[PATCH] D73270: [clang-tidy] Fix false positive in bugprone-infinite-loop

[Balogh, Ádám via Phabricator via cfe-commits]

baloghadamsoftware updated this revision to Diff 240192.
baloghadamsoftware added a comment.

Updated according to the comments.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D73270/new/

https://reviews.llvm.org/D73270

Files:
  clang-tools-extra/clang-tidy/bugprone/InfiniteLoopCheck.cpp
  clang-tools-extra/test/clang-tidy/checkers/bugprone-infinite-loop.cpp


Index: clang-tools-extra/test/clang-tidy/checkers/bugprone-infinite-loop.cpp
===================================================================
--- clang-tools-extra/test/clang-tidy/checkers/bugprone-infinite-loop.cpp
+++ clang-tools-extra/test/clang-tidy/checkers/bugprone-infinite-loop.cpp
@@ -8,6 +8,16 @@
     j++;
   }
 
+  while (int k = 10) {
+    // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: this loop is infinite; none of its condition variables () are updated in the loop body [bugprone-infinite-loop]
+    j--;
+  }
+
+  while (int k = 10) {
+    // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: this loop is infinite; none of its condition variables () 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) are updated in the loop body [bugprone-infinite-loop]
     j++;
@@ -27,6 +37,16 @@
     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 @@
     // 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);
Index: clang-tools-extra/clang-tidy/bugprone/InfiniteLoopCheck.cpp
===================================================================
--- clang-tools-extra/clang-tidy/bugprone/InfiniteLoopCheck.cpp
+++ clang-tools-extra/clang-tidy/bugprone/InfiniteLoopCheck.cpp
@@ -170,11 +170,21 @@
   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(),


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