[clang] [analyzer] Suppress out of bounds reports after weak loop assumptions (PR #109804)

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=?utf-8?q?Donát?= Nagy <donat.nagy at ericsson.com>
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/109804 at github.com>


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@@ -323,12 +342,13 @@ class ExprEngine {
 
   /// ProcessBranch - Called by CoreEngine.  Used to generate successor
   ///  nodes by processing the 'effects' of a branch condition.
-  void processBranch(const Stmt *Condition,
-                     NodeBuilderContext& BuilderCtx,
-                     ExplodedNode *Pred,
-                     ExplodedNodeSet &Dst,
-                     const CFGBlock *DstT,
-                     const CFGBlock *DstF);
+  /// If the branch condition is a loop condition, IterationsFinishedInLoop is
+  /// the number of already finished iterations (0, 1, 2...); otherwise it's
+  /// std::nullopt.
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isuckatcs wrote:

> We could introduce it, but we'd need to maintain a nested stack of loops (1 iteration in that while, then 2 iterations in the for, then 1 iteration in this other for in the function called there...) to correctly monitor the number of iterations.

You can bind the current iteration number to the AST node of the loop, as it happens with nested `ArrayInitLoopExpr` IIRC. I'm sure we already have something similar implemented.

I'd prefer using state traits here instead of modifying the engine API.



https://github.com/llvm/llvm-project/pull/109804