[clang-tidy] rename_check.py misc-string-constructor bugprone-string-constructor
Summary:
Rename misc-string-constructor to bugprone-string-constructor +
manually update the lenght of '==='s in the doc file.
Reviewers: hokein, xazax.hun
Reviewed By: hokein, xazax.hun
Subscribers: mgorny, xazax.hun, cfe-commits
Differential Revision: https://reviews.llvm.org/D40388
llvm-svn: 318916
diff --git a/clang-tools-extra/clang-tidy/bugprone/StringConstructorCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/StringConstructorCheck.cpp
new file mode 100644
index 0000000..5607ce6
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/bugprone/StringConstructorCheck.cpp
@@ -0,0 +1,134 @@
+//===--- StringConstructorCheck.cpp - clang-tidy---------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "StringConstructorCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Tooling/FixIt.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace bugprone {
+
+AST_MATCHER_P(IntegerLiteral, isBiggerThan, unsigned, N) {
+ return Node.getValue().getZExtValue() > N;
+}
+
+StringConstructorCheck::StringConstructorCheck(StringRef Name,
+ ClangTidyContext *Context)
+ : ClangTidyCheck(Name, Context),
+ WarnOnLargeLength(Options.get("WarnOnLargeLength", 1) != 0),
+ LargeLengthThreshold(Options.get("LargeLengthThreshold", 0x800000)) {}
+
+void StringConstructorCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+ Options.store(Opts, "WarnOnLargeLength", WarnOnLargeLength);
+ Options.store(Opts, "LargeLengthThreshold", LargeLengthThreshold);
+}
+
+void StringConstructorCheck::registerMatchers(MatchFinder *Finder) {
+ if (!getLangOpts().CPlusPlus)
+ return;
+
+ const auto ZeroExpr = expr(ignoringParenImpCasts(integerLiteral(equals(0))));
+ const auto CharExpr = expr(ignoringParenImpCasts(characterLiteral()));
+ const auto NegativeExpr = expr(ignoringParenImpCasts(
+ unaryOperator(hasOperatorName("-"),
+ hasUnaryOperand(integerLiteral(unless(equals(0)))))));
+ const auto LargeLengthExpr = expr(ignoringParenImpCasts(
+ integerLiteral(isBiggerThan(LargeLengthThreshold))));
+ const auto CharPtrType = type(anyOf(pointerType(), arrayType()));
+
+ // Match a string-literal; even through a declaration with initializer.
+ const auto BoundStringLiteral = stringLiteral().bind("str");
+ const auto ConstStrLiteralDecl = varDecl(
+ isDefinition(), hasType(constantArrayType()), hasType(isConstQualified()),
+ hasInitializer(ignoringParenImpCasts(BoundStringLiteral)));
+ const auto ConstPtrStrLiteralDecl = varDecl(
+ isDefinition(),
+ hasType(pointerType(pointee(isAnyCharacter(), isConstQualified()))),
+ hasInitializer(ignoringParenImpCasts(BoundStringLiteral)));
+ const auto ConstStrLiteral = expr(ignoringParenImpCasts(anyOf(
+ BoundStringLiteral, declRefExpr(hasDeclaration(anyOf(
+ ConstPtrStrLiteralDecl, ConstStrLiteralDecl))))));
+
+ // Check the fill constructor. Fills the string with n consecutive copies of
+ // character c. [i.e string(size_t n, char c);].
+ Finder->addMatcher(
+ cxxConstructExpr(
+ hasDeclaration(cxxMethodDecl(hasName("basic_string"))),
+ hasArgument(0, hasType(qualType(isInteger()))),
+ hasArgument(1, hasType(qualType(isInteger()))),
+ anyOf(
+ // Detect the expression: string('x', 40);
+ hasArgument(0, CharExpr.bind("swapped-parameter")),
+ // Detect the expression: string(0, ...);
+ hasArgument(0, ZeroExpr.bind("empty-string")),
+ // Detect the expression: string(-4, ...);
+ hasArgument(0, NegativeExpr.bind("negative-length")),
+ // Detect the expression: string(0x1234567, ...);
+ hasArgument(0, LargeLengthExpr.bind("large-length"))))
+ .bind("constructor"),
+ this);
+
+ // Check the literal string constructor with char pointer and length
+ // parameters. [i.e. string (const char* s, size_t n);]
+ Finder->addMatcher(
+ cxxConstructExpr(
+ hasDeclaration(cxxMethodDecl(hasName("basic_string"))),
+ hasArgument(0, hasType(CharPtrType)),
+ hasArgument(1, hasType(isInteger())),
+ anyOf(
+ // Detect the expression: string("...", 0);
+ hasArgument(1, ZeroExpr.bind("empty-string")),
+ // Detect the expression: string("...", -4);
+ hasArgument(1, NegativeExpr.bind("negative-length")),
+ // Detect the expression: string("lit", 0x1234567);
+ hasArgument(1, LargeLengthExpr.bind("large-length")),
+ // Detect the expression: string("lit", 5)
+ allOf(hasArgument(0, ConstStrLiteral.bind("literal-with-length")),
+ hasArgument(1, ignoringParenImpCasts(
+ integerLiteral().bind("int"))))))
+ .bind("constructor"),
+ this);
+}
+
+void StringConstructorCheck::check(const MatchFinder::MatchResult &Result) {
+ const ASTContext &Ctx = *Result.Context;
+ const auto *E = Result.Nodes.getNodeAs<CXXConstructExpr>("constructor");
+ assert(E && "missing constructor expression");
+ SourceLocation Loc = E->getLocStart();
+
+ if (Result.Nodes.getNodeAs<Expr>("swapped-parameter")) {
+ const Expr *P0 = E->getArg(0);
+ const Expr *P1 = E->getArg(1);
+ diag(Loc, "string constructor parameters are probably swapped;"
+ " expecting string(count, character)")
+ << tooling::fixit::createReplacement(*P0, *P1, Ctx)
+ << tooling::fixit::createReplacement(*P1, *P0, Ctx);
+ } else if (Result.Nodes.getNodeAs<Expr>("empty-string")) {
+ diag(Loc, "constructor creating an empty string");
+ } else if (Result.Nodes.getNodeAs<Expr>("negative-length")) {
+ diag(Loc, "negative value used as length parameter");
+ } else if (Result.Nodes.getNodeAs<Expr>("large-length")) {
+ if (WarnOnLargeLength)
+ diag(Loc, "suspicious large length parameter");
+ } else if (Result.Nodes.getNodeAs<Expr>("literal-with-length")) {
+ const auto *Str = Result.Nodes.getNodeAs<StringLiteral>("str");
+ const auto *Lit = Result.Nodes.getNodeAs<IntegerLiteral>("int");
+ if (Lit->getValue().ugt(Str->getLength())) {
+ diag(Loc, "length is bigger then string literal size");
+ }
+ }
+}
+
+} // namespace bugprone
+} // namespace tidy
+} // namespace clang