Environnment: gcc version 9.4.0 (Ubuntu 9.4.0-1ubuntu1~20.04.2)) The conditions under which this occurs are: The printed variable is of float type. There are type conversion errors in the printf. The buffer is refreshed before the printf call. Build command: gcc floatTest.c…
I'm running a openmp program (gcc and libgomp on CentOS 8.5). I used strace to inspect and found that syscall clone was called over and over again (I posed part of the log below), which I believe implies that openmp…
When I use co_spawn across multiple modules and enable optimization levels O2 or O3, I encounter a linker error during the linking phase. It appears that the compiler discards some symbols it deems unused during the linking stage. Minimal reproduce…
As we all know and love (or hate), GCC has the capability of issuing warnings when you attempt to use the printf() family of functions with mismatched type specifications. In our code, we have a number of utility functions of…
In C struct, why packed,aligned seems to do padding? I have to read a bunch of MSB/LSB bytes from a remote device using i2c. As all device data are bytes, I use uint8_t which represent exactly 8 bits that is…
I'm building an executable which needs to link to some legacy shared objects to not only use the version of symbols exported by those, but also ensure that the sections of .gnu.version_r section as is properly populated well. In short,…
I'm using the libsndfile library for a signal processing project. I'm compiling c code using gcc on a WSL Ubuntu shell. I installed libsndfile-dev using sudo apt-get install libsndfile1-dev, as well as built the cloned libsndfile repository following its instructions…
I am using pipes to display file contents. When I comment the wait command (in the last part of the parent process), I expect to see the parent process in the ps command's output (after a while, because reading is…
For purely educational purposes, I am trying to write examples with the "Constructing Function Calls builtins" (https://gcc.gnu.org/onlinedocs/gcc-13.2.0/gcc/Constructing-Calls.html#index-_005f_005fbuiltin_005fva_005farg_005fpack) I have written an example that incorporates what appears in the documentation: #include <stdio.h> extern int myprintf(FILE *f, const char *format, ...); extern…
For the following code, I hope there is a warning because a is type enum A, but the case B1 and B2 are type enum B; but I couldn't find a way to make gcc/clang warn about it. Any suggestion…