[Bug c++/55227] designated initializer for char array by string constant

2020-06-16 Thread steven.spark at gmail dot com 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55227

Szikra  changed:

   What|Removed |Added

 CC||steven.spark at gmail dot com

--- Comment #5 from Szikra  ---
I just run into this problem with gcc version 7.3.1 20180622 (release)
[ARM/embedded-7-branch revision 261907] (GNU Tools for Arm Embedded Processors
7-2018-q2-update)

Thanks J.R. Heisey and ensadc, the extra braces solved the error... for now.

I added this url to comments in case this bug is fixed and they need to be
removed.

typedef struct {
/// ...
uint16_t serverPort;
char serverAddress[128];
} ConfigParameters_t;


ConfigParameters_t __attribute__((section(".eeprom"))) eeParameters = {
/// ...
.serverPort=1234,
{.serverAddress="*"} /// weird...
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55227
};

[Bug c++/49974] missing warning for indirectly returning reference to local/temporary

2017-02-02 Thread steven.spark at gmail dot com 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=49974

--- Comment #8 from Szikra  ---
(In reply to Marc Glisse from comment #7)
> We currently warn on all the examples involving X, with -O2. We don't for Y,
> we might if there was a caller and the dangling reference was used there...

Hi, I assume you mean like this:
#include 
using namespace std;
struct Y {
Y(int& i) : r(i) { }
int& r;
};

Y f() {
int i=1;
return Y(i);
}

int main() {
Y y1= f();
cout << y1.r << endl; ///  warning: 'i' is used uninitialized in this
function [-Wuninitialized]
}

/* compiled with gcc version 6.3.0 (x86_64-posix-seh-rev1, Built by MinGW-W64
project)
g++ -std=c++11 -O2 -g3 -Wall -Wextra -Wconversion -c -fmessage-length=0 -v -o
"src\\test3.o" "..\\src\\test3.cpp" 
*/

What about this?
struct Y2 {
Y2(const int& i) : r(i) { }
const int& r;
};

We might or might not get a warning even if the reference is used.

int main() {
Y2 y2(2);
cout << y2.r << endl; ///  warning: '' is used uninitialized in
this function [-Wuninitialized]
}

and 

Y2 g_y2(22);
int main() {
cout << g_y2.r << endl; /// no warning at all
}

Or what about this?
struct Z {
Z(int i) : r(i) { }
int& r;
};

Z g_z(33);
int main() {
cout << g_z.r << endl; /// no warning
Z z(3);
cout << z.r << endl; /// no warning
}

[Bug c++/79307] g++ misses warning for reference on temporary that invokes undefined behaviour

2017-02-01 Thread steven.spark at gmail dot com 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79307

--- Comment #4 from Szikra  ---
> This is bug 44974.
> 
> > Possible duplicate of bug #44859 or bug #51270.
> 
> Looks more like bug 49974 to me.
> 
> *** This bug has been marked as a duplicate of bug 44974 ***

Hi you are right, my first example is the same as in bug 49974:

struct Y {
Y(int& i) : r(i) { }
int& r;
};

If that were fixed, it would probably solve both problem.
Though my second case might be easier to detect, or it's more obviously wrong
:)

struct TestRefIntDirect {
TestRefIntDirect(int a) : a_(a) {};
const int& a_;
};
This is wrong by in itself, in this case temporary is always created and in the
same place where it is used.

But I have a problem:
Shouldn't this be marked as duplicate of bug 49974 and not bug 44974? :)

[Bug c++/79307] New: g++ misses warning for reference on temporary that invokes undefined behaviour

2017-01-31 Thread steven.spark at gmail dot com 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79307

Bug ID: 79307
   Summary: g++ misses warning for reference on temporary that
invokes undefined behaviour
   Product: gcc
   Version: 5.3.0
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
  Assignee: unassigned at gcc dot gnu.org
  Reporter: steven.spark at gmail dot com
  Target Milestone: ---

I thought (something like) this was fixed in bug 986

Code:
struct TestRefInt {
TestRefInt(const int& a) : a_(a) {};
void DoSomething() {cout << "int:" << a_ << endl;  }
protected:
const int& a_;
};

TestRefInt tfi(55);

int main() {
TestRefInt ltfi(8);

tfi.DoSomething();
ltfi.DoSomething();
return 0;
}

The first one does not work, the second one happens to work (but only by
"accident"). 

Similar issue:

struct TestRefIntDirect {
TestRefIntDirect(int a) : a_(a) {};
void DoSomething() {cout << "int:" << a_ << endl;  }
protected:
const int& a_;
};

Lifetime of the temporary is not extended in neither case (as per C++11
standard 12.2 p5).

