1 | //===--- SourceCodeBuilders.h - Source-code building facilities -*- 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 | /// \file |
10 | /// This file collects facilities for generating source code strings. |
11 | /// |
12 | //===----------------------------------------------------------------------===// |
13 | |
14 | #ifndef LLVM_CLANG_TOOLING_TRANSFORMER_SOURCECODEBUILDERS_H |
15 | #define LLVM_CLANG_TOOLING_TRANSFORMER_SOURCECODEBUILDERS_H |
16 | |
17 | #include "clang/AST/ASTContext.h" |
18 | #include "clang/AST/Expr.h" |
19 | #include <string> |
20 | |
21 | namespace clang { |
22 | namespace tooling { |
23 | |
24 | /// \name Code analysis utilities. |
25 | /// @{ |
26 | /// Ignores implicit object-construction expressions in addition to the normal |
27 | /// implicit expressions that are ignored. |
28 | const Expr *reallyIgnoreImplicit(const Expr &E); |
29 | |
30 | /// Determines whether printing this expression in *any* expression requires |
31 | /// parentheses to preserve its meaning. This analyses is necessarily |
32 | /// conservative because it lacks information about the target context. |
33 | bool mayEverNeedParens(const Expr &E); |
34 | |
35 | /// Determines whether printing this expression to the left of a dot or arrow |
36 | /// operator requires a parentheses to preserve its meaning. Given that |
37 | /// dot/arrow are (effectively) the highest precedence, this is equivalent to |
38 | /// asking whether it ever needs parens. |
39 | inline bool needParensBeforeDotOrArrow(const Expr &E) { |
40 | return mayEverNeedParens(E); |
41 | } |
42 | |
43 | /// Determines whether printing this expression to the right of a unary operator |
44 | /// requires a parentheses to preserve its meaning. |
45 | bool needParensAfterUnaryOperator(const Expr &E); |
46 | |
47 | // Recognizes known types (and sugared versions thereof) that overload the `*` |
48 | // and `->` operator. Below is the list of currently included types, but it is |
49 | // subject to change: |
50 | // |
51 | // * std::unique_ptr, std::shared_ptr, std::weak_ptr, |
52 | // * std::optional, absl::optional, llvm::Optional, |
53 | // * absl::StatusOr, llvm::Expected. |
54 | bool isKnownPointerLikeType(QualType Ty, ASTContext &Context); |
55 | /// @} |
56 | |
57 | /// \name Basic code-string generation utilities. |
58 | /// @{ |
59 | |
60 | /// Builds source for an expression, adding parens if needed for unambiguous |
61 | /// parsing. |
62 | std::optional<std::string> buildParens(const Expr &E, |
63 | const ASTContext &Context); |
64 | |
65 | /// Builds idiomatic source for the dereferencing of `E`: prefix with `*` but |
66 | /// simplify when it already begins with `&`. \returns empty string on failure. |
67 | std::optional<std::string> buildDereference(const Expr &E, |
68 | const ASTContext &Context); |
69 | |
70 | /// Builds idiomatic source for taking the address of `E`: prefix with `&` but |
71 | /// simplify when it already begins with `*`. \returns empty string on failure. |
72 | std::optional<std::string> buildAddressOf(const Expr &E, |
73 | const ASTContext &Context); |
74 | |
75 | /// Adds a dot to the end of the given expression, but adds parentheses when |
76 | /// needed by the syntax, and simplifies to `->` when possible, e.g.: |
77 | /// |
78 | /// `x` becomes `x.` |
79 | /// `*a` becomes `a->` |
80 | /// `a+b` becomes `(a+b).` |
81 | /// |
82 | /// DEPRECATED. Use `buildAccess`. |
83 | std::optional<std::string> buildDot(const Expr &E, const ASTContext &Context); |
84 | |
85 | /// Adds an arrow to the end of the given expression, but adds parentheses |
86 | /// when needed by the syntax, and simplifies to `.` when possible, e.g.: |
87 | /// |
88 | /// `x` becomes `x->` |
89 | /// `&a` becomes `a.` |
90 | /// `a+b` becomes `(a+b)->` |
91 | /// |
92 | /// DEPRECATED. Use `buildAccess`. |
93 | std::optional<std::string> buildArrow(const Expr &E, const ASTContext &Context); |
94 | |
95 | /// Specifies how to classify pointer-like types -- like values or like pointers |
96 | /// -- with regard to generating member-access syntax. |
97 | enum class PLTClass : bool { |
98 | Value, |
99 | Pointer, |
100 | }; |
101 | |
102 | /// Adds an appropriate access operator (`.`, `->` or nothing, in the case of |
103 | /// implicit `this`) to the end of the given expression. Adds parentheses when |
104 | /// needed by the syntax and simplifies when possible. If `PLTypeClass` is |
105 | /// `Pointer`, for known pointer-like types (see `isKnownPointerLikeType`), |
106 | /// treats `operator->` and `operator*` like the built-in `->` and `*` |
107 | /// operators. |
108 | /// |
109 | /// `x` becomes `x->` or `x.`, depending on `E`'s type |
110 | /// `a+b` becomes `(a+b)->` or `(a+b).`, depending on `E`'s type |
111 | /// `&a` becomes `a.` |
112 | /// `*a` becomes `a->` |
113 | std::optional<std::string> |
114 | buildAccess(const Expr &E, ASTContext &Context, |
115 | PLTClass Classification = PLTClass::Pointer); |
116 | /// @} |
117 | |
118 | } // namespace tooling |
119 | } // namespace clang |
120 | #endif // LLVM_CLANG_TOOLING_TRANSFORMER_SOURCECODEBUILDERS_H |
121 | |