zig

commit 2e04b61275062f4a3672cdea2456effbc0cb22a5 (tree)
parent b9a1d67637cfae6206fffce78fc2e40780ef4fb5
Author: LemonBoy <thatlemon@gmail.com>
Date:   Fri,  6 Mar 2020 09:17:14 +0100

std: Work around unexported NtCurrentTeb

Apparently NtCurrentTeb is only exported for i386 and some other
platforms but not for x86_64 nor AArch64. Let's go with the flow and
provide our own NtCurrentTeb like the Windows headers do.

Thank you Microsoft.

Diffstat:
M
lib/std/os/windows.zig
 | 
20
+++++++++++++++++++-
M
lib/std/os/windows/ntdll.zig
 | 
1
-

2 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/lib/std/os/windows.zig b/lib/std/os/windows.zig
@@ -1083,8 +1083,26 @@ pub fn SetFileTime(
     }
 }
 
+pub fn teb() *TEB {
+    return switch (builtin.arch) {
+        .i386 => asm volatile (
+            \\ movl %%fs:0x18, %[ptr]
+            : [ptr] "=r" (-> *TEB)
+        ),
+        .x86_64 => asm volatile (
+            \\ movq %%gs:0x30, %[ptr]
+            : [ptr] "=r" (-> *TEB)
+        ),
+        .aarch64 => asm volatile (
+            \\ mov %[ptr], x18
+            : [ptr] "=r" (-> *TEB)
+        ),
+        else => @compileError("unsupported arch"),
+    };
+}
+
 pub fn peb() *PEB {
-    return ntdll.NtCurrentTeb().ProcessEnvironmentBlock;
+    return teb().ProcessEnvironmentBlock;
 }
 
 /// A file time is a 64-bit value that represents the number of 100-nanosecond
diff --git a/lib/std/os/windows/ntdll.zig b/lib/std/os/windows/ntdll.zig
@@ -16,7 +16,6 @@ pub extern "NtDll" fn NtQueryInformationFile(
     Length: ULONG,
     FileInformationClass: FILE_INFORMATION_CLASS,
 ) callconv(.Stdcall) NTSTATUS;
-pub extern "NtDll" fn NtCurrentTeb() callconv(.Stdcall) *TEB;
 
 pub extern "NtDll" fn NtQueryAttributesFile(
     ObjectAttributes: *OBJECT_ATTRIBUTES,