njames93 updated this revision to Diff 325428.
njames93 added a comment.
Fix potential crash if macros are used, Now we just don't try to emit a fix.
Fix issue where FixIt for member initializers would be inserted at the start of
the constructor decl due to implicit member initializers confusing it.
Streamlined method for finding where to create member initializers when there's
no member initializer list.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D97132/new/
https://reviews.llvm.org/D97132
Files:
clang-tools-extra/clang-tidy/cppcoreguidelines/PreferMemberInitializerCheck.cpp
clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines-prefer-member-initializer.cpp
Index: clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines-prefer-member-initializer.cpp
===================================================================
--- clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines-prefer-member-initializer.cpp
+++ clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines-prefer-member-initializer.cpp
@@ -488,3 +488,48 @@
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: 'x' should be initialized in a member initializer of the constructor [cppcoreguidelines-prefer-member-initializer]
// CHECK-FIXES: {{^\ *$}}
}
+
+struct SafeDependancy {
+ int m;
+ int n;
+ SafeDependancy(int M) : m(M) {
+ // CHECK-FIXES: SafeDependancy(int M) : m(M), n(m) {
+ n = m;
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: 'n' should be initialized in a member initializer of the constructor
+ }
+ // We match against direct field dependancy as well as descendant field
+ // dependancy, ensure both are accounted for.
+ SafeDependancy(short M) : m(M) {
+ // CHECK-FIXES: SafeDependancy(short M) : m(M), n(m + 1) {
+ n = m + 1;
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: 'n' should be initialized in a member initializer of the constructor
+ }
+};
+
+struct BadDependancy {
+ int m;
+ int n;
+ BadDependancy(int N) : n(N) {
+ m = n;
+ }
+ BadDependancy(short N) : n(N) {
+ m = n + 1;
+ }
+};
+
+struct InitFromVarDecl {
+ int m;
+ InitFromVarDecl() {
+ // Can't apply this fix as n is declared in the body of the constructor.
+ int n = 3;
+ m = n;
+ }
+};
+
+struct AlreadyHasInit {
+ int m = 4;
+ AlreadyHasInit() {
+ m = 3;
+ // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: 'm' should be initialized in a member initializer of the constructor
+ }
+};
Index: clang-tools-extra/clang-tidy/cppcoreguidelines/PreferMemberInitializerCheck.cpp
===================================================================
--- clang-tools-extra/clang-tidy/cppcoreguidelines/PreferMemberInitializerCheck.cpp
+++ clang-tools-extra/clang-tidy/cppcoreguidelines/PreferMemberInitializerCheck.cpp
@@ -8,7 +8,9 @@
#include "PreferMemberInitializerCheck.h"
#include "clang/AST/ASTContext.h"
+#include "clang/AST/DeclCXX.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
#include "clang/Lex/Lexer.h"
using namespace clang::ast_matchers;
@@ -55,8 +57,37 @@
return false;
}
+namespace {
+AST_MATCHER_P(FieldDecl, indexNotLessThan, unsigned, Index) {
+ return Node.getFieldIndex() >= Index;
+}
+} // namespace
+
+// Checks if Field is initialised using a field that will be initialised after
+// it.
+// TODO: Probably should guard against function calls that could have side
+// effects or if they do reference another field that's initialized before this
+// field, but is modified before the assignment.
+static bool isSafeAssignment(const FieldDecl *Field, const Expr *Init,
+ const CXXConstructorDecl *Context) {
+
+ auto MemberMatcher =
+ memberExpr(hasObjectExpression(cxxThisExpr()),
+ member(fieldDecl(indexNotLessThan(Field->getFieldIndex()))));
+
+ auto DeclMatcher = declRefExpr(
+ to(varDecl(unless(parmVarDecl()), hasDeclContext(equalsNode(Context)))));
+
+ return match(expr(anyOf(MemberMatcher, DeclMatcher,
+ hasDescendant(MemberMatcher),
+ hasDescendant(DeclMatcher))),
+ *Init, Field->getASTContext())
+ .empty();
+}
+
static const std::pair<const FieldDecl *, const Expr *>
-isAssignmentToMemberOf(const RecordDecl *Rec, const Stmt *S) {
+isAssignmentToMemberOf(const CXXRecordDecl *Rec, const Stmt *S,
+ const CXXConstructorDecl *Ctor) {
if (const auto *BO = dyn_cast<BinaryOperator>(S)) {
if (BO->getOpcode() != BO_Assign)
return std::make_pair(nullptr, nullptr);
@@ -69,8 +100,11 @@
if (!Field)
return std::make_pair(nullptr, nullptr);
- if (isa<CXXThisExpr>(ME->getBase()))
- return std::make_pair(Field, BO->getRHS()->IgnoreParenImpCasts());
+ if (!isa<CXXThisExpr>(ME->getBase()))
+ return std::make_pair(nullptr, nullptr);
+ const auto *Init = BO->getRHS()->IgnoreParenImpCasts();
+ if (isSafeAssignment(Field, Init, Ctor))
