[Bug c++/104995] New: access checking for function pointer template parameters takes place at call site
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104995
Bug ID: 104995
Summary: access checking for function pointer template
parameters takes place at call site
Product: gcc
Version: 11.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: mawww at kakoune dot org
Target Milestone: ---
The following code
```
template
void func() {
auto lambda = [&](auto&& s) { F(s); };
lambda(0);
}
struct S {
void f() { func(); }
private:
static void g(int) {}
};
```
Fails to compile on g++ 11.2.1 with the following error:
```
test.cc: In instantiation of ‘func():: [with auto:1 =
int]’:
test.cc:4:11: required from ‘void func() [with auto F = S::g]’
test.cc:8:26: required from here
test.cc:3:36: error: ‘static void S::g(int)’ is private within this context
3 | auto lambda = [&](auto&& s) { F(s); };
| ~^~~
test.cc:11:17: note: declared private here
11 | static void g(int) {}
| ^
```
Clang accepts this code, making func's body just `{ F(0); }` compiles without
errors as well.
[Bug c++/91465] [9/10 Regression] unexpected expression of kind overload (ICE)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91465 Maxime Coste changed: What|Removed |Added CC||mawww at kakoune dot org --- Comment #7 from Maxime Coste --- Any chance to get the proposed fix included in 9.3, what is currently missing ?
[Bug c++/94041] New: temporary object destructor called before the end of the full-expression
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94041
Bug ID: 94041
Summary: temporary object destructor called before the end of
the full-expression
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: mawww at kakoune dot org
Target Milestone: ---
Hello on current trunk, with no special options given, compiling the following
code:
struct Temp{ ~Temp(); };
struct A{ A(const Temp&) noexcept; };
struct B{ ~B(); };
struct Pair{ A a; B b; };
Temp make_temp() noexcept;
void foo(const Pair&) noexcept;
void bar(const Pair& p) noexcept
{
foo({A(make_temp()), p.b});
}
generates the following assembly for the bar function:
bar(Pair const&):
pushrbp
mov rbp, rsp
sub rsp, 32
mov QWORD PTR [rbp-24], rdi
lea rax, [rbp-1]
mov rdi, rax
callmake_temp()
lea rdx, [rbp-1]
lea rax, [rbp-3]
mov rsi, rdx
mov rdi, rax
callA::A(Temp const&)
lea rax, [rbp-1]
mov rdi, rax
callTemp::~Temp() [complete object destructor]
lea rax, [rbp-3]
mov rdi, rax
callfoo(Pair const&)
lea rax, [rbp-3]
mov rdi, rax
callPair::~Pair() [complete object destructor]
nop
leave
ret
Note the call to Temp::~Temp *before* the call to foo, which can lead to the A
object referring to a dangling Temp object when accessed in foo.
I believe that destructor call should only take place *after* calling foo, when
the full-expression actually ends.
This does not happen on gcc 9 and previous version, only on current trunk and
gcc-10 as provided in fedora rawhide.
[Bug c++/89217] ICE tree check: expected constructor, have error_mark in split_nonconstant_init_1
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89217 --- Comment #1 from Maxime Coste --- Forgot to mention that this is a regression since gcc 8.2.1 which compiles this code fine. It fails on gcc trunk r268563.
[Bug c++/89217] New: ICE tree check: expected constructor, have error_mark in split_nonconstant_init_1
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89217
Bug ID: 89217
Summary: ICE tree check: expected constructor, have error_mark
in split_nonconstant_init_1
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: mawww at kakoune dot org
Target Milestone: ---
Created attachment 45613
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=45613=edit
Source file that triggers the bug.
Compiling the following source (attached as well):
struct R {};
struct C
{
R* begin() const { return }
R* end() const { return }
R& r;
};
struct S
{
void f1() { f2(); }
template
void f2()
{
for (auto i : C{r}) {}
}
R& r;
};
Leads to an internal compiler error:
test.cc: In instantiation of ‘void S::f2() [with bool = true]’:
test.cc:13:26: required from here
test.cc:18:9: error: cannot convert ‘((S*)this)->S::r’ from type ‘R’ to type
‘R*’
18 | for (auto i : C{r}) {}
| ^~~
test.cc:18:9: internal compiler error: tree check: expected constructor, have
error_mark in split_nonconstant_init_1, at cp/typeck2.c:635
0x7bb804 tree_check_failed(tree_node const*, char const*, int, char const*,
...)
../.././gcc/tree.c:9813
0x671510 tree_check(tree_node*, char const*, int, char const*, tree_code)
../.././gcc/tree.h:3176
0x671510 split_nonconstant_init_1
../.././gcc/cp/typeck2.c:635
0xa5fced split_nonconstant_init(tree_node*, tree_node*)
../.././gcc/cp/typeck2.c:760
0x896f15 set_up_extended_ref_temp
../.././gcc/cp/call.c:11297
0x896f15 extend_ref_init_temps_1
../.././gcc/cp/call.c:11434
0xa628a7 store_init_value(tree_node*, tree_node*, vec**, int)
../.././gcc/cp/typeck2.c:833
0x8f07c2 check_initializer
../.././gcc/cp/decl.c:6508
0x91079c cp_finish_decl(tree_node*, tree_node*, bool, tree_node*, int)
../.././gcc/cp/decl.c:7184
0x9804b1 cp_convert_range_for(tree_node*, tree_node*, tree_node*, tree_node*,
unsigned int, bool, unsigned short)
../.././gcc/cp/parser.c:12361
0x9cf457 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
../.././gcc/cp/pt.c:17116
0x9cc449 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
../.././gcc/cp/pt.c:17212
0x9cbdce tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
../.././gcc/cp/pt.c:16896
0x9cbdce instantiate_decl(tree_node*, bool, bool)
../.././gcc/cp/pt.c:24584
0xa01f3b instantiate_pending_templates(int)
../.././gcc/cp/pt.c:24700
0x9200f0 c_parse_final_cleanups()
../.././gcc/cp/decl2.c:4792
[Bug tree-optimization/78528] New: Recursion not optimized in simple case
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78528
Bug ID: 78528
Summary: Recursion not optimized in simple case
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: mawww at kakoune dot org
Target Milestone: ---
The following code:
struct Int
{
constexpr Int(int value) : m_value(value) {}
constexpr friend Int operator+(Int lhs, Int rhs) { return {lhs.m_value +
rhs.m_value}; }
int m_value;
};
Int strlen(const char* s)
{
return *s == 0 ? 0 : strlen(s+1) + 1;
}
when compiled with `-std=c++11 -O3` generates the following assembly for the
strlen function:
_Z6strlenPKc:
.LFB4:
.cfi_startproc
cmpb$0, (%rdi)
jne .L2
xorl%eax, %eax
ret
.p2align 4,,10
.p2align 3
.L2:
cmpb$0, 1(%rdi)
movl$1, %eax
jne .L12
.L10:
ret
.p2align 4,,10
.p2align 3
.L12:
cmpb$0, 2(%rdi)
movl$2, %eax
je .L10
subq$8, %rsp
.cfi_def_cfa_offset 16
addq$3, %rdi
call_Z6strlenPKc
addq$8, %rsp
.cfi_def_cfa_offset 8
addl$3, %eax
ret
.cfi_endproc
As we can see, the generated code is still recursive, I think the optimizer
should have optimized that, is it correctly does when we use 'int' instead of
'Int'.
