Move compiler-compatibility headers into their own module

This one has no generated code.

1 files changed, 197 insertions, 0 deletions

diff --git a/src/lib/cc/compat_compiler.h b/src/lib/cc/compat_compiler.h
new file mode 100644
index 0000000000..a9a3266165
--- /dev/null
+++ b/src/lib/cc/compat_compiler.h
@@ -0,0 +1,197 @@
+/* Copyright (c) 2003-2004, Roger Dingledine
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#ifndef TOR_COMPAT_COMPILER_H
+#define TOR_COMPAT_COMPILER_H
+
+#include "orconfig.h"
+
+#if defined(__has_feature)
+#  if __has_feature(address_sanitizer)
+/* Some of the fancy glibc strcmp() macros include references to memory that
+ * clang rejects because it is off the end of a less-than-3. Clang hates this,
+ * even though those references never actually happen. */
+#    undef strcmp
+#endif /* __has_feature(address_sanitizer) */
+#endif /* defined(__has_feature) */
+
+#ifndef NULL_REP_IS_ZERO_BYTES
+#error "It seems your platform does not represent NULL as zero. We can't cope."
+#endif
+
+#ifndef DOUBLE_0_REP_IS_ZERO_BYTES
+#error "It seems your platform does not represent 0.0 as zeros. We can't cope."
+#endif
+
+#if 'a'!=97 || 'z'!=122 || 'A'!=65 || ' '!=32
+#error "It seems that you encode characters in something other than ASCII."
+#endif
+
+/* GCC can check printf and scanf types on arbitrary functions. */
+#ifdef __GNUC__
+#define CHECK_PRINTF(formatIdx, firstArg) \
+   __attribute__ ((format(printf, formatIdx, firstArg)))
+#else
+#define CHECK_PRINTF(formatIdx, firstArg)
+#endif /* defined(__GNUC__) */
+#ifdef __GNUC__
+#define CHECK_SCANF(formatIdx, firstArg) \
+   __attribute__ ((format(scanf, formatIdx, firstArg)))
+#else
+#define CHECK_SCANF(formatIdx, firstArg)
+#endif /* defined(__GNUC__) */
+
+/* What GCC do we have? */
+#ifdef __GNUC__
+#define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
+#else
+#define GCC_VERSION 0
+#endif
+
+/* Temporarily enable and disable warnings. */
+#ifdef __GNUC__
+#  define PRAGMA_STRINGIFY_(s) #s
+#  define PRAGMA_JOIN_STRINGIFY_(a,b) PRAGMA_STRINGIFY_(a ## b)
+/* Support for macro-generated pragmas (c99) */
+#  define PRAGMA_(x) _Pragma (#x)
+#  ifdef __clang__
+#    define PRAGMA_DIAGNOSTIC_(x) PRAGMA_(clang diagnostic x)
+#  else
+#    define PRAGMA_DIAGNOSTIC_(x) PRAGMA_(GCC diagnostic x)
+#  endif
+#  if defined(__clang__) || GCC_VERSION >= 406
+/* we have push/pop support */
+#    define DISABLE_GCC_WARNING(warningopt) \
+          PRAGMA_DIAGNOSTIC_(push) \
+          PRAGMA_DIAGNOSTIC_(ignored PRAGMA_JOIN_STRINGIFY_(-W,warningopt))
+#    define ENABLE_GCC_WARNING(warningopt) \
+          PRAGMA_DIAGNOSTIC_(pop)
+#else /* !(defined(__clang__) || GCC_VERSION >= 406) */
+/* older version of gcc: no push/pop support. */
+#    define DISABLE_GCC_WARNING(warningopt) \
+         PRAGMA_DIAGNOSTIC_(ignored PRAGMA_JOIN_STRINGIFY_(-W,warningopt))
+#    define ENABLE_GCC_WARNING(warningopt) \
+         PRAGMA_DIAGNOSTIC_(warning PRAGMA_JOIN_STRINGIFY_(-W,warningopt))
+#endif /* defined(__clang__) || GCC_VERSION >= 406 */
+#else /* !(defined(__GNUC__)) */
+/* not gcc at all */
+# define DISABLE_GCC_WARNING(warning)
+# define ENABLE_GCC_WARNING(warning)
+#endif /* defined(__GNUC__) */
+
+/* inline is __inline on windows. */
+#ifdef _WIN32
+#define inline __inline
+#endif
+
+/* Try to get a reasonable __func__ substitute in place. */
+#if defined(_MSC_VER)
+
+#define __func__ __FUNCTION__
+
+#else
+/* For platforms where autoconf works, make sure __func__ is defined
+ * sanely. */
+#ifndef HAVE_MACRO__func__
+#ifdef HAVE_MACRO__FUNCTION__
+#define __func__ __FUNCTION__
+#elif HAVE_MACRO__FUNC__
+#define __func__ __FUNC__
