Author: Aaron Ballman Date: 2025-05-02T07:19:36-04:00 New Revision: 3d4f979e271d2a1fe0906f4d1b16db108838f98f
URL: https://github.com/llvm/llvm-project/commit/3d4f979e271d2a1fe0906f4d1b16db108838f98f DIFF: https://github.com/llvm/llvm-project/commit/3d4f979e271d2a1fe0906f4d1b16db108838f98f.diff LOG: [C] Allow __attribute__((nonstring)) on multidimensional arrays (#138133) This addresses post-commit review feedback from the Linux kernel folks and improves compatibility with the same feature in GCC Added: Modified: clang/lib/Sema/SemaInit.cpp clang/test/Sema/attr-nonstring.c Removed: ################################################################################ diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp index db8ba8f0c9823..3e29a5bf96a0c 100644 --- a/clang/lib/Sema/SemaInit.cpp +++ b/clang/lib/Sema/SemaInit.cpp @@ -261,8 +261,22 @@ static void CheckStringInit(Expr *Str, QualType &DeclT, const ArrayType *AT, << Str->getSourceRange(); else if (StrLength - 1 == ArrayLen) { // If the entity being initialized has the nonstring attribute, then - // silence the "missing nonstring" diagnostic. - if (const ValueDecl *D = Entity.getDecl(); + // silence the "missing nonstring" diagnostic. If there's no entity, + // check whether we're initializing an array of arrays; if so, walk the + // parents to find an entity. + auto FindCorrectEntity = + [](const InitializedEntity *Entity) -> const ValueDecl * { + while (Entity) { + if (const ValueDecl *VD = Entity->getDecl()) + return VD; + if (!Entity->getType()->isArrayType()) + return nullptr; + Entity = Entity->getParent(); + } + + return nullptr; + }; + if (const ValueDecl *D = FindCorrectEntity(&Entity); !D || !D->hasAttr<NonStringAttr>()) S.Diag( Str->getBeginLoc(), diff --git a/clang/test/Sema/attr-nonstring.c b/clang/test/Sema/attr-nonstring.c index 31728e701a3fc..3838aa3bbee15 100644 --- a/clang/test/Sema/attr-nonstring.c +++ b/clang/test/Sema/attr-nonstring.c @@ -2,7 +2,7 @@ // RUN: %clang_cc1 -fsyntax-only -verify=noncxx,expected,no-nonstring -Wextra %s // RUN: %clang_cc1 -fsyntax-only -verify=noncxx,expected,compat -Wc++-unterminated-string-initialization %s // RUN: %clang_cc1 -fsyntax-only -verify=noncxx,expected,compat -Wc++-compat %s -// RUN: %clang_cc1 -fsyntax-only -verify=expected,cxx -x c++ %s +// RUN: %clang_cc1 -fsyntax-only -verify=expected,cxx -x c++ -Wno-c99-designator %s // RUN: %clang_cc1 -fsyntax-only -verify=expected,noncxx -Wno-unterminated-string-initialization %s // RUN: %clang_cc1 -fsyntax-only -verify=expected,noncxx -Wc++-compat -Wextra -Wno-unterminated-string-initialization -Wno-c++-unterminated-string-initialization %s @@ -39,3 +39,193 @@ __attribute__((nonstring)) int eek2; // expected-warning {{'nonstri // diagnostic when you overwrite more than just the null terminator. char too_big[3] = "this is too big"; // noncxx-warning {{initializer-string for char array is too long}} \ cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 16 (including the null terminating character)}} + +// Show that this also applies to arrays of objects containing strings, too. +const char md_array[][3] __attribute__((nonstring)) = { "BAR", "FOO", }; // compat-warning 2 {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error 2 {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + +struct StructWithArrays { + char string[3]; + __attribute__((nonstring)) char nonstring[3]; +}; + +struct StructWithArrays s1[] = { + { + "FOO", // no-nonstring-warning {{initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute?}} \ + compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + "BAR", // compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + }, + { + "BAZ", // no-nonstring-warning {{initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute?}} \ + compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + "BIP", // compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + } +}; + +struct Inner { + struct StructWithArrays s[2]; +}; +struct Outer { + struct Inner i[2]; +}; + +struct Outer o1[] = { // Array of Outer + { // Outer + { // Array of Inner + { // Inner + { // Array of StructWithArrays + { // StructWithArrays + "FOO", // no-nonstring-warning {{initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute?}} \ + compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + "BAR" // compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + }, + { // StructWithArrays + "BAZ", // no-nonstring-warning {{initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute?}} \ + compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + "BAT" // compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + } + } // End array of StructWithArrays + }, // End Inner + { // Inner + { // Array of StructWithArrays + { // StructWithArrays + "BIP", // no-nonstring-warning {{initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute?}} \ + compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + "BOP" // compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + }, + { // StructWithArrays + "BAP", // no-nonstring-warning {{initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute?}} \ + compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + "BUP" // compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + } + } // End array of StructWithArrays + } // End Inner + } // End array of Inner + }, // End Outer + { // Outer + { // Array of Inner + { // Inner + { // Array of StructWithArrays + { // StructWithArrays + "ABC", // no-nonstring-warning {{initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute?}} \ + compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + "CAB" // compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + }, + { // StructWithArrays + "BAC", // no-nonstring-warning {{initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute?}} \ + compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + "CBA" // compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + } + } // End array of StructWithArrays + }, // End Inner + { // Inner + { // Array of StructWithArrays + { // StructWithArrays + "XYZ", // no-nonstring-warning {{initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute?}} \ + compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + "YZX" // compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + }, + { // StructWithArrays + "ZYX", // no-nonstring-warning {{initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute?}} \ + compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + "ZXY" // compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + } + } // End array of StructWithArrays + } // End Inner + } // End array of Inner + }, // End Outer +}; + +// Do the same test as above, but using designated initializers and a more +// simple layout of the initialization. + +struct Outer o2[] = { + [0] = { + .i[0] = { + .s[0] = { + "FOO", // no-nonstring-warning {{initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute?}} \ + compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + "BAR" // compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + }, + .s[1] = { + "BAZ", // no-nonstring-warning {{initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute?}} \ + compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + "BAT" // compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + } + }, + .i[1] = { + .s[0] = { + "BIP", // no-nonstring-warning {{initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute?}} \ + compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + "BOP" // compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + }, + .s[1] = { + "BAP", // no-nonstring-warning {{initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute?}} \ + compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + "BUP" // compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + } + } + }, + [1] = { + .i[0] = { + .s[0] = { + "ABC", // no-nonstring-warning {{initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute?}} \ + compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + "CAB" // compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + }, + .s[1] = { + "BAC", // no-nonstring-warning {{initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute?}} \ + compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + "CBA" // compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + } + }, + .i[1] = { + .s[0] = { + "XYZ", // no-nonstring-warning {{initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute?}} \ + compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + "YZX" // compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + }, + .s[1] = { + "ZYX", // no-nonstring-warning {{initializer-string for character array is too long, array size is 3 but initializer has size 4 (including the null terminating character); did you mean to use the 'nonstring' attribute?}} \ + compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + "ZXY" // compat-warning {{initializer-string for character array is too long for C++, array size is 3 but initializer has size 4 (including the null terminating character)}} \ + cxx-error {{initializer-string for char array is too long, array size is 3 but initializer has size 4 (including the null terminating character)}} + } + } + } +}; _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
