lld's liberal usages of `using namespace ...` seem to confuse LLDB

Quuxplusone commented 3 years ago


Bugzilla Link	PR52553
Status	CONFIRMED
Importance	P enhancement
Reported by	Vy Nguyen (vyng@google.com)
Reported on	2021-11-18 18:25:53 -0800
Last modified on	2021-11-22 09:03:52 -0800
Version	unspecified
Hardware	PC All
CC	gkm@fb.com, jezreel@gmail.com, llvm-bugs@lists.llvm.org, smeenai@fb.com
Fixed by commit(s)
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(not really a bug - more of a question)

Should we change this? Currently this confuses the debugger and makes it a bit annoying.

Repro:

lldb -- ld64.lld.darwninnew <... rest of args>

Set a breakpoint anywhere - but for best effect, here: https://github.com/llvm/llvm-project/blob/2782cb8da0b3c180fa7c8627cb255a026f3d25a2/lld/MachO/Driver.cpp#L1141

(ie., right after symtab is set)

Try and print symtab or in.got:

(lldb) b Driver.cpp:1139
Breakpoint 1: 3 locations.
(lldb) run
Process 13244 launched: '/Users/vyng/repo/llvm-project/build_lld/bin/ld64.lld.darwinnew' (x86_64)
Process 13244 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.2
    frame #0: 0x0000000100a0856f ld64.lld.darwinnew`lld::macho::link(argsArr=ArrayRef<const char *> @ 0x00007ff7bfefeeb0, canExitEarly=true, stdoutOS=0x00000001093b83a8, stderrOS=0x00000001093b8410) at Driver.cpp:1139:12
   1136 
   1137   config = make<Configuration>();
   1138   symtab = make<SymbolTable>();
-> 1139   target = createTargetInfo(args);
   1140   depTracker =
   1141       make<DependencyTracker>(args.getLastArgValue(OPT_dependency_info));
   1142   if (errorCount())
Target 0: (ld64.lld.darwinnew) stopped.
(lldb) print symtab
(lld::elf::SymbolTable *) $0 = nullptr
(lldb) print in.got
(lld::elf::GotSection *) $1 = nullptr
(lldb) print lld::macho::in.got

Note that LLDB prints the ELF's objects rather than macho's ones!!!

Quuxplusone commented 3 years ago

P.S: Ok, maybe it doesn't confuse LLDB - but it definitely confuses me. That is, if I stop at breakpoint, I would expect to be able to refer to a variable the same way it is referenced in the code and not have to qualify it with the right namespace.

Quuxplusone commented 3 years ago

seems like LLDB's bug - closing this and open a bug in LLDB instead

Quuxplusone / LLVMBugzillaTest

lld's liberal usages of `using namespace ...` seem to confuse LLDB #51520