+#else
+#define __func__ "???"
+#endif /* defined(HAVE_MACRO__FUNCTION__) || ... */
+#endif /* !defined(HAVE_MACRO__func__) */
+#endif /* defined(_MSC_VER) */
+
+#define U64_TO_DBL(x) ((double) (x))
+#define DBL_TO_U64(x) ((uint64_t) (x))
+
+#ifdef ENUM_VALS_ARE_SIGNED
+#define ENUM_BF(t) unsigned
+#else
+/** Wrapper for having a bitfield of an enumerated type. Where possible, we
+ * just use the enumerated type (so the compiler can help us and notice
+ * problems), but if enumerated types are unsigned, we must use unsigned,
+ * so that the loss of precision doesn't make large values negative. */
+#define ENUM_BF(t) t
+#endif /* defined(ENUM_VALS_ARE_SIGNED) */
+
+/* GCC has several useful attributes. */
+#if defined(__GNUC__) && __GNUC__ >= 3
+#define ATTR_NORETURN __attribute__((noreturn))
+#define ATTR_CONST __attribute__((const))
+#define ATTR_MALLOC __attribute__((malloc))
+#define ATTR_NORETURN __attribute__((noreturn))
+#define ATTR_WUR __attribute__((warn_unused_result))
+/* Alas, nonnull is not at present a good idea for us.  We'd like to get
+ * warnings when we pass NULL where we shouldn't (which nonnull does, albeit
+ * spottily), but we don't want to tell the compiler to make optimizations
+ * with the assumption that the argument can't be NULL (since this would make
+ * many of our checks go away, and make our code less robust against
+ * programming errors).  Unfortunately, nonnull currently does both of these
+ * things, and there's no good way to split them up.
+ *
+ * #define ATTR_NONNULL(x) __attribute__((nonnull x)) */
+#define ATTR_NONNULL(x)
+#define ATTR_UNUSED __attribute__ ((unused))
+
+/** Macro: Evaluates to <b>exp</b> and hints the compiler that the value
+ * of <b>exp</b> will probably be true.
+ *
+ * In other words, "if (PREDICT_LIKELY(foo))" is the same as "if (foo)",
+ * except that it tells the compiler that the branch will be taken most of the
+ * time.  This can generate slightly better code with some CPUs.
+ */
+#define PREDICT_LIKELY(exp) __builtin_expect(!!(exp), 1)
+/** Macro: Evaluates to <b>exp</b> and hints the compiler that the value
+ * of <b>exp</b> will probably be false.
+ *
+ * In other words, "if (PREDICT_UNLIKELY(foo))" is the same as "if (foo)",
+ * except that it tells the compiler that the branch will usually not be
+ * taken.  This can generate slightly better code with some CPUs.
+ */
+#define PREDICT_UNLIKELY(exp) __builtin_expect(!!(exp), 0)
+#else /* !(defined(__GNUC__) && __GNUC__ >= 3) */
+#define ATTR_NORETURN
+#define ATTR_CONST
+#define ATTR_MALLOC
+#define ATTR_NORETURN
+#define ATTR_NONNULL(x)
+#define ATTR_UNUSED
+#define ATTR_WUR
+#define PREDICT_LIKELY(exp) (exp)
+#define PREDICT_UNLIKELY(exp) (exp)
+#endif /* defined(__GNUC__) && __GNUC__ >= 3 */
+
+/** Expands to a syntactically valid empty statement.  */
+#define STMT_NIL (void)0
+
+/** Expands to a syntactically valid empty statement, explicitly (void)ing its
+ * argument. */
+#define STMT_VOID(a) while (0) { (void)(a); }
+
+#ifdef __GNUC__
+/** STMT_BEGIN and STMT_END are used to wrap blocks inside macros so that
+ * the macro can be used as if it were a single C statement. */
+#define STMT_BEGIN (void) ({
+#define STMT_END })
+#elif defined(sun) || defined(__sun__)
+#define STMT_BEGIN if (1) {
+#define STMT_END } else STMT_NIL
+#else
+#define STMT_BEGIN do {
+#define STMT_END } while (0)
+#endif /* defined(__GNUC__) || ... */
+
+/* Some tools (like coccinelle) don't like to see operators as macro
+ * arguments. */
+#define OP_LT <
+#define OP_GT >
+#define OP_GE >=
+#define OP_LE <=
+#define OP_EQ ==
+#define OP_NE !=
+
+#endif /* !defined(TOR_COMPAT_H) */