[Bug c++/56868] New: Constexpr example in 7.1.5/5 fails to compile correctly
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56868
Bug #: 56868
Summary: Constexpr example in 7.1.5/5 fails to compile
correctly
Classification: Unclassified
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: g++...@oxyware.com
// The following example from 7.1.5/5 fails the static assert for g3(0)
constexpr int f(void *) { return 0; }
constexpr int f(...) { return 1; }
constexpr int g1() { return f(0); }
constexpr int g2(int n) { return f(n); }
constexpr int g3(int n) { return f(n*0); }
int main()
{
static_assert(g1() == 0, "g1 failed");
static_assert(g2(0) == 1, "g2 failed");
static_assert(g3(0) == 1, "g3 failed"); // fails, g3(0) returns 0 not 1
}
[Bug c++/56868] Constexpr example in 7.1.5/5 fails to compile correctly
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56868 --- Comment #1 from Hubert Matthews 2013-04-07 18:39:04 UTC --- Compiled with g++-4.7.0 -Wall -Wextra -std=c++11 on Fedora 14, 64-bit.
[Bug c++/53560] New: Internal compiler error with += and void function (invalid source)
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53560
Bug #: 53560
Summary: Internal compiler error with += and void function
(invalid source)
Classification: Unclassified
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: g++...@oxyware.com
void f() {}
int main()
{
int i = 0;
i += f();
}
This is an invalid C++ program but it causes an internal compiler error (see
below).
g++ -v -save-temps -c gives:
Using built-in specs.
COLLECT_GCC=/usr/local/bin/g++
Target: x86_64-unknown-linux-gnu
Configured with: ./configure
Thread model: posix
gcc version 4.7.0 (GCC)
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-c' '-shared-libgcc' '-mtune=generic'
'-march=x86-64'
/usr/local/libexec/gcc/x86_64-unknown-linux-gnu/4.7.0/cc1plus -E -quiet -v
-D_GNU_SOURCE argc.cpp -mtune=generic -march=x86-64 -fpch-preprocess -o argc.ii
ignoring nonexistent directory
"/usr/local/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../x86_64-unknown-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/local/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0
/usr/local/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0/x86_64-unknown-linux-gnu
/usr/local/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0/backward
/usr/local/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/include
/usr/local/include
/usr/local/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/include-fixed
/usr/include
End of search list.
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-c' '-shared-libgcc' '-mtune=generic'
'-march=x86-64'
/usr/local/libexec/gcc/x86_64-unknown-linux-gnu/4.7.0/cc1plus -fpreprocessed
argc.ii -quiet -dumpbase argc.cpp -mtune=generic -march=x86-64 -auxbase argc
-version -o argc.s
GNU C++ (GCC) version 4.7.0 (x86_64-unknown-linux-gnu)
compiled by GNU C version 4.7.0, GMP version 4.3.1, MPFR version 2.4.2, MPC
version 0.8.1
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU C++ (GCC) version 4.7.0 (x86_64-unknown-linux-gnu)
compiled by GNU C version 4.7.0, GMP version 4.3.1, MPFR version 2.4.2, MPC
version 0.8.1
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 635960e7261d0cad01689b56d992ea9a
argc.cpp: In function ‘int main()’:
argc.cpp:6:11: internal compiler error: in build_target_expr_with_type, at
cp/tree.c:587
Please submit a full bug report,
with preprocessed source if appropriate.
See for instructions.
[Bug c++/70444] New: Optimizer removes expression template
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70444
Bug ID: 70444
Summary: Optimizer removes expression template
Product: gcc
Version: 5.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: g++bug at oxyware dot com
Target Milestone: ---
The code below crashes with a SIGSEGV when compiled with g++ 5.3.1 and
optimization turned on. Gdb shows that the variable v4 has been optimized out
and is a null pointer. The code runs correctly with no optimization, -O, -Os
or -O1, but crashes with -O2 or -O3.
The bug appears to be present in previous versions of g++ back to 4.7.0 (the
earliest I can test as the code uses C++11).
The code runs correctly with clang++, with or without optimisation.
Correct functionality
$ g++ -std=c++11 % && ./a.out
$ echo $?
33
Incorrect
$ g++ -std=c++11 -O2 % && ./a.out
Segmentation fault (core dumped)
Correct
$ clang++ -std=c++11 -O3 exprtmpl.cpp && ./a.out
$ echo $?
33
$ g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/5.3.1/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --enable-bootstrap
--enable-languages=c,c++,objc,obj-c++,fortran,ada,go,lto --prefix=/usr
--mandir=/usr/share/man --infodir=/usr/share/info
--with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared
--enable-threads=posix --enable-checking=release --enable-multilib
--with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions
--enable-gnu-unique-object --enable-linker-build-id
--with-linker-hash-style=gnu --enable-plugin --enable-initfini-array
--disable-libgcj --with-default-libstdcxx-abi=gcc4-compatible --with-isl
--enable-libmpx --enable-gnu-indirect-function --with-tune=generic
--with-arch_32=i686 --build=x86_64-redhat-linux
Thread model: posix
gcc version 5.3.1 20151207 (Red Hat 5.3.1-2) (GCC)
$ clang++ -v
clang version 3.5.0 (tags/RELEASE_350/final)
Target: x86_64-redhat-linux-gnu
Thread model: posix
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-redhat-linux/5.3.1
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/5.3.1
Selected GCC installation: /usr/bin/../lib/gcc/x86_64-redhat-linux/5.3.1
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64
(Platform is 64-bit Fedora 22 on x86_64, using the distribution's version of
g++)
//-
#include
template
struct Expression {
Expression(const Left & l, const Right & r) : left(l), right(r) {}
float operator[](unsigned int index) const {
return Op::apply(left[index], right[index]);
}
const Left & left;
const Right & right;
};
struct plus {
static float apply(float l, float r) { return l + r; }
};
template
Expression operator+(const Left & l, const Right & r)
{
return Expression(l, r);
}
int main()
{
std::vector v1{2, 3.4, 5};
std::vector v2{3, 5.0, 4};
std::vector v3{4, 6.0, 1};
auto v4 = v1 + v2 + v3;
float total = 0;
for (auto i = 0u; i != v1.size(); ++i)
total += v4[i];
return total;
}
//-
[Bug c++/70444] Optimizer removes expression template
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70444 --- Comment #4 from Hubert Matthews --- Doh, mea culpa. My apologies.
[Bug c++/79031] New: [C++17] ICE with class template deduction for std::vector and std::initializer_list
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79031
Bug ID: 79031
Summary: [C++17] ICE with class template deduction for
std::vector and std::initializer_list
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: g++bug at oxyware dot com
Target Milestone: ---
#include
int main()
{
std::vector v({4});
}
//g++ 7.0.0 20170108 (experimental)
Compilation with g++ version "7.0.0 20170108 (experimental)" and -std=c++1z
fails with:
: In function 'std::vector(std::initializer_list<_Tp>, const
allocator_type&)-> std::vector<_Tp, _Alloc> [with _Tp = int; _Alloc =
std::allocator; std::vector<_Tp, _Alloc>::allocator_type =
std::allocator]':
:5:20: internal compiler error: in tsubst_copy, at cp/pt.c:14953
std::vector v({4});
^
mmap: Cannot allocate memory
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
Compiler exited with result code 1
This compiles successfully with std::vector v({4}); but not when
attempting to deduce the initializer_list type.
Possibly related to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78894
