Author: Adam Balogh Date: 2020-01-27T10:13:55+01:00 New Revision: 70f4c6e7b14f225f9628fbdab3620ce037613351
URL: https://github.com/llvm/llvm-project/commit/70f4c6e7b14f225f9628fbdab3620ce037613351 DIFF: https://github.com/llvm/llvm-project/commit/70f4c6e7b14f225f9628fbdab3620ce037613351.diff LOG: [clan-tidy] Fix false positive in bugprone-infinite-loop The checker bugprone-infinite-loop does not track changes of variables in the initialization expression of a variable declared inside the condition of the while statement. This leads to false positives, similarly to the one in the bug report https://bugs.llvm.org/show_bug.cgi?id=44618. This patch fixes this issue by enabling tracking of the variables of this expression as well. Differential Revision: https://reviews.llvm.org/D73270 Added: Modified: clang-tools-extra/clang-tidy/bugprone/InfiniteLoopCheck.cpp clang-tools-extra/test/clang-tidy/checkers/bugprone-infinite-loop.cpp Removed: ################################################################################ diff --git a/clang-tools-extra/clang-tidy/bugprone/InfiniteLoopCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/InfiniteLoopCheck.cpp index 81ae45a00896..c771ba81b250 100644 --- a/clang-tools-extra/clang-tidy/bugprone/InfiniteLoopCheck.cpp +++ b/clang-tools-extra/clang-tidy/bugprone/InfiniteLoopCheck.cpp @@ -170,17 +170,33 @@ void InfiniteLoopCheck::check(const MatchFinder::MatchResult &Result) { const auto *LoopStmt = Result.Nodes.getNodeAs<Stmt>("loop-stmt"); const auto *Func = Result.Nodes.getNodeAs<FunctionDecl>("func"); + bool ShouldHaveConditionVariables = true; + if (const auto *While = dyn_cast<WhileStmt>(LoopStmt)) { + if (const VarDecl *LoopVarDecl = While->getConditionVariable()) { + if (const Expr *Init = LoopVarDecl->getInit()) { + ShouldHaveConditionVariables = false; + Cond = Init; + } + } + } + if (isAtLeastOneCondVarChanged(Func, LoopStmt, Cond, Result.Context)) return; std::string CondVarNames = getCondVarNames(Cond); - if (CondVarNames.empty()) + if (ShouldHaveConditionVariables && CondVarNames.empty()) return; - diag(LoopStmt->getBeginLoc(), - "this loop is infinite; none of its condition variables (%0)" - " are updated in the loop body") + if (CondVarNames.empty()) { + diag(LoopStmt->getBeginLoc(), + "this loop is infinite; it does not check any variables in the" + " condition"); + } else { + diag(LoopStmt->getBeginLoc(), + "this loop is infinite; none of its condition variables (%0)" + " are updated in the loop body") << CondVarNames; + } } } // namespace bugprone diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone-infinite-loop.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone-infinite-loop.cpp index 33d94820b0f6..d89bdadf0212 100644 --- a/clang-tools-extra/test/clang-tidy/checkers/bugprone-infinite-loop.cpp +++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone-infinite-loop.cpp @@ -4,10 +4,20 @@ void simple_infinite_loop1() { int i = 0; int j = 0; while (i < 10) { - // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: this loop is infinite; none of its condition variables (i) are updated in the loop body [bugprone-infinite-loop] + // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: this loop is infinite; none of its condition variables (i) are updated in the loop body [bugprone-infinite-loop] j++; } + while (int k = 10) { + // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: this loop is infinite; it does not check any variables in the condition [bugprone-infinite-loop] + j--; + } + + while (int k = 10) { + // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: this loop is infinite; it does not check any variables in the condition [bugprone-infinite-loop] + k--; + } + do { // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: this loop is infinite; none of its condition variables (i) are updated in the loop body [bugprone-infinite-loop] j++; @@ -27,6 +37,16 @@ void simple_infinite_loop2() { j++; } + while (int k = Limit) { + // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: this loop is infinite; none of its condition variables (Limit) are updated in the loop body [bugprone-infinite-loop] + j--; + } + + while (int k = Limit) { + // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: this loop is infinite; none of its condition variables (Limit) are updated in the loop body [bugprone-infinite-loop] + k--; + } + do { // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: this loop is infinite; none of its condition variables (i, Limit) are updated in the loop body [bugprone-infinite-loop] j++; @@ -44,6 +64,22 @@ void simple_not_infinite1() { // Not an error since 'Limit' is updated. Limit--; } + + while (Limit--) { + // Not an error since 'Limit' is updated. + i++; + } + + while (int k = Limit) { + // Not an error since 'Limit' is updated. + Limit--; + } + + while (int k = Limit--) { + // Not an error since 'Limit' is updated. + i++; + } + do { Limit--; } while (i < Limit); _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
