[Bug c++/118054] New: GCC allows catch-by-value using trivial move constructor

[hstong at ca dot ibm.com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118054

            Bug ID: 118054
           Summary: GCC allows catch-by-value using trivial move
                    constructor
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Keywords: accepts-invalid
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hstong at ca dot ibm.com
  Target Milestone: ---

GCC allows catch-by-copy for classes with deleted copy constructors but trivial
move constructors.

Online compiler: https://godbolt.org/z/5cx354qvM

### SOURCE (<stdin>)
struct Base {
  Base() = default;
  Base(const Base &) = delete;
  Base(Base &&) = default;
};
struct A : Base {
  A() = default;
  A(const A &) : Base() {}
  A(A &&) = default;
};
void bar(), foo(Base *);
int main() {
  try {
    bar();
  } catch (Base b) {
    foo(&b);
  }
}


### COMPILE COMMAND
g++ -fsyntax-only -std=c++11 -xc++ -


### ACTUAL COMPILE OUTPUT
(clean compile)


### EXPECTED COMPILE OUTPUT
<stdin>: In function 'int main()':
<stdin>:15:17: error: use of deleted function 'Base::Base(const Base&)'
<stdin>:3:3: note: declared here
<stdin>:15:17: note: use '-fdiagnostics-all-candidates' to display considered
candidates


### COMPILER VERSION INFO (g++ -v)
Using built-in specs.
COLLECT_GCC=/opt/wandbox/gcc-head/bin/g++
COLLECT_LTO_WRAPPER=/opt/wandbox/gcc-head/libexec/gcc/x86_64-pc-linux-gnu/15.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../source/configure --prefix=/opt/wandbox/gcc-head
--enable-languages=c,c++ --disable-multilib --without-ppl --without-cloog-ppl
--enable-checking=release --disable-nls --enable-lto
LDFLAGS=-Wl,-rpath,/opt/wandbox/gcc-head/lib,-rpath,/opt/wandbox/gcc-head/lib64,-rpath,/opt/wandbox/gcc-head/lib32
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 15.0.0 20241214 (experimental) (GCC)