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
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334 | /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
#ifndef LO_CLANG_SHARED_PLUGINS
#include "check.hxx"
#include "compat.hxx"
#include "plugin.hxx"
#include <iostream>
#include <fstream>
#include <unordered_set>
#include <vector>
namespace
{
class RedundantFCast final : public loplugin::FilteringPlugin<RedundantFCast>
{
public:
explicit RedundantFCast(loplugin::InstantiationData const& data)
: FilteringPlugin(data)
{
}
bool VisitReturnStmt(ReturnStmt const* returnStmt)
{
if (ignoreLocation(returnStmt))
return true;
Expr const* expr = returnStmt->getRetValue();
if (!expr)
return true;
if (auto exprWithCleanups = dyn_cast<ExprWithCleanups>(expr))
expr = exprWithCleanups->getSubExpr();
if (auto cxxConstructExpr = dyn_cast<CXXConstructExpr>(expr))
{
if (cxxConstructExpr->getNumArgs() != 1)
return true;
expr = cxxConstructExpr->getArg(0);
}
if (auto materializeTemporaryExpr = dyn_cast<MaterializeTemporaryExpr>(expr))
expr = compat::getSubExpr(materializeTemporaryExpr);
auto cxxFunctionalCastExpr = dyn_cast<CXXFunctionalCastExpr>(expr);
if (!cxxFunctionalCastExpr)
return true;
auto const t1 = cxxFunctionalCastExpr->getTypeAsWritten();
auto const t2 = compat::getSubExprAsWritten(cxxFunctionalCastExpr)->getType();
if (t1.getCanonicalType().getTypePtr() != t2.getCanonicalType().getTypePtr())
return true;
if (!loplugin::isOkToRemoveArithmeticCast(compiler.getASTContext(), t1, t2,
cxxFunctionalCastExpr->getSubExpr()))
{
return true;
}
if (m_Seen.insert(cxxFunctionalCastExpr->getExprLoc()).second)
report(DiagnosticsEngine::Warning, "redundant functional cast from %0 to %1",
cxxFunctionalCastExpr->getExprLoc())
<< t2 << t1 << cxxFunctionalCastExpr->getSourceRange();
return true;
}
/* Check for the creation of unnecessary temporaries when calling a method that takes a param by const & */
bool VisitCallExpr(CallExpr const* callExpr)
{
if (ignoreLocation(callExpr))
return true;
const FunctionDecl* functionDecl;
if (isa<CXXMemberCallExpr>(callExpr))
functionDecl = dyn_cast<CXXMemberCallExpr>(callExpr)->getMethodDecl();
else
functionDecl = callExpr->getDirectCallee();
if (!functionDecl)
return true;
unsigned len = std::min(callExpr->getNumArgs(), functionDecl->getNumParams());
for (unsigned i = 0; i < len; ++i)
{
// check if param is const&
auto param = functionDecl->getParamDecl(i);
auto lvalueType = param->getType()->getAs<LValueReferenceType>();
if (!lvalueType)
continue;
if (!lvalueType->getPointeeType().isConstQualified())
continue;
auto paramClassOrStructType = lvalueType->getPointeeType()->getAs<RecordType>();
if (!paramClassOrStructType)
continue;
// check for temporary and functional cast in argument expression
auto arg = callExpr->getArg(i)->IgnoreImpCasts();
auto materializeTemporaryExpr = dyn_cast<MaterializeTemporaryExpr>(arg);
if (!materializeTemporaryExpr)
continue;
auto functionalCast = dyn_cast<CXXFunctionalCastExpr>(
compat::getSubExpr(materializeTemporaryExpr)->IgnoreImpCasts());
if (!functionalCast)
continue;
auto const t1 = functionalCast->getTypeAsWritten();
auto const t2 = compat::getSubExprAsWritten(functionalCast)->getType();
if (t1.getCanonicalType().getTypePtr() != t2.getCanonicalType().getTypePtr())
continue;
// Check that the underlying expression is of the same class/struct type as the param i.e. that we are not instantiating
// something useful
