[binutils-gdb] Warn and return for duplicated plugin

[H.J.Lu <hjl at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=c3e1c28ebfdb20ff4498bcc792228283b903d393

commit c3e1c28ebfdb20ff4498bcc792228283b903d393
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Mon Jul 4 08:55:04 2016 -0700

    Warn and return for duplicated plugin
    
    If a plugin has been loaded already, we should warn and return, instead
    of adding it on the plugin list.
    
    	PR ld/20321
    	* plugin.c (plugin_opt_plugin): Warn and return if plugin has
    	been loaded already.
    	* testsuite/ld-plugin/lto.exp: Run PR ld/20321 test.
    	* testsuite/ld-plugin/pr20321.c: New file.

Diff:
---
 ld/ChangeLog                     |  8 ++++++++
 ld/plugin.c                      | 13 +++++++++++++
 ld/testsuite/ld-plugin/lto.exp   |  3 +++
 ld/testsuite/ld-plugin/pr20321.c |  4 ++++
 4 files changed, 28 insertions(+)

diff --git a/ld/ChangeLog b/ld/ChangeLog
index 248e66e..7e24b95 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,11 @@
+2016-07-04  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/20321
+	* plugin.c (plugin_opt_plugin): Warn and return if plugin has
+	been loaded already.
+	* testsuite/ld-plugin/lto.exp: Run PR ld/20321 test.
+	* testsuite/ld-plugin/pr20321.c: New file.
+
 2016-07-04  Nick Clifton  <nickc@redhat.com>
 
 	* scripttempl/ft32.sc (__PMSIZE_): If not defined, set to 256K.
diff --git a/ld/plugin.c b/ld/plugin.c
index 4c161d1..924b59c 100644
--- a/ld/plugin.c
+++ b/ld/plugin.c
@@ -237,6 +237,7 @@ void
 plugin_opt_plugin (const char *plugin)
 {
   plugin_t *newplug;
+  plugin_t *curplug = plugins_list;
 
   newplug = xmalloc (sizeof *newplug);
   memset (newplug, 0, sizeof *newplug);
@@ -245,6 +246,18 @@ plugin_opt_plugin (const char *plugin)
   if (!newplug->dlhandle)
     einfo (_("%P%F: %s: error loading plugin: %s\n"), plugin, dlerror ());
 
+  /* Check if plugin has been loaded already.  */
+  while (curplug)
+    {
+      if (newplug->dlhandle == curplug->dlhandle)
+	{
+	  einfo (_("%P: %s: duplicated plugin\n"), plugin);
+	  free (newplug);
+	  return;
+	}
+      curplug = curplug->next;
+    }
+
   /* Chain on end, so when we run list it is in command-line order.  */
   *plugins_tail_chain_ptr = newplug;
   plugins_tail_chain_ptr = &newplug->next;
diff --git a/ld/testsuite/ld-plugin/lto.exp b/ld/testsuite/ld-plugin/lto.exp
index 80bc469..2ecb4d0 100644
--- a/ld/testsuite/ld-plugin/lto.exp
+++ b/ld/testsuite/ld-plugin/lto.exp
@@ -198,6 +198,9 @@ set lto_link_tests [list \
   [list "Build libpr20267b.a" \
    "$plug_opt" "-flto $lto_no_fat" \
    {pr20267b.c} {} "libpr20267b.a"] \
+  [list "Build pr20321" \
+   "-Wl,-plugin,$plug_so" "-flto" \
+   {pr20321.c} {} "pr20321" "c" ".*: duplicated plugin"] \
 ]
 
 if { [at_least_gcc_version 4 7] } {
diff --git a/ld/testsuite/ld-plugin/pr20321.c b/ld/testsuite/ld-plugin/pr20321.c
new file mode 100644
index 0000000..8488f4e
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr20321.c
@@ -0,0 +1,4 @@
+int main(void)
+{
+  return 0;
+}