[linux] Use cmake to detect support process_vm_readv (bug #23918)

Summary:
Some old linux versions do not have process_vm_readv function defined. Even older versions do not
have even the __NR_process_vm_readv syscall number. We use cmake to detect these situations and
fallback appropriately: in the first case, we can issue the syscall manually, while it the latter
case, we need to drop fast memory read support completely.

Test Plan: linux test suite passes

Reviewers: ovyalov, Eugene.Zelenko

Subscribers: tberghammer, lldb-commits

Differential Revision: http://reviews.llvm.org/D10727

llvm-svn: 240927

1 files changed, 0 insertions, 9 deletions

diff --git a/lldb/source/Host/android/LibcGlue.cpp b/lldb/source/Host/android/LibcGlue.cpp
index d127d6b01ad..3842fb6c2a8 100644
--- a/lldb/source/Host/android/LibcGlue.cpp
+++ b/lldb/source/Host/android/LibcGlue.cpp
@@ -12,7 +12,6 @@
 #include <android/api-level.h>
 
 #include <sys/syscall.h>
-#include <lldb/Host/linux/Uio.h>
 
 #if __ANDROID_API__ < 21
 
@@ -39,11 +38,3 @@ int posix_openpt(int flags)
 }
 
 #endif
-
-ssize_t process_vm_readv(::pid_t pid,
-			 const struct iovec *local_iov, unsigned long liovcnt,
-			 const struct iovec *remote_iov, unsigned long riovcnt,
-			 unsigned long flags)
-{
-    return syscall(__NR_process_vm_readv, pid, local_iov, liovcnt, remote_iov, riovcnt, flags);
-}