[lldb-dev] build fails on linux
dawn at burble.org
dawn at burble.org
Thu Oct 13 21:41:35 PDT 2011
So I have fixed lldb for Linux (at least on 32-bit - will have to find a
64 bit machine to test the 64-bit version).
But, the patch is gross!
So before I embarress myself with a patch, let me first ask:
1. Is there a way to test "might we be generating logs or not"? I have added
some functions and data which are only used when logging is enabled, but I
wouldn't want these to get generated in a release build. I really just want some
kind of "#ifdef DEBUG" or "#ifdef LOGGING_ENABLED".
Here's an example from the patch:
+#ifdef LOGGING_ENABLED
+
+// Some functions call other functions (eg. DoWriteMemory calls
+// DoReadMemory), so for the purposes of logging, we use a static
+// variable to keep track of the API nesting level and only print the
+// log at the top-level. FIXME: not thread safe!
+//
+// This is a bit ugly, but the alternative is to litter the code with
+// #ifdefs or hope the compiler is smart enough to optimize all this
+// away in an RTM build.
+
+static int log_nestinglevel;
+#define ATTOP_LOG_NESTLEVEL() (log_nestinglevel == 1)
+#define INC_LOG_NESTLEVEL() { log_nestinglevel++; }
+#define DEC_LOG_NESTLEVEL() { log_nestinglevel--; assert(log_nestinglevel >= 0); }
+#else
+#define ATTOP_LOG_NESTLEVEL()
+#define INC_LOG_NESTLEVEL()
+#define DEC_LOG_NESTLEVEL()
+#endif
+
2. The code is heavily endian and host platform dependent, which
seriously concerns me. I tried to find host-independent representations
for the types but came up short. Eg. what type is "void*" on the
target?
Thanks,
-Dawn
On Fri, Oct 07, 2011 at 03:17:32PM -0700, dawn at burble.org wrote:
> With the patch submitted Oct.6,2011 to lldb-commits titled
> "[Lldb-commits] patch to fix Linux build" (still awaiting review)
> the Linux build works.
>
> In addition to setting the PYTHONPATH to find lldb.py, I also needed to add
> $llvm/tools/lldb/examples/synthetic so lldb could find gnu_libstdcpp. Without
> this, you get "ImportError: No module named gnu_libstdcpp" when starting lldb.
> (Please let us know if that's not the intended gnu_libstdcpp module).
>
> When debugging a simple test case with lldb on Linux (uname -a : Linux
> ack.localdomain 2.6.39.3 #1 SMP Sat Jul 9 21:24:58 PDT 2011 i686 i686 i386
> GNU/Linux) lldb crashes with a segv in pthread_mutex_lock. I've not looked
> into this yet. Here's the stack under gdb:
>
> ack:~/dev/llvm_svnR137311/tools/lldb$gdb --args ../../Debug+Asserts/bin/lldb ~/dev/test/x GNU gdb (GDB) Fedora (7.2-51.fc14)
>
> Reading symbols from /home/dawn/dev/llvm_svnR137311/Debug+Asserts/bin/lldb...done.
> (gdb) r
> Starting program: /home/dawn/dev/llvm_svnR137311/Debug+Asserts/bin/lldb /home/dawn/dev/test/x
> [Thread debugging using libthread_db enabled]
> [New Thread 0xb46e2b70 (LWP 10309)]
> [New Thread 0xb3ee1b70 (LWP 10310)]
> [New Thread 0xb36e0b70 (LWP 10311)]
> [New Thread 0xb2edfb70 (LWP 10312)]
> Current executable set to '/home/dawn/dev/test/x' (i386).
> (lldb) r
> [New Thread 0xb22ffb70 (LWP 10313)]
> Detaching after fork from child process 10314.
>
> Program received signal SIGSEGV, Segmentation fault.
> [Switching to Thread 0xb22ffb70 (LWP 10313)]
> 0x49d6cf4d in pthread_mutex_lock () from /lib/libpthread.so.0
> Missing separate debuginfos, use: debuginfo-install glibc-2.13-2.i686 keyutils-libs-1.2-6.fc12.i686 krb5-libs-1.8.4-2.fc14.i686 libcom_err-1.41.12-6.fc14.i686 libedit-3.0-3.20090923cvs.fc14.i686 libgcc-4.5.1-4.fc14.i686 libselinux-2.0.96-6.fc14.1.i686 libstdc++-4.5.1-4.fc14.i686 ncurses-libs-5.7-9.20100703.fc14.i686 openssl-1.0.0e-1.fc14.i686 python-2.7-8.fc14.1.i686 python-libs-2.7-8.fc14.1.i686 readline-6.1-2.fc14.i386 zlib-1.2.5-2.fc14.i686
> (gdb) bt
> #0 0x49d6cf4d in pthread_mutex_lock () from /lib/libpthread.so.0
> #1 0xb620e18f in lldb_private::Mutex::Lock (mutex_ptr=0x14) at Mutex.cpp:190
> #2 0xb620ddd2 in lldb_private::Mutex::Locker::Locker (this=0xb22febe4, m=...) at Mutex.cpp:46
> #3 0xb6c710ec in ProcessMonitor::DoOperation (this=0x0, op=0xb22fec1c) at ProcessMonitor.cpp:1298
> #4 0xb6c712d6 in ProcessMonitor::ReadRegisterValue (this=0x0, offset=60, value=...)
> at ProcessMonitor.cpp:1343
> #5 0xb6c721c0 in RegisterContextLinux_i386::ReadRegister (this=0x8170ee8, reg_info=0xb7f56294,
> value=...) at RegisterContextLinux_i386.cpp:419
> #6 0xb63c9599 in lldb_private::RegisterContext::ReadRegisterAsUnsigned (this=0x8170ee8,
> reg_info=0xb7f56294, fail_value=18446744073709551615) at RegisterContext.cpp:163
> #7 0xb63c953c in lldb_private::RegisterContext::ReadRegisterAsUnsigned (this=0x8170ee8, reg=7,
> fail_value=18446744073709551615) at RegisterContext.cpp:153
> #8 0xb63c92c7 in lldb_private::RegisterContext::GetSP (this=0x8170ee8,
> fail_value=18446744073709551615) at RegisterContext.cpp:110
> #9 0xb63d210f in lldb_private::StackFrameList::GetFrameAtIndex (this=0x8170e98, idx=0)
> at StackFrameList.cpp:273
> #10 0xb63d284b in lldb_private::StackFrameList::SetDefaultFileAndLineToSelectedFrame (
> this=0x8170e98) at StackFrameList.cpp:406
> [...]
>
>
> So clearly the Linux port needs more work, and I'm not sure if I'm going to be
> able to give it the attention it needs.
>
> -Dawn
>
>
> On Mon, Sep 26, 2011 at 03:46:18PM -0700, dawn at burble.org wrote:
> >
> > I have lldb rev 140572.
> >
> > I followed the instructions here: http://lldb.llvm.org/build.html
> >
> > and updated my llvm and clang trees to the documented revision:
> > $grep -m 1 llvm_revision $lldb/scripts/build-llvm.pl
> > our $llvm_revision = "137311";
> >
> > When I build, I get:
> > [...]
> > llvm[2]: Compiling ClangUserExpression.cpp for Debug+Asserts build
> > In file included from ClangUserExpression.cpp:31:0:
> > /home/dawn/dev/llvm_svn/tools/lldb/source/Expression/../../include/lldb/Expression/ExpressionSourceCode.h:13:31:
> > fatal error: lldb-enumerations.h: No such file or directory
> > compilation terminated.
> > [...]
> >
> > Please help,
> > Thanks,
> > -Dawn
> >
> > _______________________________________________
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> > lldb-dev at cs.uiuc.edu
> > http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
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