No Debugging symbols found error even after enabling -g option - gdb

Small portion of the Makefile
CC=gcc -g -MMD
EXE=MegaCli
all:$(EXE)
LDFLAGS=-02
SOUCE_DIR=$(UNIV_VIVA_CLI)lib/linux/
LINK=g++
Ctm.o: $(SOURCE_DIR)Ctm.cpp
$(CC) $(CCFLAGS) $(SOURCE_DIR)Ctm.cpp
Before someone else have logged the same post. But my Makefile is same as the answer given to that post. But still I am getting error No Debugging Symbol found. Then I tried the below command too.
(gdb) exec - file MegaCli
error>No symbol table is loaded use the file command
Please give some solution to the above.

It's not clear how you are invoking GDB. Don't do this:
gdb
(gdb) exec - file MegaCli # I am not sure what this even means!
Do this:
gdb MegaCli
(gdb) run

Related

Debug symbols not included in gcc-compiled C++

I am building a module in C++ to be used in Python. My flow is three steps: I compile the individual C++ sources into objects, create a library, and then run a setup.py script to compile the .pyx->.cpp->.so, while referring to the library I just created.
I know I can just do everything in one step with the Cython setup.py, and that is what I used to do. The reason for splitting it into multiple steps is I'd like the C++ code to evolve on its own, in which case I would just use the compiled library in Cython/python.
So this flow works fine, when there are no bugs. The issue is I am trying to find the source of a segfault, so I'd like to get the debugging symbols so that I can run with gdb (which I installed on OSX 10.14, it was a pain but it worked).
I have a makefile, which does the following.
Step 1: Compile individual C++ source files
All the files are compiled with the bare minimum flags, but -g is there:
gcc -mmacosx-version-min=10.7 -stdlib=libc++ -std=c++14 -c -g -O0 -I ./csrc -o /Users/colinww/system-model/build/data_buffer.o csrc/data_buffer.cpp
I think even here there is a problem: when I do nm -pa data_buffer.o, I see no debug symbols. Furthermore, I get:
(base) cmac-2:system-model colinww$ dsymutil build/data_buffer.o
warning: no debug symbols in executable (-arch x86_64)
Step 2: Compile cython sources
The makefile has the line
cd $(CSRC_DIR) && CC=$(CC) CXX=$(CXX) python3 setup_csrc.py build_ext --build-lib $(BUILD)
The relevant parts of setup.py are
....
....
....
compile_args = ['-stdlib=libc++', '-std=c++14', '-O0', '-g']
link_args = ['-stdlib=libc++', '-g']
....
....
....
Extension("circbuf",
["circbuf.pyx"],
language="c++",
libraries=["cpysim"],
include_dirs = ['../build'],
library_dirs=['../build'],
extra_compile_args=compile_args,
extra_link_args=link_args),
....
....
....
ext = cythonize(extensions,
gdb_debug=True,
compiler_directives={'language_level': '3'})
setup(ext_modules=ext,
cmdclass={'build_ext': build_ext},
include_dirs=[np.get_include()])
When this is run, it generates a bunch of compilation/linking commands like
gcc -Wno-unused-result -Wsign-compare -Wunreachable-code -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -I/Users/colinww/anaconda3/include -arch x86_64 -I/Users/colinww/anaconda3/include -arch x86_64 -I. -I../build -I/Users/colinww/anaconda3/lib/python3.7/site-packages/numpy/core/include -I/Users/colinww/anaconda3/include/python3.7m -c circbuf.cpp -o build/temp.macosx-10.7-x86_64-3.7/circbuf.o -stdlib=libc++ -std=c++14 -O0 -g
and
g++ -bundle -undefined dynamic_lookup -L/Users/colinww/anaconda3/lib -arch x86_64 -L/Users/colinww/anaconda3/lib -arch x86_64 -arch x86_64 build/temp.macosx-10.7-x86_64-3.7/circbuf.o -L../build -lcpysim -o /Users/colinww/system-model/build/circbuf.cpython-37m-darwin.so -stdlib=libc++ -g
In both commands, the -g flag is present.
Step 3: Run debugger
Finally, I run my program with gdb
(base) cmac-2:sim colinww$ gdb python3
(gdb) run system_sim.py
It dumps out a ton of stuff related to system files (seems unrelated) and finally runs my program, and when it segfaults:
Thread 2 received signal SIGSEGV, Segmentation fault.
0x0000000a4585469e in cpysim::DataBuffer<double>::Write(long, long, double) () from /Users/colinww/system-model/build/circbuf.cpython-37m-darwin.so
(gdb) info local
No symbol table info available.
(gdb) where
#0 0x0000000a4585469e in cpysim::DataBuffer<double>::Write(long, long, double) () from /Users/colinww/system-model/build/circbuf.cpython-37m-darwin.so
#1 0x0000000a458d6276 in cpysim::ChannelFilter::Filter(long, long, long) () from /Users/colinww/system-model/build/chfilt.cpython-37m-darwin.so
#2 0x0000000a458b0d29 in __pyx_pf_6chfilt_6ChFilt_4filter(__pyx_obj_6chfilt_ChFilt*, long, long, long) () from /Users/colinww/system-model/build/chfilt.cpython-37m-darwin.so
#3 0x0000000a458b0144 in __pyx_pw_6chfilt_6ChFilt_5filter(_object*, _object*, _object*) () from /Users/colinww/system-model/build/chfilt.cpython-37m-darwin.so
#4 0x000000010002f1b8 in _PyMethodDef_RawFastCallKeywords ()
#5 0x000000010003be64 in _PyMethodDescr_FastCallKeywords ()
As I mentioned above, I think the problem starts in the initial compilation step. This has nothing to do with cython, I'm just calling gcc from the command line, passing the -g flag.
(base) cmac-2:system-model colinww$ gcc --version
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk/usr/include/c++/4.2.1
Apple LLVM version 10.0.1 (clang-1001.0.46.4)
Target: x86_64-apple-darwin18.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
Any help is appreciated, thank you!
UPDATE
I removed the gcc tag and changed it to clang. So I guess now I'm confused, if Apple will alias gcc to clang, doesn't that imply that in "that mode" it should behave like gcc (and, implied, someone made sure it was so).
UPDATE 2
So, I never could get the debug symbols to appear in the debugger, and had to resort to lots of interesting if-printf statements, but the problem was due to an index variable becoming undefined. So thanks for all the suggestions, but the problem is more or less resolved (until next time). Thanks!
The macOS linker doesn't link debug information into the final binary the way linkers usually do on other Unixen. Rather it leaves the debug information in the .o files and writes a "debug map" into the binary that tells the debugger how to find and link up the debug info read from the .o files. The debug map is stripped when you strip your binary.
So you have to make sure that you don't move or delete your .o files after the final link, and that you don't strip the binary you are debugging before debugging it.
You can check for the presence of the debug map by doing:
$ nm -ap <PATH_TO_BINARY> | grep OSO
You should see output like:
000000005d152f51 - 03 0001 OSO /Path/To/Build/Folder/SomeFile.o
If you don't see that the executable probably got stripped. If the .o file is no around then somebody cleaned your build folder earlier than they should have.
I also don't know if gdb knows how to read the debug map on macOS. If the debug map entries and the .o files are present, you might try lldb and see if that can find the debug info. If it can, then this is likely a gdb-on-macOS problem. If the OSO's and the .o files are all present, then something I can't guess went wrong, and it might be worth filing a bug with http://bugreporter.apple.com.

