Author: codafi Date: Wed Feb 13 14:22:23 2019 New Revision: 353984 URL: http://llvm.org/viewvc/llvm-project?rev=353984&view=rev Log: Restore Check for Unreachable Exit Block in -Winfinite-recursion
Summary: When this was rewritten in D43737, the logic changed to better explore infinite loops. The check for a reachable exit block was deleted which accidentally introduced false positives in case the exit node was unreachable. We were testing for cases like this, but @steven_wu provided an additional test case that I've included in the regression tests for this patch. Reviewers: steven_wu, rtrieu Reviewed By: steven_wu, rtrieu Subscribers: cfe-commits, steven_wu Tags: #clang Differential Revision: https://reviews.llvm.org/D58122 Modified: cfe/trunk/lib/Sema/AnalysisBasedWarnings.cpp cfe/trunk/test/SemaCXX/warn-infinite-recursion.cpp Modified: cfe/trunk/lib/Sema/AnalysisBasedWarnings.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/AnalysisBasedWarnings.cpp?rev=353984&r1=353983&r2=353984&view=diff ============================================================================== --- cfe/trunk/lib/Sema/AnalysisBasedWarnings.cpp (original) +++ cfe/trunk/lib/Sema/AnalysisBasedWarnings.cpp Wed Feb 13 14:22:23 2019 @@ -249,6 +249,10 @@ static void checkRecursiveFunction(Sema CFG *cfg = AC.getCFG(); if (!cfg) return; + // If the exit block is unreachable, skip processing the function. + if (cfg->getExit().pred_empty()) + return; + // Emit diagnostic if a recursive function call is detected for all paths. if (checkForRecursiveFunctionCall(FD, cfg)) S.Diag(Body->getBeginLoc(), diag::warn_infinite_recursive_function); Modified: cfe/trunk/test/SemaCXX/warn-infinite-recursion.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/warn-infinite-recursion.cpp?rev=353984&r1=353983&r2=353984&view=diff ============================================================================== --- cfe/trunk/test/SemaCXX/warn-infinite-recursion.cpp (original) +++ cfe/trunk/test/SemaCXX/warn-infinite-recursion.cpp Wed Feb 13 14:22:23 2019 @@ -53,19 +53,28 @@ int j() { // expected-warning{{call its return 5 + j(); } -void k() { // expected-warning{{call itself}} +// Don't warn on infinite loops +void k() { while(true) { k(); } } -// Don't warn on infinite loops void l() { while (true) {} l(); } +void m() { + static int count = 5; + if (count >0) { + count--; + l(); + } + while (true) {} +} + class S { static void a(); void b(); _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
