[DWARF DUMP] Fix infinite recursion in Type Printer.

[ayermolo]

Summary

There is an implicit circular dependency in a debug information coming from GCC.
This results in a coredump.
It tries to resolve scope for DIE TAGs that are scopeless.

[dblaikie]

Got a small source example and compilation command line (& gcc version etc)? And/or at least full dwarf dump output?

[ayermolo]

ah sorry.
can repro with gcc 9 and 11, and latest trunk
git clone https://github.com/gcc-mirror/gcc.git
cd gcc/libstdc++-v3/src/filesystem
gcc -g -gdwarf-4 -std=gnu++17 path.cc -o foo.o -c
llvm-dwarfdump --show-form --verbose --debug-info foo.o &> info

I'll try to create a small repro.

[ayermolo]

Working example:

0x000002a3:   DW_TAG_ptr_to_member_type [15]   (0x0000000b)
                DW_AT_type [DW_FORM_ref4] (cu + 0x0287 => {0x00000287} "ns::inner")
                DW_AT_containing_type [DW_FORM_ref4]  (cu + 0x0287 => {0x00000287} "ns::inner")
0x000002ac:   DW_TAG_ptr_to_member_type [15]   (0x0000000b)
                DW_AT_type [DW_FORM_ref4] (cu + 0x02b5 => {0x000002b5} "ns::inner (ns::inner *, ns::inner)")
                DW_AT_containing_type [DW_FORM_ref4]  (cu + 0x0287 => {0x00000287} "ns::inner")      
0x000002b5:   DW_TAG_subroutine_type [29] * (0x0000000b)
                DW_AT_type [DW_FORM_ref4] (cu + 0x0287 => {0x00000287} "ns::inner")
0x00000287:     DW_TAG_structure_type [16]   (0x00000282)
                  DW_AT_name [DW_FORM_strp] ( .debug_str[0x000000d6] = "inner")
                  DW_AT_declaration [DW_FORM_flag_present]  (true)
0x00000282:   DW_TAG_namespace [30] * (0x0000000b)
                DW_AT_name [DW_FORM_strp] ( .debug_str[0x000000d3] = "ns")
                
0x000000e1:   DW_TAG_template_type_parameter [5]   (0x0000003c)
                DW_AT_type [DW_FORM_ref4] (cu + 0x02a3 => {0x000002a3} "ns::inner ns::inner::*")
0x000000e6:   DW_TAG_template_type_parameter [5]   (0x0000003c)
                DW_AT_type [DW_FORM_ref4] (cu + 0x02ac => {0x000002ac} "ns::inner (ns::inner::*)()")

Couple traces through calls with DIE offsets printed.
0x000000e1: DW_TAG_template_type_parameter [5] (0x0000003c)
DW_AT_type [DW_FORM_ref4] (cu + 0x02a3 => {0x000002a3} “
appendQualifiedName: 2a3
appendUnqualifiedName: 2a3
appendUnqualifiedNameBefore: 2a3
appendQualifiedNameBefore: 287
appendScopes: 282
appendUnqualifiedName: 282
appendUnqualifiedNameBefore: 282
nsappendUnqualifiedNameAfter: 282
::appendUnqualifiedNameBefore: 287
innerappendTemplateParameters: 287

appendQualifiedName: 287
appendScopes: 282
appendUnqualifiedName: 282
appendUnqualifiedNameBefore: 282
nsappendUnqualifiedNameAfter: 282
::appendUnqualifiedName: 287
appendUnqualifiedNameBefore: 287
innerappendTemplateParameters: 287
appendUnqualifiedNameAfter: 287
::*appendUnqualifiedNameAfter: 2a3
appendUnqualifiedNameAfter: 287
")

0x000000e6: DW_TAG_template_type_parameter [5] (0x0000003c)
DW_AT_type [DW_FORM_ref4] (cu + 0x02ac => {0x000002ac} “
appendQualifiedName: 2ac
appendUnqualifiedName: 2ac
appendUnqualifiedNameBefore: 2ac
appendQualifiedNameBefore: 2b5
appendUnqualifiedNameBefore: 2b5
appendQualifiedNameBefore: 287
appendScopes: 282
appendUnqualifiedName: 282
appendUnqualifiedNameBefore: 282
nsappendUnqualifiedNameAfter: 282
::appendUnqualifiedNameBefore: 287
innerappendTemplateParameters: 287
(
appendQualifiedName: 287
appendScopes: 282
appendUnqualifiedName: 282
appendUnqualifiedNameBefore: 282
nsappendUnqualifiedNameAfter: 282
::appendUnqualifiedName: 287
appendUnqualifiedNameBefore: 287
innerappendTemplateParameters: 287
appendUnqualifiedNameAfter: 287
::*appendUnqualifiedNameAfter: 2ac
)appendUnqualifiedNameAfter: 2b5
appendUnqualifiedName: 2b5
(
appendQualifiedName: 287
appendScopes: 282
appendUnqualifiedName: 282
appendUnqualifiedNameBefore: 282
nsappendUnqualifiedNameAfter: 282
::appendUnqualifiedName: 287
appendUnqualifiedNameBefore: 287
innerappendTemplateParameters: 287
appendUnqualifiedNameAfter: 287
)appendUnqualifiedNameAfter: 287
")

[ayermolo]

Broken case. Stopping recursion after 5 iterations.

