Add a pass-through option to the plugin. The use case for this option is to

ask the linker to take another look into some library or object. The case when
one might want to do this is when codegen introduces a new undefined reference.
The canonical example is libgcc.

llvm-svn: 106303

1 files changed, 26 insertions, 0 deletions

diff --git a/llvm/tools/gold/gold-plugin.cpp b/llvm/tools/gold/gold-plugin.cpp
index 15df7d03152..c8542b17520 100644
--- a/llvm/tools/gold/gold-plugin.cpp
+++ b/llvm/tools/gold/gold-plugin.cpp
@@ -41,6 +41,7 @@ namespace {
   ld_plugin_add_symbols add_symbols = NULL;
   ld_plugin_get_symbols get_symbols = NULL;
   ld_plugin_add_input_file add_input_file = NULL;
+  ld_plugin_add_input_library add_input_library = NULL;
   ld_plugin_message message = discard_message;
 
   int api_version = 0;
@@ -64,6 +65,7 @@ namespace options {
   static generate_bc generate_bc_file = BC_NO;
   static std::string bc_path;
   static std::string as_path;
+  static std::vector<std::string> pass_through;
   // Additional options to pass into the code generator.
   // Note: This array will contain all plugin options which are not claimed
   // as plugin exclusive to pass to the code generator.
@@ -86,6 +88,9 @@ namespace options {
       } else {
         as_path = opt.substr(strlen("as="));
       }
+    } else if (opt.startswith("pass-through=")) {
+      llvm::StringRef item = opt.substr(strlen("pass-through="));
+      pass_through.push_back(item.str());
     } else if (opt == "emit-llvm") {
       generate_bc_file = BC_ONLY;
     } else if (opt == "also-emit-llvm") {
@@ -190,6 +195,9 @@ ld_plugin_status onload(ld_plugin_tv *tv) {
       case LDPT_ADD_INPUT_FILE:
         add_input_file = tv->tv_u.tv_add_input_file;
         break;
+      case LDPT_ADD_INPUT_LIBRARY:
+        add_input_library = tv->tv_u.tv_add_input_file;
+        break;
       case LDPT_MESSAGE:
         message = tv->tv_u.tv_message;
         break;
@@ -437,6 +445,24 @@ static ld_plugin_status all_symbols_read_hook(void) {
     return LDPS_ERR;
   }
 
+  for (std::vector<std::string>::iterator i = options::pass_through.begin(),
+                                          e = options::pass_through.end();
+       i != e; ++i) {
+    std::string &item = *i;
+    char *item_p = const_cast<char*>(item.c_str());
+    if (llvm::StringRef(item).startswith("-l")) {
+      if (add_input_library(item_p + 2) != LDPS_OK) {
+        (*message)(LDPL_ERROR, "Unable to add library to the link.");
+        return LDPS_ERR;
+      }
+    } else {
+      if (add_input_file(item_p) != LDPS_OK) {
+        (*message)(LDPL_ERROR, "Unable to add .o file to the link.");
+        return LDPS_ERR;
+      }
+    }
+  }
+
   Cleanup.push_back(uniqueObjPath);
 
   return LDPS_OK;