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.

2 files changed, 15 insertions, 0 deletions

diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index c637d39..58e01e4 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,8 @@
+2018-08-29  Keith Seitz  <keiths@redhat.com>
+
+	* gdb.texinfo (Compiling and injecting code in GDB): Document
+	set/show "compile-oracle" and "compile-cplus-types" commands.
+
 2018-08-22  Jan Vrany  <jan.vrany@fit.cvut.cz>
 
 	* gdb.texinfo (The -stack-list-frames Command): Update description
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 5068c0a..f2d1155 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -18689,6 +18689,16 @@ injecting the code.  The default is off.
 @item show debug compile
 Displays the current state of displaying @value{GDBN} process of
 compiling and injecting the code.
+
+@anchor{set debug compile-cplus-types}
+@item set debug compile-cplus-types
+@cindex compile C@t{++} type conversion
+Turns on or off the display of C@t{++} type conversion debugging information.
+The default is off.
+
+@item show debug compile-cplus-types
+Displays the current state of displaying debugging information for
+C@t{++} type conversion.
 @end table
 
 @subsection Compilation options for the @code{compile} command