConstantOnVariableDefinition(lldb_private::plugin::dwarf::DWARFDIE die);
};

/// Parsed form of all attributes that are relevant for type reconstruction.
Expand Down
10 changes: 5 additions & 5 deletions lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h
Original file line number Diff line number Diff line change
Expand Up @@ -343,11 +343,6 @@ class SymbolFileDWARF : public SymbolFileCommon {
return m_forward_decl_compiler_type_to_die;
}

typedef llvm::DenseMap<const DWARFDebugInfoEntry *, lldb::VariableSP>
DIEToVariableSP;

virtual DIEToVariableSP &GetDIEToVariable() { return m_die_to_variable_sp; }

virtual UniqueDWARFASTTypeMap &GetUniqueDWARFASTTypeMap();

bool ClassOrStructIsVirtual(const DWARFDIE &die);
Expand All @@ -367,6 +362,9 @@ class SymbolFileDWARF : public SymbolFileCommon {
Type *ResolveTypeUID(const DIERef &die_ref);

protected:
typedef llvm::DenseMap<const DWARFDebugInfoEntry *, lldb::VariableSP>
DIEToVariableSP;

SymbolFileDWARF(const SymbolFileDWARF &) = delete;
const SymbolFileDWARF &operator=(const SymbolFileDWARF &) = delete;

Expand Down Expand Up @@ -490,6 +488,8 @@ class SymbolFileDWARF : public SymbolFileCommon {

void UpdateExternalModuleListIfNeeded();

virtual DIEToVariableSP &GetDIEToVariable() { return m_die_to_variable_sp; }

void BuildCuTranslationTable();
std::optional<uint32_t> GetDWARFUnitIndex(uint32_t cu_idx);

Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -139,24 +139,3 @@ def test_class_with_only_constexpr_static(self):
self.expect_expr(
"ClassWithEnumAlias::enum_alias_alias", result_value="scoped_enum_case1"
)

def test_shadowed_static_inline_members(self):
"""Tests that the expression evaluator and SBAPI can both
correctly determine the requested inline static variable
in the presence of multiple variables of the same name."""

self.build()
lldbutil.run_to_name_breakpoint(self, "bar")

self.check_global_var("ns::Foo::mem", "const int", "10")

self.expect_expr("mem", result_value="10")
self.expect_expr("Foo::mem", result_value="10")
self.expect_expr("ns::Foo::mem", result_value="10")
self.expect_expr("::Foo::mem", result_value="-29")

@expectedFailureAll(bugnumber="target var doesn't honour global namespace")
def test_shadowed_static_inline_members_xfail(self):
self.build()
lldbutil.run_to_name_breakpoint(self, "bar")
self.check_global_var("::Foo::mem", "const int", "-29")
20 changes: 0 additions & 20 deletions lldb/test/API/lang/cpp/const_static_integral_member/main.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -89,25 +89,6 @@ struct ClassWithEnumAlias {
ScopedEnum::scoped_enum_case1;
};

namespace ns {
struct Foo {
constexpr static int mem = 10;

void bar() { return; }
};
} // namespace ns

struct Foo {
constexpr static int mem = -29;
};

int func() {
Foo f1;
ns::Foo f2;
f2.bar();
return ns::Foo::mem + Foo::mem;
}

int main() {
A a;

Expand Down Expand Up @@ -143,7 +124,6 @@ int main() {

auto enum_alias_val = ClassWithEnumAlias::enum_alias;
auto enum_alias_alias_val = ClassWithEnumAlias::enum_alias_alias;
auto ret = func();

return 0; // break here
}

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