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1 //===-- internal_defs.h -----------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef SCUDO_INTERNAL_DEFS_H_
10 #define SCUDO_INTERNAL_DEFS_H_
11 
12 #include "platform.h"
13 
14 #include <stdint.h>
15 
16 #ifndef SCUDO_DEBUG
17 #define SCUDO_DEBUG 0
18 #endif
19 
20 #define ARRAY_SIZE(A) (sizeof(A) / sizeof((A)[0]))
21 
22 // String related macros.
23 
24 #define STRINGIFY_(S) #S
25 #define STRINGIFY(S) STRINGIFY_(S)
26 #define CONCATENATE_(S, C) S##C
27 #define CONCATENATE(S, C) CONCATENATE_(S, C)
28 
29 // Attributes & builtins related macros.
30 
31 #define INTERFACE __attribute__((visibility("default")))
32 #define HIDDEN __attribute__((visibility("hidden")))
33 #define WEAK __attribute__((weak))
34 #define ALWAYS_INLINE inline __attribute__((always_inline))
35 #define ALIAS(X) __attribute__((alias(X)))
36 #define FORMAT(F, A) __attribute__((format(printf, F, A)))
37 #define NOINLINE __attribute__((noinline))
38 #define NORETURN __attribute__((noreturn))
39 #define LIKELY(X) __builtin_expect(!!(X), 1)
40 #define UNLIKELY(X) __builtin_expect(!!(X), 0)
41 #if defined(__i386__) || defined(__x86_64__)
42 // __builtin_prefetch(X) generates prefetchnt0 on x86
43 #define PREFETCH(X) __asm__("prefetchnta (%0)" : : "r"(X))
44 #else
45 #define PREFETCH(X) __builtin_prefetch(X)
46 #endif
47 #define UNUSED __attribute__((unused))
48 #define USED __attribute__((used))
49 #define NOEXCEPT noexcept
50 
51 // This check is only available on Clang. This is essentially an alias of
52 // C++20's 'constinit' specifier which will take care of this when (if?) we can
53 // ask all libc's that use Scudo to compile us with C++20. Dynamic
54 // initialization is bad; Scudo is designed to be lazy-initializated on the
55 // first call to malloc/free (and friends), and this generally happens in the
56 // loader somewhere in libdl's init. After the loader is done, control is
57 // transferred to libc's initialization, and the dynamic initializers are run.
58 // If there's a dynamic initializer for Scudo, then it will clobber the
59 // already-initialized Scudo, and re-initialize all its members back to default
60 // values, causing various explosions. Unfortunately, marking
61 // scudo::Allocator<>'s constructor as 'constexpr' isn't sufficient to prevent
62 // dynamic initialization, as default initialization is fine under 'constexpr'
63 // (but not 'constinit'). Clang at -O0, and gcc at all opt levels will emit a
64 // dynamic initializer for any constant-initialized variables if there is a mix
65 // of default-initialized and constant-initialized variables.
66 //
67 // If you're looking at this because your build failed, you probably introduced
68 // a new member to scudo::Allocator<> (possibly transiently) that didn't have an
69 // initializer. The fix is easy - just add one.
70 #if defined(__has_attribute)
71 #if __has_attribute(require_constant_initialization)
72 #define SCUDO_REQUIRE_CONSTANT_INITIALIZATION                                  \
73   __attribute__((__require_constant_initialization__))
74 #else
75 #define SCUDO_REQUIRE_CONSTANT_INITIALIZATION
76 #endif
77 #endif
78 
79 namespace scudo {
80 
81 typedef unsigned long uptr;
82 typedef unsigned char u8;
83 typedef unsigned short u16;
84 typedef unsigned int u32;
85 typedef unsigned long long u64;
86 typedef signed long sptr;
87 typedef signed char s8;
88 typedef signed short s16;
89 typedef signed int s32;
90 typedef signed long long s64;
91 
92 // The following two functions have platform specific implementations.
93 void outputRaw(const char *Buffer);
94 void NORETURN die();
95 
96 #define RAW_CHECK_MSG(Expr, Msg)                                               \
97   do {                                                                         \
98     if (UNLIKELY(!(Expr))) {                                                   \
99       outputRaw(Msg);                                                          \
100       die();                                                                   \
101     }                                                                          \
102   } while (false)
103 
104 #define RAW_CHECK(Expr) RAW_CHECK_MSG(Expr, #Expr)
105 
106 void NORETURN reportCheckFailed(const char *File, int Line,
107                                 const char *Condition, u64 Value1, u64 Value2);
108 
109 #define CHECK_IMPL(C1, Op, C2)                                                 \
110   do {                                                                         \
111     scudo::u64 V1 = (scudo::u64)(C1);                                          \
112     scudo::u64 V2 = (scudo::u64)(C2);                                          \
113     if (UNLIKELY(!(V1 Op V2))) {                                               \
114       scudo::reportCheckFailed(__FILE__, __LINE__,                             \
115                                "(" #C1 ") " #Op " (" #C2 ")", V1, V2);         \
116       scudo::die();                                                            \
117     }                                                                          \
118   } while (false)
119 
120 #define CHECK(A) CHECK_IMPL((A), !=, 0)
121 #define CHECK_EQ(A, B) CHECK_IMPL((A), ==, (B))
122 #define CHECK_NE(A, B) CHECK_IMPL((A), !=, (B))
123 #define CHECK_LT(A, B) CHECK_IMPL((A), <, (B))
124 #define CHECK_LE(A, B) CHECK_IMPL((A), <=, (B))
125 #define CHECK_GT(A, B) CHECK_IMPL((A), >, (B))
126 #define CHECK_GE(A, B) CHECK_IMPL((A), >=, (B))
127 
128 #if SCUDO_DEBUG
129 #define DCHECK(A) CHECK(A)
130 #define DCHECK_EQ(A, B) CHECK_EQ(A, B)
131 #define DCHECK_NE(A, B) CHECK_NE(A, B)
132 #define DCHECK_LT(A, B) CHECK_LT(A, B)
133 #define DCHECK_LE(A, B) CHECK_LE(A, B)
134 #define DCHECK_GT(A, B) CHECK_GT(A, B)
135 #define DCHECK_GE(A, B) CHECK_GE(A, B)
136 #else
137 #define DCHECK(A)                                                              \
138   do {                                                                         \
139   } while (false)
140 #define DCHECK_EQ(A, B)                                                        \
141   do {                                                                         \
142   } while (false)
143 #define DCHECK_NE(A, B)                                                        \
144   do {                                                                         \
145   } while (false)
146 #define DCHECK_LT(A, B)                                                        \
147   do {                                                                         \
148   } while (false)
149 #define DCHECK_LE(A, B)                                                        \
150   do {                                                                         \
151   } while (false)
152 #define DCHECK_GT(A, B)                                                        \
153   do {                                                                         \
154   } while (false)
155 #define DCHECK_GE(A, B)                                                        \
156   do {                                                                         \
157   } while (false)
158 #endif
159 
160 // The superfluous die() call effectively makes this macro NORETURN.
161 #define UNREACHABLE(Msg)                                                       \
162   do {                                                                         \
163     CHECK(0 && Msg);                                                           \
164     die();                                                                     \
165   } while (0)
166 
167 } // namespace scudo
168 
169 #endif // SCUDO_INTERNAL_DEFS_H_
170