Version 6.x of the GNU Compiler Collection.
Version 6.1 was released on 2016-04-27. Version 6.5. was released on 2018-10-26.
See also:
Questions tagged [gcc6]
52 questions
3
votes
1 answer
Centos6 gcc6: default ABI not picked up when compiling simple c++11 test file
I have a docker image for centos 6 with devtoolset-6 installed and I want to build my code with the new ABI available in gcc>=5, in this case gcc6. Somehow I do not get what I expect to work by default. I have tried various variations but I am at…
user1357687
- 571
- 1
- 6
- 9
3
votes
2 answers
gcc 6.1 std::result_of compilation error
Consider a small standalone use case wherein I want to determine if a type is a complete or incomplete using
#include
namespace {
struct foo {
template
std::false_type operator()(T&);
…
Recker
- 1,915
- 25
- 55
3
votes
1 answer
gcc fails to inline functions without -O2
I've recently run into a problem with compiling a piece of code after upgrading debian testing, getting the gcc 6.2.1 compiler. I've boiled it down to this simple example:
inline int func(void) {
return 0;
}
int main (int argc, char **argv) {
…
Oscar Andreasson
- 339
- 3
- 6
3
votes
1 answer
How to catch a duplicate like `-Wduplicated-cond` from GCC-6
Like the title says, for those who already know starting with GCC-6 you can catch a duplicate in an ifstatement using this Flag -Wduplicated-cond like this:
#include
int main(void){
int a = 5;
if( a == 5){
printf("First …
Michi
- 5,175
- 7
- 33
- 58
2
votes
2 answers
Boost::Signals2 slot with lambda expression fails using gcc6 on arm32
I received the following code from a colleague, broken down to the bare minimum, using Boost::Signal2 and lambda expressions. It compiles with g++ 6.x and g++ 5.4.1 (the latter with argument -std=c++11).
It should print i: 5 (should be 5)
Using a…
Reiner Huober
- 73
- 3
2
votes
2 answers
Is GCC's -Wmaybe-uninitialized generating a spurious warning with -O1 for a switch statement based on an enum?
I have a piece of code of the following form:
typedef enum {A=1,B} EnumType;
int foo (EnumType x)
{
int r;
switch (x) {
case A:
r = 1;
break;
case B:
r = 2;
break;
/*
default:
r = -1;
…
Patrick Sanan
- 2,375
- 1
- 23
- 25
2
votes
1 answer
Issues with Boost using fsanitize switch in gcc
I have been trying to take advantage of some of the GCC Instrumentation Options for runtime-checking to try and debug/diagnose issues I am having in a particular region of C++ code.
To try and narrow down the problem, I started enabling some of…
ZeroDefect
- 663
- 1
- 8
- 27
2
votes
1 answer
gcc 6.2.0 is attempting to create shared object when it shouldn't?
With non relocatable assembler code linking was never a problem up until gcc 6.2.0. I don't know the exact version that stared this, but with gcc 5.4.0 (and below) this worked:
$ gcc -o httpget ../obj/httpget.o ../../../lib/libribs2_ssl.a -lssl…
niry
- 3,238
- 22
- 34
2
votes
1 answer
gcc - openacc - Compiled program does not function properly
Recently, there have been some efforts in GCC community to support OpenACC in their compiler. So, I wanted to try it out.
Using this step-by-step tutorial (tutorial), which was close to the main documentation on GCC website, I was able to compile…
mgNobody
- 738
- 7
- 23
1
vote
1 answer
make dependencies: skip vendor and package headers with gcc?
I'm starting a new project and thinking of using gcc 6.3.1 -MM to generate the dependencies into a file called Make.Dep, that I'll include from Makefile.
The -M option outputs all headers, including system headers. The -MM option doesn't output…
Swiss Frank
- 1,985
- 15
- 33
1
vote
3 answers
Is this valid C++ code? This doesn't work how it supposed to be
int main() {
string str[5] = "ABCD";
std::cout << str[3] << std::endl;
std::cout << str[0] << std::endl;
return 0;
}
This code prints:
ABCD
ABCD
I didn't get it, how str[3] prints ABCD?
Compiler: GCC 6.3
Debu Shinobi
- 2,057
- 18
- 21
1
vote
0 answers
How to suppress cc1: warning: unrecognized command line option -Wno-implicit-fallthrough
I'm running i686-w64-mingw32-gcc -Wno-implicit-fallthrough ... with gcc 6.3.0 on Linux, and I'm getting the message:
cc1: warning: unrecognized command line option ‘-Wno-implicit-fallthrough’
How can I suppress this message? I do want to specify…
pts
- 80,836
- 20
- 110
- 183
1
vote
4 answers
Strange GCC6 optimization with builtin function
With GCC6 and the code snippet below, this test
if (i > 31 || i < 0) {
is false, and this printf is executed
printf("i > 31 || i < 0 is FALSE, where i=%d", i);
and produces this very weird output (GCC6):
i > 31 || i < 0 is FALSE, where i=32 /*…
Bludzee
- 2,733
- 5
- 38
- 46
1
vote
0 answers
Can I link objects compiled from C++ by GCC 5.4.x and 6.x?
For some reason, I have some object files compiled with GCC 5.4.x and some object files compiled with GCC 6.x . The source code is C++14 and I'm on a x86_64 machine running GNU/Linux 4.4.x.
Is it ever, at all, possible to link my objects together?…
einpoklum
- 118,144
- 57
- 340
- 684
1
vote
1 answer
Type mismatch between std::complex in C++ and complex*16 in Fortran under gcc 6 with link-time optimisation
I use some scientific computing code which calls Fortran routines from C++, which has suddenly started giving a warning under gcc 6. Here is the barebones issue:
Consider a Fortran subroutine mult defined in mult.f90:
subroutine mult(c)
complex*16…
Raziman T V
- 480
- 1
- 4
- 12