authorgravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2016-01-27 20:17:55-07:00
committergravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2016-01-27 20:17:55-07:00
loge3cc0c25718e8ff580eabce35ba845e968c74e1a
tree2eb23012fd738a6b88a68f61557985f0a907c0d4
parentd1ac1abd34318273b746763a1ce5f3055bba541c
parent401a3361ea13e7b8e063cbad29d3c0d7cc0f86a9

Merge pull request #96 from MovingtoMars/master

simple malloc and free using mmap

4 files changed, 77 insertions(+), 0 deletions(-)

CMakeLists.txt+1
...@@ -123,6 +123,7 @@ set(ZIG_STD_SRC...@@ -123,6 +123,7 @@ set(ZIG_STD_SRC
123 "${CMAKE_SOURCE_DIR}/std/syscall.zig"123 "${CMAKE_SOURCE_DIR}/std/syscall.zig"
124 "${CMAKE_SOURCE_DIR}/std/errno.zig"124 "${CMAKE_SOURCE_DIR}/std/errno.zig"
125 "${CMAKE_SOURCE_DIR}/std/rand.zig"125 "${CMAKE_SOURCE_DIR}/std/rand.zig"
126 "${CMAKE_SOURCE_DIR}/std/mem.zig"
126)127)
127128
128set(C_HEADERS_DEST "lib/zig/include")129set(C_HEADERS_DEST "lib/zig/include")
std/mem.zig created+22
...@@ -0,0 +1,22 @@
1import "syscall.zig";
2import "std.zig";
3import "errno.zig";
4
5pub fn malloc(bytes: isize) -> ?&u8 {
6 if (bytes > 4096) {
7 %%stderr.printf("TODO alloc sizes > 4096B\n");
8 return null;
9 }
10
11 const result = mmap(isize(0), 4096, MMAP_PROT_READ|MMAP_PROT_WRITE, MMAP_MAP_ANON|MMAP_MAP_SHARED, -1, 0);
12
13 if (-4096 < result && result <= 0) {
14 null
15 } else {
16 (&u8)(result)
17 }
18}
19
20pub fn free(ptr: &u8) {
21 munmap(isize(ptr), 4096);
22}
std/syscall.zig+36
...@@ -1,8 +1,22 @@...@@ -1,8 +1,22 @@
1const SYS_read = 0;1const SYS_read = 0;
2const SYS_write = 1;2const SYS_write = 1;
3const SYS_mmap = 9;
4const SYS_munmap = 11;
3const SYS_exit = 60;5const SYS_exit = 60;
4const SYS_getrandom = 318;6const SYS_getrandom = 318;
57
8// mmap constants
9pub const MMAP_PROT_NONE = 0;
10pub const MMAP_PROT_READ = 1;
11pub const MMAP_PROT_WRITE = 2;
12pub const MMAP_PROT_EXEC = 4;
13
14pub const MMAP_MAP_FILE = 0;
15pub const MMAP_MAP_SHARED = 1;
16pub const MMAP_MAP_PRIVATE = 2;
17pub const MMAP_MAP_FIXED = 16;
18pub const MMAP_MAP_ANON = 32;
19
6fn syscall1(number: isize, arg1: isize) -> isize {20fn syscall1(number: isize, arg1: isize) -> isize {
7 asm volatile ("syscall"21 asm volatile ("syscall"
8 : [ret] "={rax}" (-> isize)22 : [ret] "={rax}" (-> isize)
...@@ -17,6 +31,28 @@ fn syscall3(number: isize, arg1: isize, arg2: isize, arg3: isize) -> isize {...@@ -17,6 +31,28 @@ fn syscall3(number: isize, arg1: isize, arg2: isize, arg3: isize) -> isize {
17 : "rcx", "r11")31 : "rcx", "r11")
18}32}
1933
34fn syscall2(number: isize, arg1: isize, arg2: isize) -> isize {
35 asm volatile ("syscall"
36 : [ret] "={rax}" (-> isize)
37 : [number] "{rax}" (number), [arg1] "{rdi}" (arg1), [arg2] "{rsi}" (arg2)
38 : "rcx", "r11")
39}
40
41fn syscall6(number: isize, arg1: isize, arg2: isize, arg3: isize, arg4: isize, arg5: isize, arg6: isize) -> isize {
42 asm volatile ("syscall"
43 : [ret] "={rax}" (-> isize)
44 : [number] "{rax}" (number), [arg1] "{rdi}" (arg1), [arg2] "{rsi}" (arg2), [arg3] "{rdx}" (arg3), [arg4] "{r10}" (arg4), [arg5] "{r8}" (arg5), [arg6] "{r9}" (arg6)
45 : "rcx", "r11")
46}
47
48pub fn mmap(address: isize, length: isize, prot: isize, flags: isize, fd: isize, offset: isize) -> isize {
49 syscall6(SYS_mmap, address, length, prot, flags, fd, offset)
50}
51
52pub fn munmap(address: isize, length: isize) -> isize {
53 syscall2(SYS_munmap, address, length)
54}
55
20pub fn read(fd: isize, buf: &u8, count: isize) -> isize {56pub fn read(fd: isize, buf: &u8, count: isize) -> isize {
21 syscall3(SYS_read, isize(fd), isize(buf), count)57 syscall3(SYS_read, isize(fd), isize(buf), count)
22}58}
test/run_tests.cpp+18
...@@ -1344,6 +1344,24 @@ pub fn main(args: [][]u8) -> %void {...@@ -1344,6 +1344,24 @@ pub fn main(args: [][]u8) -> %void {
1344 %%stdout.printf("BAD\n");1344 %%stdout.printf("BAD\n");
1345 }1345 }
1346 %%stdout.printf("OK\n");1346 %%stdout.printf("OK\n");
1347}
1348 )SOURCE", "OK\n");
1349
1350 add_simple_case("malloc and free", R"SOURCE(
1351import "mem.zig";
1352import "std.zig";
1353
1354pub fn main(args: [][]u8) -> %void {
1355 var ptr = malloc(1) ?? unreachable{};
1356
1357 *ptr = 6;
1358
1359 if (*ptr != 6) {
1360 %%stdout.printf("BAD\n");
1361 }
1362 %%stdout.printf("OK\n");
1363
1364 free(ptr);
1347}1365}
1348 )SOURCE", "OK\n");1366 )SOURCE", "OK\n");
1349}1367}