From: Ted Kremenek Date: Mon, 31 May 2010 01:22:04 +0000 (+0000) Subject: After conversations with Zhongxing Xu and Jordy Rose, refine the logic in X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=a709b87de4644c05d7787f9fb246d2b4dc38bf51;p=clang After conversations with Zhongxing Xu and Jordy Rose, refine the logic in RegionStoreManager::RetrieveElement() that handles indexing into a larger scalar object to only consult the direct binding of a super region if it is a scalar. This isn't perfect yet, and a big FIXME is attached to the code. This causes the test case for PR 7218 now to pass. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@105195 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/Checker/RegionStore.cpp b/lib/Checker/RegionStore.cpp index 2200ef1002..ddcb7bee49 100644 --- a/lib/Checker/RegionStore.cpp +++ b/lib/Checker/RegionStore.cpp @@ -1173,27 +1173,33 @@ SVal RegionStoreManager::RetrieveElement(Store store, } } - // Check if the immediate super region has a direct binding. - if (const Optional &V = getDirectBinding(B, superR)) { - if (SymbolRef parentSym = V->getAsSymbol()) { - return ValMgr.getDerivedRegionValueSymbolVal(parentSym, R); - } - - if (V->isUnknownOrUndef()) - return *V; - - // Handle LazyCompoundVals for the immediate super region. Other cases - // are handled in 'RetrieveFieldOrElementCommon'. - if (const nonloc::LazyCompoundVal *LCV = - dyn_cast(V)) { - R = MRMgr.getElementRegionWithSuper(R, LCV->getRegion()); - return RetrieveElement(LCV->getStore(), R); + // Handle the case where we are indexing into a larger scalar object. + // For example, this handles: + // int x = ... + // char *y = &x; + // return *y; + // FIXME: This is a hack, and doesn't do anything really intelligent yet. + const RegionRawOffset &O = R->getAsRawOffset(); + if (const TypedRegion *baseR = dyn_cast_or_null(O.getRegion())) { + QualType baseT = baseR->getValueType(Ctx); + if (baseT->isScalarType()) { + QualType elemT = R->getElementType(); + if (elemT->isScalarType()) { + if (Ctx.getTypeSizeInChars(baseT) >= Ctx.getTypeSizeInChars(elemT)) { + if (const Optional &V = getDirectBinding(B, superR)) { + if (SymbolRef parentSym = V->getAsSymbol()) + return ValMgr.getDerivedRegionValueSymbolVal(parentSym, R); + + if (V->isUnknownOrUndef()) + return *V; + // Other cases: give up. We are indexing into a larger object + // that has some value, but we don't know how to handle that yet. + return UnknownVal(); + } + } + } } - - // Other cases: give up. - return UnknownVal(); } - return RetrieveFieldOrElementCommon(store, R, R->getElementType(), superR); } diff --git a/test/Analysis/PR7218.c b/test/Analysis/PR7218.c index bda30a7f72..635e56f053 100644 --- a/test/Analysis/PR7218.c +++ b/test/Analysis/PR7218.c @@ -1,5 +1,4 @@ // RUN: %clang_cc1 -analyze -analyzer-check-objc-mem -analyzer-store region -verify %s -// XFAIL: * char PR7218(char a) { char buf[2]; buf[0] = a;