Tested with MinGW 5.3.0, avr-g++ 4.8.1, 4.9.2.

I would like if warning were produced for these. Any help would be appreciated.

I posted more details on stack overflow
http://stackoverflow.com/questions/41928634/c11-scoping-and-lifetime-of-temporary-bound-to-a-const-reference-gcc

Possible duplicate of bug #44859 or bug #51270.

[Bug c++/58798] class with a class reference member generates unjustified warning

2017-01-30 Thread steven.spark at gmail dot com 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58798

--- Comment #5 from Szikra  ---
(In reply to Jonathan Wakely from comment #4)
> Because the warning isn't controlled by the -Wpacked option. If it was, it
> would say [-Wpacked] after the warning. I think that's a bug, every warning
> should be controlled by some -Wxxx option.

Thanks, good to know. So does this require a separate bug report, or can
someone change the status and confirm this one?

[Bug c++/58798] class with a class reference member generates unjustified warning

2017-01-29 Thread steven.spark at gmail dot com 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58798

--- Comment #3 from Szikra  ---
The warning is still there if I use the -Wno-packed option:
g++  -std=gnu++11 -fpack-struct -Wno-packed eeprom.cpp -o eeprom
Why?

I have found a suggestion to hide warning about ignored attributes:
#pragma clang diagnostic ignored "-Wignored-attributes"
which doesn't seem to have a GCC equivalent. :(

[Bug c++/58798] class with a class reference member generates unjustified warning

2017-01-29 Thread steven.spark at gmail dot com 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58798

--- Comment #2 from Szikra  ---
Created attachment 40615
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40615&action=edit
preprocessed test case

Compiled with 
g++  --save-temps -std=gnu++11 -fpack-struct eeprom.cpp -o eeprom 
eeprom.cpp: In instantiation of 'class EepromAccessor':
eeprom.cpp:29:16:   required from here
eeprom.cpp:16:8: warning: ignoring packed attribute because of unpacked non-POD
field 'unsigned int& EepromAccessor::data_'
 T& data_;
^

[Bug c++/58798] class with a class reference member generates unjustified warning

2017-01-29 Thread steven.spark at gmail dot com 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58798

Szikra  changed:

   What|Removed |Added

 CC||steven.spark at gmail dot com

--- Comment #1 from Szikra  ---
I'm having a similar issue.

Got here from here:
http://stackoverflow.com/questions/35152877/ignoring-packed-attribute-because-of-unpacked-non-pod-field

I'm not sure if this is a bug or not, I'm looking ways to get rid of the
warning message. (without removing -fpack-struct from the command line)

How can I do that?
Any '#pragma GCC diagnostic ignored' I can use?

My compiler output looks something like this:
...common/eeprom.hpp: In instantiation of 'class
FromEeprom::EepromAccessor':
../src/test.cpp:193:29:   required from here
…common/eeprom.hpp:119:8: warning: ignoring packed attribute because of
unpacked non-POD field 'long unsigned int& FromEeprom::EepromAccessor::data_' [enabled by default]

GCC Versions:
AVR8/GNU C Compiler : 4.8.1, 4.9.2 (latest I could find for AVR on Windows)

similar result with MinGW 5.3:
g++  -std=gnu++11 -fpack-struct eeprom.cpp -o eeprom

 from test/eeprom.cpp:19:
./common/eeprom.hpp: In instantiation of 'class
FromEeprom::EepromAccessor':
test/eeprom.cpp:30:16:   required from here
./common/eeprom.hpp:119:8: warning: ignoring packed attribute because of
unpacked non-POD field 'unsigned int& FromEeprom::EepromAccessor::data_'
 T& data_;

