gdb: fix pretty printing max depth behaviour

The 'print max-depth' feature incorrectly causes GDB to skip printing
the string representation of pretty printed variables if the variable
is stored at a nested depth corresponding to the set max-depth value.
This change ensures that it is always printed before checking whether
the maximum print depth has been reached.

Regression tested with GCC 7.3.0 on x86_64, ppc64le, aarch64.

gdb/ChangeLog:

	* cp-valprint.c (cp_print_value): Replaced duplicate code.
	* guile/scm-pretty-print.c (ppscm_print_children): Check max_depth
	just before printing child values.
	(gdbscm_apply_val_pretty_printer): Don't check max_depth before
	printing string representation.
	* python/py-prettyprint.c (print_children): Check max_depth just
	before printing child values.
	(gdbpy_apply_val_pretty_printer): Don't check max_depth before
	printing string representation.

gdb/testsuite/ChangeLog:

	* gdb.python/py-format-string.c: Added a variable to test.
	* gdb.python/py-format-string.exp: Check string representation is
	printed at appropriate max_depth settings.
	* gdb.python/py-nested-maps.exp: Likewise.
	* gdb.guile/scm-pretty-print.exp: Add additional tests.

3 files changed, 18 insertions, 3 deletions

diff --git a/gdb/testsuite/gdb.python/py-format-string.c b/gdb/testsuite/gdb.python/py-format-string.c
index 763fcc6..450971c 100644
--- a/gdb/testsuite/gdb.python/py-format-string.c
+++ b/gdb/testsuite/gdb.python/py-format-string.c
@@ -23,6 +23,11 @@ typedef struct point
   int y;
 } point_t;
 
+typedef struct
+{
+  point_t the_point;
+} struct_point_t;
+
 typedef union
 {
   int an_int;
@@ -84,6 +89,7 @@ main ()
   point_t &a_point_t_ref = a_point_t;
 #endif
   struct point another_point = { 123, 456 };
+  struct_point_t a_struct_with_point = { a_point_t };
 
   struct_union_t a_struct_with_union;
   /* Fill the union in an endianness-independent way.  */
diff --git a/gdb/testsuite/gdb.python/py-format-string.exp b/gdb/testsuite/gdb.python/py-format-string.exp
index ed82ee2..ea5e958 100644
--- a/gdb/testsuite/gdb.python/py-format-string.exp
+++ b/gdb/testsuite/gdb.python/py-format-string.exp
@@ -126,6 +126,7 @@ set default_regexp_dict [dict create \
   "a_point_t_pointer"		$default_pointer_regexp \
   "a_point_t_ref"		"Pretty Point \\(42, 12\\)" \
   "another_point"		"Pretty Point \\(123, 456\\)" \
+  "a_struct_with_point"		"\\{the_point = Pretty Point \\(42, 12\\)\\}" \
   "a_struct_with_union"		"\\{the_union = \\{an_int = 707406378, a_char = 42 '\\*'\\}\\}" \
   "an_enum"			"ENUM_BAR" \
   "a_string"			"${default_pointer_regexp} \"hello world\"" \
@@ -722,18 +723,26 @@ proc_with_prefix test_max_depth {} {
     set opts "max_depth=-1"
     with_test_prefix $opts {
 	check_format_string "a_struct_with_union" $opts
+	check_format_string "a_point_t" $opts "Pretty Point \\(42, 12\\)"
+	check_format_string "a_struct_with_point" $opts
     }
     set opts "max_depth=0"
     with_test_prefix $opts {
 	check_format_string "a_struct_with_union" $opts "\\{\.\.\.\\}"
+	check_format_string "a_point_t" $opts "Pretty Point \\(42, 12\\)"
+	check_format_string "a_struct_with_point" $opts "\\{\.\.\.\\}"
     }
     set opts "max_depth=1"
     with_test_prefix $opts {
 	check_format_string "a_struct_with_union" $opts "\\{the_union = \\{\.\.\.\\}\\}"
+	check_format_string "a_point_t" $opts "Pretty Point \\(42, 12\\)"
+	check_format_string "a_struct_with_point" $opts
     }
     set opts "max_depth=2"
     with_test_prefix $opts {
 	check_format_string "a_struct_with_union" $opts
+	check_format_string "a_point_t" $opts "Pretty Point \\(42, 12\\)"
+	check_format_string "a_struct_with_point" $opts
     }
 }
 
