Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(736)

Side by Side Diff: src/base/macros.h

Issue 2175193003: Remove NaCl support. (Closed) Base URL: https://chromium.googlesource.com/v8/v8.git@master
Patch Set: fix Created 4 years, 4 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View unified diff | Download patch
« no previous file with comments | « src/base/cpu.cc ('k') | src/base/platform/platform-aix.cc » ('j') | no next file with comments »
Toggle Intra-line Diffs ('i') | Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
OLDNEW
1 // Copyright 2014 the V8 project authors. All rights reserved. 1 // Copyright 2014 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be 2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file. 3 // found in the LICENSE file.
4 4
5 #ifndef V8_BASE_MACROS_H_ 5 #ifndef V8_BASE_MACROS_H_
6 #define V8_BASE_MACROS_H_ 6 #define V8_BASE_MACROS_H_
7 7
8 #include "src/base/compiler-specific.h" 8 #include "src/base/compiler-specific.h"
9 #include "src/base/format-macros.h" 9 #include "src/base/format-macros.h"
10 #include "src/base/logging.h" 10 #include "src/base/logging.h"
11 11
12 12
13 // TODO(all) Replace all uses of this macro with C++'s offsetof. To do that, we 13 // TODO(all) Replace all uses of this macro with C++'s offsetof. To do that, we
14 // have to make sure that only standard-layout types and simple field 14 // have to make sure that only standard-layout types and simple field
15 // designators are used. 15 // designators are used.
16 #define OFFSET_OF(type, field) \ 16 #define OFFSET_OF(type, field) \
17 (reinterpret_cast<intptr_t>(&(reinterpret_cast<type*>(16)->field)) - 16) 17 (reinterpret_cast<intptr_t>(&(reinterpret_cast<type*>(16)->field)) - 16)
18 18
19 19
20 #if V8_OS_NACL
21
22 // ARRAYSIZE_UNSAFE performs essentially the same calculation as arraysize,
23 // but can be used on anonymous types or types defined inside
24 // functions. It's less safe than arraysize as it accepts some
25 // (although not all) pointers. Therefore, you should use arraysize
26 // whenever possible.
27 //
28 // The expression ARRAYSIZE_UNSAFE(a) is a compile-time constant of type
29 // size_t.
30 //
31 // ARRAYSIZE_UNSAFE catches a few type errors. If you see a compiler error
32 //
33 // "warning: division by zero in ..."
34 //
35 // when using ARRAYSIZE_UNSAFE, you are (wrongfully) giving it a pointer.
36 // You should only use ARRAYSIZE_UNSAFE on statically allocated arrays.
37 //
38 // The following comments are on the implementation details, and can
39 // be ignored by the users.
40 //
41 // ARRAYSIZE_UNSAFE(arr) works by inspecting sizeof(arr) (the # of bytes in
42 // the array) and sizeof(*(arr)) (the # of bytes in one array
43 // element). If the former is divisible by the latter, perhaps arr is
44 // indeed an array, in which case the division result is the # of
45 // elements in the array. Otherwise, arr cannot possibly be an array,
46 // and we generate a compiler error to prevent the code from
47 // compiling.
48 //
49 // Since the size of bool is implementation-defined, we need to cast
50 // !(sizeof(a) & sizeof(*(a))) to size_t in order to ensure the final
51 // result has type size_t.
52 //
53 // This macro is not perfect as it wrongfully accepts certain
54 // pointers, namely where the pointer size is divisible by the pointee
55 // size. Since all our code has to go through a 32-bit compiler,
56 // where a pointer is 4 bytes, this means all pointers to a type whose
57 // size is 3 or greater than 4 will be (righteously) rejected.
58 #define ARRAYSIZE_UNSAFE(a) \
59 ((sizeof(a) / sizeof(*(a))) / \
60 static_cast<size_t>(!(sizeof(a) % sizeof(*(a))))) // NOLINT
61
62 // TODO(bmeurer): For some reason, the NaCl toolchain cannot handle the correct
63 // definition of arraysize() below, so we have to use the unsafe version for
64 // now.