0x0000002a:   DW_TAG_namespace [165] * (0x0000000b)
                DW_AT_name [DW_FORM_string] ("std")
                DW_AT_decl_file [DW_FORM_data1] ("/mnt/gvfs/third-party2/libgcc/d1129753c8361ac8e9453c0f4291337a4507ebe6/11.x/platform010/5684a5a/include/c++/11.x/x86_64-facebook-linux/bits/c++config.h")
                DW_AT_decl_line [DW_FORM_data2] (285)
                DW_AT_decl_column [DW_FORM_data1] (0x0b)
                DW_AT_sibling [DW_FORM_ref4]  (cu + 0x10f07 => {0x00010f07})
0x0000d630:     DW_TAG_class_type [46] * (0x0000002a)
                  DW_AT_name [DW_FORM_strp] ( .debug_str[0x0000ab0d] = "codecvt_base")
                  DW_AT_byte_size [DW_FORM_data1] (0x01)
                  DW_AT_decl_file [DW_FORM_data1] ("/mnt/gvfs/third-party2/libgcc/d1129753c8361ac8e9453c0f4291337a4507ebe6/11.x/platform010/5684a5a/include/c++/11.x/bits/codecvt.h")
                  DW_AT_decl_line [DW_FORM_data1] (49)
                  DW_AT_decl_column [DW_FORM_data1] (0x09)
                  DW_AT_sibling [DW_FORM_ref4]  (cu + 0xd667 => {0x0000d667})
0x0000d63d:       DW_TAG_enumeration_type [188] * (0x0000d630)
                    DW_AT_name [DW_FORM_strp] ( .debug_str[0x00006ad2] = "result")
                    DW_AT_encoding [DW_FORM_data1]  (DW_ATE_unsigned)
                    DW_AT_byte_size [DW_FORM_data1] (0x04)
                    DW_AT_type [DW_FORM_ref4] (cu + 0x13950 => {0x00013950} "unsigned int")
                    DW_AT_decl_file [DW_FORM_data1] ("/mnt/gvfs/third-party2/libgcc/d1129753c8361ac8e9453c0f4291337a4507ebe6/11.x/platform010/5684a5a/include/c++/11.x/bits/codecvt.h")
                    DW_AT_decl_line [DW_FORM_data1] (52)
                    DW_AT_decl_column [DW_FORM_data1] (0x0a)
                    DW_AT_accessibility [DW_FORM_data1] (DW_ACCESS_public)
0x0001711e:     DW_TAG_subroutine_type [117] * (0x0001706b)
                  DW_AT_type [DW_FORM_ref4] (cu + 0xd63d => {0x0000d63d} "std::codecvt_base::result")
                  DW_AT_object_pointer [DW_FORM_ref4] (cu + 0x1712b => {0x0001712b})
                  DW_AT_sibling [DW_FORM_ref4]  (cu + 0x1715f => {0x0001715f})
0x0001712b:       DW_TAG_formal_parameter [2]   (0x0001711e)
                    DW_AT_type [DW_FORM_ref4] (cu + 0x17130 => {0x00017130} "std::codecvt_base::result (std::codecvt_base::result (std::codecvt_base::result (std::codecvt_base::result (std::codecvt_base::result (::std::codecvt_base::result (::const _Codecvt ::std::codecvt_base::result (::const _Codecvt ::std::codecvt_base::result (::const _Codecvt ::std::codecvt_base::result (::const _Codecvt ::std::codecvt_base::result (::const _Codecvt *")
0x00017130:       DW_TAG_pointer_type [10]   (0x0001711e)
                    DW_AT_byte_size [DW_FORM_data1] (0x08)
                    DW_AT_type [DW_FORM_ref4] (cu + 0x17136 => {0x00017136} "std::codecvt_base::result (std::codecvt_base::result (std::codecvt_base::result (std::codecvt_base::result (std::codecvt_base::result (std::codecvt_base::result (::std::codecvt_base::result (::const _Codecvt *::std::codecvt_base::result (::const _Codecvt *::std::codecvt_base::result (::const _Codecvt *::std::codecvt_base::result (::const _Codecvt *::std::codecvt_base::result (::const _Codecvt *::const _Codecvt")
0x00017136:       DW_TAG_const_type [9]   (0x0001711e)
                    DW_AT_type [DW_FORM_ref4] (cu + 0x17106 => {0x00017106} "_Codecvt")

0x0001712b: DW_TAG_formal_parameter [2] (0x0001711e)
DW_AT_type [DW_FORM_ref4] (cu + 0x17130 => {0x00017130} “
appendQualifiedName: 17130
appendScopes: 1711e
appendUnqualifiedName: 1711e
appendUnqualifiedNameBefore: 1711e
appendQualifiedNameBefore: d63d
appendScopes: d630
appendScopes: 2a
appendUnqualifiedName: 2a
appendUnqualifiedNameBefore: 2a
stdappendUnqualifiedNameAfter: 2a
::appendUnqualifiedName: d630
appendUnqualifiedNameBefore: d630
codecvt_baseappendTemplateParameters: d630
appendUnqualifiedNameAfter: d630
::appendUnqualifiedNameBefore: d63d
resultappendTemplateParameters: d63d
appendUnqualifiedNameAfter: 1711e
appendUnqualifiedName: 1711e
(
appendQualifiedName: 17130
appendScopes: 1711e
appendUnqualifiedName: 1711e
appendUnqualifiedNameBefore: 1711e
appendQualifiedNameBefore: d63d
appendScopes: d630
appendScopes: 2a
appendUnqualifiedName: 2a
appendUnqualifiedNameBefore: 2a
stdappendUnqualifiedNameAfter: 2a
::appendUnqualifiedName: d630
appendUnqualifiedNameBefore: d630
codecvt_baseappendTemplateParameters: d630
appendUnqualifiedNameAfter: d630
::appendUnqualifiedNameBefore: d63d
resultappendTemplateParameters: d63d
appendUnqualifiedNameAfter: 1711e
appendUnqualifiedName: 1711e
(
appendQualifiedName: 17130
....