diff --git a/gdb/testsuite/gdb.python/py-nested-maps.exp b/gdb/testsuite/gdb.python/py-nested-maps.exp
index 49cefa8..befc48c 100644
--- a/gdb/testsuite/gdb.python/py-nested-maps.exp
+++ b/gdb/testsuite/gdb.python/py-nested-maps.exp
@@ -222,15 +222,15 @@ with_test_prefix "headers=on" {
     with_test_prefix "pretty=off" {
 	gdb_print_expr_at_depths "*m1" \
 	    [list \
-		 "\{\\.\\.\\.\}" \
+		 "pp_map = \{\\.\\.\\.\}" \
 		 "pp_map = \{\\\[\{a = 3, b = 4\}\\\] = \{\\.\\.\\.\}, \\\[\{a = 4, b = 5\}\\\] = \{\\.\\.\\.\}, \\\[\{a = 5, b = 6\}\\\] = \{\\.\\.\\.\}\}" \
 		 "pp_map = \{\\\[\{a = 3, b = 4\}\\\] = \{x = 0, y = 1, z = 2\}, \\\[\{a = 4, b = 5\}\\\] = \{x = 3, y = 4, z = 5\}, \\\[\{a = 5, b = 6\}\\\] = \{x = 6, y = 7, z = 8\}\}" \
 		]
 
 	gdb_print_expr_at_depths "*mm" \
 	    [list \
-		 "\{\\.\\.\\.\}" \
-		 "pp_map_map = \{\\\[$hex \"m1\"\\\] = \{\\.\\.\\.\}, \\\[$hex \"m2\"\\\] = \{\\.\\.\\.\}\}" \
+		 "pp_map_map = \{\\.\\.\\.\}" \
+		 "pp_map_map = \{\\\[$hex \"m1\"\\\] = pp_map = \{\\.\\.\\.\}, \\\[$hex \"m2\"\\\] = pp_map = \{\\.\\.\\.\}\}" \
 		 "pp_map_map = \{\\\[$hex \"m1\"\\\] = pp_map = \{\\\[\{a = 3, b = 4\}\\\] = \{\\.\\.\\.\}, \\\[\{a = 4, b = 5\}\\\] = \{\\.\\.\\.\}, \\\[\{a = 5, b = 6\}\\\] = \{\\.\\.\\.\}\}, \\\[$hex \"m2\"\\\] = pp_map = \{\\\[\{a = 6, b = 7\}\\\] = \{\\.\\.\\.\}, \\\[\{a = 7, b = 8\}\\\] = \{\\.\\.\\.\}, \\\[\{a = 8, b = 9\}\\\] = \{\\.\\.\\.\}\}\}" \
 		 "pp_map_map = \{\\\[$hex \"m1\"\\\] = pp_map = \{\\\[\{a = 3, b = 4\}\\\] = \{x = 0, y = 1, z = 2\}, \\\[\{a = 4, b = 5\}\\\] = \{x = 3, y = 4, z = 5\}, \\\[\{a = 5, b = 6\}\\\] = \{x = 6, y = 7, z = 8\}\}, \\\[$hex \"m2\"\\\] = pp_map = \{\\\[\{a = 6, b = 7\}\\\] = \{x = 9, y = 0, z = 1\}, \\\[\{a = 7, b = 8\}\\\] = \{x = 2, y = 3, z = 4\}, \\\[\{a = 8, b = 9\}\\\] = \{x = 5, y = 6, z = 7\}\}\}" \
 		]