65 #define arraysize ARRAYSIZE_UNSAFE
66
67 #else // V8_OS_NACL
68
69 // The arraysize(arr) macro returns the # of elements in an array arr. 20 // The arraysize(arr) macro returns the # of elements in an array arr.
70 // The expression is a compile-time constant, and therefore can be 21 // The expression is a compile-time constant, and therefore can be
71 // used in defining new arrays, for example. If you use arraysize on 22 // used in defining new arrays, for example. If you use arraysize on
72 // a pointer by mistake, you will get a compile-time error. 23 // a pointer by mistake, you will get a compile-time error.
73 // 24 //
74 // One caveat is that arraysize() doesn't accept any array of an 25 // One caveat is that arraysize() doesn't accept any array of an
75 // anonymous type or a type defined inside a function. In these rare 26 // anonymous type or a type defined inside a function. In these rare
76 // cases, you have to use the unsafe ARRAYSIZE_UNSAFE() macro below. This is 27 // cases, you have to use the unsafe ARRAYSIZE_UNSAFE() macro below. This is
77 // due to a limitation in C++'s template system. The limitation might 28 // due to a limitation in C++'s template system. The limitation might
78 // eventually be removed, but it hasn't happened yet. 29 // eventually be removed, but it hasn't happened yet.
79 #define arraysize(array) (sizeof(ArraySizeHelper(array))) 30 #define arraysize(array) (sizeof(ArraySizeHelper(array)))
80 31
81 32
82 // This template function declaration is used in defining arraysize. 33 // This template function declaration is used in defining arraysize.
83 // Note that the function doesn't need an implementation, as we only 34 // Note that the function doesn't need an implementation, as we only
84 // use its type. 35 // use its type.
85 template <typename T, size_t N> 36 template <typename T, size_t N>
86 char (&ArraySizeHelper(T (&array)[N]))[N]; 37 char (&ArraySizeHelper(T (&array)[N]))[N];
87 38
88 39
89 #if !V8_CC_MSVC 40 #if !V8_CC_MSVC
90 // That gcc wants both of these prototypes seems mysterious. VC, for 41 // That gcc wants both of these prototypes seems mysterious. VC, for
91 // its part, can't decide which to use (another mystery). Matching of 42 // its part, can't decide which to use (another mystery). Matching of
92 // template overloads: the final frontier. 43 // template overloads: the final frontier.
93 template <typename T, size_t N> 44 template <typename T, size_t N>
94 char (&ArraySizeHelper(const T (&array)[N]))[N]; 45 char (&ArraySizeHelper(const T (&array)[N]))[N];
95 #endif 46 #endif
96 47
97 #endif // V8_OS_NACL
98
99 48
100 // bit_cast<Dest,Source> is a template function that implements the 49 // bit_cast<Dest,Source> is a template function that implements the
101 // equivalent of "*reinterpret_cast<Dest*>(&source)". We need this in 50 // equivalent of "*reinterpret_cast<Dest*>(&source)". We need this in
102 // very low-level functions like the protobuf library and fast math 51 // very low-level functions like the protobuf library and fast math
103 // support. 52 // support.
104 // 53 //
105 // float f = 3.14159265358979; 54 // float f = 3.14159265358979;
106 // int i = bit_cast<int32>(f); 55 // int i = bit_cast<int32>(f);
107 // // i = 0x40490fdb 56 // // i = 0x40490fdb
108 // 57 //
(...skipping 232 matching lines...) Expand 10 before | Expand all | Expand 10 after
341 290
342 template <> 291 template <>
343 inline bool is_fundamental<uint8_t>() { 292 inline bool is_fundamental<uint8_t>() {
344 return true; 293 return true;
345 } 294 }
346 295
347 } // namespace base 296 } // namespace base
348 } // namespace v8 297 } // namespace v8
349 298
350 #endif // V8_BASE_MACROS_H_ 299 #endif // V8_BASE_MACROS_H_
OLDNEW
« no previous file with comments | « src/base/cpu.cc ('k') | src/base/platform/platform-aix.cc » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698