/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/include/clang/AST/OSLog.h
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1 | | //= OSLog.h - Analysis of calls to os_log builtins --*- 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 | | // This file defines APIs for determining the layout of the data buffer for |
10 | | // os_log() and os_trace(). |
11 | | // |
12 | | //===----------------------------------------------------------------------===// |
13 | | |
14 | | #ifndef LLVM_CLANG_AST_OSLOG_H |
15 | | #define LLVM_CLANG_AST_OSLOG_H |
16 | | |
17 | | #include "clang/AST/ASTContext.h" |
18 | | #include "clang/AST/Expr.h" |
19 | | |
20 | | namespace clang { |
21 | | namespace analyze_os_log { |
22 | | |
23 | | /// An OSLogBufferItem represents a single item in the data written by a call |
24 | | /// to os_log() or os_trace(). |
25 | | class OSLogBufferItem { |
26 | | public: |
27 | | enum Kind { |
28 | | // The item is a scalar (int, float, raw pointer, etc.). No further copying |
29 | | // is required. This is the only kind allowed by os_trace(). |
30 | | ScalarKind = 0, |
31 | | |
32 | | // The item is a count, which describes the length of the following item to |
33 | | // be copied. A count may only be followed by an item of kind StringKind, |
34 | | // WideStringKind, or PointerKind. |
35 | | CountKind, |
36 | | |
37 | | // The item is a pointer to a C string. If preceded by a count 'n', |
38 | | // os_log() will copy at most 'n' bytes from the pointer. |
39 | | StringKind, |
40 | | |
41 | | // The item is a pointer to a block of raw data. This item must be preceded |
42 | | // by a count 'n'. os_log() will copy exactly 'n' bytes from the pointer. |
43 | | PointerKind, |
44 | | |
45 | | // The item is a pointer to an Objective-C object. os_log() may retain the |
46 | | // object for later processing. |
47 | | ObjCObjKind, |
48 | | |
49 | | // The item is a pointer to wide-char string. |
50 | | WideStringKind, |
51 | | |
52 | | // The item is corresponding to the '%m' format specifier, no value is |
53 | | // populated in the buffer and the runtime is loading the errno value. |
54 | | ErrnoKind, |
55 | | |
56 | | // The item is a mask type. |
57 | | MaskKind |
58 | | }; |
59 | | |
60 | | enum { |
61 | | // The item is marked "private" in the format string. |
62 | | IsPrivate = 0x1, |
63 | | |
64 | | // The item is marked "public" in the format string. |
65 | | IsPublic = 0x2, |
66 | | |
67 | | // The item is marked "sensitive" in the format string. |
68 | | IsSensitive = 0x4 | IsPrivate |
69 | | }; |
70 | | |
71 | | private: |
72 | | Kind TheKind = ScalarKind; |
73 | | const Expr *TheExpr = nullptr; |
74 | | CharUnits ConstValue; |
75 | | CharUnits Size; // size of the data, not including the header bytes |
76 | | unsigned Flags = 0; |
77 | | StringRef MaskType; |
78 | | |
79 | | public: |
80 | | OSLogBufferItem(Kind kind, const Expr *expr, CharUnits size, unsigned flags, |
81 | | StringRef maskType = StringRef()) |
82 | | : TheKind(kind), TheExpr(expr), Size(size), Flags(flags), |
83 | 3.03k | MaskType(maskType) { |
84 | 3.03k | assert(((Flags == 0) || (Flags == IsPrivate) || (Flags == IsPublic) || |
85 | 3.03k | (Flags == IsSensitive)) && |
86 | 3.03k | "unexpected privacy flag"); |
87 | 3.03k | } |
88 | | |
89 | | OSLogBufferItem(ASTContext &Ctx, CharUnits value, unsigned flags) |
90 | | : TheKind(CountKind), ConstValue(value), |
91 | 8 | Size(Ctx.getTypeSizeInChars(Ctx.IntTy)), Flags(flags) {} |
92 | | |
93 | 144 | unsigned char getDescriptorByte() const { |
94 | 144 | unsigned char result = Flags; |
95 | 144 | result |= ((unsigned)getKind()) << 4; |
96 | 144 | return result; |
97 | 144 | } |
98 | | |
99 | 288 | unsigned char getSizeByte() const { return size().getQuantity(); } |
100 | | |
101 | 339 | Kind getKind() const { return TheKind; } |
102 | 140 | bool getIsPrivate() const { return (Flags & IsPrivate) != 0; } |
103 | | |
104 | 80 | const Expr *getExpr() const { return TheExpr; } |
105 | 2 | CharUnits getConstValue() const { return ConstValue; } |
106 | 3.30k | CharUnits size() const { return Size; } |
107 | | |
108 | 48 | StringRef getMaskType() const { return MaskType; } |
109 | | }; |
110 | | |
111 | | class OSLogBufferLayout { |
112 | | public: |
113 | | SmallVector<OSLogBufferItem, 4> Items; |
114 | | |
115 | | enum Flags { HasPrivateItems = 1, HasNonScalarItems = 1 << 1 }; |
116 | | |
117 | 1.16k | CharUnits size() const { |
118 | 1.16k | CharUnits result; |
119 | 1.16k | result += CharUnits::fromQuantity(2); // summary byte, num-args byte |
120 | 2.95k | for (auto &item : Items) { |
121 | | // descriptor byte, size byte |
122 | 2.95k | result += item.size() + CharUnits::fromQuantity(2); |
123 | 2.95k | } |
124 | 1.16k | return result; |
125 | 1.16k | } |
126 | | |
127 | 95 | bool hasPrivateItems() const { |
128 | 95 | return llvm::any_of( |
129 | 140 | Items, [](const OSLogBufferItem &Item) { return Item.getIsPrivate(); }); |
130 | 95 | } |
131 | | |
132 | 95 | bool hasNonScalarOrMask() const { |
133 | 111 | return llvm::any_of(Items, [](const OSLogBufferItem &Item) { |
134 | 111 | return Item.getKind() != OSLogBufferItem::ScalarKind || |
135 | 111 | !Item.getMaskType().empty()32 ; |
136 | 111 | }); |
137 | 95 | } |
138 | | |
139 | 95 | unsigned char getSummaryByte() const { |
140 | 95 | unsigned char result = 0; |
141 | 95 | if (hasPrivateItems()) |
142 | 20 | result |= HasPrivateItems; |
143 | 95 | if (hasNonScalarOrMask()) |
144 | 79 | result |= HasNonScalarItems; |
145 | 95 | return result; |
146 | 95 | } |
147 | | |
148 | 95 | unsigned char getNumArgsByte() const { return Items.size(); } |
149 | | }; |
150 | | |
151 | | // Given a call 'E' to one of the builtins __builtin_os_log_format() or |
152 | | // __builtin_os_log_format_buffer_size(), compute the layout of the buffer that |
153 | | // the call will write into and store it in 'layout'. Returns 'false' if there |
154 | | // was some error encountered while computing the layout, and 'true' otherwise. |
155 | | bool computeOSLogBufferLayout(clang::ASTContext &Ctx, const clang::CallExpr *E, |
156 | | OSLogBufferLayout &layout); |
157 | | |
158 | | } // namespace analyze_os_log |
159 | | } // namespace clang |
160 | | #endif |