[PATCH 6/6] Remove some unneeded checks in Guile code

[Tom Tromey <tom@tromey.com>]

The Guile code generally checks to see if an htab is non-null before
destroying it.  However, the registry code already ensures this, so we
can change these checks to asserts and simplify the code a little.
---
 gdb/guile/scm-block.c  | 8 +++-----
 gdb/guile/scm-frame.c  | 8 +++-----
 gdb/guile/scm-symbol.c | 8 +++-----
 gdb/guile/scm-symtab.c | 8 +++-----
 gdb/guile/scm-type.c   | 9 +++------
 5 files changed, 15 insertions(+), 26 deletions(-)

diff --git a/gdb/guile/scm-block.c b/gdb/guile/scm-block.c
index a29c2db58f1..07c6a2bd5e5 100644
--- a/gdb/guile/scm-block.c
+++ b/gdb/guile/scm-block.c
@@ -97,11 +97,9 @@ struct bkscm_deleter
 
   void operator() (htab_t htab)
   {
-    if (htab != NULL)
-      {
-	htab_traverse_noresize (htab, bkscm_mark_block_invalid, NULL);
-	htab_delete (htab);
-      }
+    gdb_assert (htab != nullptr);
+    htab_traverse_noresize (htab, bkscm_mark_block_invalid, NULL);
+    htab_delete (htab);
   }
 };
 
diff --git a/gdb/guile/scm-frame.c b/gdb/guile/scm-frame.c
index 4132bb246d8..159603b8008 100644
--- a/gdb/guile/scm-frame.c
+++ b/gdb/guile/scm-frame.c
@@ -95,11 +95,9 @@ struct frscm_deleter
 
   void operator() (htab_t htab)
   {
-    if (htab != NULL)
-      {
-	htab_traverse_noresize (htab, frscm_mark_frame_invalid, NULL);
-	htab_delete (htab);
-      }
+    gdb_assert (htab != nullptr);
+    htab_traverse_noresize (htab, frscm_mark_frame_invalid, NULL);
+    htab_delete (htab);
   }
 };
 
diff --git a/gdb/guile/scm-symbol.c b/gdb/guile/scm-symbol.c
index 0b96e5a02c1..78917bdbed0 100644
--- a/gdb/guile/scm-symbol.c
+++ b/gdb/guile/scm-symbol.c
@@ -70,11 +70,9 @@ struct syscm_deleter
 
   void operator() (htab_t htab)
   {
-    if (htab != NULL)
-      {
-	htab_traverse_noresize (htab, syscm_mark_symbol_invalid, NULL);
-	htab_delete (htab);
-      }
+    gdb_assert (htab != nullptr);
+    htab_traverse_noresize (htab, syscm_mark_symbol_invalid, NULL);
+    htab_delete (htab);
   }
 };
 
diff --git a/gdb/guile/scm-symtab.c b/gdb/guile/scm-symtab.c
index 940823147bf..2ff66c49d51 100644
--- a/gdb/guile/scm-symtab.c
+++ b/gdb/guile/scm-symtab.c
@@ -98,11 +98,9 @@ struct stscm_deleter
 
   void operator() (htab_t htab)
   {
-    if (htab != NULL)
-      {
-	htab_traverse_noresize (htab, stscm_mark_symtab_invalid, NULL);
-	htab_delete (htab);
-      }
+    gdb_assert (htab != nullptr);
+    htab_traverse_noresize (htab, stscm_mark_symtab_invalid, NULL);
+    htab_delete (htab);
   }
 };
 
diff --git a/gdb/guile/scm-type.c b/gdb/guile/scm-type.c
index 2dadbefb3a4..5cb1cabe14d 100644
--- a/gdb/guile/scm-type.c
+++ b/gdb/guile/scm-type.c
@@ -93,13 +93,10 @@ struct tyscm_deleter
     if (!gdb_scheme_initialized)
       return;
 
+    gdb_assert (htab != nullptr);
     htab_up copied_types = create_copied_types_hash ();
-
-    if (htab != NULL)
-      {
-	htab_traverse_noresize (htab, tyscm_copy_type_recursive, copied_types.get ());
-	htab_delete (htab);
-      }
+    htab_traverse_noresize (htab, tyscm_copy_type_recursive, copied_types.get ());
+    htab_delete (htab);
   }
 };
 
-- 
2.34.1