Hi,
C++ constructors return void, even though the D front-end semantic
treats them as implicitly returning `this'. To handle this correctly,
the object reference is cached and used as the result of the expression.
Bootstrapped and regression tested on x86_64-linux-gnu/-mx32/-m32,
committed to mainline, and backported to the gcc-11 release branch.
Regards,
Iain
---
gcc/d/ChangeLog:
PR d/101664
* expr.cc (ExprVisitor::visit (CallExp *)): Use object expression as
result for C++ constructor calls.
gcc/testsuite/ChangeLog:
PR d/101664
* gdc.dg/extern-c++/extern-c++.exp: New.
* gdc.dg/extern-c++/pr101664.d: New test.
* gdc.dg/extern-c++/pr101664_1.cc: New test.
---
gcc/d/expr.cc | 13 +++++++
.../gdc.dg/extern-c++/extern-c++.exp | 39 +++++++++++++++++++
gcc/testsuite/gdc.dg/extern-c++/pr101664.d | 15 +++++++
gcc/testsuite/gdc.dg/extern-c++/pr101664_1.cc | 10 +++++
4 files changed, 77 insertions(+)
create mode 100644 gcc/testsuite/gdc.dg/extern-c++/extern-c++.exp
create mode 100644 gcc/testsuite/gdc.dg/extern-c++/pr101664.d
create mode 100644 gcc/testsuite/gdc.dg/extern-c++/pr101664_1.cc
diff --git a/gcc/d/expr.cc b/gcc/d/expr.cc
index 99ca958c7c4..85269c6b2be 100644
--- a/gcc/d/expr.cc
+++ b/gcc/d/expr.cc
@@ -1751,6 +1751,7 @@ public:
tree callee = NULL_TREE;
tree object = NULL_TREE;
tree cleanup = NULL_TREE;
+ tree returnvalue = NULL_TREE;
TypeFunction *tf = NULL;
/* Calls to delegates can sometimes look like this. */
@@ -1819,6 +1820,15 @@ public:
else
fndecl = build_address (fndecl);
+ /* C++ constructors return void, even though front-end semantic
+ treats them as implicitly returning `this'. Set returnvalue
+ to override the result of this expression. */
+ if (fd->isCtorDeclaration () && fd->linkage == LINKcpp)
+ {
+ thisexp = d_save_expr (thisexp);
+ returnvalue = thisexp;
+ }
+
callee = build_method_call (fndecl, thisexp, fd->type);
}
}
@@ -1885,6 +1895,9 @@ public:
build the call expression. */
tree exp = d_build_call (tf, callee, object, e->arguments);
+ if (returnvalue != NULL_TREE)
+ exp = compound_expr (exp, returnvalue);
+
if (tf->isref)
exp = build_deref (exp);
diff --git a/gcc/testsuite/gdc.dg/extern-c++/extern-c++.exp
b/gcc/testsuite/gdc.dg/extern-c++/extern-c++.exp
new file mode 100644
index 00000000000..d38f993faaf
--- /dev/null
+++ b/gcc/testsuite/gdc.dg/extern-c++/extern-c++.exp
@@ -0,0 +1,39 @@
+# Copyright (C) 2021 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3. If not see
+# <http://www.gnu.org/licenses/>.
+
+# Load support procs.
+load_lib gdc-dg.exp
+
+# We are mixing D and C++ code, need to pull in libstdc++
+global GDC_INCLUDE_CXX_FLAGS
+set GDC_INCLUDE_CXX_FLAGS 1
+
+# Initialize `dg'.
+dg-init
+
+# Main loop.
+if [check_no_compiler_messages extern_c++_tests assembly {
+ // C++
+ int main() { return 0; }
+}] {
+ gdc-dg-runtest [lsort \
+ [glob -nocomplain $srcdir/$subdir/*.d ] ] "" ""
+}
+
+set GDC_INCLUDE_CXX_FLAGS 0
+
+# All done.
+dg-finish
diff --git a/gcc/testsuite/gdc.dg/extern-c++/pr101664.d
b/gcc/testsuite/gdc.dg/extern-c++/pr101664.d
new file mode 100644
index 00000000000..57b3d903582
--- /dev/null
+++ b/gcc/testsuite/gdc.dg/extern-c++/pr101664.d
@@ -0,0 +1,15 @@
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101664
+// { dg-do run }
+// { dg-options "-O2" }
+// { dg-additional-sources "pr101664_1.cc" }
+
+extern(C++) struct S101664
+{
+ int i;
+ this(int);
+}
+
+void main()
+{
+ assert(S101664(1).i == 1);
+}
diff --git a/gcc/testsuite/gdc.dg/extern-c++/pr101664_1.cc
b/gcc/testsuite/gdc.dg/extern-c++/pr101664_1.cc
new file mode 100644
index 00000000000..066e784293d
--- /dev/null
+++ b/gcc/testsuite/gdc.dg/extern-c++/pr101664_1.cc
@@ -0,0 +1,10 @@
+struct S101664
+{
+ int i;
+ S101664 (int n);
+};
+
+S101664::S101664 (int n)
+ : i(n)
+{
+}
--
2.30.2