Compile Pro*C in AIX 7 (64bit)

I try to migrate the old Pro*C program from HP to AIX, after changed some setting, I can make the binary file but fail to execute. Seems I now facing wrong library used (lib32/libclntsh.a).
Here is the error
0509-036 Cannot load program PROGNAME because of the following errors:
0509-150 Dependent module SOMEPATH/lib32/libclntsh.a(shr.o) could not be loaded.
0509-103 The module has an invalid magic number.
I build the program by setting object mode to 64
export OBJECT_MODE=64
Here is the full image when I make the binary
/PATHA/bin/oraxlc -O3 -q64 -DSS_64BIT_SERVER -I. -c MYPROG.c "MYPROG.c", line 2051.25: 1506-342 (W) "/*" detected in comment.
/PATHA/bin/oraxlc -o GLMJLUSB GLMJLUSB.o -L/PATHA/lib/ -lclntsh -lld -lm `cat /PATHA/lib/sysliblist` -lm -lc_r -lpthreads +DD64
/PATHB/bin/.orig/xlc: 1501-228 (W) input file +DD64 not found
Is there any way I can specify not to use the problem library, and use the 64bit version instead?
I don't know much about Pro*C and AIX, so any help is welcome. Thanks.
(Not really an answer yet, expect many edits).
Do you have a Makefile? If not, create one:
.SUFFIXES: .pc
PROC = ${ORACLE_HOME}/bin/proc
PROCFLAGS = code=ansi lines=yes
.pc.c:
${PROC} ${PROCFLAGS} $<
Keep improving it, until you can successfully precompile your *.pc files into *.c files.
Note: it is way easier, if you have GNU!make instead of prehistoric!make

How can I tell GCC to use custom library for -l instead of the system one?