0x00017130: DW_TAG_pointer_type [10] (0x0001711e)
DW_AT_byte_size [DW_FORM_data1] (0x08)
DW_AT_type [DW_FORM_ref4] (cu + 0x17136 => {0x00017136} “
appendQualifiedName: 17136
appendScopes: 1711e
appendUnqualifiedName: 1711e
appendUnqualifiedNameBefore: 1711e
appendQualifiedNameBefore: d63d
appendScopes: d630
appendScopes: 2a
appendUnqualifiedName: 2a
appendUnqualifiedNameBefore: 2a
stdappendUnqualifiedNameAfter: 2a
::appendUnqualifiedName: d630
appendUnqualifiedNameBefore: d630
codecvt_baseappendTemplateParameters: d630
appendUnqualifiedNameAfter: d630
::appendUnqualifiedNameBefore: d63d
resultappendTemplateParameters: d63d
appendUnqualifiedNameAfter: 1711e
appendUnqualifiedName: 1711e
(
appendQualifiedName: 17130
appendScopes: 1711e
appendUnqualifiedName: 1711e
appendUnqualifiedNameBefore: 1711e
appendQualifiedNameBefore: d63d
appendScopes: d630
appendScopes: 2a
appendUnqualifiedName: 2a
appendUnqualifiedNameBefore: 2a
stdappendUnqualifiedNameAfter: 2a
::appendUnqualifiedName: d630
appendUnqualifiedNameBefore: d630
codecvt_baseappendTemplateParameters: d630
appendUnqualifiedNameAfter: d630
::appendUnqualifiedNameBefore: d63d
resultappendTemplateParameters: d63d
appendUnqualifiedNameAfter: 1711e
appendUnqualifiedName: 1711e
(
appendQualifiedName: 17130
....

[ayermolo]

"Minimal" repro. Still relies on some std stuff. :(

#include <streambuf>
#include <bits/codecvt.h>
namespace std
{
    inline bool
    __str_codecvt_out()
    {
      using _State = std::mbstate_t;
      using _CharT = wchar_t;
      using _Codecvt = codecvt<_CharT, char, _State>;
      using _ConvFn
  = codecvt_base::result
    (_Codecvt::*)(_State&, const _CharT*, const _CharT*, const _CharT*&,
      char*, char*, char*&) const;
      _ConvFn __fn = &codecvt<_CharT, char, _State>::out;
      return true;
    }

bool test() {
    return __str_codecvt_out();
}
}

[dblaikie]

If you could provide preprocessed source (ideally reduced further with cvise or similar) that'd be good. (I'm still out for a week, or I'd look at it further/sooner.

[ayermolo]

In D132900#3762755, @dblaikie wrote:

If you could provide preprocessed source (ideally reduced further with cvise or similar) that'd be good. (I'm still out for a week, or I'd look at it further/sooner.

Yeah, will try to reduce it more later this week.

[ayermolo]

OK. I think this is a minimal self contained repro:

class codecvt_base
{
  public:
    enum result {
      ok
    };
};

class __codecvt_abstract_base
    : public codecvt_base
{
    public:
      result out(const wchar_t* __from) const {
	    return result::ok;
      }
    };

    class codecvt
    : public __codecvt_abstract_base{};

    inline bool
    __str_codecvt_out()
    {
      using _Codecvt = codecvt;
      using _ConvFn = codecvt_base::result
    (_Codecvt::*)(const wchar_t*) const;
      _ConvFn __fn = &codecvt::out;
      return true;
    }

bool test() {
    return __str_codecvt_out();
}

Replacing (_Codecvt::*)(const wchar_t*) const; with (codecvt::*)(const wchar_t*) const;
Produces debug info that can be parsed by dwarfdumper.

[dblaikie]

Reduced down to:

struct t1;

void f1() {
  using t2 = t1;
  void (t2::* __fn)();
}

Still investigating.

[ayermolo]

In D132900#3780904, @dblaikie wrote:

Reduced down to:

struct t1;

void f1() {
  using t2 = t1;
  void (t2::* __fn)();
}

Still investigating.

Ah! Thanks.

[dblaikie]

llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp

301–303

Avoid the extra lookup.

Though more generally this solution is probably incorrect - presumably it would cause problems for any type that isn't circular, but references the same type twice? eg: "void(x::y, x::y)" would fail/bail out unnecessarily?

To catch the recursion correctly, we'd probably have to use scope chains (walking back up the list of "these are the types we're printing" and see if the type is in the list) or use scoped insertion/removal into the set (each time we go down into a type we add to the set, each time we back out, we remove from the set)?

[dblaikie]

In D132900#3780904, @dblaikie wrote:

Reduced down to:

struct t1;

void f1() {
  using t2 = t1;
  void (t2::* __fn)();
}

Still investigating.

Ah, so the critical difference between GCC and Clang's DWARF on this is that GCC creates the pointer type (when it's pointer-to-local-typedef) inside the subroutine_type (it's probably trying to create it inside the function, since the pointer type, while not strictly scoped, would only be usable inside the function type anyway) - this creates the infinite recursion when trying to print the scope of the pointer type (really a pointer type is unscoped, since it's unnamed - maybe we could fix it so we don't print out any scope info for unnameable types (anonymous structs/classes/etc are still logically scoped even though they don't have a name, for instance - but pointer types never really have a scope/name, just a representation))

[ayermolo]

llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp

301–303

oh yeah I don't think this is a right way. It breaks at least one unit test.

[ayermolo]

This comment was removed by ayermolo.

[ayermolo]

Something like this? With other types to add that do not have scope, and test.

[ayermolo]

some cleanup

[dblaikie]

llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp

300–301

Might be inclined to use a switch here, rather than a set lookup - and it's probably easier to make a positive list of the things that are scoped than those that aren't.

