compile: New 'compile print'

It is planned the existing GDB command 'print' will be able to evaluate its
expressions using the compiler.  There will be some option to choose between
the existing GDB evaluation and the compiler evaluation.  But as an
intermediate step this patch provides the expression printing feature as a new
command.

I can imagine it could be also called 'maintenance compile print' as in the
future one should be able to use its functionality by the normal 'print'
command.

There was a discussion with Eli about the command name:
	https://sourceware.org/ml/gdb-patches/2015-03/msg00880.html
As there were no other comments yet I haven't renamed it yet, before there is
some confirmation about settlement on the final name.

Support for the GDB '@' operator to create arrays has been submitted for GCC:
	[gcc patch] libcc1: '@' GDB array operator
	https://gcc.gnu.org/ml/gcc-patches/2015-03/msg01451.html


gdb/ChangeLog
2015-05-16  Jan Kratochvil  <jan.kratochvil@redhat.com>
	    Phil Muldoon  <pmuldoon@redhat.com>

	* NEWS (Changes since GDB 7.9): Add compile print.
	* compile/compile-c-support.c (add_code_header, add_code_footer)
	(c_compute_program): Add COMPILE_I_PRINT_ADDRESS_SCOPE and
	COMPILE_I_PRINT_VALUE_SCOPE.
	* compile/compile-internal.h (COMPILE_I_PRINT_OUT_ARG_TYPE)
	(COMPILE_I_PRINT_OUT_ARG, COMPILE_I_EXPR_VAL, COMPILE_I_EXPR_PTR_TYPE):
	New.
	* compile/compile-object-load.c: Include block.h.
	(get_out_value_type): New function.
	(compile_object_load): Handle COMPILE_I_PRINT_ADDRESS_SCOPE and
	COMPILE_I_PRINT_VALUE_SCOPE.  Set compile_module's OUT_VALUE_ADDR and
	OUT_VALUE_TYPE.
	* compile/compile-object-load.h (struct compile_module): Add fields
	out_value_addr and out_value_type.
	* compile/compile-object-run.c: Include valprint.h and compile.h.
	(struct do_module_cleanup): Add fields out_value_addr and
	out_value_type.
	(do_module_cleanup): Handle COMPILE_I_PRINT_ADDRESS_SCOPE and
	COMPILE_I_PRINT_VALUE_SCOPE.
	(compile_object_run): Propagate out_value_addr and out_value_type.
	Pass OUT_VALUE_ADDR.
	* compile/compile.c: Include valprint.h.
	(compile_print_value, compile_print_command): New functions.
	(eval_compile_command): Handle failed COMPILE_I_PRINT_ADDRESS_SCOPE.
	(_initialize_compile): Update compile code help text.  Install
	compile_print_command.
	* compile/compile.h (compile_print_value): New prototype.
	* defs.h (enum compile_i_scope_types): Add
	COMPILE_I_PRINT_ADDRESS_SCOPE and COMPILE_I_PRINT_VALUE_SCOPE.

gdb/doc/ChangeLog
2015-05-16  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* gdb.texinfo (Compiling and Injecting Code): Add compile print.

gdb/testsuite/ChangeLog
2015-05-16  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* gdb.compile/compile-print.c: New file.
	* gdb.compile/compile-print.exp: New file.

2 files changed, 23 insertions, 0 deletions

diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index 849deb8..10bb579 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,7 @@
+2015-05-16  Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+	* gdb.texinfo (Compiling and Injecting Code): Add compile print.
+
 2015-05-12  Don Breazeal  <donb@codesourcery.com>
 
 	* gdb.texinfo (Forks): Note that fork debugging is
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index cb9cd35..1665372 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -17221,6 +17221,25 @@ compile file /home/user/example.c
 @end smallexample
 @end table
 
+@table @code
+@item compile print @var{expr}
+@itemx compile print /@var{f} @var{expr}
+Compile and execute @var{expr} with the compiler language found as the
+current language in @value{GDBN} (@pxref{Languages}).  By default the
+value of @var{expr} is printed in a format appropriate to its data type;
+you can choose a different format by specifying @samp{/@var{f}}, where
+@var{f} is a letter specifying the format; see @ref{Output Formats,,Output
+Formats}.
+
+@item compile print
+@itemx compile print /@var{f}
+@cindex reprint the last value
+Alternatively you can enter the expression (source code producing it) as
+multiple lines of text.  To enter this mode, invoke the @samp{compile print}
+command without any text following the command.  This will start the
+multiple-line editor.
+@end table
+
 @noindent
 The process of compiling and injecting the code can be inspected using: