Delete several blocks of unused code. (WebAssembly#294)

* Delete several blocks of unused code.

Delete several pieces of code from libc-bottom-half/cloudlibc that aren't in
use on wasi-libc.

* Delete more of `_CLOCK_PROCESS_CPUTIME_ID` or `_CLOCK_THREAD_CPUTIME_ID`.

Author: Dan Gohman

expected/wasm32-wasi/posix/predefined-macros.txt

@@ -1,7 +1,5 @@
 _CLOCK_MONOTONIC
-_CLOCK_PROCESS_CPUTIME_ID
 _CLOCK_REALTIME
-_CLOCK_THREAD_CPUTIME_ID
 _Exit
 _Fork
 _IO_feof_unlocked

expected/wasm32-wasi/single/defined-symbols.txt

@@ -6,7 +6,6 @@
 #define COMMON_TIME_H
 
 #include <common/limits.h>
-#include <common/overflow.h>
 
 #include <sys/time.h>
 
@@ -16,43 +15,6 @@
 
 #define NSEC_PER_SEC 1000000000
 
-// Timezone agnostic conversion routines.
-int __localtime_utc(time_t, struct tm *);
-void __mktime_utc(const struct tm *, struct timespec *);
-
-static inline bool is_leap(time_t year) {
-  year %= 400;
-  if (year < 0)
-    year += 400;
-  return ((year % 4) == 0 && (year % 100) != 0) || year == 100;
-}
-
-// Gets the length of the months in a year.
-static inline const char *get_months(time_t year) {
-  static const char leap[12] = {
-      31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31,
-  };
-  static const char common[12] = {
-      31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31,
-  };
-  return is_leap(year) ? leap : common;
-}
-
-// Gets the cumulative length of the months in a year.
-static inline const short *get_months_cumulative(time_t year) {
-  static const short leap[13] = {
-      0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366,
-  };
-  static const short common[13] = {
-      0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365,
-  };
-  return is_leap(year) ? leap : common;
-}
-
-static inline short get_ydays(time_t year) {
-  return is_leap(year) ? 366 : 365;
-}
-
 static inline bool timespec_to_timestamp_exact(
     const struct timespec *timespec, __wasi_timestamp_t *timestamp) {
   // Invalid nanoseconds field.
@@ -64,8 +26,8 @@ static inline bool timespec_to_timestamp_exact(
     return false;
 
   // Make sure our timestamp does not overflow.
-  return !mul_overflow(timespec->tv_sec, NSEC_PER_SEC, timestamp) &&
-         !add_overflow(*timestamp, timespec->tv_nsec, timestamp);
+  return !__builtin_mul_overflow(timespec->tv_sec, NSEC_PER_SEC, timestamp) &&
+         !__builtin_add_overflow(*timestamp, timespec->tv_nsec, timestamp);
 }
 
 static inline bool timespec_to_timestamp_clamp(
@@ -77,8 +39,8 @@ static inline bool timespec_to_timestamp_clamp(
   if (timespec->tv_sec < 0) {
     // Timestamps before the Epoch are not supported.
     *timestamp = 0;
-  } else if (mul_overflow(timespec->tv_sec, NSEC_PER_SEC, timestamp) ||
-             add_overflow(*timestamp, timespec->tv_nsec, timestamp)) {
+  } else if (__builtin_mul_overflow(timespec->tv_sec, NSEC_PER_SEC, timestamp) ||
+             __builtin_add_overflow(*timestamp, timespec->tv_nsec, timestamp)) {
     // Make sure our timestamp does not overflow.
     *timestamp = NUMERIC_MAX(__wasi_timestamp_t);
   }

libc-bottom-half/cloudlibc/src/common/errno.h

@@ -24,126 +24,13 @@
 #ifndef ___CDEFS_H_
 #define ___CDEFS_H_
 
-// Version information.
-#define __cloudlibc__ 1
-#define __cloudlibc_major__ 0
-#define __cloudlibc_minor__ 102
-
-#ifdef __cplusplus
-#define __BEGIN_DECLS extern "C" {
-#define __END_DECLS }
-#else
-#define __BEGIN_DECLS
-#define __END_DECLS
-#endif
-
-// Whether we should provide inline versions of functions. Due to C++'s
-// support for namespaces, it is generally a bad idea to declare
-// function macros.
-#ifdef __cplusplus
-#define _CLOUDLIBC_INLINE_FUNCTIONS 0
-#else
-#define _CLOUDLIBC_INLINE_FUNCTIONS 1
-#endif
-
 // Compiler-independent annotations.
 