[ayermolo]

llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp

300–301

Unfortunately this doesn't work for:

class codecvt_base
{
  public:
    enum result {
      ok
    };
};

class __codecvt_abstract_base
    : public codecvt_base
{
    public:
      result out(const wchar_t* __from) const {
      return result::ok;
      }
    };

    class codecvt
    : public __codecvt_abstract_base{};

    inline bool
    __str_codecvt_out()
    {
      using _Codecvt = codecvt;
      using _ConvFn = codecvt_base::result
    (_Codecvt::*)(const wchar_t*) const;
      _ConvFn __fn = &codecvt::out;
      return true;
    }

bool test() {
    return __str_codecvt_out();
}

It prints out this before eventually crashing.
0x00000133: DW_TAG_formal_parameter [8] (0x00000126)

DW_AT_type [DW_FORM_ref4] (cu + 0x0138 => {0x00000138} "codecvt_base::result (codecvt_base::result (codecvt_base::result (codecvt_base::result (codecvt_base::result (codecvt_base::result (codecvt_base::result (codecvt_base::result (codecvt_base::result (codecvt_base::result (::codecvt_base::result (::const _Codecvt *::codecvt_base::result (::const _Codecvt *::codecvt_base::result (::const _Codecvt *::codecvt_base::result (::const _Codecvt *::codecvt_base::result (::const _Codecvt *::codecvt_base::result (::const _Codecvt *::codecvt_base::result (::const _Codecvt *::codecvt_base::result (::const _Codecvt *::codecvt_base::result (::const _Codecvt *::codecvt_base::result (::const _Codecvt *")

Maybe better approach is to apply this allow list approach to DWARFTypePrinter::appendScopes? So it will return unless it's one of those TAGs.

[dblaikie]

llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp

300–301

I don't think it'd work to do this in appendScopes because appendScopes gets passed the scope, not the thing that's being scoped - and the determination on whether to skip scopes should be on the type being scoped, not the scoping.

Could you reduce the test down a bit - help understand what's interesting about this? I guess there's some other place that appends scopes that needs handling? Looks like the only other uses is appendQualifiedNameBefore - so I guess the handling needs to be in both of those, which sounds plausible/reasonable.

But yeah, maybe sinking a wrapper. appendQualification or something, which just does the if (D) / check the type, then appendScopes(D.getParent())

[ayermolo]

llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp

300–301

k, will try next week. Thx for helping with this.

[ayermolo]

class codecvt
{
  public:
    void out() const {}
};


void test() {
  using _Codecvt = codecvt;
  using _ConvFn = void(_Codecvt::*)() const;
  _ConvFn __fn = &_Codecvt::out;
}

So in both cases key to pathological case seems to be it's going through:
appendSubroutineNameAfter: DW_TAG_subroutine_type
appendQualifiedName: DW_TAG_pointer_type

[ayermolo]

llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp

544

Maybe here is a better check? Something like D.getTag() == DW_TAG_subroutine_type, and also check T tag?

[dblaikie]

In D132900#3801329, @ayermolo wrote:

class codecvt
{
  public:
    void out() const {}
};


void test() {
  using _Codecvt = codecvt;
  using _ConvFn = void(_Codecvt::*)() const;
  _ConvFn __fn = &_Codecvt::out;
}

So in both cases key to pathological case seems to be it's going through:
appendSubroutineNameAfter: DW_TAG_subroutine_type
appendQualifiedName: DW_TAG_pointer_type

So in this test case, with the patch I proposed (to have an explicit allowed list of names that get scopes, and so everything else doesn't get scopes) you got infinite recursion? Could you paste the stack trace in more detail - I'm a bit confused how we'd get infinite recursion on a pointer type if we're not printing scopes for pointer types anymore.

llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp

544

I'm not sure what you're referring to here, unfortunately - you mean adding a condition here in appendSubroutineNameAfter, around the appendQualifiedName call? I don't think so, but I'm not sure.

[ayermolo]

Circled back with fresh eyes. So this example passes with trunk. So looks like current allow list (below), regresses it.