But with the added errors:
In file included from
C:/mingw-w64/x86_64-5.3.0-posix-seh-rt_v4-rev0/mingw64/x86_64-w64-mingw32/include/c++/ios:42:0,
 from
C:/mingw-w64/x86_64-5.3.0-posix-seh-rt_v4-rev0/mingw64/x86_64-w64-mingw32/include/c++/ostream:38,
 from
C:/mingw-w64/x86_64-5.3.0-posix-seh-rt_v4-rev0/mingw64/x86_64-w64-mingw32/include/c++/iostream:39,
 from test/eeprom.cpp:23:
C:/mingw-w64/x86_64-5.3.0-posix-seh-rt_v4-rev0/mingw64/x86_64-w64-mingw32/include/c++/bits/ios_base.h:
In member function 'std::ios_base::fmtflags
std::ios_base::setf(std::ios_base::fmtflags)':
C:/mingw-w64/x86_64-5.3.0-posix-seh-rt_v4-rev0/mingw64/x86_64-w64-mingw32/include/c++/bits/ios_base.h:649:7:
error: cannot bind packed field
'((std::ios_base*)this)->std::ios_base::_M_flags' to 'std::_Ios_Fmtflags&'
   _M_flags |= __fmtfl;
   ^
C:/mingw-w64/x86_64-5.3.0-posix-seh-rt_v4-rev0/mingw64/x86_64-w64-mingw32/include/c++/bits/ios_base.h:
In member function 'std::ios_base::fmtflags
std::ios_base::setf(std::ios_base::fmtflags, std::ios_base::fmtflags)':
C:/mingw-w64/x86_64-5.3.0-posix-seh-rt_v4-rev0/mingw64/x86_64-w64-mingw32/include/c++/bits/ios_base.h:666:7:
error: cannot bind packed field
'((std::ios_base*)this)->std::ios_base::_M_flags' to 'std::_Ios_Fmtflags&'
   _M_flags &= ~__mask;
   ^
C:/mingw-w64/x86_64-5.3.0-posix-seh-rt_v4-rev0/mingw64/x86_64-w64-mingw32/include/c++/bits/ios_base.h:667:7:
error: cannot bind packed field
'((std::ios_base*)this)->std::ios_base::_M_flags' to 'std::_Ios_Fmtflags&'
   _M_flags |= (__fmtfl & __mask);
   ^
C:/mingw-w64/x86_64-5.3.0-posix-seh-rt_v4-rev0/mingw64/x86_64-w64-mingw32/include/c++/bits/ios_base.h:
In member function 'void std::ios_base::unsetf(std::ios_base::fmtflags)':
C:/mingw-w64/x86_64-5.3.0-posix-seh-rt_v4-rev0/mingw64/x86_64-w64-mingw32/include/c++/bits/ios_base.h:679:7:
error: cannot bind packed field
'((std::ios_base*)this)->std::ios_base::_M_flags' to 'std::_Ios_Fmtflags&'
 { _M_flags &= ~__mask; }
   ^
C:/mingw-w64/x86_64-5.3.0-posix-seh-rt_v4-rev0/mingw64/x86_64-w64-mingw32/include/c++/bits/ios_base.h:
In member function 'long int& std::ios_base::iword(int)':
C:/mingw-w64/x86_64-5.3.0-posix-seh-rt_v4-rev0/mingw64/x86_64-w64-mingw32/include/c++/bits/ios_base.h:813:21:
error: cannot bind packed field '__word.std::ios_base::_Words::_M_iword' to
'long int&'
   return __word._M_iword;
 ^
C:/mingw-w64/x86_64-5.3.0-posix-seh-rt_v4-rev0/mingw64/x86_64-w64-mingw32/include/c++/bits/ios_base.h:
In member function 'void*& std::ios_base::pword(int)':
C:/mingw-w64/x86_64-5.3.0-posix-seh-rt_v4-rev0/mingw64/x86_64-w64-mingw32/include/c++/bits/ios_base.h:834:21:
error: cannot bind packed field '__word.std::ios_base::_Words::_M_pword' to
'void*&'
   return __word._M_pword;
 ^
Here is a code to reproduce:
//#include 
//using namespace std;

#define EEMEM /// fake

template
class EepromAccessor {
public:
EepromAccessor(T& data) : data_(data) {};
inline operator T() {   return (data_);} /// fake Get
inline EepromAccessor& operator=(const T& val) { ///

[Bug c++/70774] New: constexpr function with reference parameter gives reinterpret_cast from integer to pointer error

2016-04-23 Thread steven.spark at gmail dot com 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70774

Bug ID: 70774
   Summary: constexpr function with reference parameter gives
reinterpret_cast from integer to pointer error
   Product: gcc
   Version: 4.9.2
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
  Assignee: unassigned at gcc dot gnu.org
  Reporter: steven.spark at gmail dot com
  Target Milestone: ---

Here is the simplified code:

--
#define PORTX (*(volatile unsigned char *)(0x1B))

constexpr volatile unsigned char * testRef(volatile unsigned char & x) {
return &x;
}
volatile unsigned char* addr = testRef(PORTX); /// OK

constexpr volatile unsigned char* addr2 = testRef(PORTX); /// error: 
   /// reinterpret_cast from integer to pointer
--


This compiled without problem with gcc 4.8.1, but fails with 4.9.2.


