Questions tagged [gcc]
GCC is the GNU Compiler Collection. It's the de facto standard compiler for C, C++, Go, Fortran, and Ada on Linux and supports many other languages and platforms as well.
6,958
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Removing trailing newline character from fgets() input
I am trying to get some data from the user and send it to another function in gcc. The code is something like this.
printf("Enter your Name: ");
if (!(fgets(Name, sizeof Name, stdin) != NULL)) {
...
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116
votes
3
answers
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How to remove "noise" from GCC/clang assembly output?
I want to inspect the assembly output of applying boost::variant in my code in order to see which intermediate calls are optimized away.
When I compile the following example (with GCC 5.3 using g++ -...
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votes
11
answers
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Why does the order in which libraries are linked sometimes cause errors in GCC?
Why does the order in which libraries are linked sometimes cause errors in GCC?
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answer
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32-bit absolute addresses no longer allowed in x86-64 Linux?
64 bit Linux uses the small memory model by default, which puts all code and static data below the 2GB address limit. This makes sure that you can use 32-bit absolute addresses. Older versions of gcc ...
- 4,540
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votes
12
answers
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Multiple glibc libraries on a single host
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 ...
- 272k
107
votes
3
answers
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Is gcc 4.8 or earlier buggy about regular expressions?
I am trying to use std::regex in a C++11 piece of code, but it appears that the support is a bit buggy. An example:
#include <regex>
#include <iostream>
int main (int argc, const char * ...
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votes
5
answers
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Why does GCC use multiplication by a strange number in implementing integer division?
I've been reading about div and mul assembly operations, and I decided to see them in action by writing a simple program in C:
File division.c
#include <stdlib.h>
#include <stdio.h>
int ...
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votes
11
answers
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Why does flowing off the end of a non-void function without returning a value not produce a compiler error?
Ever since I realized many years ago, that this doesn't produce an error by default (in GCC at least), I've always wondered why?
I understand that you can issue compiler flags to produce a warning, ...
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votes
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fatal error: Python.h: No such file or directory
I am trying to build a shared library using a C extension file but first I have to generate the output file using the command below:
gcc -Wall utilsmodule.c -o Utilc
After executing the command, I ...
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26
votes
1
answer
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How to load address of function or label into register
I am trying to load the address of 'main' into a register (R10) in the GNU Assembler. I am unable to. Here I what I have and the error message I receive.
main:
lea main, %r10
I also tried the ...
user11810714
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votes
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answers
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Why is scanf() causing infinite loop in this code?
I've a small C-program which just reads numbers from stdin, one at each loop cycle. If the user inputs some NaN, an error should be printed to the console and the input prompt should return again. On ...
user208785
36
votes
3
answers
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Why doesn't GCC use partial registers?
Disassembling write(1,"hi",3) on linux, built with gcc -s -nostdlib -nostartfiles -O3 results in:
ba03000000 mov edx, 3 ; thanks for the correction jester!
bf01000000 mov edi, 1
31c0 ...
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votes
21
answers
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Undefined reference to vtable
When building my C++ program, I'm getting the error message
undefined reference to 'vtable...
What is the cause of this problem? How do I fix it?
It so happens that I'm getting the error for the ...
- 7,033
18
votes
1
answer
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How can I indicate that the memory *pointed* to by an inline ASM argument may be used?
Consider the following small function:
void foo(int* iptr) {
iptr[10] = 1;
__asm__ volatile ("nop"::"r"(iptr):);
iptr[10] = 2;
}
Using gcc, this compiles to:
foo:
nop
...
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697
votes
31
answers
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How to automatically generate a stacktrace when my program crashes
I am working on Linux with the GCC compiler. When my C++ program crashes I would like it to automatically generate a stacktrace.
My program is being run by many different users and it also runs on ...
- 16.7k