From 7e9822cc55065b7c450dda254340765794e11fe3 Mon Sep 17 00:00:00 2001 From: eahcmrh Date: Fri, 11 Jun 2021 17:44:06 +0200 Subject: [PATCH] Revert "[Sema] Address-space sensitive check for unbounded arrays (v2)" This reverts commit e42a347b74400b7212ceaaea6d39562a0435df42. --- clang/include/clang/Basic/DiagnosticSemaKinds.td | 8 --- clang/lib/Sema/SemaChecking.cpp | 89 ++++-------------------- clang/test/Sema/const-eval.c | 8 +-- clang/test/Sema/unbounded-array-bounds.c | 80 --------------------- clang/test/SemaCXX/constant-expression-cxx14.cpp | 3 +- 5 files changed, 18 insertions(+), 170 deletions(-) delete mode 100644 clang/test/Sema/unbounded-array-bounds.c diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index c07e6f9..af242cf 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -9176,14 +9176,6 @@ def warn_array_index_precedes_bounds : Warning< def warn_array_index_exceeds_bounds : Warning< "array index %0 is past the end of the array (which contains %1 " "element%s2)">, InGroup; -def warn_ptr_arith_exceeds_max_addressable_bounds : Warning< - "the pointer incremented by %0 refers past the last possible element for an array in %1-bit " - "address space containing %2-bit (%3-byte) elements (max possible %4 element%s5)">, - InGroup; -def warn_array_index_exceeds_max_addressable_bounds : Warning< - "array index %0 refers past the last possible element for an array in %1-bit " - "address space containing %2-bit (%3-byte) elements (max possible %4 element%s5)">, - InGroup; def note_array_declared_here : Note< "array %0 declared here">; diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp index 309cb7c..9149829 100644 --- a/clang/lib/Sema/SemaChecking.cpp +++ b/clang/lib/Sema/SemaChecking.cpp @@ -14536,11 +14536,11 @@ void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr, const ConstantArrayType *ArrayTy = Context.getAsConstantArrayType(BaseExpr->getType()); - const Type *BaseType = - ArrayTy == nullptr ? nullptr : ArrayTy->getElementType().getTypePtr(); - bool IsUnboundedArray = (BaseType == nullptr); - if (EffectiveType->isDependentType() || - (!IsUnboundedArray && BaseType->isDependentType())) + if (!ArrayTy) + return; + + const Type *BaseType = ArrayTy->getElementType().getTypePtr(); + if (EffectiveType->isDependentType() || BaseType->isDependentType()) return; Expr::EvalResult Result; @@ -14548,10 +14548,8 @@ void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr, return; llvm::APSInt index = Result.Val.getInt(); - if (IndexNegated) { - index.setIsUnsigned(false); + if (IndexNegated) index = -index; - } const NamedDecl *ND = nullptr; if (const DeclRefExpr *DRE = dyn_cast(BaseExpr)) @@ -14559,69 +14557,6 @@ void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr, if (const MemberExpr *ME = dyn_cast(BaseExpr)) ND = ME->getMemberDecl(); - if (IsUnboundedArray) { - if (index.isUnsigned() || !index.isNegative()) { - const auto &ASTC = getASTContext(); - unsigned AddrBits = - ASTC.getTargetInfo().getPointerWidth(ASTC.getTargetAddressSpace( - EffectiveType->getCanonicalTypeInternal())); - if (index.getBitWidth() < AddrBits) - index = index.zext(AddrBits); - CharUnits ElemCharUnits = ASTC.getTypeSizeInChars(EffectiveType); - llvm::APInt ElemBytes(index.getBitWidth(), ElemCharUnits.getQuantity()); - // If index has more active bits than address space, we already know - // we have a bounds violation to warn about. Otherwise, compute - // address of (index + 1)th element, and warn about bounds violation - // only if that address exceeds address space. - if (index.getActiveBits() <= AddrBits) { - bool Overflow; - llvm::APInt Product(index); - Product += 1; - Product = Product.umul_ov(ElemBytes, Overflow); - if (!Overflow && Product.getActiveBits() <= AddrBits) - return; - } - - // Need to compute max possible elements in address space, since that - // is included in diag message. - llvm::APInt MaxElems = llvm::APInt::getMaxValue(AddrBits); - MaxElems = MaxElems.zext(std::max(AddrBits + 1, ElemBytes.getBitWidth())); - MaxElems += 1; - ElemBytes = ElemBytes.zextOrTrunc(MaxElems.getBitWidth()); - MaxElems = MaxElems.udiv(ElemBytes); - - unsigned DiagID = - ASE ? diag::warn_array_index_exceeds_max_addressable_bounds - : diag::warn_ptr_arith_exceeds_max_addressable_bounds; - - // Diag message shows element size in bits and in "bytes" (platform- - // dependent CharUnits) - DiagRuntimeBehavior(BaseExpr->getBeginLoc(), BaseExpr, - PDiag(DiagID) - << index.toString(10, true) << AddrBits - << (unsigned)ASTC.toBits(ElemCharUnits) - << ElemBytes.toString(10, false) - << MaxElems.toString(10, false) - << (unsigned)MaxElems.getLimitedValue(~0U) - << IndexExpr->getSourceRange()); - - if (!ND) { - // Try harder to find a NamedDecl to point at in the note. - while (const auto *ASE = dyn_cast(BaseExpr)) - BaseExpr = ASE->getBase()->IgnoreParenCasts(); - if (const auto *DRE = dyn_cast(BaseExpr)) - ND = DRE->getDecl(); - if (const auto *ME = dyn_cast(BaseExpr)) - ND = ME->getMemberDecl(); - } - - if (ND) - DiagRuntimeBehavior(ND->getBeginLoc(), BaseExpr, - PDiag(diag::note_array_declared_here) << ND); - } - return; - } - if (index.isUnsigned() || !index.isNegative()) { // It is possible that the type of the base expression after // IgnoreParenCasts is incomplete, even though the type of the base @@ -14684,8 +14619,9 @@ void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr, } } - unsigned DiagID = ASE ? diag::warn_array_index_exceeds_bounds - : diag::warn_ptr_arith_exceeds_bounds; + unsigned DiagID = diag::warn_ptr_arith_exceeds_bounds; + if (ASE) + DiagID = diag::warn_array_index_exceeds_bounds; DiagRuntimeBehavior(BaseExpr->getBeginLoc(), BaseExpr, PDiag(DiagID) << toString(index, 10, true) @@ -14706,11 +14642,12 @@ void Sema::CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr, if (!ND) { // Try harder to find a NamedDecl to point at in the note. - while (const auto *ASE = dyn_cast(BaseExpr)) + while (const ArraySubscriptExpr *ASE = + dyn_cast(BaseExpr)) BaseExpr = ASE->getBase()->IgnoreParenCasts(); - if (const auto *DRE = dyn_cast(BaseExpr)) + if (const DeclRefExpr *DRE = dyn_cast(BaseExpr)) ND = DRE->getDecl(); - if (const auto *ME = dyn_cast(BaseExpr)) + if (const MemberExpr *ME = dyn_cast(BaseExpr)) ND = ME->getMemberDecl(); } diff --git a/clang/test/Sema/const-eval.c b/clang/test/Sema/const-eval.c index 427b056..c3cecc0 100644 --- a/clang/test/Sema/const-eval.c +++ b/clang/test/Sema/const-eval.c @@ -140,10 +140,10 @@ EVAL_EXPR(52, &pr24622 == (void *)&PR24622); // expected-error {{not an integer // We evaluate these by providing 2s' complement semantics in constant // expressions, like we do for integers. -void *PR28739a = (__int128)(unsigned long)-1 + &PR28739a; // expected-warning {{the pointer incremented by 18446744073709551615 refers past the last possible element for an array in 64-bit address space containing 64-bit (8-byte) elements (max possible 2305843009213693952 elements)}} -void *PR28739b = &PR28739b + (__int128)(unsigned long)-1; // expected-warning {{refers past the last possible element}} -__int128 PR28739c = (&PR28739c + (__int128)(unsigned long)-1) - &PR28739c; // expected-warning {{refers past the last possible element}} -void *PR28739d = &(&PR28739d)[(__int128)(unsigned long)-1]; // expected-warning {{refers past the last possible element}} +void *PR28739a = (__int128)(unsigned long)-1 + &PR28739a; +void *PR28739b = &PR28739b + (__int128)(unsigned long)-1; +__int128 PR28739c = (&PR28739c + (__int128)(unsigned long)-1) - &PR28739c; +void *PR28739d = &(&PR28739d)[(__int128)(unsigned long)-1]; struct PR35214_X { int k; diff --git a/clang/test/Sema/unbounded-array-bounds.c b/clang/test/Sema/unbounded-array-bounds.c deleted file mode 100644 index d47463f..0000000 --- a/clang/test/Sema/unbounded-array-bounds.c +++ /dev/null @@ -1,80 +0,0 @@ -// RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -fsyntax-only %s 2>&1 | FileCheck --check-prefix=CHECK-X86-ADDR64 %s \ -// RUN: --implicit-check-not 'past the last possible element' -// RUN: %clang_cc1 -triple i386-pc-linux-gnu -fsyntax-only %s 2>&1 | FileCheck --check-prefix=CHECK-I386-ADDR32 %s \ -// RUN: --implicit-check-not 'past the last possible element' -// RUN: %clang_cc1 -triple avr-pc-linux-gnu -fsyntax-only %s 2>&1 | FileCheck --check-prefix=CHECK-AVR-ADDR16 %s \ -// RUN: --implicit-check-not 'past the last possible element' - -struct S { - long long a; - char b; - long long c; - short d; -}; - -struct S s[]; - -void f1() { - ++s[3].a; - ++s[7073650413200313099].b; - // CHECK-X86-ADDR64: :[[@LINE-1]]:5: warning: array index 7073650413200313099 refers past the last possible element for an array in 64-bit address space containing 256-bit (32-byte) elements (max possible 576460752303423488 elements) - // CHECK-I386-ADDR32: :[[@LINE-2]]:5: warning: {{.