I have a custom build of SQLite3 at /somepath, so /somepath/.libs contains libsqlite3.so.0.8.6 and the symbolic links to it. I wanted to link a program against it and assumed
g++ -O3 -g -fPIC -I /somepath -I /somepath/src -L /somepath/.libs -lsqlite3 -o myfile.so myfile.cpp
would work. It compiles, but I get a segmentation fault due to some problem in my code, and when trying to debug I run into the issues which look like LD_PRELOAD not working with my program and Setting my lib for LD_PRELOAD makes some processes produce loader errors: I can run LD_PRELOAD=myfile.so /somepath/sqlite3 ..., but under GDB I get symbol lookup error and LD_DEBUG=all LD_PRELOAD=myfile.so gdc -c core /somepath/sqlite3 ... reveals symbols are getting looked up in /usr/lib/x86_64-linux-gnu/libsqlite3.so.0 instead of /somepath/libsqlite3.so.0, and unsurprisingly missing the symbols for functions added in the custom build. How can I fix this and debug my code?
The -lsqlite3 argument should be last. Order of arguments to g++ matters a lot. You should read more about runpath and perhaps pass -Wl,-rpath,/somepath/.libs
You may want to pass -v once to g++ to understand what is happening (what programs are actually running). You might also pass -Wl,--verbose to ask a more verbose link.
Then you can use ldd on your executable (and also readelf) to find out more what are its link time dependencies.
With suitable arguments to g++ you should not need additional options to gdb
From http://visualgdb.com/gdbreference/commands/set_solib-search-path
Inside gdb use the commands below.
set solib-search-path [Directories]
show solib-search-path

eclipse cdt: calling make file from command line and adding version number

two simple questions:
how do i call eclipse cdt generated make file with all the environment variable ? for example, my make file is generated at location PROJECT_FOLDER_ROOT/Debug/makefile , and if i try to call it:
khan#khan-P55A-UD3P:~/git/gcc/libGCC/Debug$ make -k -j5 all
Building file: ../src/utility/Versioning.cpp
Invoking: Cross G++ Compiler
mipsel-openwrt-linux-g++ -I/home/khan/carambola.pristine/staging_dir/target-mipsel_r2_uClibc-0.9.33.2/usr/include -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"src/utility/Versioning.d" -MT"src/utility/Versioning.d" -o "src/utility/Versioning.o" "../src/utility/Versioning.cpp"
/bin/sh: 1: mipsel-openwrt-linux-g++: not found
make: * [src/utility/Versioning.o] Error 127
make: Target `all' not remade because of errors.
it is looking for mipsel-openwrt-linux-g++ , which is an environment variable for the eclipse build system . how to include it in the command line usage?
second question:
is there any way to automatically increment build number in CDT ? google search was not helpful in this regard.
right after asking here, it managed to figure out the eclipse makefile issue:
i wrote this script to do it. hope it helps someone:
#!/bin/bash
CURRENT_PATH=$PWD
DEBUG_FOLDER_PATH=$CURRENT_PATH/Debug
TOOLCHAIN_PATH=/home/khan/carambola.pristine/staging_dir/toolchain-mipsel_r2_gcc-4.7-linaro_uClibc-0.9.33.2/bin
cd $DEBUG_FOLDER_PATH
export CWD=$DEBUG_FOLDER_PATH
export PWD=$DEBUG_FOLDER_PATH
export PATH=$TOOLCHAIN_PATH:$PATH
echo $CWD
echo $PWD
echo $PATH
make -k -j5 $1 $2 $3 $4
however, i am still looking for a way to increment build number somehow. any help would be appreciated.
thnkyou

gdb says "cannot open shared object file"

I have one binary and one shared library.
The shared library is compiled with:
all:
g++ -g -shared -fpic $(SOURCES) -o libmisc.so
the binary is compiled with:
LIBS=-L../../misc/src
LDFLAGS=-lmisc
all:
g++ -g -o mainx $(INCLUDE) $(SOURCE) $(LIBS) $(LDFLAGS)
I set in ~/.bashrc
export LD_LIBRARY_PATH=/mnt/sda5/Programming/misc/src/
to the libmisc.so output path.
Debugging from console works fine:
gdb mainx
However from Emacs22, launching gdb fails with the following message:
Starting program: /mnt/sda5/Programming/main/src/mainx
/mnt/sda5/Programming/main/src/mainx: error while loading shared libraries: libmisc.so: cannot open shared object file: No such file or directory
This looks very tricky for the moment, and I couldn't solve it. I am not sure if this a emacs's problem, or I should pass a parameter in gdb's command line.
Emacs probably does not read your .bashrc before it invokes gdb. Try to put 'set solib-search-path' and 'set solib-absolute-path in your .gdbinit file instead
Emacs doesn't invoke gdb via bash, but rather invokes it directly, and so .bashrc changes do not take effect and LD_LIBRARY_PATH is not set.
If you quit emacs, open a new shell (so LD_LIBRARY_PATH is set), start emacs in it, and then do M-X gdb, then it would work.
Setting solib-search-path in GDB is a hack.
A much better fix is to build the executable in such a way that it doesn't need LD_LIBRARY_PATH to begin with:
LDFLAGS=-lmisc -Wl,-rpath=/mnt/sda5/Programming/misc/src
Another way is to create a .gdbinit file in your $HOME and set the LD_LIBRARY_PATH there:
# file .gdbinit
set env LD_LIBRARY_PATH=/mnt/sda5/Programming/misc/src/
This is convenient if you need to debug with that LD_LIBRARY_PATH frequently (and don't want to remember running emacs from your shell every time).