Stack dump:
0.  Program arguments: /home/ayermolo/local/llvm-build-debug/bin/llvm-dwarfdump --show-form --verbose --debug-info --choose-strategy=1 --enable-verbose-mode=false repro.o
  #0 0x000055cc332c360a llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/Support/Unix/Signals.inc:569:11
  #1 0x000055cc332c37bb PrintStackTraceSignalHandler(void*) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/Support/Unix/Signals.inc:636:1
  #2 0x000055cc332c1e36 llvm::sys::RunSignalHandlers() /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/Support/Signals.cpp:103:5
  #3 0x000055cc332c3ea5 SignalHandler(int) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/Support/Unix/Signals.inc:407:1
  #4 0x00007f54e2edbce0 __restore_rt (/lib64/libpthread.so.0+0x12ce0)
  #5 0x000055cc32d645a4 llvm::StringRef::size() const /home/ayermolo/local/server-llvm/llvm-project/llvm/include/llvm/ADT/StringRef.h:137:0
  #6 0x000055cc32dbafe5 llvm::DataExtractor::size() const /home/ayermolo/local/server-llvm/llvm-project/llvm/include/llvm/Support/DataExtractor.h:688:25
  #7 0x000055cc32db7ee9 llvm::DataExtractor::isValidOffset(unsigned long) const /home/ayermolo/local/server-llvm/llvm-project/llvm/include/llvm/Support/DataExtractor.h:665:61
  #8 0x000055cc32db8348 llvm::DataExtractor::isValidOffsetForDataOfSize(unsigned long, unsigned long) const /home/ayermolo/local/server-llvm/llvm-project/llvm/include/llvm/Support/DataExtractor.h:673:41
  #9 0x000055cc331d9500 llvm::DataExtractor::prepareRead(unsigned long, unsigned long, llvm::Error*) const /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/Support/DataExtractor.cpp:19:7
 #10 0x000055cc331da839 unsigned int llvm::DataExtractor::getU<unsigned int>(unsigned long*, llvm::Error*) const /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/Support/DataExtractor.cpp:47:7
 #11 0x000055cc331d97c5 llvm::DataExtractor::getU32(unsigned long*, llvm::Error*) const /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/Support/DataExtractor.cpp:108:3
 #12 0x000055cc331d9912 llvm::DataExtractor::getUnsigned(unsigned long*, unsigned int, llvm::Error*) const /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/Support/DataExtractor.cpp:133:12
 #13 0x000055cc32dfac8b llvm::DWARFDataExtractor::getRelocatedValue(unsigned int, unsigned long*, unsigned long*, llvm::Error*) const /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFDataExtractor.cpp:58:12
 #14 0x000055cc32e52caa llvm::DWARFFormValue::extractValue(llvm::DWARFDataExtractor const&, unsigned long*, llvm::dwarf::FormParams, llvm::DWARFContext const*, llvm::DWARFUnit const*) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFFormValue.cpp:311:25
 #15 0x000055cc32e005f9 llvm::DWARFFormValue::extractValue(llvm::DWARFDataExtractor const&, unsigned long*, llvm::dwarf::FormParams, llvm::DWARFUnit const*) /home/ayermolo/local/server-llvm/llvm-project/llvm/include/llvm/DebugInfo/DWARF/DWARFFormValue.h:104:5
 #16 0x000055cc32dffd93 llvm::DWARFAbbreviationDeclaration::getAttributeValueFromOffset(unsigned int, unsigned long, llvm::DWARFUnit const&) const /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFAbbreviationDeclaration.cpp:181:7
 #17 0x000055cc32dffe7c llvm::DWARFAbbreviationDeclaration::getAttributeValue(unsigned long, llvm::dwarf::Attribute, llvm::DWARFUnit const&) const /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFAbbreviationDeclaration.cpp:0:10
 #18 0x000055cc32e3dd9a llvm::DWARFDie::find(llvm::dwarf::Attribute) const /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp:257:5
 #19 0x000055cc32e3e1e8 llvm::DWARFDie::getAttributeValueAsReferencedDie(llvm::dwarf::Attribute) const /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFDie.cpp:310:32
 #20 0x000055cc32e462b4 llvm::resolveReferencedType(llvm::DWARFDie, llvm::dwarf::Attribute) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:94:12
 #21 0x000055cc32e47051 llvm::DWARFTypePrinter::appendUnqualifiedNameBefore(llvm::DWARFDie, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*)::$_0::operator()() const /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:135:40
 #22 0x000055cc32e466ef llvm::DWARFTypePrinter::appendUnqualifiedNameBefore(llvm::DWARFDie, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:139:36
 #23 0x000055cc32e498e7 llvm::DWARFTypePrinter::appendUnqualifiedName(llvm::DWARFDie, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:572:22
 #24 0x000055cc32e472d3 llvm::DWARFTypePrinter::appendQualifiedName(llvm::DWARFDie) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:351:1
 #25 0x000055cc32e4905b llvm::DWARFTypePrinter::appendSubroutineNameAfter(llvm::DWARFDie, llvm::DWARFDie, bool, bool, bool) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:584:5
 #26 0x000055cc32e4898d llvm::DWARFTypePrinter::appendUnqualifiedNameAfter(llvm::DWARFDie, llvm::DWARFDie, bool) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:253:5
 #27 0x000055cc32e4992b llvm::DWARFTypePrinter::appendUnqualifiedName(llvm::DWARFDie, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:574:3
 #28 0x000055cc32e4986e llvm::DWARFTypePrinter::appendScopes(llvm::DWARFDie) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:707:5
 #29 0x000055cc32e46506 llvm::DWARFTypePrinter::appendQualifiedNameBefore(llvm::DWARFDie) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:0:7
 #30 0x000055cc32e463f2 llvm::DWARFTypePrinter::appendPointerLikeTypeBefore(llvm::DWARFDie, llvm::DWARFDie, llvm::StringRef) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:115:3
 #31 0x000055cc32e4673d llvm::DWARFTypePrinter::appendUnqualifiedNameBefore(llvm::DWARFDie, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:140:5
 #32 0x000055cc32e498e7 llvm::DWARFTypePrinter::appendUnqualifiedName(llvm::DWARFDie, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:572:22
 #33 0x000055cc32e472d3 llvm::DWARFTypePrinter::appendQualifiedName(llvm::DWARFDie) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:351:1
 #34 0x000055cc32e4905b llvm::DWARFTypePrinter::appendSubroutineNameAfter(llvm::DWARFDie, llvm::DWARFDie, bool, bool, bool) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:584:5
 #35 0x000055cc32e4898d llvm::DWARFTypePrinter::appendUnqualifiedNameAfter(llvm::DWARFDie, llvm::DWARFDie, bool) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:253:5
 #36 0x000055cc32e4992b llvm::DWARFTypePrinter::appendUnqualifiedName(llvm::DWARFDie, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:574:3
 #37 0x000055cc32e4986e llvm::DWARFTypePrinter::appendScopes(llvm::DWARFDie) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:707:5
 #38 0x000055cc32e46506 llvm::DWARFTypePrinter::appendQualifiedNameBefore(llvm::DWARFDie) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:0:7
 #39 0x000055cc32e463f2 llvm::DWARFTypePrinter::appendPointerLikeTypeBefore(llvm::DWARFDie, llvm::DWARFDie, llvm::StringRef) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:115:3
 #40 0x000055cc32e4673d llvm::DWARFTypePrinter::appendUnqualifiedNameBefore(llvm::DWARFDie, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:140:5
 #41 0x000055cc32e498e7 llvm::DWARFTypePrinter::appendUnqualifiedName(llvm::DWARFDie, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:572:22
 #42 0x000055cc32e472d3 llvm::DWARFTypePrinter::appendQualifiedName(llvm::DWARFDie) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:351:1
 #43 0x000055cc32e4905b llvm::DWARFTypePrinter::appendSubroutineNameAfter(llvm::DWARFDie, llvm::DWARFDie, bool, bool, bool) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:584:5
 #44 0x000055cc32e4898d llvm::DWARFTypePrinter::appendUnqualifiedNameAfter(llvm::DWARFDie, llvm::DWARFDie, bool) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:253:5
 #45 0x000055cc32e4992b llvm::DWARFTypePrinter::appendUnqualifiedName(llvm::DWARFDie, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*) /home/ayermolo/local/server-llvm/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp:574:3

