Timm =?utf-8?q?Bäder?= <tbae...@redhat.com> Message-ID: In-Reply-To: <llvm/llvm-project/pull/69223/cl...@github.com>
https://github.com/tbaederr updated https://github.com/llvm/llvm-project/pull/69223 >From 8f92935def398da8de21146e4e308a49746ae320 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbae...@redhat.com> Date: Mon, 16 Oct 2023 17:51:44 +0200 Subject: [PATCH 1/2] [clang][Interp] Only diagnose null field access in constant contexts --- clang/lib/AST/Interp/Interp.h | 2 +- clang/lib/AST/Interp/Pointer.h | 4 +++- clang/test/AST/Interp/c.c | 12 +++++++++++ clang/test/AST/Interp/records.cpp | 33 +++++++++++++++++++++++++++++++ 4 files changed, 49 insertions(+), 2 deletions(-) diff --git a/clang/lib/AST/Interp/Interp.h b/clang/lib/AST/Interp/Interp.h index e3e6a4cec63b194..8c943a48cdcc0ac 100644 --- a/clang/lib/AST/Interp/Interp.h +++ b/clang/lib/AST/Interp/Interp.h @@ -1159,7 +1159,7 @@ inline bool GetPtrGlobal(InterpState &S, CodePtr OpPC, uint32_t I) { /// 2) Pushes Pointer.atField(Off) on the stack inline bool GetPtrField(InterpState &S, CodePtr OpPC, uint32_t Off) { const Pointer &Ptr = S.Stk.pop<Pointer>(); - if (!CheckNull(S, OpPC, Ptr, CSK_Field)) + if (S.inConstantContext() && !CheckNull(S, OpPC, Ptr, CSK_Field)) return false; if (!CheckExtern(S, OpPC, Ptr)) return false; diff --git a/clang/lib/AST/Interp/Pointer.h b/clang/lib/AST/Interp/Pointer.h index d5279e757f04764..c6a2f371764d02f 100644 --- a/clang/lib/AST/Interp/Pointer.h +++ b/clang/lib/AST/Interp/Pointer.h @@ -295,7 +295,7 @@ class Pointer { bool isUnion() const; /// Checks if the storage is extern. - bool isExtern() const { return Pointee->isExtern(); } + bool isExtern() const { return Pointee && Pointee->isExtern(); } /// Checks if the storage is static. bool isStatic() const { return Pointee->isStatic(); } /// Checks if the storage is temporary. @@ -348,6 +348,8 @@ class Pointer { /// Checks if the index is one past end. bool isOnePastEnd() const { + if (!Pointee) + return false; return isElementPastEnd() || getSize() == getOffset(); } diff --git a/clang/test/AST/Interp/c.c b/clang/test/AST/Interp/c.c index 974ca72702f7dd0..637915328576af1 100644 --- a/clang/test/AST/Interp/c.c +++ b/clang/test/AST/Interp/c.c @@ -47,3 +47,15 @@ _Static_assert(&a != 0, ""); // ref-warning {{always true}} \ // expected-warning {{always true}} \ // pedantic-expected-warning {{always true}} \ // pedantic-expected-warning {{is a GNU extension}} + +struct y {int x,y;}; +int a2[(long)&((struct y*)0)->y]; // expected-warning {{folded to constant array}} \ + // pedantic-expected-warning {{folded to constant array}} \ + // ref-warning {{folded to constant array}} \ + // pedantic-ref-warning {{folded to constant array}} + +const struct y *yy = (struct y*)0; +const long L = (long)(&(yy->y)); // expected-error {{not a compile-time constant}} \ + // pedantic-expected-error {{not a compile-time constant}} \ + // ref-error {{not a compile-time constant}} \ + // pedantic-ref-error {{not a compile-time constant}} diff --git a/clang/test/AST/Interp/records.cpp b/clang/test/AST/Interp/records.cpp index 3c866825d1f077c..0c341a62c89fa13 100644 --- a/clang/test/AST/Interp/records.cpp +++ b/clang/test/AST/Interp/records.cpp @@ -1089,3 +1089,36 @@ namespace DelegatingConstructors { static_assert(d4.a == 10, ""); static_assert(d4.b == 12, ""); } + +namespace AccessOnNullptr { + struct F { + int a; + }; + + constexpr int a() { // expected-error {{never produces a constant expression}} \ + // ref-error {{never produces a constant expression}} + F *f = nullptr; + + f->a = 0; // expected-note 2{{cannot access field of null pointer}} \ + // ref-note 2{{cannot access field of null pointer}} + return f->a; + } + static_assert(a() == 0, ""); // expected-error {{not an integral constant expression}} \ + // expected-note {{in call to 'a()'}} \ + // ref-error {{not an integral constant expression}} \ + // ref-note {{in call to 'a()'}} + + constexpr int a2() { // expected-error {{never produces a constant expression}} \ + // ref-error {{never produces a constant expression}} + F *f = nullptr; + + + const int *a = &(f->a); // expected-note 2{{cannot access field of null pointer}} \ + // ref-note 2{{cannot access field of null pointer}} + return f->a; + } + static_assert(a2() == 0, ""); // expected-error {{not an integral constant expression}} \ + // expected-note {{in call to 'a2()'}} \ + // ref-error {{not an integral constant expression}} \ + // ref-note {{in call to 'a2()'}} +} >From e59c068eb2c9c0a50f70928964e518958b95434b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbae...@redhat.com> Date: Mon, 16 Oct 2023 19:02:50 +0200 Subject: [PATCH 2/2] Cast pointers to intptr_t instead of long --- clang/test/AST/Interp/c.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/clang/test/AST/Interp/c.c b/clang/test/AST/Interp/c.c index 637915328576af1..e980cf9d963224e 100644 --- a/clang/test/AST/Interp/c.c +++ b/clang/test/AST/Interp/c.c @@ -3,6 +3,8 @@ // RUN: %clang_cc1 -verify=ref -std=c11 %s // RUN: %clang_cc1 -pedantic -verify=pedantic-ref -std=c11 %s +typedef __INTPTR_TYPE__ intptr_t; + _Static_assert(1, ""); _Static_assert(0 != 1, ""); _Static_assert(1.0 == 1.0, ""); // pedantic-ref-warning {{not an integer constant expression}} \ @@ -49,13 +51,13 @@ _Static_assert(&a != 0, ""); // ref-warning {{always true}} \ // pedantic-expected-warning {{is a GNU extension}} struct y {int x,y;}; -int a2[(long)&((struct y*)0)->y]; // expected-warning {{folded to constant array}} \ - // pedantic-expected-warning {{folded to constant array}} \ - // ref-warning {{folded to constant array}} \ - // pedantic-ref-warning {{folded to constant array}} +int a2[(intptr_t)&((struct y*)0)->y]; // expected-warning {{folded to constant array}} \ + // pedantic-expected-warning {{folded to constant array}} \ + // ref-warning {{folded to constant array}} \ + // pedantic-ref-warning {{folded to constant array}} const struct y *yy = (struct y*)0; -const long L = (long)(&(yy->y)); // expected-error {{not a compile-time constant}} \ - // pedantic-expected-error {{not a compile-time constant}} \ - // ref-error {{not a compile-time constant}} \ - // pedantic-ref-error {{not a compile-time constant}} +const intptr_t L = (intptr_t)(&(yy->y)); // expected-error {{not a compile-time constant}} \ + // pedantic-expected-error {{not a compile-time constant}} \ + // ref-error {{not a compile-time constant}} \ + // pedantic-ref-error {{not a compile-time constant}} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
