From 78c7e344859f0ebc213550fdf55838a2bf38aaeb Mon Sep 17 00:00:00 2001 From: Chandler Carruth Date: Tue, 5 Apr 2011 21:36:30 +0000 Subject: Commit a bit of a hack to fully handle the situation where variables are marked explicitly as uninitialized through direct self initialization: int x = x; With r128894 we prevented warnings about this code, and this patch teaches the analysis engine to continue analyzing subsequent uses of 'x'. This should wrap up PR9624. There is still an open question of whether we should suppress the maybe-uninitialized warnings resulting from variables initialized in this fashion. The definitely-uninitialized uses should always be warned. llvm-svn: 128932 --- clang/lib/Analysis/UninitializedValues.cpp | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) (limited to 'clang/lib/Analysis/UninitializedValues.cpp') diff --git a/clang/lib/Analysis/UninitializedValues.cpp b/clang/lib/Analysis/UninitializedValues.cpp index 3dde41f2272..062857d86ee 100644 --- a/clang/lib/Analysis/UninitializedValues.cpp +++ b/clang/lib/Analysis/UninitializedValues.cpp @@ -472,12 +472,24 @@ void TransferFunctions::VisitDeclStmt(DeclStmt *ds) { DI != DE; ++DI) { if (VarDecl *vd = dyn_cast(*DI)) { if (isTrackedVar(vd)) { - if (Stmt *init = vd->getInit()) { + if (Expr *init = vd->getInit()) { Visit(init); - vals[vd] = Initialized; + + // If the initializer consists solely of a reference to itself, we + // explicitly mark the variable as uninitialized. This allows code + // like the following: + // + // int x = x; + // + // to deliberately leave a variable uninitialized. Different analysis + // clients can detect this pattern and adjust their reporting + // appropriately, but we need to continue to analyze subsequent uses + // of the variable. + DeclRefExpr *DRE = dyn_cast(init->IgnoreParenImpCasts()); + vals[vd] = (DRE && DRE->getDecl() == vd) ? Uninitialized + : Initialized; } - } - else if (Stmt *init = vd->getInit()) { + } else if (Stmt *init = vd->getInit()) { Visit(init); } } -- cgit v1.2.3