Print out with TAGS:

0x000000a1:       DW_TAG_formal_parameter [4]   (0x00000098)
                    DW_AT_type [DW_FORM_ref4] (cu + 0x00a6 => {0x000000a6} "
appendQualifiedName:  a6 : DW_TAG_pointer_type
appendUnqualifiedName:  a6 : DW_TAG_pointer_type
appendUnqualifiedNameBefore:  a6 : DW_TAG_pointer_type
appendPointerLikeTypeBefore:  a6 : DW_TAG_pointer_type
appendQualifiedNameBefore:  ac : DW_TAG_const_type
appendScopes:   98 : DW_TAG_subroutine_type
appendScopes:   5e : DW_TAG_subprogram
appendUnqualifiedName:  98 : DW_TAG_subroutine_type
appendUnqualifiedNameBefore:  98 : DW_TAG_subroutine_type
void appendUnqualifiedNameAfter:  98 : DW_TAG_subroutine_type
appendSubroutineNameAfter:  98 : DW_TAG_subroutine_type
(
appendQualifiedName:  a6 : DW_TAG_pointer_type
appendUnqualifiedName:  a6 : DW_TAG_pointer_type
appendUnqualifiedNameBefore:  a6 : DW_TAG_pointer_type
appendPointerLikeTypeBefore:  a6 : DW_TAG_pointer_type
appendQualifiedNameBefore:  ac : DW_TAG_const_type
appendScopes:   98 : DW_TAG_subroutine_type
appendScopes:   5e : DW_TAG_subprogram
appendUnqualifiedName:  98 : DW_TAG_subroutine_type
appendUnqualifiedNameBefore:  98 : DW_TAG_subroutine_type
void appendUnqualifiedNameAfter:  98 : DW_TAG_subroutine_type
appendSubroutineNameAfter:  98 : DW_TAG_subroutine_type
(
appendQualifiedName:  a6 : DW_TAG_pointer_type
appendUnqualifiedName:  a6 : DW_TAG_pointer_type
appendUnqualifiedNameBefore:  a6 : DW_TAG_pointer_type
appendPointerLikeTypeBefore:  a6 : DW_TAG_pointer_type
appendQualifiedNameBefore:  ac : DW_TAG_const_type
appendScopes:   98 : DW_TAG_subroutine_type
appendScopes:   5e : DW_TAG_subprogram
appendUnqualifiedName:  98 : DW_TAG_subroutine_type
appendUnqualifiedNameBefore:  98 : DW_TAG_subroutine_type
void appendUnqualifiedNameAfter:  98 : DW_TAG_subroutine_type
appendSubroutineNameAfter:  98 : DW_TAG_subroutine_type

switch (D.getTag()) {
      case dwarf::DW_TAG_structure_type:
      case dwarf::DW_TAG_class_type:
      case dwarf::DW_TAG_union_type:
      case dwarf::DW_TAG_namespace:
      case DW_TAG_enumeration_type:
        appendScopes(D.getParent());
        break;
      default:
        break;
      }

[ayermolo]

llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp

544

Yep exactly.

[dblaikie]

So, I'm not sure what failures you're seeing, but I tried this locally:

$ git diff
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp b/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp
index 2d8add64537c..969a6525d821 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp
@@ -284,12 +284,32 @@ void DWARFTypePrinter::appendUnqualifiedNameAfter(
 
 void DWARFTypePrinter::appendQualifiedName(DWARFDie D) {
   if (D)
-    appendScopes(D.getParent());
+    switch (D.getTag()) {
+    case dwarf::DW_TAG_structure_type:
+    case dwarf::DW_TAG_class_type:
+    case dwarf::DW_TAG_union_type:
+    case dwarf::DW_TAG_namespace:
+    case dwarf::DW_TAG_enumeration_type:
+      appendScopes(D.getParent());
+      break;
+    default:
+      break;
+    }
   appendUnqualifiedName(D);
 }
 DWARFDie DWARFTypePrinter::appendQualifiedNameBefore(DWARFDie D) {
   if (D)
-    appendScopes(D.getParent());
+    switch (D.getTag()) {
+    case dwarf::DW_TAG_structure_type:
+    case dwarf::DW_TAG_class_type:
+    case dwarf::DW_TAG_union_type:
+    case dwarf::DW_TAG_namespace:
+    case dwarf::DW_TAG_enumeration_type:
+      appendScopes(D.getParent());
+      break;
+    default:
+      break;
+    }
   return appendUnqualifiedNameBefore(D);
 }
 bool DWARFTypePrinter::appendTemplateParameters(DWARFDie D,
@@ -516,7 +536,7 @@ void DWARFTypePrinter::appendSubroutineNameAfter(
   for (DWARFDie P : D) {
     if (P.getTag() != DW_TAG_formal_parameter &&
         P.getTag() != DW_TAG_unspecified_parameters)
-      return;
+      continue;
     DWARFDie T = resolveReferencedType(P);
     if (SkipFirstParamIfArtificial && RealFirst && P.find(DW_AT_artificial)) {
       FirstParamIfArtificial = T;

and I tried the initial test case and the follow-up one and they seem to work correctly without assertions/crashes/infinite recursion for me.

Can you help me understand what you're hitting up against?