*}} past the last possible element {{.*}} in 32-bit {{.*}} (max possible 178956970 elements) - // CHECK-AVR-ADDR16: :[[@LINE-3]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 3276 elements) - ++s[7073650].c; - // CHECK-AVR-ADDR16: :[[@LINE-1]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 3276 elements) -} - -long long ll[]; - -void f2() { - ++ll[3]; - ++ll[2705843009213693952]; - // CHECK-X86-ADDR64: :[[@LINE-1]]:5: warning: {{.*}} past the last possible element {{.*}} in 64-bit {{.*}} (max possible 2305843009213693952 elements) - // CHECK-I386-ADDR32: :[[@LINE-2]]:5: warning: {{.*}} past the last possible element {{.*}} in 32-bit {{.*}} (max possible 536870912 elements) - // CHECK-AVR-ADDR16: :[[@LINE-3]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 8192 elements) - ++ll[847073650]; - // CHECK-I386-ADDR32: :[[@LINE-1]]:5: warning: {{.*}} past the last possible element {{.*}} in 32-bit {{.*}} (max possible 536870912 elements) - // CHECK-AVR-ADDR16: :[[@LINE-2]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 8192 elements) -} - -void f3(struct S p[]) { - ++p[3].a; - ++p[7073650413200313099].b; - // CHECK-X86-ADDR64: :[[@LINE-1]]:5: warning: {{.*}} past the last possible element {{.*}} in 64-bit {{.*}} (max possible 576460752303423488 elements) - // CHECK-I386-ADDR32: :[[@LINE-2]]:5: warning: {{.*}} past the last possible element {{.*}} in 32-bit {{.*}} (max possible 178956970 elements) - // CHECK-AVR-ADDR16: :[[@LINE-3]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 3276 elements) - ++p[7073650].c; - // CHECK-AVR-ADDR16: :[[@LINE-1]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 3276 elements) -} - -void f4(struct S *p) { - p += 3; - p += 7073650413200313099; - // CHECK-X86-ADDR64: :[[@LINE-1]]:3: warning: the pointer incremented by 7073650413200313099 refers past the last possible element for an array in 64-bit address space containing 256-bit (32-byte) elements (max possible 576460752303423488 elements) - // CHECK-I386-ADDR32: :[[@LINE-2]]:3: warning: {{.*}} past the last possible element {{.*}} in 32-bit {{.*}} (max possible 178956970 elements) - // CHECK-AVR-ADDR16: :[[@LINE-3]]:3: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 3276 elements) - p += 7073650; - // CHECK-AVR-ADDR16: :[[@LINE-1]]:3: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 3276 elements) -} - -struct BQ { - struct S bigblock[3276]; -}; - -struct BQ bq[]; - -void f5() { - ++bq[0].bigblock[0].a; - ++bq[1].bigblock[0].a; - // CHECK-AVR-ADDR16: :[[@LINE-1]]:5: warning: {{.*}} past the last possible element {{.*}} in 16-bit {{.*}} (max possible 1 element) -} - -void f6() { - int ints[] = {1, 3, 5, 7, 8, 6, 4, 5, 9}; - int const n_ints = sizeof(ints) / sizeof(int); - unsigned long long const N = 3; - - int *middle = &ints[0] + n_ints / 2; - // Should NOT produce a warning. - *(middle + 5 - N) = 22; -} diff --git a/clang/test/SemaCXX/constant-expression-cxx14.cpp b/clang/test/SemaCXX/constant-expression-cxx14.cpp index 6d213ba..016d900 100644 --- a/clang/test/SemaCXX/constant-expression-cxx14.cpp +++ b/clang/test/SemaCXX/constant-expression-cxx14.cpp @@ -1027,9 +1027,8 @@ constexpr int S = sum(Cs); // expected-error{{must be initialized by a constant } constexpr void PR28739(int n) { // expected-error {{never produces a constant}} - int *p = &n; // expected-note {{array 'p' declared here}} + int *p = &n; p += (__int128)(unsigned long)-1; // expected-note {{cannot refer to element 18446744073709551615 of non-array object in a constant expression}} - // expected-warning@-1 {{the pointer incremented by 18446744073709551615 refers past the last possible element for an array in 64-bit address space containing 32-bit (4-byte) elements (max possible 4611686018427387904 elements)}} } constexpr void Void(int n) { -- 2.7.4