introduce -fcallgraph-info option

This was first submitted many years ago
https://gcc.gnu.org/ml/gcc-patches/2010-10/msg02468.html



The command line option -fcallgraph-info is added and makes the
compiler generate another output file (xxx.ci) for each compilation
unit (or LTO partitoin), which is a valid VCG file (you can launch
your favorite VCG viewer on it unmodified) and contains the "final"
callgraph of the unit.  "final" is a bit of a misnomer as this is
actually the callgraph at RTL expansion time, but since most
high-level optimizations are done at the Tree level and RTL doesn't
usually fiddle with calls, it's final in almost all cases.  Moreover,
the nodes can be decorated with additional info: -fcallgraph-info=su
adds stack usage info and -fcallgraph-info=da dynamic allocation info.


for  gcc/ChangeLog
From  Eric Botcazou  <ebotcazou@adacore.com>, Alexandre Oliva  <oliva@adacore.com>

	* common.opt (-fcallgraph-info[=]): New option.
	* doc/invoke.texi (Developer options): Document it.
	* opts.c (common_handle_option): Handle it.
	* builtins.c (expand_builtin_alloca): Record allocation if
	-fcallgraph-info=da.
	* calls.c (expand_call): If -fcallgraph-info, record the call.
	(emit_library_call_value_1): Likewise.
	* flag-types.h (enum callgraph_info_type): New type.
	* explow.c: Include stringpool.h.
	(set_stack_check_libfunc): Set SET_SYMBOL_REF_DECL on the symbol.
	* function.c (allocate_stack_usage_info): New.
	(allocate_struct_function): Call it for -fcallgraph-info.
	(prepare_function_start): Call it otherwise.
	(record_final_call, record_dynamic_alloc): New.
	* function.h (struct callinfo_callee): New.
	(CALLEE_FROM_CGRAPH_P): New.
	(struct callinfo_dalloc): New.
	(struct stack_usage): Add callees and dallocs.
	(record_final_call, record_dynamic_alloc): Declare.
	* gimplify.c (gimplify_decl_expr): Record dynamically-allocated
	object if -fcallgraph-info=da.
	* optabs-libfuncs.c (build_libfunc_function): Keep SYMBOL_REF_DECL.
	* print-tree.h (print_decl_identifier): Declare.
	(PRINT_DECL_ORIGIN, PRINT_DECL_NAME, PRINT_DECL_UNIQUE_NAME): New.
	* print-tree.c: Include print-tree.h.
	(print_decl_identifier): New function.
	* toplev.c: Include print-tree.h.
	(callgraph_info_file): New global variable.
	(callgraph_info_external_printed): Likewise.
	(output_stack_usage): Rename to...
	(output_stack_usage_1): ... this.  Make it static, add cf
	parameter.  If -fcallgraph-info=su, print stack usage to cf.
	If -fstack-usage, use print_decl_identifier for
	pretty-printing.
	(INDIRECT_CALL_NAME): New.
	(dump_final_node_vcg_start): New.
	(dump_final_callee_vcg, dump_final_node_vcg): New.
	(output_stack_usage): New.
	(lang_dependent_init): Open and start file if
	-fcallgraph-info.  Allocated callgraph_info_external_printed.
	(finalize): If callgraph_info_file is not null, finish it,
	close it, and release callgraph_info_external_printed.

for  gcc/ada/ChangeLog

	* gcc-interface/misc.c (callgraph_info_file): Delete.

Co-Authored-By: Alexandre Oliva <oliva@adacore.com>

From-SVN: r277876