[libc-commits] [libc] 2c73c26 - [libc] Add Convenience syscall Template Function

[Alex Brachet via libc-commits]

Author: Alex Brachet
Date: 2020-02-13T14:39:16-05:00
New Revision: 2c73c266665108ab84a27b11c7860db4bd839225

URL: https://github.com/llvm/llvm-project/commit/2c73c266665108ab84a27b11c7860db4bd839225
DIFF: https://github.com/llvm/llvm-project/commit/2c73c266665108ab84a27b11c7860db4bd839225.diff

LOG: [libc] Add Convenience syscall Template Function

Summary: This patch adds a convenience template function so we don't need to cast all types to `long` manually when calling `__llvm_libc::syscall`.

Reviewers: sivachandra, MaskRay, gchatelet

Reviewed By: sivachandra

Subscribers: libc-commits, tschuett

Differential Revision: https://reviews.llvm.org/D74530

Added: 
    

Modified: 
    libc/config/linux/x86_64/syscall.h.inc
    libc/test/config/linux/x86_64/syscall_test.cpp

Removed: 
    


################################################################################
diff  --git a/libc/config/linux/x86_64/syscall.h.inc b/libc/config/linux/x86_64/syscall.h.inc
index 4659aa09a480..ee3b5e5bfc0d 100644
--- a/libc/config/linux/x86_64/syscall.h.inc
+++ b/libc/config/linux/x86_64/syscall.h.inc
@@ -94,6 +94,13 @@ __attribute__((always_inline)) inline long syscall(long __number, long __arg1,
   return retcode;
 }
 
+template <typename... Ts>
+__attribute__((always_inline)) inline long syscall(long __number, Ts... ts) {
+  static_assert(sizeof...(Ts) <= 6, "Too many arguments for syscall");
+  return syscall(__number, (long)ts...);
+}
+
+
 #undef SYSCALL_CLOBBER_LIST
 
 } // namespace __llvm_libc

diff  --git a/libc/test/config/linux/x86_64/syscall_test.cpp b/libc/test/config/linux/x86_64/syscall_test.cpp
index efab1444d35c..8db7a85256e7 100644
--- a/libc/test/config/linux/x86_64/syscall_test.cpp
+++ b/libc/test/config/linux/x86_64/syscall_test.cpp
@@ -36,4 +36,9 @@ TEST(X86_64_SyscallTest, APITest) {
       [](long n, long a1, long a2, long a3, long a4, long a5, long a6) {
         return __llvm_libc::syscall(n, a1, a2, a3, a4, a5, a6);
       });
+
+  std::function<long(long, void *)> notLongType(
+      [](long n, void *a1) {
+        return __llvm_libc::syscall(n, a1);
+      });
 }