From 730da15840c998319918da668defcf4a51410b12 Mon Sep 17 00:00:00 2001 From: Elliott Hughes Date: Thu, 28 Feb 2013 10:51:14 -0800 Subject: [PATCH] Avoid changing the C++ ABI with ssize_t. Bug: 8253769 Change-Id: Ia325003ed6e59da553e2bdde7c43515bc191b8ba --- libc/include/sys/types.h | 9 +++++++++ tests/stdio_test.cpp | 9 ++++++++- 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/libc/include/sys/types.h b/libc/include/sys/types.h index 459159fe9..850e22ec5 100644 --- a/libc/include/sys/types.h +++ b/libc/include/sys/types.h @@ -85,8 +85,17 @@ typedef .... pthread_t; #ifndef _SSIZE_T_DEFINED_ #define _SSIZE_T_DEFINED_ +/* Traditionally, bionic's ssize_t was "long int". This causes GCC to emit warnings when you + * pass a ssize_t to a printf-style function. The correct type is __kernel_ssize_t, which is + * "int", which isn't an ABI change for C code (because they're the same size) but is an ABI + * change for C++ because "int" and "long int" mangle to "i" and "l" respectively. So until + * we can fix the ABI, this is the best we can do. http://b/8253769. */ +#if defined(__cplusplus) +typedef long int ssize_t; +#else typedef __kernel_ssize_t ssize_t; #endif +#endif typedef __kernel_suseconds_t suseconds_t; typedef __kernel_time_t time_t; diff --git a/tests/stdio_test.cpp b/tests/stdio_test.cpp index d2311fd54..196c725aa 100644 --- a/tests/stdio_test.cpp +++ b/tests/stdio_test.cpp @@ -171,10 +171,17 @@ TEST(stdio, getline_invalid) { } TEST(stdio, printf_ssize_t) { - // We used to have a ssize_t definition that confused GCC into saying: +#if __BIONIC__ + // http://b/8253769 + ASSERT_EQ(sizeof(__kernel_ssize_t), sizeof(long int)); + ASSERT_EQ(sizeof(ssize_t), sizeof(long int)); +#else + // TODO: add a .c file so we can test this for bionic --- our C ssize_t is fine. + // For our 32-bit C++ ABI, we have a ssize_t definition that confuses 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); +#endif }