* ldlang.h (struct lang_input_statement_flags): Add pushed

        member.
        * ldlex.h (enum option_values): Add OPTION_PUSH_STATE and
        OPTION_POP_STATE.
        * lexsup.c (ld_options): Add entries for --push-state and
        --pop-state.
        (parse_args): Handle OPTION_PUSH_STATE and OPTION_POP_STATE.
        * ld.texinfo: Document --push-state and --pop-state.

5 files changed, 67 insertions, 0 deletions

diff --git a/ld/ChangeLog b/ld/ChangeLog
index b34d360..b80e69f 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,14 @@
+2014-08-08  Ulrich Drepper  <drepper@gmail.com>
+
+	* ldlang.h (struct lang_input_statement_flags): Add pushed
+	member.
+	* ldlex.h (enum option_values): Add OPTION_PUSH_STATE and
+	OPTION_POP_STATE.
+	* lexsup.c (ld_options): Add entries for --push-state and
+	--pop-state.
+	(parse_args): Handle OPTION_PUSH_STATE and OPTION_POP_STATE.
+	* ld.texinfo: Document --push-state and --pop-state.
+
 2014-08-06  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR14918
diff --git a/ld/ld.texinfo b/ld/ld.texinfo
index 5762dc6..b559b4f 100644
--- a/ld/ld.texinfo
+++ b/ld/ld.texinfo
@@ -827,6 +827,34 @@ the linker may make more use of this option.  Also currently there is
 no difference in the linker's behaviour for different non-zero values
 of this option.  Again this may change with future releases.
 
+@kindex --push-state
+@cindex push state governing input file handling
+@item --push-state
+The @option{--push-state} allows to preserve the current state of the
+flags which govern the input file handling so that they can all be
+restored with one corresponding @option{--pop-state} option.
+
+The option which are covered are: @option{-Bdynamic}, @option{-Bstatic},
+@option{-dn}, @option{-dy}, @option{-call_shared}, @option{-non_shared},
+@option{-static}, @option{-N}, @option{-n}, @option{--whole-archive},
+@option{--no-whole-archive}, @option{-r}, @option{-Ur},
+@option{--copy-dt-needed-entries}, @option{--no-copy-dt-needed-entries},
+@option{--as-needed}, @option{--no-as-needed}, and @option{-a}.
+
+One target for this option are specifications for @file{pkg-config}.  When
+used with the @option{--libs} option all possibly needed libraries are
+listed and then possibly linked with all the time.  It is better to return
+something as follows:
+
+@smallexample
+-Wl,--push-state,--as-needed -libone -libtwo -Wl,--pop-state
+@end smallexample
+
+@kindex --pop-state
+@cindex pop state governing input file handling
+Undoes the effect of --push-state, restores the previous values of the
+flags governing input file handling.
+
 @kindex -q
 @kindex --emit-relocs
 @cindex retain relocations in final executable
diff --git a/ld/ldlang.h b/ld/ldlang.h
index 0f7fdd4..45420cd 100644
--- a/ld/ldlang.h
+++ b/ld/ldlang.h
@@ -282,6 +282,9 @@ struct lang_input_statement_flags
   /* Set if reloading an archive or --as-needed lib.  */
   unsigned int reload : 1;
 #endif /* ENABLE_PLUGINS */
+
+  /* Head of list of pushed flags.  */
+  struct lang_input_statement_flags *pushed;
 };
 
 typedef struct lang_input_statement_struct
diff --git a/ld/ldlex.h b/ld/ldlex.h
index b2753c3..63f4c81 100644
--- a/ld/ldlex.h
+++ b/ld/ldlex.h
@@ -137,6 +137,8 @@ enum option_values
   OPTION_DEFAULT_SCRIPT,
   OPTION_PRINT_OUTPUT_FORMAT,
   OPTION_IGNORE_UNRESOLVED_SYMBOL,
+  OPTION_PUSH_STATE,
+  OPTION_POP_STATE,
 };
 
 /* The initial parser states.  */
diff --git a/ld/lexsup.c b/ld/lexsup.c
index 52b4fdb..3a1ea9e 100644
--- a/ld/lexsup.c
+++ b/ld/lexsup.c
@@ -505,6 +505,12 @@ static const struct ld_option ld_options[] =
     OPTION_IGNORE_UNRESOLVED_SYMBOL},
     '\0', N_("SYMBOL"),
     N_("Unresolved SYMBOL will not cause an error or warning"), TWO_DASHES },
+  { {"push-state", no_argument, NULL, OPTION_PUSH_STATE},
+    '\0', NULL, N_("Push state of flags governing input file handling"),
+    TWO_DASHES },
+  { {"pop-state", no_argument, NULL, OPTION_POP_STATE},
+    '\0', NULL, N_("Pop state of flags governing input file handling"),
+    TWO_DASHES },
 };
 
 #define OPTION_COUNT ARRAY_SIZE (ld_options)
@@ -1444,6 +1450,23 @@ parse_args (unsigned argc, char **argv)
               einfo (_("%P%X: --hash-size needs a numeric argument\n"));
           }
           break;
+
+	case OPTION_PUSH_STATE:
+	  input_flags.pushed = xmemdup (&input_flags,
+					sizeof (input_flags),
+					sizeof (input_flags));
+	  break;
+
+	case OPTION_POP_STATE:
+	  if (input_flags.pushed == NULL)
+	    einfo (_("%P%F: no state pushed before popping\n"));
+	  else
+	    {
+	      struct lang_input_statement_flags *oldp = input_flags.pushed;
+	      memcpy (&input_flags, oldp, sizeof (input_flags));
+	      free (oldp);
+	    }
+	  break;
 	}
     }