Fix build on Android where bionic does have termios2.

Author: khuey

CMakeLists.txt

@@ -396,6 +396,15 @@ else()
   message(AUTHOR_WARNING "backtrace(3) not present in execinfo.h. Automatic backtraces for failures in rr are disabled.")
 endif()
 
+include(CheckTypeSize)
+set(SAVE_CMAKE_EXTRA_INCLUDE_FILES "${CMAKE_EXTRA_INCLUDE_FILES}")
+list(APPEND CMAKE_EXTRA_INCLUDE_FILES "termios.h")
+check_type_size("struct termios2" SIZEOF_TERMIOS2)
+if(HAVE_SIZEOF_TERMIOS2)
+  add_definitions(-DHAVE_TERMIOS2)
+endif()
+set(CMAKE_EXTRA_INCLUDE_FILES "${SAVE_CMAKE_EXTRA_INCLUDE_FILES}")
+
 # Test only symbols
 check_symbol_exists(pthread_mutexattr_setrobust "pthread.h" HAVE_ROBUST_MUTEX)
 

src/record_syscall.cc

@@ -103,8 +103,9 @@
 
 using namespace std;
 
+#ifndef HAVE_TERMIOS2
 // The kernel header that defines this conflicts badly with glibc headers
-// so we define it ourselves.
+// (but not bionic, which does define this) so we define it ourselves.
 // NB: We need this struct defined so that the preprocessor macro for
 // TCGETS2 will evaluate. But we use IOCTL_MASK_SIZE on it and we use
 // the size from the tracee to determine how many bytes to record, so
@@ -119,6 +120,7 @@ struct termios2 {
   speed_t c_ispeed;
   speed_t c_ospeed;
 };
+#endif
 
 namespace rr {
 

src/test/ioctl_tty.c

@@ -2,7 +2,8 @@
 
 #include "util.h"
 
-/* We have to define termios2 ourselves. See
+#ifndef HAVE_TERMIOS2
+/* We have to define termios2 ourselves with glibc. See
  * https://github.com/npat-efault/picocom/blob/1acf1ddabaf3576b4023c4f6f09c5a3e4b086fb8/termios2.txt
  * for the long explanation.
  */
@@ -16,6 +17,7 @@ struct termios2 {
   speed_t c_ispeed;
   speed_t c_ospeed;
 };
+#endif
 
 int main(void) {
   int fd;