dumpfile.c: add indentation via DUMP_VECT_SCOPE

This patch adds a concept of nested "scopes" to dumpfile.c's dump_*_loc
calls, and wires it up to the DUMP_VECT_SCOPE macro in tree-vectorizer.h,
so that the nested structure is shown in -fopt-info by indentation.

For example, this converts -fopt-info-all e.g. from:

test.c:8:3: note: === analyzing loop ===
test.c:8:3: note: === analyze_loop_nest ===
test.c:8:3: note: === vect_analyze_loop_form ===
test.c:8:3: note: === get_loop_niters ===
test.c:8:3: note: symbolic number of iterations is (unsigned int) n_9(D)
test.c:8:3: note: not vectorized: loop contains function calls or data references that cannot be analyzed
test.c:8:3: note: vectorized 0 loops in function

to:

test.c:8:3: note: === analyzing loop ===
test.c:8:3: note:  === analyze_loop_nest ===
test.c:8:3: note:   === vect_analyze_loop_form ===
test.c:8:3: note:    === get_loop_niters ===
test.c:8:3: note:   symbolic number of iterations is (unsigned int) n_9(D)
test.c:8:3: note:   not vectorized: loop contains function calls or data references that cannot be analyzed
test.c:8:3: note: vectorized 0 loops in function

showing that the "symbolic number of iterations" message is within
the "=== analyze_loop_nest ===" (and not within the
"=== vect_analyze_loop_form ===").

This is also enabling work for followups involving optimization records
(allowing the records to directly capture the nested structure of the
dump messages).

gcc/ChangeLog:
	* dumpfile.c (dump_loc): Add indentation based on scope depth.
	(dump_scope_depth): New variable.
	(get_dump_scope_depth): New function.
	(dump_begin_scope): New function.
	(dump_end_scope): New function.
	* dumpfile.h (get_dump_scope_depth): New declaration.
	(dump_begin_scope): New declaration.
	(dump_end_scope): New declaration.
	(class auto_dump_scope): New class.
	(AUTO_DUMP_SCOPE): New macro.
	* tree-vectorizer.h (DUMP_VECT_SCOPE): Reimplement in terms of
	AUTO_DUMP_SCOPE.

From-SVN: r262246

1 files changed, 39 insertions, 0 deletions

diff --git a/gcc/dumpfile.h b/gcc/dumpfile.h
index 489f92e6d1a..9828a3f550c 100644
--- a/gcc/dumpfile.h
+++ b/gcc/dumpfile.h
@@ -459,6 +459,45 @@ dump_enabled_p (void)
   return dumps_are_enabled;
 }
 
+/* Managing nested scopes, so that dumps can express the call chain
+   leading to a dump message.  */
+
+extern unsigned int get_dump_scope_depth ();
+extern void dump_begin_scope (const char *name, const dump_location_t &loc);
+extern void dump_end_scope ();
+
+/* Implementation detail of the AUTO_DUMP_SCOPE macro below.
+
+   A RAII-style class intended to make it easy to emit dump
+   information about entering and exiting a collection of nested
+   function calls.  */
+
+class auto_dump_scope
+{
+ public:
+  auto_dump_scope (const char *name, dump_location_t loc)
+  {
+    if (dump_enabled_p ())
+      dump_begin_scope (name, loc);
+  }
+  ~auto_dump_scope ()
+  {
+    if (dump_enabled_p ())
+      dump_end_scope ();
+  }
+};
+
+/* A macro for calling:
+     dump_begin_scope (NAME, LOC);
+   via an RAII object, thus printing "=== MSG ===\n" to the dumpfile etc,
+   and then calling
+     dump_end_scope ();
+   once the object goes out of scope, thus capturing the nesting of
+   the scopes.  */
+
+#define AUTO_DUMP_SCOPE(NAME, LOC) \
+  auto_dump_scope scope (NAME, LOC)
+
 namespace gcc {
 
 class dump_manager