Questions tagged [gcc-warning]
GCC is the GNU Compiler Collection, encompassing the gcc C compiler and the g++ C++ compiler, among others. It has powerful warning facilities that can reveal coding errors in C and C++ code.
gcc-warning
849
questions
3
votes
2
answers
109
views
GCC 14 "possibly dangling reference to a temporary" warning or not, depending on the function argument
In the following C++ code GCC 14 with -Wall -Wextra flags produces a possibly dangling reference warning for function g(), but not f(). Why?
/* getval.h */
#include <string>
std::string const &...
- 75
-1
votes
1
answer
64
views
how to debug "*** buffer overflow detected ***: program_name terminated" along with _FORTIFY_SOURCE=2
My program crashes with the message "*** buffer overflow detected ***: program_name terminated", and I suspect it may be related to the compiler option "_FORTIFY_SOURCE=2" that I ...
- 5,982
0
votes
1
answer
51
views
How can I convert from .asm to .obj to .exe?
I am trying to write a simple Hello World Program using assembly and NASM. This is the code:
section .data
hello db 'Hello, World!', 0 ; The string to print
section .text
global _start
...
0
votes
0
answers
26
views
gcc make error on windows, how to resolve?
I'm trying to compile squid, a proxy and cache server, on windows using MinGW32 and MSYS32 for use with IIS and the make check and make install process is failing with these messages:
In file included ...
2
votes
2
answers
120
views
Yet another warning: ‘<anonymous>’ may be used uninitialized
I saw many other questions about the very same warning, but my code seems different.
And, over all, I get this only with -Os option.
#include <iostream>
using namespace std ;
template <class ...
- 527
0
votes
0
answers
72
views
Can I ask GCC to give me a warning or error on empty structs?
I just had the worst problem ever in my mixed C/C++ project.
The C code is the production code, the C++ is the testing environment. We are compiling with MinGW GCC, but developing on Qt Creator which ...
- 1,163
1
vote
3
answers
95
views
GCC -Woverride-init warning with anonymous structs in a union
I need to define a type formed with 2 24-bit fields (48 bits in total). I didn't find a way to do it with bitfields in a struct. So I defined my type with a union and 2 anonymous structs :
typedef ...
- 11
0
votes
0
answers
30
views
"warning: 'x' may be used uninitialized in this function ", but only for -Os
I have this piece of code. My minimal example reads:
//compile with: g++ -Wmaybe-uninitialized -Os -c
extern void use_x(int x);
extern int get_x(bool &have_x) __attribute__((access(write_only,1)...
- 670
3
votes
1
answer
122
views
Missing GCC "-Wformat" warnings for "%p" with char* etc
If I compile the following code with -std=c17 -Wall -Wextra -Wpedantic with GCC 13.2.0, I get no warnings, despite not using void* in arguments corresponding to "%p" format specifiers.
#...
- 9,965
2
votes
2
answers
117
views
GCC: trying to use -Werror or -pedantic using pragmas
In files being compiled using gcc (several .c and .cpp files) I have currently something like:
#if defined(__GNUC__) && !defined(__clang__)
#pragma GCC diagnostic warning "-Wall"
...
- 11.4k
1
vote
0
answers
68
views
Neither -Wunused-result, nor --warn-unused-result generates warnings about unused results
This (simplest-example) program is set up so main() calls the makeKey() function and fails to check the return value ...Which demonstrates why, when programming, especially security critical code [I'm ...
- 160
4
votes
2
answers
123
views
GCC Format attribute not working on function pointer with "using" alias
As the ISO C++ Guidelines recommends, we should use using instead of typedef. However, recently I had to code some debug logging where the attribute would be helpful for compile-time diagnostics.
When ...
- 949
-5
votes
3
answers
143
views
Compiler prints HelloWorld whereas Chat GPT says it should only print Hello [closed]
Below is the code I'm compiling:
#include <stdio.h>
void main()
{
printf("Hello%cWorld\n", 0);
}
Below is the compiler output:
HelloWorld
Bing Chat-GPT response:start
Below is ...
- 9
1
vote
0
answers
20
views
what to do if this error "storage size of `temp_q_trig1' isn't known" occurs in ST programming
I have been programming on ST for some time but I am not familiar with data types and its errors especially the compiler based ones
What is that error and what is the cost of the error and how to ...
0
votes
1
answer
132
views
How to resolve C printf %b format warnings
I am getting warning for below program
#include <stdio.h>
int main(void)
{
int num = 0xff;
printf("%B\n", num);
printf("%b\n", ~num);
printf("%b\n",...
- 1,536