Disable some pretty-printers when gdb is rust-enabled

A rust-enabled gdb already knows how to display string slices,
structs, tuples, and enums (and after #54004, the pretty-printers
can't handle enums at all).  This patch disables these pretty-printers
when gdb is rust-enabled.

The "gdb-pretty-struct-and-enums-pre-gdb-7-7.rs" test is renamed,
because it does not seem to depend on any behavior of that version of
gdb, and because gdb 7.7 is 4 years old now.

1 files changed, 25 insertions, 18 deletions

diff --git a/src/etc/gdb_rust_pretty_printing.py b/src/etc/gdb_rust_pretty_printing.py
index e6d5ef1a23f..a5c8e73f919 100755
--- a/src/etc/gdb_rust_pretty_printing.py
+++ b/src/etc/gdb_rust_pretty_printing.py
@@ -18,6 +18,8 @@ import debugger_pretty_printers_common as rustpp
 if sys.version_info[0] >= 3:
     xrange = range
 
+rust_enabled = 'set language rust' in gdb.execute('complete set language ru', to_string = True)
+
 #===============================================================================
 # GDB Pretty Printing Module for Rust
 #===============================================================================
@@ -99,27 +101,9 @@ def rust_pretty_printer_lookup_function(gdb_val):
     val = GdbValue(gdb_val)
     type_kind = val.type.get_type_kind()
 
-    if type_kind == rustpp.TYPE_KIND_EMPTY:
-        return RustEmptyPrinter(val)
-
-    if type_kind == rustpp.TYPE_KIND_REGULAR_STRUCT:
-        return RustStructPrinter(val,
-                                 omit_first_field = False,
-                                 omit_type_name = False,
-                                 is_tuple_like = False)
-
-    if type_kind == rustpp.TYPE_KIND_STRUCT_VARIANT:
-        return RustStructPrinter(val,
-                                 omit_first_field = True,
-                                 omit_type_name = False,
-                                 is_tuple_like = False)
-
     if type_kind == rustpp.TYPE_KIND_SLICE:
         return RustSlicePrinter(val)
 
-    if type_kind == rustpp.TYPE_KIND_STR_SLICE:
-        return RustStringSlicePrinter(val)
-
     if type_kind == rustpp.TYPE_KIND_STD_VEC:
         return RustStdVecPrinter(val)
 
@@ -138,6 +122,29 @@ def rust_pretty_printer_lookup_function(gdb_val):
     if type_kind == rustpp.TYPE_KIND_OS_STRING:
         return RustOsStringPrinter(val)
 
+    # Checks after this point should only be for "compiler" types --
+    # things that gdb's Rust language support knows about.
+    if rust_enabled:
+        return None
+
+    if type_kind == rustpp.TYPE_KIND_EMPTY:
+        return RustEmptyPrinter(val)
+
+    if type_kind == rustpp.TYPE_KIND_REGULAR_STRUCT:
+        return RustStructPrinter(val,
+                                 omit_first_field = False,
+                                 omit_type_name = False,
+                                 is_tuple_like = False)
+
+    if type_kind == rustpp.TYPE_KIND_STRUCT_VARIANT:
+        return RustStructPrinter(val,
+                                 omit_first_field = True,
+                                 omit_type_name = False,
+                                 is_tuple_like = False)
+
+    if type_kind == rustpp.TYPE_KIND_STR_SLICE:
+        return RustStringSlicePrinter(val)
+
     if type_kind == rustpp.TYPE_KIND_TUPLE:
         return RustStructPrinter(val,
                                  omit_first_field = False,