From eac0a8bc3070e45047fff57e7b024a059289a36d Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Thu, 21 Jan 2016 15:36:25 -0800
Subject: bootstrap: Add directives to not double-link libs

Have all Cargo-built crates pass `--cfg cargobuild` and then add appropriate
`#[cfg]` definitions to all crates to avoid linking anything if this is passed.
This should help allow libstd to compile with both the makefiles and with Cargo.
---
 src/libstd/sys/common/gnu/libbacktrace.rs | 2 +-
 src/libstd/sys/common/unwind/gcc.rs       | 3 +++
 src/libstd/sys/unix/os.rs                 | 3 ++-
 src/libstd/sys/windows/c.rs               | 3 +++
 4 files changed, 9 insertions(+), 2 deletions(-)

(limited to 'src/libstd/sys')

diff --git a/src/libstd/sys/common/gnu/libbacktrace.rs b/src/libstd/sys/common/gnu/libbacktrace.rs
index f8463388384..8b3cb04030c 100644
--- a/src/libstd/sys/common/gnu/libbacktrace.rs
+++ b/src/libstd/sys/common/gnu/libbacktrace.rs
@@ -40,7 +40,7 @@ pub fn print(w: &mut Write, idx: isize, addr: *mut libc::c_void,
                       errnum: libc::c_int);
     enum backtrace_state {}
     #[link(name = "backtrace", kind = "static")]
-    #[cfg(not(test))]
+    #[cfg(all(not(test), not(cargobuild)))]
     extern {}
 
     extern {
diff --git a/src/libstd/sys/common/unwind/gcc.rs b/src/libstd/sys/common/unwind/gcc.rs
index 12cd07a4f4f..7cf9e2a54bd 100644
--- a/src/libstd/sys/common/unwind/gcc.rs
+++ b/src/libstd/sys/common/unwind/gcc.rs
@@ -252,6 +252,9 @@ pub mod eh_frame_registry {
     // See also: rtbegin.rs, `unwind` module.
 
     #[link(name = "gcc_eh")]
+    #[cfg(not(cargobuild))]
+    extern {}
+
     extern {
         fn __register_frame_info(eh_frame_begin: *const u8, object: *mut u8);
         fn __deregister_frame_info(eh_frame_begin: *const u8, object: *mut u8);
diff --git a/src/libstd/sys/unix/os.rs b/src/libstd/sys/unix/os.rs
index 9def3adc303..b6a0bd84409 100644
--- a/src/libstd/sys/unix/os.rs
+++ b/src/libstd/sys/unix/os.rs
@@ -339,7 +339,6 @@ pub fn args() -> Args {
 pub fn args() -> Args {
     use mem;
 
-    #[link(name = "objc")]
     extern {
         fn sel_registerName(name: *const libc::c_uchar) -> Sel;
         fn objc_msgSend(obj: NsId, sel: Sel, ...) -> NsId;
@@ -347,6 +346,8 @@ pub fn args() -> Args {
     }
 
     #[link(name = "Foundation", kind = "framework")]
+    #[link(name = "objc")]
+    #[cfg(not(cargobuild))]
     extern {}
 
     type Sel = *const libc::c_void;
diff --git a/src/libstd/sys/windows/c.rs b/src/libstd/sys/windows/c.rs
index 6e8090a2235..9fdeb0aef14 100644
--- a/src/libstd/sys/windows/c.rs
+++ b/src/libstd/sys/windows/c.rs
@@ -966,6 +966,9 @@ pub enum EXCEPTION_DISPOSITION {
 #[link(name = "userenv")]
 #[link(name = "shell32")]
 #[link(name = "advapi32")]
+#[cfg(not(cargobuild))]
+extern {}
+
 extern "system" {
     pub fn WSAStartup(wVersionRequested: WORD,
                       lpWSAData: LPWSADATA) -> c_int;
-- 
cgit 1.4.1-3-g733a5