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/* Generic GDB-side plugin
Copyright (C) 2020 Free Software Foundation, Inc.
This file is part of GCC.
GCC 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.
GCC 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/>. */
#ifndef CC1_PLUGIN_GDBCTX_HH
#define CC1_PLUGIN_GDBCTX_HH
namespace cc1_plugin
{
// The compiler context that we hand back to our caller.
// Due to this, the entire implementation is in this header.
template<typename T>
struct base_gdb_plugin : public T
{
base_gdb_plugin (const char *plugin_name_, const char *base_name,
int version)
: verbose (false),
plugin_name (plugin_name_),
fe_version (version),
compiler_name (base_name),
compilerp (new compiler (verbose))
{
vtable =
{
GCC_FE_VERSION_1,
do_set_arguments_v0,
do_set_source_file,
do_set_print_callback,
do_compile_v0,
do_destroy,
do_set_verbose,
do_compile,
do_set_arguments,
do_set_triplet_regexp,
do_set_driver_filename,
};
this->base.ops = &vtable;
}
virtual ~base_gdb_plugin () = default;
// A convenience function to print something.
void print (const char *str)
{
this->print_function (this->print_datum, str);
}
// Set the verbose flag.
void set_verbose (bool v)
{
verbose = v;
if (compilerp != nullptr)
compilerp->set_verbose (v);
}
// Make a new connection.
void set_connection (int fd, int aux_fd)
{
connection.reset (new local_connection (fd, aux_fd, this));
}
// This is called just before compilation begins. It should set
// any needed callbacks on the connection.
virtual void add_callbacks () = 0;
// A local subclass of connection that holds a back-pointer to the
// context object that we provide to our caller.
class local_connection : public cc1_plugin::connection
{
public:
local_connection (int fd, int aux_fd, base_gdb_plugin<T> *b)
: connection (fd, aux_fd),
back_ptr (b)
{
}
void print (const char *buf) override
{
back_ptr->print (buf);
}
base_gdb_plugin<T> *back_ptr;
};
std::unique_ptr<local_connection> connection;
void (*print_function) (void *datum, const char *message) = nullptr;
void *print_datum = nullptr;
std::vector<std::string> args;
std::string source_file;
/* Non-zero as an equivalent to gcc driver option "-v". */
bool verbose;
const char *plugin_name;
int fe_version;
const char *compiler_name;
std::unique_ptr<cc1_plugin::compiler> compilerp;
private:
struct gcc_base_vtable vtable;
static inline base_gdb_plugin<T> *
get_self (gcc_base_context *s)
{
T *sub = (T *) s;
return static_cast<base_gdb_plugin<T> *> (sub);
}
static void
do_set_verbose (struct gcc_base_context *s, int /* bool */ verbose)
{
base_gdb_plugin<T> *self = get_self (s);
self->set_verbose (verbose != 0);
}
static char *
do_set_arguments (struct gcc_base_context *s,
int argc, char **argv)
{
base_gdb_plugin<T> *self = get_self (s);
std::string compiler;
char *errmsg = self->compilerp->find (self->compiler_name, compiler);
if (errmsg != NULL)
return errmsg;
self->args.push_back (compiler);
for (int i = 0; i < argc; ++i)
self->args.push_back (argv[i]);
return NULL;
}
static char *
do_set_triplet_regexp (struct gcc_base_context *s,
const char *triplet_regexp)
{
base_gdb_plugin<T> *self = get_self (s);
self->compilerp.reset
(new cc1_plugin::compiler_triplet_regexp (self->verbose,
triplet_regexp));
return NULL;
}
static char *
do_set_driver_filename (struct gcc_base_context *s,
const char *driver_filename)
{
base_gdb_plugin<T> *self = get_self (s);
self->compilerp.reset
(new cc1_plugin::compiler_driver_filename (self->verbose,
driver_filename));
return NULL;
}
static char *
do_set_arguments_v0 (struct gcc_base_context *s,
const char *triplet_regexp,
int argc, char **argv)
{
char *errmsg = do_set_triplet_regexp (s, triplet_regexp);
if (errmsg != NULL)
return errmsg;
return do_set_arguments (s, argc, argv);
}
static void
do_set_source_file (struct gcc_base_context *s,
const char *file)
{
base_gdb_plugin<T> *self = get_self (s);
self->source_file = file;
}
static void
do_set_print_callback (struct gcc_base_context *s,
void (*print_function) (void *datum,
const char *message),
void *datum)
{
base_gdb_plugin<T> *self = get_self (s);
self->print_function = print_function;
self->print_datum = datum;
}
int fork_exec (char **argv, int spair_fds[2], int stderr_fds[2])
{
pid_t child_pid = fork ();
if (child_pid == -1)
{
close (spair_fds[0]);
close (spair_fds[1]);
close (stderr_fds[0]);
close (stderr_fds[1]);
return 0;
}
if (child_pid == 0)
{
// Child.
