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| author | Jason Merrill <jason@redhat.com> | 2021-02-08 17:04:03 -0500 |
|---|---|---|
| committer | Jason Merrill <jason@redhat.com> | 2021-02-08 20:51:51 -0500 |
| commit | bdbca69e0720fa9062fe71782235141f629ae006 (patch) | |
| tree | b5725094dbdc7b69cac93772cd65a2cfae07ea83 /gcc | |
| parent | a8dd2b3e96590ceccead63d28fc91c956a5f1a73 (diff) | |
| download | gcc-bdbca69e0720fa9062fe71782235141f629ae006.zip gcc-bdbca69e0720fa9062fe71782235141f629ae006.tar.gz gcc-bdbca69e0720fa9062fe71782235141f629ae006.tar.bz2 | |
c++: generic lambda, fn* conv, empty class [PR98326]
Here, in the thunk returned from the captureless lambda conversion to
pointer-to-function, we try to pass through invisible reference parameters
by reference, without doing a copy. The empty class copy optimization was
messing that up.
gcc/cp/ChangeLog:
PR c++/98326
PR c++/20408
* cp-gimplify.c (simple_empty_class_p): Don't touch an invisiref
parm.
gcc/testsuite/ChangeLog:
PR c++/98326
* g++.dg/cpp1y/lambda-generic-empty1.C: New test.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/cp/cp-gimplify.c | 12 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/cpp1y/lambda-generic-empty1.C | 9 |
2 files changed, 21 insertions, 0 deletions
diff --git a/gcc/cp/cp-gimplify.c b/gcc/cp/cp-gimplify.c index 4d0e92c..1c5e15b 100644 --- a/gcc/cp/cp-gimplify.c +++ b/gcc/cp/cp-gimplify.c @@ -324,6 +324,18 @@ simple_empty_class_p (tree type, tree op, tree_code code) && TYPE_HAS_TRIVIAL_DESTRUCTOR (type)) /* The TARGET_EXPR is itself a simple copy, look through it. */ return simple_empty_class_p (type, TARGET_EXPR_INITIAL (op), code); + + if (TREE_CODE (op) == PARM_DECL + && TREE_ADDRESSABLE (TREE_TYPE (op))) + { + tree fn = DECL_CONTEXT (op); + if (DECL_THUNK_P (fn) + || lambda_static_thunk_p (fn)) + /* In a thunk, we pass through invisible reference parms, so this isn't + actually a copy. */ + return false; + } + return (TREE_CODE (op) == EMPTY_CLASS_EXPR || code == MODIFY_EXPR diff --git a/gcc/testsuite/g++.dg/cpp1y/lambda-generic-empty1.C b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-empty1.C new file mode 100644 index 0000000..ffb0cf1 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-empty1.C @@ -0,0 +1,9 @@ +// PR c++/98326 +// { dg-do compile { target c++14 } } + +struct A { + A() = default; + A(const A&) {} +}; + +void (*fptr)(A) = [](auto){}; |