From: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>
Date: Mon, 30 Nov 2020 21:55:32 +0300
Subject: Load libdebuginfod library on demand


diff --git a/binutils/Makefile.am b/binutils/Makefile.am
index defaced..defaced 100644
--- a/binutils/Makefile.am
+++ b/binutils/Makefile.am
@@ -53,7 +53,7 @@ AM_CFLAGS = $(WARN_CFLAGS) $(ZLIBINC)
 AM_CFLAGS_FOR_BUILD = $(WARN_CFLAGS_FOR_BUILD) $(ZLIBINC)
 LIBICONV = @LIBICONV@
 
-DEBUGINFOD_LIBS = @DEBUGINFOD_LIBS@
+DEBUGINFOD_LIBS =
 
 # these two are almost the same program
 AR_PROG=ar
diff --git a/binutils/Makefile.in b/binutils/Makefile.in
index defaced..defaced 100644
--- a/binutils/Makefile.in
+++ b/binutils/Makefile.in
@@ -425,7 +425,7 @@ CPPFLAGS = @CPPFLAGS@
 CYGPATH_W = @CYGPATH_W@
 DATADIRNAME = @DATADIRNAME@
 DEBUGINFOD_CFLAGS = @DEBUGINFOD_CFLAGS@
-DEBUGINFOD_LIBS = @DEBUGINFOD_LIBS@
+DEBUGINFOD_LIBS =
 DEFS = @DEFS@
 DEMANGLER_NAME = @DEMANGLER_NAME@
 DEPDIR = @DEPDIR@
diff --git a/binutils/dwarf.c b/binutils/dwarf.c
index defaced..defaced 100644
--- a/binutils/dwarf.c
+++ b/binutils/dwarf.c
@@ -33,7 +33,12 @@
 #include <assert.h>
 
 #ifdef HAVE_LIBDEBUGINFOD
+#include <dlfcn.h>
 #include <elfutils/debuginfod.h>
+
+static __typeof__ (debuginfod_begin) *fp_debuginfod_begin;
+static __typeof__ (debuginfod_find_debuginfo) *fp_debuginfod_find_debuginfo;
+static __typeof__ (debuginfod_end) *fp_debuginfod_end;
 #endif
 
 #include <limits.h>
@@ -10936,6 +10941,44 @@ add_separate_debug_file (const char * filename, void * handle)
 }
 
 #if HAVE_LIBDEBUGINFOD
+static int
+debuginfod_load(void)
+{
+  static int debuginfod_loaded = -1;
+
+  if (debuginfod_loaded >= 0)
+    return debuginfod_loaded;
+
+  debuginfod_loaded = 0;
+
+  char *urls = getenv (DEBUGINFOD_URLS_ENV_VAR);
+  if (urls == NULL || urls[0] == '\0')
+    return debuginfod_loaded;
+
+  void *debuginfod_so = dlopen("libdebuginfod.so.1", RTLD_LAZY);
+  if (debuginfod_so != NULL)
+    {
+      fp_debuginfod_begin = dlsym (debuginfod_so, "debuginfod_begin");
+      fp_debuginfod_find_debuginfo = dlsym (debuginfod_so,
+					    "debuginfod_find_debuginfo");
+      fp_debuginfod_end = dlsym (debuginfod_so, "debuginfod_end");
+
+      /* We either get them all, or we get none.  */
+      if (fp_debuginfod_begin == NULL
+		|| fp_debuginfod_find_debuginfo == NULL
+		|| fp_debuginfod_end == NULL)
+	{
+	  fp_debuginfod_begin = NULL;
+	  fp_debuginfod_find_debuginfo = NULL;
+	  fp_debuginfod_end = NULL;
+	  dlclose (debuginfod_so);
+	}
+      else
+	debuginfod_loaded = 1;
+    }
+  return debuginfod_loaded;
+}
+
 /* Query debuginfod servers for the target debuglink or debugaltlink
    file. If successful, store the path of the file in filename and
    return TRUE, otherwise return FALSE.  */
@@ -10978,14 +11021,14 @@ debuginfod_fetch_separate_debug_info (struct dwarf_section * section,
       int fd;
       debuginfod_client * client;
 
-      client = debuginfod_begin ();
+      client = fp_debuginfod_begin ();
       if (client == NULL)
         return false;
 
       /* Query debuginfod servers for the target file. If found its path
          will be stored in filename.  */
-      fd = debuginfod_find_debuginfo (client, build_id, build_id_len, filename);
-      debuginfod_end (client);
+      fd = fp_debuginfod_find_debuginfo (client, build_id, build_id_len, filename);
+      fp_debuginfod_end (client);
 
       /* Only free build_id if we allocated space for a hex string
          in get_build_id ().  */
@@ -11117,7 +11160,8 @@ load_separate_debug_info (const char *            main_filename,
   {
     char * tmp_filename;
 
-    if (debuginfod_fetch_separate_debug_info (xlink,
+    if (debuginfod_load() > 0 &&
+	debuginfod_fetch_separate_debug_info (xlink,
                                               & tmp_filename,
                                               file))
       {