dup2 (stderr_fds[1], 1);
dup2 (stderr_fds[1], 2);
close (stderr_fds[0]);
close (stderr_fds[1]);
close (spair_fds[0]);
execvp (argv[0], argv);
_exit (127);
}
else
{
// Parent.
close (spair_fds[1]);
close (stderr_fds[1]);
cc1_plugin::status result = cc1_plugin::FAIL;
if (connection->send ('H')
&& ::cc1_plugin::marshall (connection.get (), fe_version))
result = connection->wait_for_query ();
close (spair_fds[0]);
close (stderr_fds[0]);
while (true)
{
int status;
if (waitpid (child_pid, &status, 0) == -1)
{
if (errno != EINTR)
return 0;
}
if (!WIFEXITED (status) || WEXITSTATUS (status) != 0)
return 0;
break;
}
if (!result)
return 0;
return 1;
}
}
static int
do_compile (struct gcc_base_context *s,
const char *filename)
{
base_gdb_plugin<T> *self = get_self (s);
int fds[2];
if (socketpair (AF_UNIX, SOCK_STREAM, 0, fds) != 0)
{
self->print ("could not create socketpair\n");
return 0;
}
int stderr_fds[2];
if (pipe (stderr_fds) != 0)
{
self->print ("could not create pipe\n");
close (fds[0]);
close (fds[1]);
return 0;
}
self->args.push_back (std::string ("-fplugin=") + self->plugin_name);
self->args.push_back (std::string ("-fplugin-arg-") + self->plugin_name
+ "-fd=" + std::to_string (fds[1]));
self->args.push_back (self->source_file);
self->args.push_back ("-c");
self->args.push_back ("-o");
self->args.push_back (filename);
if (self->verbose)
self->args.push_back ("-v");
self->set_connection (fds[0], stderr_fds[0]);
self->add_callbacks ();
std::vector<char *> argv (self->args.size () + 1);
for (unsigned int i = 0; i < self->args.size (); ++i)
argv[i] = const_cast<char *> (self->args[i].c_str ());
return self->fork_exec (argv.data (), fds, stderr_fds);
}
static int
do_compile_v0 (struct gcc_base_context *s, const char *filename,
int verbose)
{
do_set_verbose (s, verbose);
return do_compile (s, filename);
}
static void
do_destroy (struct gcc_base_context *s)
{
base_gdb_plugin<T> *self = get_self (s);
delete self;
}
};
// Instances of this rpc<> template function are installed into the
// "vtable"s. These functions are parameterized by type and method
// name and forward the call via the connection.
template<typename CTX, typename R, const char *&NAME, typename... Arg>
R rpc (CTX *s, Arg... rest)
{
base_gdb_plugin<CTX> *self = (base_gdb_plugin<CTX> *) s;
R result;
if (!cc1_plugin::call (self->connection.get (), NAME, &result, rest...))
return 0;
return result;
}
}
#endif // CC1_PLUGIN_GDBCTX_HH