Using built-in specs.
COLLECT_GCC=avr-g++.exe
Target: avr
Configured with:
/home/toolsbuild/workspace/avr8-gnu-toolchain/src/gcc/configure
LDFLAGS=-L/home/toolsbuild/workspace/avr8-gnu-toolchain/avr8-gnu-toolchain-win32_x86-hostlibs/lib
CPPFLAGS= --target=avr --host=i686-w64-mingw32 --build=x86_64-pc-linux-gnu
--prefix=/home/toolsbuild/workspace/avr8-gnu-toolchain/avr8-gnu-toolchain-win32_x86
--libdir=/home/toolsbuild/workspace/avr8-gnu-toolchain/avr8-gnu-toolchain-win32_x86/lib
--enable-languages=c,c++ --with-dwarf2 --enable-doc --disable-shared
--disable-libada --disable-libssp --disable-nls --with-avrlibc=yes
--with-mpfr=/home/toolsbuild/workspace/avr8-gnu-toolchain/avr8-gnu-toolchain-win32_x86-hostlibs
--with-gmp=/home/toolsbuild/workspace/avr8-gnu-toolchain/avr8-gnu-toolchain-win32_x86-hostlibs
--with-mpc=/home/toolsbuild/workspace/avr8-gnu-toolchain/avr8-gnu-toolchain-win32_x86-hostlibs
--enable-win32-registry=avrtoolchain
--with-pkgversion=AVR_8_bit_GNU_Toolchain_3.5.0_1662
--with-bugurl=http://www.atmel.com
Thread model: single
gcc version 4.9.2 (AVR_8_bit_GNU_Toolchain_3.5.0_1662) 



I'm writing code for AVR micro controller where every byte counts, so compile
time evaluation is key. I was trying out the new Atmel Studio 7 IDE which comes
with the new 4.9.2 gcc when I came across this problem. In my real world code
I'm using constexpr constructor and constexpr instances of my pin handler class
- to make life easier and encapsulate port, data direction and other registers. 

Note: If I use pointer instead of reference then it compiles fine:

constexpr volatile unsigned char * testAddr(volatile unsigned char * x) {
return x;
}
constexpr volatile unsigned char* addr3 = testAddr(&PORTX); /// OK


Why is this? Am I doing something wrong? How can I use (port) references in
constexpr functions?

This also does NOT work:

constexpr volatile unsigned char& ref5 = PORTX; /// error

[Bug c/61813] New: __attribute__((__packed__)) does not pack struct containing uint16_t with uint32_t

2014-07-15 Thread steven.spark at gmail dot com 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61813

Bug ID: 61813
   Summary: __attribute__((__packed__)) does not pack struct
containing uint16_t with uint32_t
   Product: gcc
   Version: unknown
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c
  Assignee: unassigned at gcc dot gnu.org
  Reporter: steven.spark at gmail dot com

Created attachment 33125
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33125&action=edit
preprocessed bugreport_packed.c

Test case:
typedef struct __attribute__((__packed__)) {
uint16_t a;///  2
uint32_t b; /// +4
uint32_t c[8];  /// +4*8 = 38
} foo_t;

but the size of foo_t is 40 (instead of the 38 which it should be). (It does
not matter where I put the packed attribute.)