(this ^ patch isn't quite ready - would be good to refactor out the two switches into a single switch to avoid code duplication & possibly adding extra test coverage for that return -> continue change that lets the function type be fully printed despite non-parameter DIEs in the subroutine type)

[ayermolo]

In D132900#3812611, @dblaikie wrote:

So, I'm not sure what failures you're seeing, but I tried this locally:

$ git diff
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp b/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp
index 2d8add64537c..969a6525d821 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp
@@ -284,12 +284,32 @@ void DWARFTypePrinter::appendUnqualifiedNameAfter(
 
 void DWARFTypePrinter::appendQualifiedName(DWARFDie D) {
   if (D)
-    appendScopes(D.getParent());
+    switch (D.getTag()) {
+    case dwarf::DW_TAG_structure_type:
+    case dwarf::DW_TAG_class_type:
+    case dwarf::DW_TAG_union_type:
+    case dwarf::DW_TAG_namespace:
+    case dwarf::DW_TAG_enumeration_type:
+      appendScopes(D.getParent());
+      break;
+    default:
+      break;
+    }
   appendUnqualifiedName(D);
 }
 DWARFDie DWARFTypePrinter::appendQualifiedNameBefore(DWARFDie D) {
   if (D)
-    appendScopes(D.getParent());
+    switch (D.getTag()) {
+    case dwarf::DW_TAG_structure_type:
+    case dwarf::DW_TAG_class_type:
+    case dwarf::DW_TAG_union_type:
+    case dwarf::DW_TAG_namespace:
+    case dwarf::DW_TAG_enumeration_type:
+      appendScopes(D.getParent());
+      break;
+    default:
+      break;
+    }
   return appendUnqualifiedNameBefore(D);
 }
 bool DWARFTypePrinter::appendTemplateParameters(DWARFDie D,
@@ -516,7 +536,7 @@ void DWARFTypePrinter::appendSubroutineNameAfter(
   for (DWARFDie P : D) {
     if (P.getTag() != DW_TAG_formal_parameter &&
         P.getTag() != DW_TAG_unspecified_parameters)
-      return;
+      continue;
     DWARFDie T = resolveReferencedType(P);
     if (SkipFirstParamIfArtificial && RealFirst && P.find(DW_AT_artificial)) {
       FirstParamIfArtificial = T;

and I tried the initial test case and the follow-up one and they seem to work correctly without assertions/crashes/infinite recursion for me.

Can you help me understand what you're hitting up against?

(this ^ patch isn't quite ready - would be good to refactor out the two switches into a single switch to avoid code duplication & possibly adding extra test coverage for that return -> continue change that lets the function type be fully printed despite non-parameter DIEs in the subroutine type)

Sorry was on PTO.
Ah, so I only had the check in appendQualifiedName. I might have miss understood your original comment. Thanks for pointing this out!

[ayermolo]

new version

[dblaikie]

Sounds good, thanks!

llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp

294

no need for the break after return

[ayermolo]

address comment

[ayermolo]

Thanks for all the help!

llvm/lib/DebugInfo/DWARF/DWARFTypePrinter.cpp

void DWARFTypePrinter::appendUnqualifiedNameAfter(
   case DW_TAG_base_type:
   case DW_TAG_namespace:
   */
   default:
     break;
   }
 }
 
+/// Returns True if the DIE TAG is one of the ones that is scopped.
+static bool scopedTAGs(dwarf::Tag Tag) {
+  switch (Tag) {
+  case dwarf::DW_TAG_structure_type:
+  case dwarf::DW_TAG_class_type:
+  case dwarf::DW_TAG_union_type:
+  case dwarf::DW_TAG_namespace:
+  case dwarf::DW_TAG_enumeration_type:
+    return true;
+  default:
+    break;
+  }
+  return false;
+}
 void DWARFTypePrinter::appendQualifiedName(DWARFDie D) {
-  if (D)
+  if (D && scopedTAGs(D.getTag()))
     appendScopes(D.getParent());
   appendUnqualifiedName(D);
 }
 DWARFDie DWARFTypePrinter::appendQualifiedNameBefore(DWARFDie D) {
-  if (D)
+  if (D && scopedTAGs(D.getTag()))
     appendScopes(D.getParent());
   return appendUnqualifiedNameBefore(D);
 }
 bool DWARFTypePrinter::appendTemplateParameters(DWARFDie D,
                                                 bool *FirstParameter) {
   bool FirstParameterValue = true;
   bool IsTemplate = false;
   if (!FirstParameter)
if (SkipFirstParamIfArtificial && RealFirst && P.find(DW_AT_artificial)) {
       FirstParamIfArtificial = T;
       RealFirst = false;
       continue;
     }
     if (!First) {
       OS << ", ";
     }
     First = false;
     if (P.getTag() == DW_TAG_unspecified_parameters)
       OS << "...";
     else
       appendQualifiedName(T);
   }
   EndedWithTemplate = false;
   OS << ')';
   if (FirstParamIfArtificial) {
     if (DWARFDie P = FirstParamIfArtificial) {

