1 /*
2  * Copyright (C) 2011 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ART_LIBARTBASE_BASE_GLOBALS_H_
18 #define ART_LIBARTBASE_BASE_GLOBALS_H_
19 
20 #include <stddef.h>
21 #include <stdint.h>
22 
23 namespace art {
24 
25 static constexpr size_t KB = 1024;
26 static constexpr size_t MB = KB * KB;
27 static constexpr size_t GB = KB * KB * KB;
28 
29 // Runtime sizes.
30 static constexpr size_t kBitsPerByte = 8;
31 static constexpr size_t kBitsPerByteLog2 = 3;
32 static constexpr int kBitsPerIntPtrT = sizeof(intptr_t) * kBitsPerByte;
33 
34 // Required stack alignment
35 static constexpr size_t kStackAlignment = 16;
36 
37 // System page size. We check this against sysconf(_SC_PAGE_SIZE) at runtime, but use a simple
38 // compile-time constant so the compiler can generate better code.
39 static constexpr int kPageSize = 4096;
40 
41 // Clion, clang analyzer, etc can falsely believe that "if (kIsDebugBuild)" always
42 // returns the same value. By wrapping into a call to another constexpr function, we force it
43 // to realize that is not actually always evaluating to the same value.
GlobalsReturnSelf(bool self)44 static constexpr bool GlobalsReturnSelf(bool self) { return self; }
45 
46 // Whether or not this is a debug build. Useful in conditionals where NDEBUG isn't.
47 // TODO: Use only __clang_analyzer__ here. b/64455231
48 #if defined(NDEBUG) && !defined(__CLION_IDE__)
49 static constexpr bool kIsDebugBuild = GlobalsReturnSelf(false);
50 #else
51 static constexpr bool kIsDebugBuild = GlobalsReturnSelf(true);
52 #endif
53 
54 #if defined(ART_PGO_INSTRUMENTATION)
55 static constexpr bool kIsPGOInstrumentation = true;
56 #else
57 static constexpr bool kIsPGOInstrumentation = false;
58 #endif
59 
60 // ART_TARGET - Defined for target builds of ART.
61 // ART_TARGET_LINUX - Defined for target Linux builds of ART.
62 // ART_TARGET_ANDROID - Defined for target Android builds of ART.
63 // ART_TARGET_FUCHSIA - Defined for Fuchsia builds of ART.
64 // Note: Either ART_TARGET_LINUX, ART_TARGET_ANDROID or ART_TARGET_FUCHSIA
65 //       need to be set when ART_TARGET is set.
66 // Note: When ART_TARGET_LINUX is defined mem_map.h will not be using Ashmem for memory mappings
67 // (usually only available on Android kernels).
68 #if defined(ART_TARGET)
69 // Useful in conditionals where ART_TARGET isn't.
70 static constexpr bool kIsTargetBuild = true;
71 # if defined(ART_TARGET_LINUX)
72 static constexpr bool kIsTargetLinux = true;
73 static constexpr bool kIsTargetFuchsia = false;
74 # elif defined(ART_TARGET_ANDROID)
75 static constexpr bool kIsTargetLinux = false;
76 static constexpr bool kIsTargetFuchsia = false;
77 # elif defined(ART_TARGET_FUCHSIA)
78 static constexpr bool kIsTargetLinux = false;
79 static constexpr bool kIsTargetFuchsia = true;
80 # else
81 # error "Either ART_TARGET_LINUX, ART_TARGET_ANDROID or ART_TARGET_FUCHSIA " \
82         "needs to be defined for target builds."
83 # endif
84 #else
85 static constexpr bool kIsTargetBuild = false;
86 # if defined(ART_TARGET_LINUX)
87 # error "ART_TARGET_LINUX defined for host build."
88 # elif defined(ART_TARGET_ANDROID)
89 # error "ART_TARGET_ANDROID defined for host build."
90 # elif defined(ART_TARGET_FUCHSIA)
91 # error "ART_TARGET_FUCHSIA defined for host build."
92 # else
93 static constexpr bool kIsTargetLinux = false;
94 static constexpr bool kIsTargetFuchsia = false;
95 # endif
96 #endif
97 
98 // Additional statically-linked ART binaries (dex2oats, oatdumps, etc.) are
99 // always available on the host
100 #if !defined(ART_TARGET)
101 static constexpr bool kHostStaticBuildEnabled = true;
102 #else
103 static constexpr bool kHostStaticBuildEnabled = false;
104 #endif
105 
106 }  // namespace art
107 
108 #endif  // ART_LIBARTBASE_BASE_GLOBALS_H_
109