use architecture-specific ssize_t definition

after change 32822 was rejected, this is the more light-weight
version of the fix: libc/include/sys/types.h already - via
libc/kernel/common/linux/posix_types.h - includes a definition
of __kernel_ssize_t from libc/kernel/arch-*/asm/posix_types.h
which is architecture-specific, toolchain-agnostic and also
gets rid of the gcc -Wformat warning (which it issues correctly,
since this i̲s̲ indeed a bug in bionic)

Change-Id: Ie4503ab16628bc25815a836d07556f665e9795c7

1 files changed, 9 insertions, 0 deletions

diff --git a/tests/stdio_test.cpp b/tests/stdio_test.cpp
index 70a71fb87..d2311fd54 100644
--- a/tests/stdio_test.cpp
+++ b/tests/stdio_test.cpp
@@ -169,3 +169,12 @@ TEST(stdio, getline_invalid) {
   ASSERT_EQ(getline(&buffer, &buffer_length, fp), -1);
   ASSERT_EQ(EBADF, errno);
 }
+
+TEST(stdio, printf_ssize_t) {
+  // We used to have a ssize_t definition that confused GCC into saying:
+  // error: format '%zd' expects argument of type 'signed size_t',
+  //     but argument 4 has type 'ssize_t {aka long int}' [-Werror=format]
+  ssize_t v = 1;
+  char buf[32];
+  snprintf(buf, sizeof(buf), "%zd", v);
+}