https://gcc.gnu.org/g:d9c90c82d900fdae95df4499bf5f0a4ecb903b53
commit r15-942-gd9c90c82d900fdae95df4499bf5f0a4ecb903b53
Author: Thomas Schwinge <tschwi...@baylibre.com>
Date: Tue May 28 23:20:29 2024 +0200
nvptx target: Global constructor, destructor support, via nvptx-tools 'ld'
The function attributes 'constructor', 'destructor', and 'init_priority' now
work, as do the C++ features making use of this. Test cases with effective
target 'global_constructor' and 'init_priority' now generally work, and
'check-gcc-c++' test results greatly improve; no more
"sorry, unimplemented: global constructors not supported on this target".
For proper execution test results, this depends on
<https://github.com/SourceryTools/nvptx-tools/commit/96f8fc59a757767b9e98157d95c21e9fef22a93b>
"ld: Global constructor/destructor support".
gcc/
* config/nvptx/nvptx.h: Configure global constructor, destructor
support.
gcc/testsuite/
* gcc.dg/no_profile_instrument_function-attr-1.c: GCC/nvptx is
'NO_DOT_IN_LABEL' but not 'NO_DOLLAR_IN_LABEL', so '$' may apper
in identifiers.
* lib/target-supports.exp
(check_effective_target_global_constructor): Enable for nvptx.
libgcc/
* config/nvptx/crt0.c (__gbl_ctors): New weak function.
(__main): Invoke it.
* config/nvptx/gbl-ctors.c: New.
* config/nvptx/t-nvptx: Configure global constructor, destructor
support.
Diff:
---
gcc/config/nvptx/nvptx.h | 14 +++-
.../gcc.dg/no_profile_instrument_function-attr-1.c | 2 +-
gcc/testsuite/lib/target-supports.exp | 3 +-
libgcc/config/nvptx/crt0.c | 12 ++++
libgcc/config/nvptx/gbl-ctors.c | 74 ++++++++++++++++++++++
libgcc/config/nvptx/t-nvptx | 9 ++-
6 files changed, 109 insertions(+), 5 deletions(-)
diff --git a/gcc/config/nvptx/nvptx.h b/gcc/config/nvptx/nvptx.h
index e282aad1b73..74f4a68924c 100644
--- a/gcc/config/nvptx/nvptx.h
+++ b/gcc/config/nvptx/nvptx.h
@@ -356,7 +356,19 @@ struct GTY(()) machine_function
#define MOVE_MAX 8
#define MOVE_RATIO(SPEED) 4
#define FUNCTION_MODE QImode
-#define HAS_INIT_SECTION 1
+
+/* Implement global constructor, destructor support in a conceptually simpler
+ way than using 'collect2' (the program): implement the respective
+ functionality in the nvptx-tools 'ld'. This however still requires the
+ compiler-side effects corresponding to 'USE_COLLECT2': the global
+ constructor, destructor support functions need to have external linkage, and
+ therefore names that are "unique across the whole link". Use
+ '!targetm.have_ctors_dtors' to achieve this (..., and thus don't need to
+ provide 'targetm.asm_out.constructor', 'targetm.asm_out.destructor'). */
+#define TARGET_HAVE_CTORS_DTORS false
+
+/* See 'libgcc/config/nvptx/crt0.c' for wrapping of 'main'. */
+#define HAS_INIT_SECTION
/* The C++ front end insists to link against libstdc++ -- which we don't build.
Tell it to instead link against the innocuous libgcc. */
diff --git a/gcc/testsuite/gcc.dg/no_profile_instrument_function-attr-1.c
b/gcc/testsuite/gcc.dg/no_profile_instrument_function-attr-1.c
index 909f8a68479..5b4101cf596 100644
--- a/gcc/testsuite/gcc.dg/no_profile_instrument_function-attr-1.c
+++ b/gcc/testsuite/gcc.dg/no_profile_instrument_function-attr-1.c
@@ -18,7 +18,7 @@ int main ()
return foo ();
}
-/* { dg-final { scan-tree-dump-times "__gcov0\[._\]main.* = PROF_edge_counter"
1 "optimized"} } */
+/* { dg-final { scan-tree-dump-times "__gcov0\[$._\]main.* =
PROF_edge_counter" 1 "optimized"} } */
/* { dg-final { scan-tree-dump-times "__gcov_indirect_call_profiler_v" 1
"optimized" } } */
/* { dg-final { scan-tree-dump-times "__gcov_time_profiler_counter = " 1
"optimized" } } */
/* { dg-final { scan-tree-dump-times "__gcov_init" 1 "optimized" } } */
diff --git a/gcc/testsuite/lib/target-supports.exp
b/gcc/testsuite/lib/target-supports.exp
index f0f6da52275..a3992faab5e 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -942,8 +942,7 @@ proc check_effective_target_nonlocal_goto {} {
