I’m building a simple C++ program and I want to temporarily substitute a system supplied shared library with a more recent version of it, for development and testing. I tried setting the LD_LIBRARY_PATH variable but the linker (ld) failed with: /usr/bin/ld: cannot find -lyaml-cpp I expected that to work because according to the ld man … Read more
I’m compiling my C++ app using GCC 4.3. Instead of manually selecting the optimization flags I’m using -march=native, which in theory should add all optimization flags applicable to the hardware I’m compiling on. But how can I check which flags is it actually using? 5 Answers 5
I want to run ‘make install’ so I have everything I need, but I’d like it to install the things in their own folder as opposed to the system’s /usr/bin etc. is that possible? even if it references tools in the /usr/bin etc.? 7 Answers 7
I understand gcc’s –ffast-math flag can greatly increase speed for float ops, and goes outside of IEEE standards, but I can’t seem to find information on what is really happening when it’s on. Can anyone please explain some of the details and maybe give a clear example of how something would change if the flag … Read more
I am trying to compile Android source code under Ubuntu 10.04. I get an error saying, /usr/bin/ld: cannot find -lz Can you please tell me how can I fix it? What does cannot find -lz mean? Here’s the full error message: external/qemu/Makefile.android:1101: warning: overriding commands for target `external/qemu/android/avd/hw-config-defs.h’ external/qemu/Makefile.android:933: warning: ignoring old commands for target … Read more
I know I can generate debug symbol using -g option. However the symbol is embeded in the target file. Could gcc generate debug symbol outside the result executable/library? Like .pdb file of windows VC++ compiler did. 5 Answers 5
I’m trying to create a hello world project for Linux dynamic libraries (.so files). So I have a file hello.c: #include <stdio.h> void hello() { printf(“Hello world!\n”); } How do I create a .so file that exports hello(), using gcc from the command line? 1 Answer 1
On a Unix system, where does gcc look for header files? I spent a little time this morning looking for some system header files, so I thought this would be good information to have here. 9 Answers 9
In errno.h, this variable is declared as extern int errno; so my question is, is it safe to check errno value after some calls or use perror() in multi-threaded code. Is this a thread safe variable? If not, then whats the alternative ? I am using linux with gcc on x86 architecture. 8 Answers 8
My linux (SLES-8) server currently has glibc-2.2.5-235, but I have a program which won’t work on this version and requires glibc-2.3.3. Is it possible to have multiple glibcs installed on the same host? This is the error I get when I run my program on the old glibc: ./myapp: /lib/i686/libc.so.6: version `GLIBC_2.3′ not found (required … Read more