+ return std::make_pair(Field, Init);
} else if (const auto *COCE = dyn_cast<CXXOperatorCallExpr>(S)) {
if (COCE->getOperator() != OO_Equal)
return std::make_pair(nullptr, nullptr);
@@ -84,8 +118,11 @@
if (!Field)
return std::make_pair(nullptr, nullptr);
- if (isa<CXXThisExpr>(ME->getBase()))
- return std::make_pair(Field, COCE->getArg(1)->IgnoreParenImpCasts());
+ if (!isa<CXXThisExpr>(ME->getBase()))
+ return std::make_pair(nullptr, nullptr);
+ const auto *Init = COCE->getArg(1)->IgnoreParenImpCasts();
+ if (isSafeAssignment(Field, Init, Ctor))
+ return std::make_pair(Field, Init);
}
return std::make_pair(nullptr, nullptr);
@@ -118,14 +155,12 @@
const auto *Body = cast<CompoundStmt>(Ctor->getBody());
const CXXRecordDecl *Class = Ctor->getParent();
- SourceLocation InsertPos;
bool FirstToCtorInits = true;
for (const Stmt *S : Body->body()) {
if (S->getBeginLoc().isMacroID()) {
- StringRef MacroName =
- Lexer::getImmediateMacroName(S->getBeginLoc(), *Result.SourceManager,
- getLangOpts());
+ StringRef MacroName = Lexer::getImmediateMacroName(
+ S->getBeginLoc(), *Result.SourceManager, getLangOpts());
if (MacroName.contains_lower("assert"))
return;
}
@@ -143,97 +178,116 @@
const FieldDecl *Field;
const Expr *InitValue;
- std::tie(Field, InitValue) = isAssignmentToMemberOf(Class, S);
+ std::tie(Field, InitValue) = isAssignmentToMemberOf(Class, S, Ctor);
if (Field) {
if (IsUseDefaultMemberInitEnabled && getLangOpts().CPlusPlus11 &&
Ctor->isDefaultConstructor() &&
(getLangOpts().CPlusPlus20 || !Field->isBitField()) &&
+ !Field->hasInClassInitializer() &&
(!isa<RecordDecl>(Class->getDeclContext()) ||
!cast<RecordDecl>(Class->getDeclContext())->isUnion()) &&
shouldBeDefaultMemberInitializer(InitValue)) {
+ bool InvalidFix = false;
SourceLocation FieldEnd =
Lexer::getLocForEndOfToken(Field->getSourceRange().getEnd(), 0,
*Result.SourceManager, getLangOpts());
- SmallString<128> Insertion(
- {UseAssignment ? " = " : "{",
- Lexer::getSourceText(
- CharSourceRange(InitValue->getSourceRange(), true),
- *Result.SourceManager, getLangOpts()),
- UseAssignment ? "" : "}"});
-
- SourceLocation SemiColonEnd =
- Lexer::findNextToken(S->getEndLoc(), *Result.SourceManager,
- getLangOpts())
- ->getEndLoc();
- CharSourceRange StmtRange =
- CharSourceRange::getCharRange(S->getBeginLoc(), SemiColonEnd);
-
- diag(S->getBeginLoc(), "%0 should be initialized in an in-class"
- " default member initializer")
- << Field << FixItHint::CreateInsertion(FieldEnd, Insertion)
- << FixItHint::CreateRemoval(StmtRange);
+ InvalidFix |= FieldEnd.isInvalid() || FieldEnd.isMacroID();
+ SourceLocation SemiColonEnd;
+ if (auto NextToken = Lexer::findNextToken(
+ S->getEndLoc(), *Result.SourceManager, getLangOpts()))
+ SemiColonEnd = NextToken->getEndLoc();
+ else
+ InvalidFix = true;
+ auto Diag =
+ diag(S->getBeginLoc(), "%0 should be initialized in an in-class"
+ " default member initializer")
+ << Field;
+ if (!InvalidFix) {
+ CharSourceRange StmtRange =
+ CharSourceRange::getCharRange(S->getBeginLoc(), SemiColonEnd);
+
+ SmallString<128> Insertion(
+ {UseAssignment ? " = " : "{",
+ Lexer::getSourceText(
+ CharSourceRange(InitValue->getSourceRange(), true),
+ *Result.SourceManager, getLangOpts()),
+ UseAssignment ? "" : "}"});
+
+ Diag << FixItHint::CreateInsertion(FieldEnd, Insertion)
+ << FixItHint::CreateRemoval(StmtRange);
+ }
} else {
- SmallString<128> Insertion;
+ StringRef InsertPrefix = "";
+ SourceLocation InsertPos;
bool AddComma = false;
- if (!Ctor->getNumCtorInitializers() && FirstToCtorInits) {
- SourceLocation BodyPos = Ctor->getBody()->getBeginLoc();
- SourceLocation NextPos = Ctor->getBeginLoc();
- do {
- InsertPos = NextPos;
- NextPos = Lexer::findNextToken(NextPos, *Result.SourceManager,
- getLangOpts())
- ->getLocation();
- } while (NextPos != BodyPos);
- InsertPos = Lexer::getLocForEndOfToken(
- InsertPos, 0, *Result.SourceManager, getLangOpts());
-
- Insertion = " : ";
- } else {
- bool Found = false;
- unsigned Index = Field->getFieldIndex();
- for (const auto *Init : Ctor->inits()) {
- if (Init->isMemberInitializer()) {
- if (Index < Init->getMember()->getFieldIndex()) {
- InsertPos = Init->getSourceLocation();
- Found = true;
- break;
- }
- }
+ bool InvalidFix = false;
+ unsigned Index = Field->getFieldIndex();
+ const CXXCtorInitializer *LastInListInit = nullptr;
+ for (const CXXCtorInitializer *Init : Ctor->inits()) {
+ if (!Init->isWritten())
+ continue;
+ if (Init->isMemberInitializer() &&
+ Index < Init->getMember()->getFieldIndex()) {
+ InsertPos = Init->getSourceLocation();
+ // There are initializers after the one we are inserting, so add a
+ // comma after this insertion in order to not break anything.