llvm/test/DebugInfo/X86/dwarfdump-infinite-loop.s

+# Test object to verify that dwarfdump does not go into infinite recursion due
+# to trying to print fully resolved name.
+# RUN: llvm-mc -triple x86_64-unknown-linux %s -filetype=obj -o %t.o
+# RUN: llvm-dwarfdump --debug-info=0x62 %t.o | FileCheck %s
+
+# CHECK: DW_TAG_formal_parameter
+# CHECK-NEXT: DW_AT_type
+# CHECK-SAME: "t2 *"
+
+# gcc -g -gdwarf-4 -std=gnu++17 -c -gz=none -S reproSmall.cpp -o reproSmall.s
+# struct t1;
+# void f1() {
+#   using t2 = t1;
+#   void (t2::* __fn)();
+# }
+
+.section  .debug_info,"",@progbits
+.Ldebug_info0:
+  .long 0x88
+  .value  0x4
+  .long .Ldebug_abbrev0
+  .byte 0x8
+  .uleb128 0x1
+  .long .LASF0
+  .byte 0x4
+  .long .LASF1
+  .long .LASF2
+  .quad 0
+  .quad 0
+  .long .Ldebug_line0
+  .uleb128 0x2
+  .string "f1"
+  .byte 0x1
+  .byte 0x3
+  .byte 0x6
+  .long .LASF3
+  .quad 0
+  .quad 0
+  .uleb128 0x1
+  .byte 0x9c
+  .long 0x87
+  .uleb128 0x3
+  .string "t2"
+  .byte 0x1
+  .byte 0x4
+  .byte 0x9
+  .long 0x87
+  .uleb128 0x4
+  .long 0x62
+  .long 0x6e
+  .uleb128 0x5
+  .long 0x67
+  .uleb128 0x6
+  .byte 0x8
+  .long 0x4e
+  .byte 0
+  .uleb128 0x7
+  .long 0x87
+  .long 0x59
+  .uleb128 0x8
+  .long .LASF4
+  .byte 0x1
+  .byte 0x5
+  .byte 0xf
+  .long 0x6e
+  .uleb128 0x2
+  .byte 0x91
+  .sleb128 -32
+  .byte 0
+  .uleb128 0x9
+  .string "t1"
+  .byte 0
+  .section  .debug_abbrev,"",@progbits
+.Ldebug_abbrev0:
+  .uleb128 0x1
+  .uleb128 0x11
+  .byte 0x1
+  .uleb128 0x25
+  .uleb128 0xe
+  .uleb128 0x13
+  .uleb128 0xb
+  .uleb128 0x3
+  .uleb128 0xe
+  .uleb128 0x1b
+  .uleb128 0xe
+  .uleb128 0x11
+  .uleb128 0x1
+  .uleb128 0x12
+  .uleb128 0x7
+  .uleb128 0x10
+  .uleb128 0x17
+  .byte 0
+  .byte 0
+  .uleb128 0x2
+  .uleb128 0x2e
+  .byte 0x1
+  .uleb128 0x3f
+  .uleb128 0x19
+  .uleb128 0x3
+  .uleb128 0x8
+  .uleb128 0x3a
+  .uleb128 0xb
+  .uleb128 0x3b
+  .uleb128 0xb
+  .uleb128 0x39
+  .uleb128 0xb
+  .uleb128 0x6e
+  .uleb128 0xe
+  .uleb128 0x11
+  .uleb128 0x1
+  .uleb128 0x12
+  .uleb128 0x7
+  .uleb128 0x40
+  .uleb128 0x18
+  .uleb128 0x2117
+  .uleb128 0x19
+  .uleb128 0x1
+  .uleb128 0x13
+  .byte 0
+  .byte 0
+  .uleb128 0x3
+  .uleb128 0x16
+  .byte 0
+  .uleb128 0x3
+  .uleb128 0x8
+  .uleb128 0x3a
+  .uleb128 0xb
+  .uleb128 0x3b
+  .uleb128 0xb
+  .uleb128 0x39
+  .uleb128 0xb
+  .uleb128 0x49
+  .uleb128 0x13
+  .byte 0
+  .byte 0
+  .uleb128 0x4
+  .uleb128 0x15
+  .byte 0x1
+  .uleb128 0x64
+  .uleb128 0x13
+  .uleb128 0x1
+  .uleb128 0x13
+  .byte 0
+  .byte 0
+  .uleb128 0x5
+  .uleb128 0x5
+  .byte 0
+  .uleb128 0x49
+  .uleb128 0x13
+  .uleb128 0x34
+  .uleb128 0x19
+  .byte 0
+  .byte 0
+  .uleb128 0x6
+  .uleb128 0xf
+  .byte 0
+  .uleb128 0xb
+  .uleb128 0xb
+  .uleb128 0x49
+  .uleb128 0x13
+  .byte 0
+  .byte 0
+  .uleb128 0x7
+  .uleb128 0x1f
+  .byte 0
+  .uleb128 0x1d
+  .uleb128 0x13
+  .uleb128 0x49
+  .uleb128 0x13
+  .byte 0
+  .byte 0
+  .uleb128 0x8
+  .uleb128 0x34
+  .byte 0
+  .uleb128 0x3
+  .uleb128 0xe
+  .uleb128 0x3a
+  .uleb128 0xb
+  .uleb128 0x3b
+  .uleb128 0xb
+  .uleb128 0x39
+  .uleb128 0xb
+  .uleb128 0x49
+  .uleb128 0x13
+  .uleb128 0x2
+  .uleb128 0x18
+  .byte 0
+  .byte 0
+  .uleb128 0x9
+  .uleb128 0x13
+  .byte 0
+  .uleb128 0x3
+  .uleb128 0x8
+  .uleb128 0x3c
+  .uleb128 0x19
+  .byte 0
+  .byte 0
+  .byte 0
+  .section  .debug_aranges,"",@progbits
+  .long 0x2c
+  .value  0x2
+  .long .Ldebug_info0
+  .byte 0x8
+  .byte 0
+  .value  0
+  .value  0
+  .quad 0
+  .quad 0
+  .quad 0
+  .quad 0
+  .section  .debug_line,"",@progbits
+.Ldebug_line0:
+  .section  .debug_str,"MS",@progbits,1
+.LASF0:
+  .string "GNU C++17 11.x -mtune=generic -march=x86-64 -g -gdwarf-4 -gz=none -std=gnu++17"
+.LASF4:
+  .string "__fn"
+.LASF2:
+  .string "."
+.LASF1:
+  .string "reproSmall.cpp"
+.LASF3:
+  .string "_Z2f1v"
+  .ident  "GCC: (GNU) 11.x"