if (t1.getCanonicalType().getTypePtr() != paramClassOrStructType)
continue;
// Don't warn about (necessary) cast from braced-init-list in non-deduced contexts:
if (lvalueType->getPointeeType()->getAs<SubstTemplateTypeParmType>() != nullptr
&& loplugin::TypeCheck(t1).ClassOrStruct("initializer_list").StdNamespace()
&& isa<CXXStdInitializerListExpr>(compat::getSubExprAsWritten(functionalCast)))
{
continue;
}
if (m_Seen.insert(arg->getExprLoc()).second)
{
report(DiagnosticsEngine::Warning, "redundant functional cast from %0 to %1",
arg->getExprLoc())
<< t2 << t1 << arg->getSourceRange();
report(DiagnosticsEngine::Note, "in call to method here", param->getLocation())
<< param->getSourceRange();
}
}
return true;
}
/* Check for the creation of unnecessary temporaries when calling a constructor that takes a param by const & */
bool VisitCXXConstructExpr(CXXConstructExpr const* callExpr)
{
if (ignoreLocation(callExpr))
return true;
const CXXConstructorDecl* functionDecl = callExpr->getConstructor();
unsigned len = std::min(callExpr->getNumArgs(), functionDecl->getNumParams());
for (unsigned i = 0; i < len; ++i)
{
// check if param is const&
auto param = functionDecl->getParamDecl(i);
auto lvalueType = param->getType()->getAs<LValueReferenceType>();
if (!lvalueType)
continue;
if (!lvalueType->getPointeeType().isConstQualified())
continue;
auto paramClassOrStructType = lvalueType->getPointeeType()->getAs<RecordType>();
if (!paramClassOrStructType)
continue;
// check for temporary and functional cast in argument expression
auto arg = callExpr->getArg(i)->IgnoreImplicit();
auto functionalCast = dyn_cast<CXXFunctionalCastExpr>(arg);
if (!functionalCast)
continue;
auto const t1 = functionalCast->getTypeAsWritten();
auto const t2 = compat::getSubExprAsWritten(functionalCast)->getType();
if (t1.getCanonicalType().getTypePtr() != t2.getCanonicalType().getTypePtr())
continue;
// Check that the underlying expression is of the same class/struct type as the param i.e. that we are not instantiating
// something useful
if (t1.getCanonicalType().getTypePtr() != paramClassOrStructType)
continue;
if (m_Seen.insert(arg->getExprLoc()).second)
{
report(DiagnosticsEngine::Warning, "redundant functional cast from %0 to %1",
arg->getExprLoc())
<< t2 << t1 << arg->getSourceRange();
report(DiagnosticsEngine::Note, "in call to method here", param->getLocation())
<< param->getSourceRange();
}
}
return true;
}
// Find redundant cast to std::function, where clang reports
// two different types for the inner and outer
bool isRedundantStdFunctionCast(CXXFunctionalCastExpr const* expr)
{
bool deduced = false;
QualType target;
auto const written = expr->getTypeAsWritten();
if (auto const t1 = written->getAs<DeducedTemplateSpecializationType>())
{
auto const decl = t1->getTemplateName().getAsTemplateDecl();
if (!decl)
{
return false;
}
if (!loplugin::DeclCheck(decl->getTemplatedDecl())
.ClassOrStruct("function")
.StdNamespace())
{
return false;
}
deduced = true;
}
else if (auto const t2 = written->getAs<TemplateSpecializationType>())
{
auto const decl = t2->getTemplateName().getAsTemplateDecl();
if (!decl)
{
return false;
}
if (!loplugin::DeclCheck(decl->getTemplatedDecl())
.ClassOrStruct("function")
.StdNamespace())
{
return false;
}
if (t2->getNumArgs() != 1)
{
if (isDebugMode())
{
report(DiagnosticsEngine::Fatal,
"TODO: unexpected std::function with %0 template arguments",
expr->getExprLoc())
<< t2->getNumArgs() << expr->getSourceRange();
}
return false;
}
