[clang-tidy] Fixed abseil-time-subtraction to work on C++17

[jvikstrom]

Summary

Fixed abseil-time-subtraction to work on C++17

[gribozavr]

clang-tools-extra/clang-tidy/abseil/TimeSubtractionCheck.cpp

45

Use anyOf() instead two selectFirsts?

[jvikstrom]

Using anyOf instead of multiple selectFirsts

clang-tools-extra/clang-tidy/abseil/TimeSubtractionCheck.cpp

static bool InsideMacroDefinition(const MatchFinder::MatchResult &Result,
   return !clang::Lexer::makeFileCharRange(
               clang::CharSourceRange::getCharRange(Range),
               *Result.SourceManager, Result.Context->getLangOpts())
               .isValid();
 }
 
 static bool isConstructorAssignment(const MatchFinder::MatchResult &Result,
                                     const Expr *Node) {
+  // For C++14 and earlier there are elidable constructors that must be matched
+  // in hasParent. The elidable constructors do not exist in C++17 and later and
+  // therefore an additional check that does not match against the elidable
+  // constructors are needed for this case.
   return selectFirst<const Expr>(
-             "e", match(expr(hasParent(materializeTemporaryExpr(hasParent(
+             "e",
+             match(expr(anyOf(
+                       callExpr(hasParent(materializeTemporaryExpr(hasParent(
                                     cxxConstructExpr(hasParent(exprWithCleanups(
                                         hasParent(varDecl()))))))))
-                            .bind("e"),
-                        *Node, *Result.Context)) != nullptr;
+                       callExpr(hasParent(varDecl())).bind("e"))),
 }
 
 static bool isArgument(const MatchFinder::MatchResult &Result,
                        const Expr *Node) {
+  // For the same reason as in isConstructorAssignment two separate selectFirsts
+  // need to be checked here
   return selectFirst<const Expr>(
              "e",
-             match(expr(hasParent(
-                            materializeTemporaryExpr(hasParent(cxxConstructExpr(
+             match(
+                 expr(anyOf(
+                     expr(hasParent(materializeTemporaryExpr(
+                              hasParent(cxxConstructExpr(
                                   hasParent(callExpr()),
                                   unless(hasParent(cxxOperatorCallExpr())))))))
                          .bind("e"),
-                   *Node, *Result.Context)) != nullptr;
+                     expr(hasParent(callExpr()),
+                          unless(hasParent(cxxOperatorCallExpr())))
+                         .bind("e"))),
 }
 
 static bool isReturn(const MatchFinder::MatchResult &Result, const Expr *Node) {
+  // For the same reason as in isConstructorAssignment two separate selectFirsts
+  // need to be checked here
   return selectFirst<const Expr>(
-             "e", match(expr(hasParent(materializeTemporaryExpr(hasParent(
-                                 cxxConstructExpr(hasParent(exprWithCleanups(
-                                     hasParent(returnStmt()))))))))
-                            .bind("e"),
-                        *Node, *Result.Context)) != nullptr;
+             "e",
+             match(expr(anyOf(
+                       expr(hasParent(materializeTemporaryExpr(hasParent(
+                       expr(hasParent(returnStmt())).bind("e"))),
 }
 
 static bool parensRequired(const MatchFinder::MatchResult &Result,
                            const Expr *Node) {
   // TODO: Figure out any more contexts in which we can omit the surrounding
   // parentheses.
   return !(isConstructorAssignment(Result, Node) || isArgument(Result, Node) ||
            isReturn(Result, Node));

clang-tools-extra/test/clang-tidy/abseil-time-subtraction.cpp

-// RUN: %check_clang_tidy -std=c++11,c++14 %s abseil-time-subtraction %t -- -- -I %S/Inputs
+// RUN: %check_clang_tidy -std=c++11-or-later %s abseil-time-subtraction %t -- -- -I %S/Inputs
 // FIXME: Fix the checker to work in C++17 mode.
 
 #include "absl/time/time.h"
 
 void g(absl::Duration d);
 
 void f() {
   absl::Time t;