在 2017年08月03日 17:21, Leslie Zhai 写道:
/opt/gcc-6.3/bin/gcc -fplugin=./dragonegg.so test/hello.c -wrapper
gdb,--args
GNU gdb (GDB) Fedora 7.12.1-48.fc25
...
Reading symbols from
/opt/gcc-6.3/libexec/gcc/x86_64-redhat-linux-gnu/6.3.0/cc1...done.
(gdb) b /data/project/xiangzhai/gcc-6.3.0/gcc/passes.c:2288
Breakpoint 1 at 0x91b8d4: file ../../gcc/passes.c, line 2288.
(gdb) r
Starting program:
/opt/gcc-6.3/libexec/gcc/x86_64-redhat-linux-gnu/6.3.0/cc1 -quiet
-iplugindir=/opt/gcc-6.3/lib/gcc/x86_64-redhat-linux-gnu/6.3.0/plugin
test/hello.c
-iplugindir=/opt/gcc-6.3/lib/gcc/x86_64-redhat-linux-gnu/6.3.0/plugin
-quiet -dumpbase hello.c -mtune=generic -march=x86-64 -auxbase hello
-fplugin=./dragonegg.so -o /tmp/cco7mKtB.s
...
Breakpoint 1, execute_one_pass (pass=pass@entry=0x1c7b730) at
../../gcc/passes.c:2288
warning: Source file is more recent than executable.
2288 current_pass = pass;
(gdb) p pass
$1 = (opt_pass *) 0x1c7b730
(gdb) p current_pass
$2 = (opt_pass *) 0x0
(gdb) n
2292 gate_status = pass->gate (cfun);
(gdb) p current_pass
$3 = (opt_pass *) 0x1c7b730
(gdb) p gate_status
$4 = false
(gdb) n
2293 gate_status = override_gate_status (pass,
current_function_decl, gate_status);
(gdb) p gate_status
$5 = false
(gdb) n
2292 gate_status = pass->gate (cfun);
(gdb) p gate_status
$6 = false
(gdb) n
2293 gate_status = override_gate_status (pass,
current_function_decl, gate_status);
(gdb) n
2296 invoke_plugin_callbacks (PLUGIN_OVERRIDE_GATE, &gate_status);
(gdb) p gate_status
$7 = true
(gdb) n
2293 gate_status = override_gate_status (pass,
current_function_decl, gate_status);
(gdb) n
2296 invoke_plugin_callbacks (PLUGIN_OVERRIDE_GATE, &gate_status);
(gdb) n
2298 if (!gate_status)
(gdb) p gate_status
$8 = true
(gdb) n
...
(gdb) n
2336 todo_after = pass->execute (cfun); <--- gcc called execute
hook?
(gdb) p todo_after
$9 = 0
(gdb) n
2338 if (todo_after & TODO_discard_function)
(gdb) p todo_after
$10 = 0
(gdb)
2336 todo_after = pass->execute (cfun); <--- gcc called execute
hook? but why not dragonegg
https://github.com/xiangzhai/dragonegg/blob/gcc-6_3-branch/src/Backend.cpp#L2103
在 2017年08月03日 11:24, Leslie Zhai 写道:
Hi GCC developers,
As ChangeLog-2013 mentioned:
2013-08-05 David Malcolm <dmalc...@redhat.com>
This is the automated part of the conversion of passes from C
structs to C++ classes.
...
* auto-inc-dec.c (pass_inc_dec): Convert from a global struct to a
subclass of rtl_opt_pass along with...
so I migrate struct rtl_opt_pass:
https://github.com/llvm-mirror/dragonegg/blob/master/src/Backend.cpp#L1731
static struct rtl_opt_pass pass_rtl_emit_function = { {
RTL_PASS, "rtl_emit_function", /* name */
#if (GCC_MINOR > 7)
OPTGROUP_NONE, /* optinfo_flags */
#endif
NULL, /* gate */
rtl_emit_function, /* execute */
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
TV_NONE, /* tv_id */
PROP_ssa | PROP_gimple_leh | PROP_cfg, /* properties_required */
0, /* properties_provided */
PROP_ssa | PROP_trees, /* properties_destroyed */
TODO_verify_ssa | TODO_verify_flow | TODO_verify_stmts, /*
todo_flags_start */
TODO_ggc_collect /* todo_flags_finish */
} };
to GCC v6.x C++ classes' style:
https://github.com/xiangzhai/dragonegg/blob/gcc-6_3-branch/src/Backend.cpp#L2072
const pass_data pass_data_rtl_emit_function = {
RTL_PASS, /* type */
"rtl_emit_function", /* name */
OPTGROUP_NONE, /* optinfo_flags */
TV_NONE, /* tv_id */
PROP_ssa | PROP_gimple_leh | PROP_cfg, /* properties_required */
0, /* properties_provided */
PROP_ssa | PROP_trees, /* properties_destroyed */
0, /* todo_flags_start */
0, /* todo_flags_finish */
};
class pass_rtl_emit_function : public rtl_opt_pass {
public:
pass_rtl_emit_function(gcc::context *ctxt)
: rtl_opt_pass(pass_data_rtl_emit_function, ctxt) {}
unsigned int execute(function *) { return rtl_emit_function(); }
opt_pass *clone() { return this; }
};
GCC v4.6 will call the callback `rtl_emit_function`, but GCC v6.x
will not, did I forget something? is there some options need to be
set? please give me some hint, thanks a lot!
PS: GCC v6.x *call* the callback `rtl_emit_function`
https://github.com/xiangzhai/dragonball/blob/master/tests/plugin.cpp#L67
in this testcase, I will check the source code about
register_callback, rtl_opt_pass, and opt_pass.
I found it!
with -flto option, for example: gcc -mmpx -fplugin=./plugin.so -flto
bare.c -wrapper gdb,--args
or add
flag_lto = "";
to the testcase plugin.cpp
https://github.com/xiangzhai/dragonball/blob/master/tests/plugin.cpp#L110
then pass_rtl_emit_function's execute will not be called, position_pass
(gcc/passes.c) failed to Insert the *new pass* info at the proper
position, then traverse the list of pass in the execute_pass_list_1,
there is *no* pass_rtl_emit_function at all, so execute_one_pass never
call its execute hook.
but as ChangeLog-2014 mentioned:
2014-11-13 Ilya Verbin <ilya.ver...@intel.com>
Ilya Tocar <ilya.to...@intel.com>
Andrey Turetskiy <andrey.turets...@intel.com>
Bernd Schmidt <ber...@codesourcery.com>
...
Replace flag_lto with flag_generate_lto before lto_streamer_hooks_init.
...
why GCC v4.6 is still able to work
https://github.com/xiangzhai/dragonegg/blob/master/src/Backend.cpp#L1939
but GCC v6.x or v8.x (git-20170816) couldn't, please give me some hint
about the difference between GCC v4.6's LTO and GCC v6.x or v8.x (git),
thanks a lot!
--
Regards,
Leslie Zhai - a LLVM developer https://reviews.llvm.org/p/xiangzhai/