-#ifndef __has_builtin
-#define __has_builtin(x) 0
-#endif
-#ifndef __has_extension
-#define __has_extension(x) __has_feature(x)
-#endif
-#ifndef __has_feature
-#define __has_feature(x) 0
-#endif
-
-#define __offsetof(type, member) __builtin_offsetof(type, member)
-#define __containerof(ptr, type, member) \
-  ((type *)((char *)(ptr)-__offsetof(type, member)))
-
-#define __extname(x) __asm__(x)
-#define __malloc_like __attribute__((__malloc__))
-#define __pure2 __attribute__((__const__))
-#define __pure __attribute__((__pure__))
-#define __section(x) __attribute__((__section__(x)))
-#define __unused __attribute__((__unused__))
-#define __used __attribute__((__used__))
-#define __weak_symbol __attribute__((__weak__))
-
-// Format string argument type checking.
-#define __printflike(format, va) \
-  __attribute__((__format__(__printf__, format, va)))
-#define __scanflike(format, va) \
-  __attribute__((__format__(__scanf__, format, va)))
-// TODO(ed): Enable this once supported by LLVM:
-// https://llvm.org/bugs/show_bug.cgi?id=16810
-#define __wprintflike(format, va)
-#define __wscanflike(format, va)
-
 #define __strong_reference(oldsym, newsym) \
   extern __typeof__(oldsym) newsym __attribute__((__alias__(#oldsym)))
 
 // Convenience macros.
 
 #define __arraycount(x) (sizeof(x) / sizeof((x)[0]))
-#define __howmany(x, y) (((x) + (y)-1) / (y))
-#define __rounddown(x, y) (((x) / (y)) * (y))
-#define __roundup(x, y) ((((x) + (y)-1) / (y)) * (y))
-
-// Lock annotations.
-
-#if __has_extension(c_thread_safety_attributes)
-#define __lock_annotate(x) __attribute__((x))
-#else
-#define __lock_annotate(x)
-#endif
-
-#define __lockable __lock_annotate(lockable)
-
-#define __locks_exclusive(...) \
-  __lock_annotate(exclusive_lock_function(__VA_ARGS__))
-#define __locks_shared(...) __lock_annotate(shared_lock_function(__VA_ARGS__))
-
-#define __trylocks_exclusive(...) \
-  __lock_annotate(exclusive_trylock_function(__VA_ARGS__))
-#define __trylocks_shared(...) \
-  __lock_annotate(shared_trylock_function(__VA_ARGS__))
-
-#define __unlocks(...) __lock_annotate(unlock_function(__VA_ARGS__))
-
-#define __asserts_exclusive(...) \
-  __lock_annotate(assert_exclusive_lock(__VA_ARGS__))
-#define __asserts_shared(...) __lock_annotate(assert_shared_lock(__VA_ARGS__))
-
-#define __requires_exclusive(...) \
-  __lock_annotate(exclusive_locks_required(__VA_ARGS__))
-#define __requires_shared(...) \
-  __lock_annotate(shared_locks_required(__VA_ARGS__))
-#define __requires_unlocked(...) __lock_annotate(locks_excluded(__VA_ARGS__))
-
-#define __no_lock_analysis __lock_annotate(no_thread_safety_analysis)
-
-#define __guarded_by(x) __lock_annotate(guarded_by(x))
-#define __pt_guarded_by(x) __lock_annotate(pt_guarded_by(x))
-
-// Const preservation.
-//
-// Functions like strchr() allow you to silently discard a const
-// qualifier from a string. This macro can be used to wrap such
-// functions to propagate the const keyword where possible.
-//
-// This macro has many limitations, such as only being able to detect
-// constness for void, char and wchar_t. For Clang, it also doesn't seem
-// to work on string literals.
-
-#define __preserve_const(type, name, arg, ...) \
-  _Generic(arg,                                                    \
-           const void *: (const type *)name(__VA_ARGS__),          \
-           const char *: (const type *)name(__VA_ARGS__),          \
-           const signed char *: (const type *)name(__VA_ARGS__),   \
-           const unsigned char *: (const type *)name(__VA_ARGS__), \
-           const __wchar_t *: (const type *)name(__VA_ARGS__),     \
-           default: name(__VA_ARGS__))
 
 #endif