bfd: Close the file descriptor if there is no archive fd

Close the file descriptor if there is no archive plugin file descriptor
to avoid running out of file descriptors on thin archives with many
archive members.

bfd/

	PR ld/28138
	* plugin.c (bfd_plugin_close_file_descriptor): Close the file
	descriptor there is no archive plugin file descriptor.

ld/

	PR ld/28138
	* testsuite/ld-plugin/lto.exp: Run ld/28138 tests.
	* testsuite/ld-plugin/pr28138.c: New file.
	* testsuite/ld-plugin/pr28138-1.c: Likewise.
	* testsuite/ld-plugin/pr28138-2.c: Likewise.
	* testsuite/ld-plugin/pr28138-3.c: Likewise.
	* testsuite/ld-plugin/pr28138-4.c: Likewise.
	* testsuite/ld-plugin/pr28138-5.c: Likewise.
	* testsuite/ld-plugin/pr28138-6.c: Likewise.
	* testsuite/ld-plugin/pr28138-7.c: Likewise.

9 files changed, 92 insertions, 0 deletions

diff --git a/ld/testsuite/ld-plugin/lto.exp b/ld/testsuite/ld-plugin/lto.exp
index def69e4..63be062 100644
--- a/ld/testsuite/ld-plugin/lto.exp
+++ b/ld/testsuite/ld-plugin/lto.exp
@@ -930,4 +930,34 @@ if { [check_lto_fat_available] } {
     }
 }
 
+run_cc_link_tests [list \
+    [list \
+	"Build pr28138.a" \
+	"-T" "" \
+	{pr28138-1.c pr28138-2.c pr28138-3.c pr28138-4.c pr28138-5.c \
+	 pr28138-6.c pr28138-7.c} {} "pr28138.a" \
+    ] \
+    [list \
+	"Build pr28138.o" \
+	"" "" \
+	{pr28138.c} {} \
+    ] \
+]
+
+set exec_output [run_host_cmd "sh" \
+			      "-c \"ulimit -n 20; \
+			      $CC -Btmpdir/ld -o tmpdir/pr28138 \
+			      tmpdir/pr28138.o tmpdir/pr28138.a\""]
+set exec_output [prune_warnings $exec_output]
+if [string match "" $exec_output] then {
+    set exec_output [run_host_cmd "tmpdir/pr28138" ""]
+    if [string match "PASS" $exec_output] then {
+	pass "PR ld/28138"
+    } else {
+	fail "PR ld/28138"
+    }
+} else {
+    fail "PR ld/28138"
+}
+
 restore_notify
diff --git a/ld/testsuite/ld-plugin/pr28138-1.c b/ld/testsuite/ld-plugin/pr28138-1.c
new file mode 100644
index 0000000..51d119e
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr28138-1.c
@@ -0,0 +1,6 @@
+extern int a0(void);
+int
+a1(void)
+{
+  return 1 + a0();
+}
diff --git a/ld/testsuite/ld-plugin/pr28138-2.c b/ld/testsuite/ld-plugin/pr28138-2.c
new file mode 100644
index 0000000..1120cd7
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr28138-2.c
@@ -0,0 +1,6 @@
+extern int a1(void);
+int
+a2(void)
+{
+  return 1 + a1();
+}
diff --git a/ld/testsuite/ld-plugin/pr28138-3.c b/ld/testsuite/ld-plugin/pr28138-3.c
new file mode 100644
index 0000000..ec46494
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr28138-3.c
@@ -0,0 +1,6 @@
+extern int a2(void);
+int
+a3(void)
+{
+  return 1 + a2();
+}
diff --git a/ld/testsuite/ld-plugin/pr28138-4.c b/ld/testsuite/ld-plugin/pr28138-4.c
new file mode 100644
index 0000000..475701b
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr28138-4.c
@@ -0,0 +1,6 @@
+extern int a3(void);
+int
+a4(void)
+{
+  return 1 + a3();
+}
diff --git a/ld/testsuite/ld-plugin/pr28138-5.c b/ld/testsuite/ld-plugin/pr28138-5.c
new file mode 100644
index 0000000..e24f86c
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr28138-5.c
@@ -0,0 +1,6 @@
+extern int a4(void);
+int
+a5(void)
+{
+  return 1 + a4();
+}
diff --git a/ld/testsuite/ld-plugin/pr28138-6.c b/ld/testsuite/ld-plugin/pr28138-6.c
new file mode 100644
index 0000000..b5b938b
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr28138-6.c
@@ -0,0 +1,6 @@
+extern int a5(void);
+int
+a6(void)
+{
+  return 1 + a5();
+}
diff --git a/ld/testsuite/ld-plugin/pr28138-7.c b/ld/testsuite/ld-plugin/pr28138-7.c
new file mode 100644
index 0000000..4ef75bf
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr28138-7.c
@@ -0,0 +1,6 @@
+extern int a6(void);
+int
+a7(void)
+{
+  return 1 + a6();
+}
diff --git a/ld/testsuite/ld-plugin/pr28138.c b/ld/testsuite/ld-plugin/pr28138.c
new file mode 100644
index 0000000..68252c9
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr28138.c
@@ -0,0 +1,20 @@
+#include <stdio.h>
+
+extern int a7(void);
+
+int
+a0(void)
+{
+  return 0;
+}
+
+int
+main()
+{
+  if (a7() == 7)
+    {
+      printf ("PASS\n");
+      return 0;
+    }
+  return 1;
+}