+ AddComma = true;
+ break;
}
-
- if (!Found) {
- if (Ctor->getNumCtorInitializers()) {
- InsertPos = Lexer::getLocForEndOfToken(
- (*Ctor->init_rbegin())->getSourceRange().getEnd(), 0,
- *Result.SourceManager, getLangOpts());
- }
- Insertion = ", ";
+ LastInListInit = Init;
+ }
+ if (InsertPos.isInvalid()) {
+ if (LastInListInit) {
+ InsertPos = Lexer::getLocForEndOfToken(
+ LastInListInit->getRParenLoc(), 0, *Result.SourceManager,
+ getLangOpts());
+ // Inserting after the last constructor initializer, so we need a
+ // comma.
+ InsertPrefix = ", ";
} else {
- AddComma = true;
+ InsertPos = Lexer::getLocForEndOfToken(
+ Ctor->getTypeSourceInfo()
+ ->getTypeLoc()
+ .getAs<clang::FunctionTypeLoc>()
+ .getLocalRangeEnd(),
+ 0, *Result.SourceManager, getLangOpts());
+
+ // If this is first time in the loop, there are no initializers so
+ // `:` declares member initialization list. If this is a subsequent
+ // pass then we have already inserted a `:` so continue with a
+ // comma.
+ InsertPrefix = FirstToCtorInits ? " : " : ", ";
}
}
- Insertion.append(
- {Field->getName(), "(",
- Lexer::getSourceText(
- CharSourceRange(InitValue->getSourceRange(), true),
- *Result.SourceManager, getLangOpts()),
- AddComma ? "), " : ")"});
-
- SourceLocation SemiColonEnd =
- Lexer::findNextToken(S->getEndLoc(), *Result.SourceManager,
- getLangOpts())
- ->getEndLoc();
- CharSourceRange StmtRange =
- CharSourceRange::getCharRange(S->getBeginLoc(), SemiColonEnd);
-
- diag(S->getBeginLoc(), "%0 should be initialized in a member"
- " initializer of the constructor")
- << Field
- << FixItHint::CreateInsertion(InsertPos, Insertion,
- FirstToCtorInits)
- << FixItHint::CreateRemoval(StmtRange);
- FirstToCtorInits = false;
+ InvalidFix |= InsertPos.isMacroID();
+
+ SourceLocation SemiColonEnd;
+ if (auto NextToken = Lexer::findNextToken(
+ S->getEndLoc(), *Result.SourceManager, getLangOpts()))
+ SemiColonEnd = NextToken->getEndLoc();
+ else
+ InvalidFix = true;
+
+ auto Diag =
+ diag(S->getBeginLoc(), "%0 should be initialized in a member"
+ " initializer of the constructor")
+ << Field;
+ if (!InvalidFix) {
+
+ CharSourceRange StmtRange =
+ CharSourceRange::getCharRange(S->getBeginLoc(), SemiColonEnd);
+ SmallString<128> Insertion(
+ {InsertPrefix, Field->getName(), "(",
+ Lexer::getSourceText(
+ CharSourceRange(InitValue->getSourceRange(), true),
+ *Result.SourceManager, getLangOpts()),
+ AddComma ? "), " : ")"});
+ Diag << FixItHint::CreateInsertion(InsertPos, Insertion,
+ FirstToCtorInits)
+ << FixItHint::CreateRemoval(StmtRange);
+ FirstToCtorInits = false;
+ }
}
}
}
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