C++ compile support

This patch adds *basic* support for C++ to the compile feature.  It does
most simple type conversions, including everything that C compile does and
your basic "with-classes" type of C++.

I've written a new compile-support.exp support file which adds a new test
facility for automating and simplifying "compile print" vs "compile code"
testing.  See testsuite/lib/compile-support.exp and CompileExpression
for more on that.  The tests use this facility extensively.

This initial support has several glaring omissions:
- No template support at all
  I have follow-on patches for this, but they add much complexity
  to this "basic" support.  Consequently, they will be submitted separately.
- Cannot print functions
  The code template needs tweaking, and I simply haven't gotten to it yet.
- So-called "special function" support is not included
  Using constructors, destructors, operators, etc will not work. I have
  follow-on patches for that, but they require some work because of the
  recent churn in symbol searching.
- There are several test suite references to "compile/1234" bugs.
  I will file bugs and update the test suite's bug references before pushing
  these patches.

The test suite started as a copy of the original C-language support, but
I have written tests to exercise the basic functionality of the plug-in.

I've added a new option for outputting debug messages for C++ type-conversion
("debug compile-cplus-types").

gdb/ChangeLog:

	* Makefile.in (SUBDIR_GCC_COMPILE_SRCS): Add compile-cplus-symbols.c
	and compile-cplus-types.c.
	(HFILES_NO_SRCDIR): Add gcc-cp-plugin.h.
	* c-lang.c (cplus_language_defn): Set C++ compile functions.
	* c-lang.h (cplus_get_compile_context, cplus_compute_program):
	Declare.
	* compile/compile-c-support.c: Include compile-cplus.h.
	(load_libcompile): Templatize.
	(get_compile_context): "New" function.
	(c_get_compile_context): Use get_compile_context.
	(cplus_get_compile_context): New function.
	(cplus_push_user_expression, cplus_pop_user_expression)
	(cplus_add_code_header, cplus_add_input, cplus_compile_program)
	(cplus_compute_program): Define new structs/functions.
	* compile/compile-cplus-symmbols.c: New file.
	* compile/compile-cplus-types.c: New file.
	* compile/compile-cplus.h: New file.
	* compile/compile-internal.h (debug_compile_oracle, GCC_TYPE_NONE):
	Declare.
	* compile/compile-object-load.c (get_out_value_type): Use
	strncmp_iw when comparing symbol names.
	(compile_object_load): Add mst_bss and mst_data.
	* compile/compile.c (_initialize_compile): Remove
	-Wno-implicit-function-declaration from `compile_args'.
	* compile/gcc-cp-plugin.h: New file.
	* NEWS: Mention C++ compile support and new debug options.

gdb/testsuite/ChangeLog:

	* gdb.compile/compile-cplus-anonymous.cc: New file.
	* gdb.compile/compile-cplus-anonymous.exp: New file.
	* gdb.compile/compile-cplus-array-decay.cc: New file.
	* gdb.compile/compile-cplus-array-decay.exp: New file.
	* gdb.compile/compile-cplus-inherit.cc: New file.
	* gdb.compile/compile-cplus-inherit.exp: New file.
	* gdb.compile/compile-cplus-member.cc: New file.
	* gdb.compile/compile-cplus-member.exp: New file.
	* gdb.compile/compile-cplus-method.cc: New file.
	* gdb.compile/compile-cplus-method.exp: New file.
	* gdb.compile/compile-cplus-mod.c: "New" file.
	* gdb.compile/compile-cplus-namespace.cc: New file.
	* gdb.compile/compile-cplus-namespace.exp: New file.
	* gdb.compile/compile-cplus-nested.cc: New file.
	* gdb.compile/compile-cplus-nested.exp: New file.
	* gdb.compile/compile-cplus-print.c: "New" file.
	* gdb.compile/compile-cplus-print.exp: "New" file.
	* gdb.compile/compile-cplus-virtual.cc: New file.
	* gdb.compile/compile-cplus-virtual.exp: New file.
	* gdb.compile/compile-cplus.c: "New" file.
	* gdb.compile/compile-cplus.exp: "New" file.
	* lib/compile-support.exp: New file.

doc/ChangeLog:

	* gdb.texinfo (Compiling and injecting code in GDB): Document
	set/show "compile-oracle" and "compile-cplus-types" commands.

1 files changed, 91 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.compile/compile-cplus-method.cc b/gdb/testsuite/gdb.compile/compile-cplus-method.cc
new file mode 100644
index 0000000..3993493
--- /dev/null
+++ b/gdb/testsuite/gdb.compile/compile-cplus-method.cc
@@ -0,0 +1,91 @@
+/* Copyright 2015-2018 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 this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+class A;
+static int get_value (const A* a);
+
+class A
+{
+public:
+  typedef int ATYPE;
+
+  A () : a_ (21) {}
+  ATYPE get_var () { return a_; }
+  ATYPE get_var (unsigned long a) { return 100; }
+  ATYPE get_var (ATYPE a) { return 101; }
+  ATYPE get_var (float a) { return 102; }
+  ATYPE get_var (void *a) { return 103;}
+  ATYPE get_var (A& lr) { return 104; }
+  ATYPE get_var (A const& lr) { return 105; }
+
+  ATYPE get_var1 (int n) { return a_ << n; }
+  ATYPE get_var2 (int incr, unsigned n) { return (a_ + incr) << n; }
+
+  static ATYPE get_1 (int a) { return a + 1; }
+  static ATYPE get_2 (int a, int b) { return a + b + 2; }
+
+  friend ATYPE get_value (const A*);
+
+private:
+  ATYPE a_;
+};
+
+static A::ATYPE
+get_value (A::ATYPE a)
+{
+  return a;
+}
+
+static A::ATYPE
+get_value (const A* a)
+{
+  return a->a_;
+}
+
+static A::ATYPE
+get_value ()
+{
+  return 200;
+}
+
+typedef int (A::*PMF) (A::ATYPE);
+
+int
+main ()
+{
+  A *a = new A ();
+  int var = 1234;
+  float f = 1.23;
+  unsigned long ul = 0xdeadbeef;
+  A const* ac = a;
+
+  PMF pmf = &A::get_var;
+  PMF *pmf_p = &pmf;
+
+  var -= a->get_var ();		// break here
+  var -= a->get_var (1);
+  var -= a->get_var (ul);
+  var -= a->get_var (f);
+  var -= a->get_var (a);
+  var -= a->get_var (*a);
+  var -= a->get_var (*ac);
+  var -= a->get_var1 (1);
+  var -= a->get_var2 (1, 2);
+  var += (a->*pmf) (1);
+  var -= (a->**pmf_p) (1);
+
+  return var - A::get_1 (1) + A::get_2 (1, 2) + get_value ()
+    + get_value (get_value ()) + get_value (a);
+}