if (t2->getArg(0).getKind() != TemplateArgument::Type)
{
if (isDebugMode())
{
report(DiagnosticsEngine::Fatal,
"TODO: unexpected std::function with non-type template argument",
expr->getExprLoc())
<< expr->getSourceRange();
}
return false;
}
target = t2->getArg(0).getAsType();
}
else
{
return false;
}
auto cxxConstruct = dyn_cast<CXXConstructExpr>(compat::IgnoreImplicit(expr->getSubExpr()));
if (!cxxConstruct)
return false;
auto const lambda = dyn_cast<LambdaExpr>(cxxConstruct->getArg(0));
if (!lambda)
return false;
if (deduced)
// std::function([...](Args)->Ret{...}) should always be redundant:
return true;
auto const decl = lambda->getCallOperator();
std::vector<QualType> args;
for (unsigned i = 0; i != decl->getNumParams(); ++i)
{
args.push_back(decl->getParamDecl(i)->getType());
}
auto const source
= compiler.getASTContext().getFunctionType(decl->getReturnType(), args, {});
// std::function<Ret1(Args1)>([...](Args2)->Ret2{...}) is redundant if target Ret1(Args1)
// matches source Ret2(Args2):
return target.getCanonicalType() == source.getCanonicalType();
}
bool VisitCXXFunctionalCastExpr(CXXFunctionalCastExpr const* expr)
{
if (ignoreLocation(expr))
return true;
// specifying the name for an init-list is necessary sometimes
if (isa<InitListExpr>(expr->getSubExpr()->IgnoreImplicit()))
return true;
if (isa<CXXStdInitializerListExpr>(expr->getSubExpr()->IgnoreImplicit()))
return true;
auto const t1 = expr->getTypeAsWritten();
auto const t2 = compat::getSubExprAsWritten(expr)->getType();
if (!(t1.getCanonicalType().getTypePtr() == t2.getCanonicalType().getTypePtr()
|| isRedundantStdFunctionCast(expr)))
{
return true;
}
// (a) we do a lot of int/sal_Int32 kind of casts which might be platform necessary?
// (b) we do bool/bool casts in unit tests to avoid one of the other plugins
// so just ignore this kind of thing for now
if (const auto* BT = dyn_cast<BuiltinType>(t1->getUnqualifiedDesugaredType()))
{
auto k = BT->getKind();
if (k == BuiltinType::Double || k == BuiltinType::Float
|| (k >= BuiltinType::Bool && k <= BuiltinType::Int128))
return true;
}
if (const auto* BT = dyn_cast<BuiltinType>(t2->getUnqualifiedDesugaredType()))
{
auto k = BT->getKind();
if (k == BuiltinType::Double || k == BuiltinType::Float
|| (k >= BuiltinType::Bool && k <= BuiltinType::Int128))
return true;
}
auto tc = loplugin::TypeCheck(t1);
if (tc.Typedef("sal_Int32").GlobalNamespace())
return true;
if (m_Seen.insert(expr->getExprLoc()).second)
report(DiagnosticsEngine::Warning, "redundant functional cast from %0 to %1",
expr->getExprLoc())
<< t2 << t1 << expr->getSourceRange();
//getParentStmt(expr)->dump();
return true;
}
bool preRun() override
{
if (!compiler.getLangOpts().CPlusPlus)
return false;
std::string fn = handler.getMainFileName().str();
loplugin::normalizeDotDotInFilePath(fn);
// necessary on some other platforms
if (fn == SRCDIR "/sal/osl/unx/socket.cxx")<--- If condition 'fn==SRCDIR' is true, the function will return/exit
return false;
// compile-time check of constant
if (fn == SRCDIR "/bridges/source/jni_uno/jni_bridge.cxx")<--- Testing identical condition 'fn==SRCDIR'
return false;
return true;
}
void run() override
{
if (preRun())
TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
}
std::unordered_set<SourceLocation> m_Seen;
};
static loplugin::Plugin::Registration<RedundantFCast> redundantfcast("redundantfcast");
} // namespace
#endif // LO_CLANG_SHARED_PLUGINS
/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */
|