1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
|
//===--- Extract.cpp - Clang refactoring library --------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief Implements the "extract" refactoring that can pull code into
/// new functions, methods or declare new variables.
///
//===----------------------------------------------------------------------===//
#include "clang/AST/ASTContext.h"
#include "clang/AST/Expr.h"
#include "clang/Rewrite/Core/Rewriter.h"
#include "clang/Tooling/Refactoring/RefactoringAction.h"
#include "clang/Tooling/Refactoring/RefactoringActionRules.h"
#include "clang/Tooling/Refactoring/RefactoringOptions.h"
namespace clang {
namespace tooling {
namespace {
/// Returns true if \c E is a simple literal or a reference expression that
/// should not be extracted.
bool isSimpleExpression(const Expr *E) {
if (!E)
return false;
switch (E->IgnoreParenCasts()->getStmtClass()) {
case Stmt::DeclRefExprClass:
case Stmt::PredefinedExprClass:
case Stmt::IntegerLiteralClass:
case Stmt::FloatingLiteralClass:
case Stmt::ImaginaryLiteralClass:
case Stmt::CharacterLiteralClass:
case Stmt::StringLiteralClass:
return true;
default:
return false;
}
}
class ExtractableCodeSelectionRequirement final
: public CodeRangeASTSelectionRequirement {
public:
Expected<CodeRangeASTSelection>
evaluate(RefactoringRuleContext &Context) const {
Expected<CodeRangeASTSelection> Selection =
CodeRangeASTSelectionRequirement::evaluate(Context);
if (!Selection)
return Selection.takeError();
CodeRangeASTSelection &Code = *Selection;
// We would like to extract code out of functions/methods/blocks.
// Prohibit extraction from things like global variable / field
// initializers and other top-level expressions.
if (!Code.isInFunctionLikeBodyOfCode())
return Context.createDiagnosticError(
diag::err_refactor_code_outside_of_function);
// Avoid extraction of simple literals and references.
if (Code.size() == 1 && isSimpleExpression(dyn_cast<Expr>(Code[0])))
return Context.createDiagnosticError(
diag::err_refactor_extract_simple_expression);
// FIXME (Alex L): Prohibit extraction of Objective-C property setters.
return Selection;
}
};
class ExtractFunction final : public SourceChangeRefactoringRule {
public:
ExtractFunction(CodeRangeASTSelection Code, Optional<std::string> DeclName)
: Code(std::move(Code)),
DeclName(DeclName ? std::move(*DeclName) : "extracted") {}
Expected<AtomicChanges>
createSourceReplacements(RefactoringRuleContext &Context) override;
private:
CodeRangeASTSelection Code;
// FIXME: Account for naming collisions:
// - error when name is specified by user.
// - rename to "extractedN" when name is implicit.
std::string DeclName;
};
SourceLocation computeFunctionExtractionLocation(const Decl *D) {
// FIXME (Alex L): Method -> function extraction should place function before
// C++ record if the method is defined inside the record.
return D->getLocStart();
}
// FIXME: Support C++ method extraction.
// FIXME: Support Objective-C method extraction.
Expected<AtomicChanges>
ExtractFunction::createSourceReplacements(RefactoringRuleContext &Context) {
const Decl *ParentDecl = Code.getFunctionLikeNearestParent();
assert(ParentDecl && "missing parent");
// Compute the source range of the code that should be extracted.
SourceRange ExtractedRange(Code[0]->getLocStart(),
Code[Code.size() - 1]->getLocEnd());
// FIXME (Alex L): Add code that accounts for macro locations.
ASTContext &AST = Context.getASTContext();
SourceManager &SM = AST.getSourceManager();
const LangOptions &LangOpts = AST.getLangOpts();
Rewriter ExtractedCodeRewriter(SM, LangOpts);
// FIXME: Capture used variables.
// Compute the return type.
QualType ReturnType = AST.VoidTy;
// FIXME (Alex L): Account for the return statement in extracted code.
// FIXME (Alex L): Check for lexical expression instead.
bool IsExpr = Code.size() == 1 && isa<Expr>(Code[0]);
if (IsExpr) {
// FIXME (Alex L): Get a more user-friendly type if needed.
ReturnType = cast<Expr>(Code[0])->getType();
}
// FIXME: Rewrite the extracted code performing any required adjustments.
// FIXME: Capture any field if necessary (method -> function extraction).
// FIXME: Sort captured variables by name.
// FIXME: Capture 'this' / 'self' if necessary.
// FIXME: Compute the actual parameter types.
// Compute the location of the extracted declaration.
SourceLocation ExtractedDeclLocation =
computeFunctionExtractionLocation(ParentDecl);
// FIXME: Adjust the location to account for any preceding comments.
// FIXME: Adjust with PP awareness like in Sema to get correct 'bool'
// treatment.
PrintingPolicy PP = AST.getPrintingPolicy();
// FIXME: PP.UseStdFunctionForLambda = true;
PP.SuppressStrongLifetime = true;
PP.SuppressLifetimeQualifiers = true;
PP.SuppressUnwrittenScope = true;
AtomicChange Change(SM, ExtractedDeclLocation);
// Create the replacement for the extracted declaration.
{
std::string ExtractedCode;
llvm::raw_string_ostream OS(ExtractedCode);
// FIXME: Use 'inline' in header.
OS << "static ";
ReturnType.print(OS, PP, DeclName);
OS << '(';
// FIXME: Arguments.
OS << ')';
// Function body.
OS << " {\n";
if (IsExpr && !ReturnType->isVoidType())
OS << "return ";
OS << ExtractedCodeRewriter.getRewrittenText(ExtractedRange);
// FIXME: Compute the correct semicolon policy.
OS << ';';
OS << "\n}\n\n";
auto Err = Change.insert(SM, ExtractedDeclLocation, OS.str());
if (Err)
return std::move(Err);
}
// Create the replacement for the call to the extracted declaration.
{
std::string ReplacedCode;
llvm::raw_string_ostream OS(ReplacedCode);
OS << DeclName << '(';
// FIXME: Forward arguments.
OS << ')';
// FIXME: Add semicolon if needed.
auto Err = Change.replace(
SM, CharSourceRange::getTokenRange(ExtractedRange), OS.str());
if (Err)
return std::move(Err);
}
// FIXME: Add support for assocciated symbol location to AtomicChange to mark
// the ranges of the name of the extracted declaration.
return AtomicChanges{std::move(Change)};
}
class DeclNameOption final : public OptionalRefactoringOption<std::string> {
public:
StringRef getName() const { return "name"; }
StringRef getDescription() const {
return "Name of the extracted declaration";
}
};
class ExtractRefactoring final : public RefactoringAction {
public:
StringRef getCommand() const override { return "extract"; }
StringRef getDescription() const override {
return "(WIP action; use with caution!) Extracts code into a new function "
"/ method / variable";
}
/// Returns a set of refactoring actions rules that are defined by this
/// action.
RefactoringActionRules createActionRules() const override {
RefactoringActionRules Rules;
Rules.push_back(createRefactoringActionRule<ExtractFunction>(
ExtractableCodeSelectionRequirement(),
OptionRequirement<DeclNameOption>()));
return Rules;
}
};
} // end anonymous namespace
std::unique_ptr<RefactoringAction> createExtractAction() {
return llvm::make_unique<ExtractRefactoring>();
}
} // end namespace tooling
} // end namespace clang
|
