[PATCH] guile: fix smob exports

[George Barrett <bob@bob131.so>]

Before Guile v2.1[1], calls to `scm_make_smob_type' implicitly
added the created class to the exports list of (oop goops); v2.1+ does
not implicitly create bindings in any modules. This means that the GDB
manual subsection documenting exported types is not quite right when
GDB is linked against Guile <v2.1 (types are exported from (oop
goops)) instead of (gdb)) and incorrect when linked against Guile
v2.1+ (types are not bound to any variables at all!).

This commit makes a small change to GDB's smob registration machinery
to make sure registered smobs get exported from the current
module. This will likely cause warnings to the user about conflicting
exports if they load both (gdb) and (oop goops) from a GDB linked
against Guile v2.0, but it shouldn't impact functionality (and seemed
preferable to trying to un-export bindings from (oop goops) if v2.0
was detected).

[1]: This changed with Guile commit
     28d0871b553a3959a6c59e2e4caec1c1509f8595

gdb/ChangeLog:

2021-05-20  George Barrett  <bob@bob131.so>

	* guile/scm-gsmob.c (gdbscm_make_smob_type): Export registered
	smob type from the current module.

gdb/testsuite/ChangeLog:

2021-05-20  George Barrett  <bob@bob131.so>

	* gdb.guile/scm-gsmob.exp (test exports): Add tests to make
	sure the smob types currently listed in the GDB manual get
	exported from the (gdb) module.
---
 gdb/guile/scm-gsmob.c                 |  9 ++++++++-
 gdb/testsuite/gdb.guile/scm-gsmob.exp | 28 +++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/gdb/guile/scm-gsmob.c b/gdb/guile/scm-gsmob.c
index c623b07d26c..a8ab63a67b5 100644
--- a/gdb/guile/scm-gsmob.c
+++ b/gdb/guile/scm-gsmob.c
@@ -96,7 +96,8 @@ gdbscm_is_gsmob (SCM scm)
   return slot != NULL;
 }
 
-/* Call this to register a smob, instead of scm_make_smob_type.  */
+/* Call this to register a smob, instead of scm_make_smob_type.
+   Exports the created smob type from the current module.  */
 
 scm_t_bits
 gdbscm_make_smob_type (const char *name, size_t size)
@@ -104,6 +105,12 @@ gdbscm_make_smob_type (const char *name, size_t size)
   scm_t_bits result = scm_make_smob_type (name, size);
 
   register_gsmob (result);
+
+  SCM smob_type = scm_smob_type_class (result);
+  SCM smob_type_name = scm_class_name (smob_type);
+  scm_define (smob_type_name, smob_type);
+  scm_module_export (scm_current_module (), scm_list_1 (smob_type_name));
+
   return result;
 }
 
diff --git a/gdb/testsuite/gdb.guile/scm-gsmob.exp b/gdb/testsuite/gdb.guile/scm-gsmob.exp
index 90c32df7dda..d2a77198a23 100644
--- a/gdb/testsuite/gdb.guile/scm-gsmob.exp
+++ b/gdb/testsuite/gdb.guile/scm-gsmob.exp
@@ -66,3 +66,31 @@ set prop_list [lsort $prop_list]
 verbose -log "prop_list: $prop_list"
 gdb_test "gu (print (sort (map car (object-properties arch)) (lambda (a b) (string<? (symbol->string a) (symbol->string b)))))" \
     "= \\($prop_list\\)" "object-properties"
+
+# Check that smob classes are exported properly
+with_test_prefix "test exports" {
+    # For is-a? and <class>
+    gdb_scm_test_silent_cmd "gu (use-modules (oop goops))" "import goops"
+    gdb_test_no_output "gu (define-syntax-rule (gdb-exports-class? x) (is-a? (@ (gdb) x) <class>))"
+
+    gdb_test "gu (print (gdb-exports-class? <gdb:arch>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:block>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:block-symbols-iterator>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:breakpoint>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:command>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:exception>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:frame>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:iterator>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:lazy-string>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:objfile>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:parameter>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:pretty-printer>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:pretty-printer-worker>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:progspace>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:symbol>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:symtab>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:sal>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:type>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:field>))" "= #t"
+    gdb_test "gu (print (gdb-exports-class? <gdb:value>))" "= #t"
+}
-- 
2.31.1