# Return 1 if global constructors are supported, 0 otherwise.
proc check_effective_target_global_constructor {} {
- if { [istarget nvptx-*-*]
- || [istarget bpf-*-*] } {
+ if { [istarget bpf-*-*] } {
return 0
}
return 1
diff --git a/libgcc/config/nvptx/crt0.c b/libgcc/config/nvptx/crt0.c
index e37a6fb40d3..47e8ec44c19 100644
--- a/libgcc/config/nvptx/crt0.c
+++ b/libgcc/config/nvptx/crt0.c
@@ -32,6 +32,16 @@ void *__nvptx_stacks[32] __attribute__((shared,nocommon));
/* Likewise for -muniform-simt. */
unsigned __nvptx_uni[32] __attribute__((shared,nocommon));
+/* Global constructor/destructor support. Dummy; if necessary, overridden via
+ 'gbl-ctors.c'. */
+
+extern void __gbl_ctors (void);
+
+void __attribute__((weak))
+__gbl_ctors (void)
+{
+}
+
extern void __main (int *, int, void **) __attribute__((kernel));
void
@@ -47,5 +57,7 @@ __main (int *rval_ptr, int argc, void **argv)
__nvptx_stacks[0] = stack + sizeof stack;
__nvptx_uni[0] = 0;
+ __gbl_ctors ();
+
exit (main (argc, argv));
}
diff --git a/libgcc/config/nvptx/gbl-ctors.c b/libgcc/config/nvptx/gbl-ctors.c
new file mode 100644
index 00000000000..a2ca053e5e3
--- /dev/null
+++ b/libgcc/config/nvptx/gbl-ctors.c
@@ -0,0 +1,74 @@
+/* Global constructor/destructor support
+
+ Copyright (C) 2024 Free Software Foundation, Inc.
+
+ This file 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, or (at your option) any
+ later version.
+
+ This file 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.
+
+ Under Section 7 of GPL version 3, you are granted additional
+ permissions described in the GCC Runtime Library Exception, version
+ 3.1, as published by the Free Software Foundation.
+
+ You should have received a copy of the GNU General Public License and
+ a copy of the GCC Runtime Library Exception along with this program;
+ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include "auto-target.h"
+
+#ifdef HAVE_STDLIB_H
+# include <stdlib.h>
+#endif
+#include "gbl-ctors.h"
+
+extern int atexit (void (*function) (void));
+
+
+/* Handler functions ('static', in contrast to the 'gbl-ctors.h'
+ prototypes). */
+
+static void __static_do_global_ctors (void);
+
+static void
+__static_do_global_ctors (void)
+{
+ __SIZE_TYPE__ nptrs = (__SIZE_TYPE__) __CTOR_LIST__[0];
+ for (__SIZE_TYPE__ i = nptrs; i >= 1; --i)
+ __CTOR_LIST__[i] ();
+}
+
+static void __static_do_global_dtors (void);
+
+static void
+__static_do_global_dtors (void)
+{
+ func_ptr *p = __DTOR_LIST__;
+ ++p;
+ for (; *p; ++p)
+ (*p) ();
+}
+
+
+/* For nvptx target configurations, override the 'crt0.c' dummy. */
+
+extern void __gbl_ctors (void);
+
+void
+__gbl_ctors (void)
+{
+ __static_do_global_ctors ();
+ atexit (__static_do_global_dtors);
+}
+
+
+/* The following symbol just provides a means for the nvptx-tools 'ld' to
+ trigger linking in this file. */
+
+int __trigger_gbl_ctors;
diff --git a/libgcc/config/nvptx/t-nvptx b/libgcc/config/nvptx/t-nvptx
index 49fdb557b56..260ed6334db 100644
--- a/libgcc/config/nvptx/t-nvptx
+++ b/libgcc/config/nvptx/t-nvptx
@@ -6,8 +6,10 @@ LIB2ADD=$(srcdir)/config/nvptx/reduction.c \
LIB2ADD += $(srcdir)/c++-minimal/guard.c
LIB2ADDEH=
-LIB2FUNCS_EXCLUDE=__main
+LIB2FUNCS_EXCLUDE=
+# Wrapping of 'main'.
+LIB2FUNCS_EXCLUDE += __main
crt0.o: $(srcdir)/config/nvptx/crt0.c
$(crt_compile) -c $<
@@ -15,3 +17,8 @@ crt0.o: $(srcdir)/config/nvptx/crt0.c
# support it, and it may cause the build to fail, because of alloca usage, for
# example.
INHIBIT_LIBC_CFLAGS = -Dinhibit_libc
+
+# Support for global constructors/destructors is implemented via the
+# nvptx-tools 'ld' and the following helpers.
+LIB2ADD += $(srcdir)/config/nvptx/gbl-ctors.c
+LIB2FUNCS_EXCLUDE += _ctors