I'm using the latest released mingw to date (4.8.1 rev 5).
I'm compiling on Windows 7 x64 (with mingw).
GCC config:
Target: x86_64-w64-mingw32
Configured with: ../../../src/gcc-4.8.1/configure --host=x86_64-w64-mingw32
--build=x86_64-w64-mingw32 --target=x86_64-w64-mingw32 --prefix=/mingw64
--with-sysroot=/tmp/x64-481-win32-seh-r5/mingw64 --enable-shared
--enable-static --disable-multilib
--enable-languages=ada,c,c++,fortran,objc,obj-c++,lto
--enable-libstdcxx-time=yes --enable-threads=win32 --enable-libgomp
--enable-lto --enable-graphite --enable-checking=release
--enable-fully-dynamic-string --enable-version-specific-runtime-libs
--disable-isl-version-check --disable-cloog-version-check
--disable-libstdcxx-pch --disable-libstdcxx-debug --enable-bootstrap
--disable-rpath --disable-win32-registry --disable-nls --disable-werror
--disable-symvers --with-gnu-as --with-gnu-ld --with-arch=nocona
--with-tune=core2 --with-libiconv --with-system-zlib
--with-gmp=/tmp/mingw-prereq/x86_64-w64-mingw32-static
--with-mpfr=/tmp/mingw-prereq/x86_64-w64-mingw32-static
--with-mpc=/tmp/mingw-prereq/x86_64-w64-mingw32-static
--with-isl=/tmp/mingw-prereq/x86_64-w64-mingw32-static
--with-cloog=/tmp/mingw-prereq/x86_64-w64-mingw32-static
--enable-cloog-backend=isl --with-pkgversion='rev5, Built by MinGW-W64 project'
--with-bugurl=http://sourceforge.net/projects/mingw-w64 CFLAGS='-O2 -pipe
-I/tmp/x64-481-win32-seh-r5/libs/include -I/tmp/mingw-prereq/x64-zlib/include
-I/tmp/mingw-prereq/x86_64-w64-mingw32-static/include' CXXFLAGS='-O2 -pipe
-I/tmp/x64-481-win32-seh-r5/libs/include -I/tmp/mingw-prereq/x64-zlib/include
-I/tmp/mingw-prereq/x86_64-w64-mingw32-static/include' CPPFLAGS= LDFLAGS='-pipe
-L/tmp/x64-481-win32-seh-r5/libs/lib -L/tmp/mingw-prereq/x64-zlib/lib
-L/tmp/mingw-prereq/x86_64-w64-mingw32-static/lib
-L/tmp/x64-481-win32-seh-r5/mingw64/opt/lib '
Thread model: win32
gcc version 4.8.1 (rev5, Built by MinGW-W64 project) 

command line 
gcc bugreport_packed.c
or
gcc -v -save-temps  -Wall -Wextra bugreport_packed.c

complete comiler output:
Using built-in specs.
COLLECT_GCC=C:\MinGW\x64-4.8.1-win32-seh-rev5\mingw64\bin\gcc
COLLECT_LTO_WRAPPER=c:/mingw/x64-4.8.1-win32-seh-rev5/mingw64/bin/../libexec/gcc/x86_64-w64-mingw32/4.8.1/lto-wrapper.exe
Target: x86_64-w64-mingw32
Configured with: ../../../src/gcc-4.8.1/configure --host=x86_64-w64-mingw32
--build=x86_64-w64-mingw32 --target=x86_64-w64-mingw32 --prefix=/mingw64
--with-sysroot=/tmp/x64-481-win32-seh-r5/mingw64 --enable-shared
--enable-static --disable-multilib
--enable-languages=ada,c,c++,fortran,objc,obj-c++,lto
--enable-libstdcxx-time=yes --enable-threads=win32 --enable-libgomp
--enable-lto --enable-graphite --enable-checking=release
--enable-fully-dynamic-string --enable-version-specific-runtime-libs
--disable-isl-version-check --disable-cloog-version-check
--disable-libstdcxx-pch --disable-libstdcxx-debug --enable-bootstrap
--disable-rpath --disable-win32-registry --disable-nls --disable-werror
--disable-symvers --with-gnu-as --with-gnu-ld --with-arch=nocona
--with-tune=core2 --with-libiconv --with-system-zlib
--with-gmp=/tmp/mingw-prereq/x86_64-w64-mingw32-static
--with-mpfr=/tmp/mingw-prereq/x86_64-w64-mingw32-static
--with-mpc=/tmp/mingw-prereq/x86_64-w64-mingw32-static
--with-isl=/tmp/mingw-prereq/x86_64-w64-mingw32-static
--with-cloog=/tmp/mingw-prereq/x86_64-w64-mingw32-static
--enable-cloog-backend=isl --with-pkgversion='rev5, Built by MinGW-W64 project'
--with-bugurl=http://sourceforge.net/projects/mingw-w64 CFLAGS='-O2 -pipe
-I/tmp/x64-481-win32-seh-r5/libs/include -I/tmp/mingw-prereq/x64-zlib/include
-I/tmp/mingw-prereq/x86_64-w64-mingw32-static/include' CXXFLAGS='-O2 -pipe
-I/tmp/x64-481-win32-seh-r5/libs/include -I/tmp/mingw-prereq/x64-zlib/include
-I/tmp/mingw-prereq/x86_64-w64-mingw32-static/include' CPPFLAGS= LDFLAGS='-pipe
-L/tmp/x64-481-win32-seh-r5/libs/lib -L/tmp/mingw-prereq/x64-zlib/lib
-L/tmp/mingw-prereq/x86_64-w64-mingw32-static/lib
-L/tmp/x64-481-win32-seh-r5/mingw64/opt/lib '
Thread model: