I'm using gcc on GNU/Linux and the debug-files and headers of libc and libstd++ are installed. But I don't know how to tell gdb to use the source-code of them, especially to debug into libstd++.
The source-code of libstdc++ itself seems to be provided in a complicated structure. I think the directory command is the right choice. I'm using here Debian/Ubuntu and downloaded the source with apt-get source libstdc++6 into my home-directory.
I'm pretty sure I didn't need take special steps for this with Fedora (some years ago). Maybe Fedora was prepared in a special way for this. So I will be glad about general instructions, which fit for every distribution.
Thank you
Update
I figured out, that I need to compile with -D_GLIBCXX_DEBUG in addition to -g, so compile command looks like $ g++ -o test test.cpp -g -D_GLIBCXX_DEBUG.
Furthermore I got warning about missing pretty printers, which I solved as described here:
http://gcc.gnu.org/onlinedocs/libstdc++/manual/debug.html#debug.gdb
Now I can debug into libstdc++, but I always got this message:
Breakpoint 1, main () at test.cpp:9
9 string str = "str";
(gdb) s
std::allocator<char>::allocator (this=0x7fffffffe1e0)
at /build/buildd/gcc-4.7-4.7.2/build/x86_64-linux-gnu/libstdc++-v3/include/bits/allocator.h:104
104 /build/buildd/gcc-4.7-4.7.2/build/x86_64-linux-gnu/libstdc++-v3/include/bits/allocator.h: No such file or directory.
(gdb) s
std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string (
this=0x7fffffffe1c0, __s=0x402930 "str", __a=...)
at /usr/include/c++/4.7/bits/basic_string.tcc:217
217 __s + npos, __a), __a)
I don't need to set the directory in gdb to the my downloaded source (I' think it search through my home-directory). So I thought I need a different command to fix this and found "set substitute-path" and pointed it to /home/username/gcc-4.7-4.7.2/gcc-4.7.2/libstdc++-v3 but I doesn't work. Why does gdb look for allocator.h in the completely wrong place?
First find out the sources from :-
https://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/index.html
Later compile libstdc++ with DEBUG_FLAGS set it ON.
Then, try it out to debug with gdb.
Related
Under Windows with same i686-w64-mingw32-gcc I have two C++ projects. Both with "-ggdb -g3 -O0" - the smaller project I can debug in Eclipse but the larger one says "No source available". Both projects with " -static-libgcc -static-libstdc++"
I am failing to figure out what breaks it :(
Smaller project happy gdb:
Larger prodject not happy gdb:
Good makefile:
https://github.com/rusefi/rusefi/blob/temp_branch/unit_tests/Makefile
https://github.com/rusefi/rusefi/blob/temp_branch/unit_tests/rules.mk
Bad makefile:
https://github.com/rusefi/rusefi/blob/temp_branch/win32_functional_tests/Makefile
https://github.com/rusefi/rusefi/blob/temp_branch/win32_functional_tests/rules.mk
Both projects show symbols with objdump.exe --syms:
Good project symbols:
https://github.com/rusefi/rusefi/blob/temp_branch/unit_tests/symbols
Bad project symbols:
https://github.com/rusefi/rusefi/blob/temp_branch/win32_functional_tests/symbols
I would like to be able to debug both projects. What am I doing wrong? :(
Update: I've found a work-around:
i686-w64-mingw32-gcc (32bit embedded into Cygwin64) does not work with gdb from cygwin64
but if everything is base 32 bit cygwin things work as expected! Just to reiterate - one project works with 32 compiler from cygwin64 while another one does not, so something must be different - but since I have a workaround I am good.
I start saying that i am a newbie in programming and then i am not sure i will be able to explain well my problem.
I had some c++ code i wrote, this code are loaded and used by some R functions.
To compile the code i used the following:
R CMD SHLIB MyCode.cpp
and i loaded the library in R with
dyn.load("MyCOde.so")
Sometimes i built also an R package and i was able to load it into R.
If i do all these stuff on a Mac with mountain lion everything work fine, but now that i switched to mavericks, i have some problems. The R CMD SHLIB MyCode.cpp command works but when i used dyn.load("MyCOde.so") i get the following text:
Errore in dyn.load(paste(dir_function, "MyCOde.so", sep = "")) :
unable to load shared object 'MyCOde.so':
dlopen(MyCOde.so, 6): Symbol not found: __ZNSt8ios_base4InitC1Ev
Referenced from: MyCOde.so
Expected in: flat namespace
in MyCOde.so
Moreover if i try to load the package in R, i get the following
ld: warning: directory not found for option '-L/usr/local/lib/gcc/x86_64-apple-darwin13.0.0/4.8.2'
ld: library not found for -lquadmath
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [MyCode.so] Error 1
Can someone helps me?
Based on the helpful website of:
thecoatlessprofessor
Type this into your terminal shell:
curl -O http://r.research.att.com/libs/gfortran-4.8.2-darwin13.tar.bz2
sudo tar fvxz gfortran-4.8.2-darwin13.tar.bz2 -C /
This will create what you need to resume compiling as before.
Since it starts to work I can publish the answer for such a cases.
When you change the compiler and standard libraries - please note that different libraries have different implementation and different standard support. Changing the basement of your system might require total rebuild of your system with the new C++ standard library.
Your libraries are not the exception. So if have the errors in your linker like this:
warning: directory not found for option
'-L/usr/local/lib/gcc/x86_64-apple-darwin13.0.0/4.8.2'
apply next algorithm:
Check whether the directory /usr/local/lib/gcc/x86_64-apple-darwin13.0.0/4.8.2 still exists. I bet it is not.
Check if you still have the libstdc++ from the missed compiler? Usually if you upgrade the same compiler and the C++ standard library ABI does not change everything should continue to work. If the ABI changed or you switch standard C++ library and compiler - you face the massive system rebuild.
Recompile your library and apps with the new C++ standard library and compiler.
I am attempting to install libzdb on my macbook however I see the following error message when running the configure:
configure:13334: error: setjmp is required
the setjmp.h file resides within /usr/include and is specified within my "$PATH" as
/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin:/usr/include
Can someone please advise as to how i can rectify this issue?
thanks in advance
I've stumbled across this error while building one of my own programs when I wanted to use setjmp() and longjmp(). For some reason, the toolchain that resides in / on OS X is flawed, and the <setjmp.h> header file is missing the declarations and data types.
To fix it, I had to download Xcode (damn!) and tell the compiler to look for the headers in the freshly installed MacOSX10.7.sdk (or 8) folder:
clang -Wall -o foo foo.c -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.7.sdk
ok finally figured it out. For those who have seen messages like this be warned that the configure logs can be misleading. It turned out the binary built fine, however it was failing during runtime because a few mysql libraries could not be found. using the following command *export DYLD_LIBRARY_PATH=/usr/local/mysql/lib/* would fix the problem
I have just downloaded clang 3.3 (homebrew) from the LLVM web page to my mac (OS X 10.8.4), but get this compiler error when using std=c++11 stdlib=libc++:
In file included from /usr/include/c++/v1/string:434:
In file included from /usr/include/c++/v1/algorithm:594:
In file included from /usr/include/c++/v1/memory:590:
In file included from /usr/include/c++/v1/typeinfo:61:
/usr/include/c++/v1/exception:146:5: error: an attribute list cannot appear here
_LIBCPP_NORETURN friend void rethrow_exception(exception_ptr);
^~~~~~~~~~~~~~~~
/usr/include/c++/v1/__config:190:28: note: expanded from macro '_LIBCPP_NORETURN'
# define _LIBCPP_NORETURN [[noreturn]]
^~~~~~~~~~~~
It seems that I also need another libc++ (even though it was said that it was 100% complete on MAC ...), but I cannot find any. Any help appreciated. Just for your info:
> clang++ -v
clang version 3.3 (tags/RELEASE_33/final)
Target: x86_64-apple-darwin12.4.0
Thread model: posix
And, yes, I googled it and found this: http://comments.gmane.org/gmane.comp.compilers.llvm.bugs/24138 claiming it's resolved in libc++ trunk ???
Okay, as suggested by Howard, I've downloaded tip-of-the-trunk libc++ into /opt/local/share/libcxx, but have trouble building it. The manual says to cd libcxx/lib, export TRIPLE=-apple-, and run ./buildit. I presume this implies bash (I'm usually a tcsh user, so I moved my .tcshrc, got a new shell and started bash). I did that and the compilations worked, but the library build failed. Apparently ./buildit doesn't see $TRIPLE=-apple-, as it picks the wrong LDSHARED_FLAG (not that on line 81, but that on line 103, which is to be used if $TRIPLE is not set), even though echo $TRIPLE yields -apple- as it should. When I add the statement echo TRIPLE = $TRIPLE at the top of buildit, it reports nothing. How come? What is wrong here?
The failure was that because the wrong LDSHARED_FLAG was picked the loading didn't work (ld complaint about the unknown option -soname which, I think, makes sense under linux). I don't know why buildit (a #! /bin/sh file) didn't pick up the TRIPLE environment variable (it did pick up several unwanted ones such as CXX and CC). I now simply added TRIPLE=-apple- at the top of that file and it did built the library. However, the loader spitted out several warnings all of which were of the form
ld: warning: direct access in ___cxa_bad_typeid to global weak symbol typeinfo for std::bad_typeid means the weak symbol cannot be overridden at runtime. This was likely caused by different translation units being compiled with different visibility settings.
But most importantly, it works (the compilation at least, I have yet to test the library). I have one final question. The advice was to use -I and -L to tell the compiler about the whereabouts of this version. Is it not possible to put it into the usual place /usr/include/c++/v1/? Note that Xcode has its version somewhere else anyway and I had put in a symbolic link (/usr/include/c++/v1/) to that one to get my homebrew clang 3.2 working (after the some Xcode update). What about the library? Can I also put it in a standard place?
