Allow opting-out of rpath usage

By default, the compiler and libraries are all still built with rpaths, but this
can be opted out of with --disable-rpath to ./configure or --no-rpath to rustc.

cc #5219

Author: alexcrichton

Makefile.in

@@ -124,6 +124,12 @@ endif
 ifdef TRACE
   CFG_RUSTC_FLAGS += -Z trace
 endif
+ifdef DISABLE_RPATH
+# NOTE: make this CFG_RUSTC_FLAGS after stage0 snapshot
+RUSTFLAGS_STAGE1 += --no-rpath
+RUSTFLAGS_STAGE2 += --no-rpath
+RUSTFLAGS_STAGE3 += --no-rpath
+endif
 
 # The executables crated during this compilation process have no need to include
 # static copies of libstd and libextra. We also generate dynamic versions of all
@@ -541,8 +547,21 @@ CFGFLAG$(1)_T_$(2)_H_$(3) = stage1
 endif
 endif
 
+ifdef CFG_DISABLE_RPATH
+ifeq ($$(OSTYPE_$(3)),apple-darwin)
+  RPATH_VAR$(1)_T_$(2)_H_$(3) := \
+      DYLD_LIBRARY_PATH="$$$$DYLD_LIBRARY_PATH:$$(HLIB$(1)_H_$(3))"
+else
+  RPATH_VAR$(1)_T_$(2)_H_$(3) := \
+      LD_LIBRARY_PATH="$$$$LD_LIBRARY_PATH:$$(HLIB$(1)_H_$(3))"
+endif
+else
+    RPATH_VAR$(1)_T_$(2)_H_$(3) :=
+endif
+
 STAGE$(1)_T_$(2)_H_$(3) := 						\
-	$$(Q)$$(call CFG_RUN_TARG_$(3),$(1),				\
+	$$(Q)$$(RPATH_VAR$(1)_T_$(2)_H_$(3))                            \
+		$$(call CFG_RUN_TARG_$(3),$(1),				\
 		$$(CFG_VALGRIND_COMPILE$(1)) 			\
 		$$(HBIN$(1)_H_$(3))/rustc$$(X_$(3))			\
 		--cfg $$(CFGFLAG$(1)_T_$(2)_H_$(3))			\

configure

@@ -382,6 +382,7 @@ opt ccache 0 "invoke gcc/clang via ccache to reuse object files between builds"
 opt local-rust 0 "use an installed rustc rather than downloading a snapshot"
 opt pax-flags 0 "apply PaX flags to rustc binaries (required for GRSecurity/PaX-patched kernels)"
 opt inject-std-version 1 "inject the current compiler version of libstd into programs"
+opt rpath 1 "build rpaths into rustc itself"
 valopt prefix "/usr/local" "set installation prefix"
 valopt local-rust-root "/usr/local" "set prefix for local rust binary"
 valopt llvm-root "" "set LLVM root"

src/librustc/back/link.rs

@@ -1089,8 +1089,10 @@ fn link_args(sess: Session,
             args.push(~"-dynamiclib");
             args.push(~"-Wl,-dylib");
             // FIXME (#9639): This needs to handle non-utf8 paths
-            args.push(~"-Wl,-install_name,@rpath/" +
-                      out_filename.filename_str().unwrap());
+            if !sess.opts.no_rpath {
+                args.push(~"-Wl,-install_name,@rpath/" +
+                          out_filename.filename_str().unwrap());
+            }
         } else {
             args.push(~"-shared")
         }
@@ -1108,7 +1110,9 @@ fn link_args(sess: Session,
     // FIXME (#2397): At some point we want to rpath our guesses as to
     // where extern libraries might live, based on the
     // addl_lib_search_paths
-    args.push_all(rpath::get_rpath_flags(sess, out_filename));
+    if !sess.opts.no_rpath {
+        args.push_all(rpath::get_rpath_flags(sess, out_filename));
+    }
 
     // Finally add all the linker arguments provided on the command line along
     // with any #[link_args] attributes found inside the crate

src/librustc/driver/driver.rs

@@ -734,6 +734,7 @@ pub fn build_session_options(binary: ~str,
     let parse_only = matches.opt_present("parse-only");
     let no_trans = matches.opt_present("no-trans");
     let no_analysis = matches.opt_present("no-analysis");
+    let no_rpath = matches.opt_present("no-rpath");
 
     let lint_levels = [lint::allow, lint::warn,
                        lint::deny, lint::forbid];
@@ -888,6 +889,7 @@ pub fn build_session_options(binary: ~str,
         parse_only: parse_only,
         no_trans: no_trans,
         no_analysis: no_analysis,
+        no_rpath: no_rpath,
         debugging_opts: debugging_opts,
         android_cross_path: android_cross_path,
         write_dependency_info: write_dependency_info,
@@ -995,6 +997,7 @@ pub fn optgroups() -> ~[getopts::groups::OptGroup] {
                         \"list\" will list all of the available passes", "NAMES"),
   optopt("", "llvm-args", "A list of arguments to pass to llvm, comma \
                            separated", "ARGS"),
+  optflag("", "no-rpath", "Disables setting the rpath in libs/exes"),
   optopt( "",  "out-dir",
                         "Write output to compiler-chosen filename
                           in <dir>", "DIR"),

src/librustc/driver/session.rs

@@ -170,6 +170,7 @@ pub struct Options {
     parse_only: bool,
     no_trans: bool,
     no_analysis: bool,
+    no_rpath: bool,
     debugging_opts: u64,
     android_cross_path: Option<~str>,
     /// Whether to write dependency files. It's (enabled, optional filename).
@@ -388,6 +389,7 @@ pub fn basic_options() -> @Options {
         parse_only: false,
         no_trans: false,
         no_analysis: false,
+        no_rpath: false,
         debugging_opts: 0,
         android_cross_path: None,
         write_dependency_info: (false, None),