Convert some C functions to rust functions

Right now on linux, an empty executable with LTO still depends on librt becaues
of the clock_gettime function in rust_builtin.o, but this commit moves this
dependency into a rust function which is subject to elimination via LTO.

At the same time, this also drops libstd's dependency on librt on unices that
are not OSX because the library is only used by extra::time (and now the
dependency is listed in that module instead).

2 files changed, 102 insertions, 10 deletions

diff --git a/src/libstd/libc.rs b/src/libstd/libc.rs
index 2696e27c373..fdfc28d9d10 100644
--- a/src/libstd/libc.rs
+++ b/src/libstd/libc.rs
@@ -226,7 +226,8 @@ pub mod types {
         pub mod common {
             pub mod posix01 {
                 use libc::types::common::c95::{c_void};
-                use libc::types::os::arch::c95::{c_char, c_ulong, size_t};
+                use libc::types::os::arch::c95::{c_char, c_ulong, size_t,
+                                                 time_t, suseconds_t, c_long};
 
                 pub type pthread_t = c_ulong;
 
@@ -241,6 +242,18 @@ pub mod types {
                     __unused4: *c_void,
                     __unused5: *c_void,
                 }
+
+                pub struct timeval {
+                    tv_sec: time_t,
+                    tv_usec: suseconds_t,
+                }
+
+                pub struct timespec {
+                    tv_sec: time_t,
+                    tv_nsec: c_long,
+                }
+
+                pub enum timezone {}
             }
             pub mod bsd44 {
                 pub type socklen_t = u32;
@@ -298,6 +311,7 @@ pub mod types {
                 pub type ptrdiff_t = i32;
                 pub type clock_t = i32;
                 pub type time_t = i32;
+                pub type suseconds_t = i32;
                 pub type wchar_t = i32;
             }
             pub mod c99 {
@@ -481,6 +495,7 @@ pub mod types {
                 pub type ptrdiff_t = i64;
                 pub type clock_t = i64;
                 pub type time_t = i64;
+                pub type suseconds_t = i64;
                 pub type wchar_t = i32;
             }
             pub mod c99 {
@@ -553,7 +568,8 @@ pub mod types {
         pub mod common {
             pub mod posix01 {
                 use libc::types::common::c95::{c_void};
-                use libc::types::os::arch::c95::{c_char, c_int, size_t};
+                use libc::types::os::arch::c95::{c_char, c_int, size_t,
+                                                 time_t, suseconds_t, c_long};
                 use libc::types::os::arch::c99::{uintptr_t};
 
                 pub type pthread_t = uintptr_t;
@@ -573,6 +589,18 @@ pub mod types {
                     __unused7: *c_void,
                     __unused8: *c_void,
                 }
+
+                pub struct timeval {
+                    tv_sec: time_t,
+                    tv_usec: suseconds_t,
+                }
+
+                pub struct timespec {
+                    tv_sec: time_t,
+                    tv_nsec: c_long,
+                }
+
+                pub enum timezone {}
             }
             pub mod bsd44 {
                 pub type socklen_t = u32;
@@ -633,6 +661,7 @@ pub mod types {
                 pub type ptrdiff_t = i64;
                 pub type clock_t = i32;
                 pub type time_t = i64;
+                pub type suseconds_t = i64;
                 pub type wchar_t = i32;
             }
             pub mod c99 {
@@ -709,7 +738,8 @@ pub mod types {
     pub mod os {
         pub mod common {
             pub mod posix01 {
-                use libc::types::os::arch::c95::c_short;
+                use libc::types::os::arch::c95::{c_short, time_t, suseconds_t,
+                                                 c_long};
                 use libc::types::os::arch::extra::{int64, time64_t};
                 use libc::types::os::arch::posix88::{dev_t, ino_t};
                 use libc::types::os::arch::posix88::mode_t;
@@ -735,6 +765,18 @@ pub mod types {
                     actime: time64_t,
                     modtime: time64_t,
                 }
+
+                pub struct timeval {
+                    tv_sec: time_t,
+                    tv_usec: suseconds_t,
+                }
+
+                pub struct timespec {
+                    tv_sec: time_t,
+                    tv_nsec: c_long,
+                }
+
+                pub enum timezone {}
             }
 
             pub mod bsd44 {
@@ -807,6 +849,11 @@ pub mod types {
                 #[cfg(target_arch = "x86_64")]
                 pub type time_t = i64;
 
+                #[cfg(target_arch = "x86")]
+                pub type suseconds_t = i32;
+                #[cfg(target_arch = "x86_64")]
+                pub type suseconds_t = i64;
+
                 pub type wchar_t = u16;
             }
 
@@ -983,6 +1030,13 @@ pub mod types {
                 }
 
                 pub type LPOVERLAPPED = *mut OVERLAPPED;
+
+                pub struct FILETIME {
+                    dwLowDateTime: DWORD,
+                    dwHighDateTime: DWORD,
+                }
+
+                pub type LPFILETIME = *mut FILETIME;
             }
         }
     }
@@ -991,8 +1045,9 @@ pub mod types {
     pub mod os {
         pub mod common {
             pub mod posix01 {
-                use libc::types::common::c95::{c_void};
-                use libc::types::os::arch::c95::{c_char, c_int, size_t};
+                use libc::types::common::c95::c_void;
+                use libc::types::os::arch::c95::{c_char, c_int, size_t,
+                                                 time_t, suseconds_t, c_long};
                 use libc::types::os::arch::c99::{uintptr_t};
 
                 pub type pthread_t = uintptr_t;
@@ -1012,6 +1067,18 @@ pub mod types {
                     __unused7: *c_void,
                     __unused8: *c_void,
                 }
+
+                pub struct timeval {
+                    tv_sec: time_t,
+                    tv_usec: suseconds_t,
+                }
+
+                pub struct timespec {
+                    tv_sec: time_t,
+                    tv_nsec: c_long,
+                }
+
+                pub enum timezone {}
             }
 
             pub mod bsd44 {
@@ -1075,6 +1142,7 @@ pub mod types {
                 pub type ptrdiff_t = i32;
                 pub type clock_t = u32;
                 pub type time_t = i32;
+                pub type suseconds_t = i32;
                 pub type wchar_t = i32;
             }
             pub mod c99 {
@@ -1144,6 +1212,12 @@ pub mod types {
             pub mod bsd44 {
             }
             pub mod extra {
+                pub struct mach_timebase_info {
+                    numer: u32,
+                    denom: u32,
+                }
+
+                pub type mach_timebase_info_data_t = mach_timebase_info;
             }
         }
 
@@ -1165,6 +1239,7 @@ pub mod types {
                 pub type ptrdiff_t = i64;
                 pub type clock_t = u64;
                 pub type time_t = i64;
+                pub type suseconds_t = i32;
                 pub type wchar_t = i32;
             }
             pub mod c99 {
@@ -1235,6 +1310,12 @@ pub mod types {
             pub mod bsd44 {
             }
             pub mod extra {
+                pub struct mach_timebase_info {
+                    numer: u32,
+                    denom: u32,
+                }
+
+                pub type mach_timebase_info_data_t = mach_timebase_info;
             }
         }
     }
@@ -2047,6 +2128,9 @@ pub mod consts {
 
             pub static PTHREAD_CREATE_JOINABLE: c_int = 0;
             pub static PTHREAD_CREATE_DETACHED: c_int = 1;
+
+            pub static CLOCK_REALTIME: c_int = 0;
+            pub static CLOCK_MONOTONIC: c_int = 1;
         }
         pub mod posix08 {
         }
@@ -2467,6 +2551,9 @@ pub mod consts {
 
             pub static PTHREAD_CREATE_JOINABLE: c_int = 0;
             pub static PTHREAD_CREATE_DETACHED: c_int = 1;
+
+            pub static CLOCK_REALTIME: c_int = 0;
+            pub static CLOCK_MONOTONIC: c_int = 4;
         }
         pub mod posix08 {
         }
@@ -3609,8 +3696,7 @@ pub mod funcs {
     #[cfg(target_os = "freebsd")]
     pub mod bsd44 {
         use libc::types::common::c95::{c_void};
-        use libc::types::os::arch::c95::{c_char, c_uchar, c_int, c_uint,
-                                         size_t};
+        use libc::types::os::arch::c95::{c_char, c_uchar, c_int, c_uint, size_t};
 
         extern {
             pub fn sysctl(name: *c_int,
@@ -3694,7 +3780,7 @@ pub mod funcs {
                                                LPMEMORY_BASIC_INFORMATION,
                                                LPSYSTEM_INFO};
             use libc::types::os::arch::extra::{HANDLE, LPHANDLE, LARGE_INTEGER,
-                                               PLARGE_INTEGER};
+                                               PLARGE_INTEGER, LPFILETIME};
 
             extern "system" {
                 pub fn GetEnvironmentVariableW(n: LPCWSTR,
@@ -3838,6 +3924,14 @@ pub mod funcs {
                                         lpNewFilePointer: PLARGE_INTEGER,
                                         dwMoveMethod: DWORD) -> BOOL;
                 pub fn SetEndOfFile(hFile: HANDLE) -> BOOL;
+
+                pub fn GetSystemTimeAsFileTime(
+                            lpSystemTimeAsFileTime: LPFILETIME);
+
+                pub fn QueryPerformanceFrequency(
+                            lpFrequency: *mut LARGE_INTEGER) -> BOOL;
+                pub fn QueryPerformanceCounter(
+                            lpPerformanceCount: *mut LARGE_INTEGER) -> BOOL;
             }
         }
 
diff --git a/src/libstd/rtdeps.rs b/src/libstd/rtdeps.rs
index 1ecfc1f25d0..045cdf574f6 100644
--- a/src/libstd/rtdeps.rs
+++ b/src/libstd/rtdeps.rs
@@ -22,7 +22,6 @@ extern {}
 // On linux librt and libdl are indirect dependencies via rustrt,
 // and binutils 2.22+ won't add them automatically
 #[cfg(target_os = "linux")]
-#[link(name = "rt")]
 #[link(name = "dl")]
 #[link(name = "m")]
 #[link(name = "pthread")]
@@ -36,7 +35,6 @@ extern {}
 
 #[cfg(target_os = "freebsd")]
 #[link(name = "execinfo")]
-#[link(name = "rt")]
 #[link(name = "pthread")]
 extern {}