Here is the home page of libc++:
http://libcxx.llvm.org
You can download the tip-of-trunk libc++ from there. You can tell clang to point to your download with -nostdinc++ -I<path-to-libc++>/include. You can also tell clang to link to your tip-of-trunk libc++ with -L<path-to-libc++>/lib and export DYLD_LIBRARY_PATH=<path-to-libcxx>/lib. The directions are all on the libc++ home page.
Xcode is the easiest way to get clang + libc++. But if you want the very latest, this is the place to go.
Congratulations!
Don't worry about the ld warning. It is a harmless ld bug that will be fixed in a future release. I see it on 10.8.4 too and it doesn't hurt anything.
The libc++ headers no longer live at /usr/include/c++/v1. Xcode has migrated them into itself. Having libc++ headers at /usr/include/c++/v1 from older installs has been a source of confusion and bugs. I regularly use -nostdinc++ -I to point to the libc++ headers I want (I often have several versions going at the same time), and that works well for me.
It is possible for you to replace your /usr/lib/libc++.1.dylib with that you have built. I do not recommend doing this. I have to sometimes to do a proper test, but I always do so very carefully because sometimes this causes me to have to reboot onto a backup disk and restore my /usr/lib to its original state. If you do go this route, it is a very good idea to have a backup of the original /usr/lib/libc++.1.dylib very handy.
I recommend instead -L on the command line, and export DYLD_LIBRARY_PATH=<path-to-libcxx>/lib in the shell. More than one person (including myself) has gotten their computer into a really nasty place by not following this advice.
If you run testit (under test/), all you need is DYLD_LIBRARY_PATH in that shell. The testit script is set up to point to the right places without an install.
Also I recommend figuring out why you had to modify buildit. No one else is seeing that behavior. printenv on your command line may help in this endeavor.
libc++ is updated often. We try to keep tip-of-trunk always in a shippable state.
I'm working on RHEL WS 4.5.
I've obtained the glibc source rpm matching this system, opened it to get its contents using rpm2cpio.
Working in that tree, I've created a patch to mtrace.c (i want to add more stack backtrace levels) and incorporated it in the spec file and created a new set of RPMs including the debuginfo rpms.
I installed all of these on a test vm (created from the same RH base image) and can confirm that my changes are included.
But with more complex executions, I crash in mtrace.c ... but gdb can't find the debug information so I don't get line number info and I can't actually debug the failure.
Based on dates, I think I can confirm that the debug information is installed on the test system in /usr/src/debug/glibc-2.3.6/
I tried
sharedlibrary libc*
in gdb and it tells me the symbols are already loaded.
My test includes a locally built python and full symbols are found for python.
My sense is that perhaps glibc isn't being built under rpmbuild with debug enabled. I've reviewed the glibc.spec file and even built with
_enable_debug_packages
defined as 1 which looked like it might influence the result. My review of the configure scripts invoked during the rpmbuild build step didn't give me any hints.
Hmmmm .. just found /usr/lib/debug/lib/libc-2.3.4.so.debug
and /usr/lib/debug/lib/tls/i486/libc-2.3.4.so.debug
but both of these are reported as stripped by the file command.
It appears that you are installing non-matching RPMs:
/usr/src/debug/glibc-2.3.6
just found /usr/lib/debug/lib/libc-2.3.4.so.debug
There are not for the same version; there is no way they came from the same -debuginfo RPM.
both of these are reported as stripped by the file command.
These should not show as stripped. Either they were not built correctly, or your strip is busted.
Also note that you don't actually have to get all of this working to debug your problem. In the RPMBUILD directory, you should be able to find the glibc build directory, with full-debug libc.so.6. Just copy that library into your VM, and you wouldn't have to worry about the debuginfo RPM.
Try verifying that debug info for mtrace.c is indeed present. First see if the separate debug info for GLIBC knows about a compilation unit called mtrace.c:
$ eu-readelf -w /usr/lib/debug/lib64/libc-2.15.so.debug > t
$ grep mtrace t
name (strp) "mtrace.c"
name (strp) "mtrace"
1 0 0 0 mtrace.c
[10480] "mtrace.c"
[104bb] "mtrace"
[5052] symbol: mtrace, CUs: 446
Then see if GDB actually finds the source file from the glibc-debuginfo RPM:
(gdb) set pagination off
(gdb) start # pause your test program right after main()
(gdb) set logging on
Copying output to gdb.txt.
(gdb) info sources
Quit GDB then grep for mtrace in gdb.txt and you should find something like /usr/src/debug/glibc-2.15-a316c1f/malloc/mtrace.c
This works with GDB 7.4. I'm not sure the GDB version shipped with RHEL 4.5 supports all the command used above. Building upstream GDB from source is in fact easier than Python though.
When trying to add strack traces to mtrace, make sure you don't call malloc() directly or indirectly in the GLIBC malloc hooks.