/* RUN: %clang_cc1 -std=c89 -verify=expected,c89only -pedantic -Wno-c11-extensions %s RUN: %clang_cc1 -std=c99 -verify=expected -pedantic -Wno-c11-extensions %s RUN: %clang_cc1 -std=c11 -verify=expected -pedantic %s RUN: %clang_cc1 -std=c17 -verify=expected -pedantic %s RUN: %clang_cc1 -std=c2x -verify=expected -pedantic %s */ /* The following are DRs which do not require tests to demonstrate * conformance or nonconformance. * * WG14 DR401: yes * "happens before" can not be cyclic * * WG14 DR402: yes * Memory model coherence is not aligned with C++11 * * WG14 DR404: yes * Joke fragment remains in a footnote * * WG14 DR406: yes * Visible sequences of side effects are redundant * * WG14 DR415: yes * Missing divide by zero entry in Annex J * * WG14 DR417: yes * Annex J not updated with necessary aligned_alloc entries * * WG14 DR419: yes * Generic Functions * * WG14 DR420: yes * Sytax error in specification of for-statement * * WG14 DR425: yes * No specification for the access to variables with temporary lifetime * * WG14 DR434: yes * Possible defect report: Missing constraint w.r.t. Atomic * * WG14 DR435: yes * Possible defect report: Missing constraint w.r.t. Imaginary * * WG14 DR436: yes * Request for interpretation of C11 6.8.5#6 * Note: This is not really testable because it requires -O1 or higher for LLVM * to perform its reachability analysis and -Wunreachable-code only verifies * diagnostic behavior, not runtime behavior. Also, both are a matter of QoI as * to what they optimize/diagnose. But if someone thinks of a way to test this, * we can add a test case for it then. * * WG14 DR448: yes * What are the semantics of a # non-directive? * * WG14 DR454: yes * ATOMIC_VAR_INIT (issues 3 and 4) * * WG14 DR455: yes * ATOMIC_VAR_INIT issue 5 * * WG14 DR459: yes * atomic_load missing const qualifier * * WG14 DR475: yes * Misleading Atomic library references to atomic types * * WG14 DR485: yes * Problem with the specification of ATOMIC_VAR_INIT * * WG14 DR486: yes * Inconsistent specification for arithmetic on atomic objects * * WG14 DR490: yes * Unwritten Assumptions About if-then */ /* WG14 DR412: yes * #elif * * Note: this is testing that #elif behaves the same as #else followed by #if. */ #if 1 #elif this is not a valid expression #else #if this is not a valid expression #endif #endif /* WG14 DR413: yes * Initialization */ void dr413(void) { typedef struct { int k; int l; int a[2]; } T; typedef struct { int i; T t; } S; /* Ensure that explicit initialization (.t = { ... }) takes precedence over a * later implicit partial initialization (.t.l = 41). The value should be 42, * not 0. */ _Static_assert((S){ /* c89only-warning {{compound literals are a C99-specific feature}} expected-warning {{expression is not an integer constant expression; folding it to a constant is a GNU extension}} */ 1, .t = { /* c89only-warning {{designated initializers are a C99 feature}} */ .l = 43, /* c89only-warning {{designated initializers are a C99 feature}} expected-note {{previous initialization is here}} */ .k = 42, .a[1] = 19, /* expected-note {{previous initialization is here}} */ .a[0] = 18 }, .t.l = 41, /* expected-warning {{initializer overrides prior initialization of this subobject}} */ .t.a[1] = 17 /* expected-warning {{initializer overrides prior initialization of this subobject}} */ }.t.k == 42, ""); } /* WG14 DR423: partial * Defect Report relative to n1570: underspecification for qualified rvalues */ /* FIXME: this should pass because the qualifier on the return type should be * dropped when forming the function type. */ const int dr423_const(void); int dr423_nonconst(void); _Static_assert(__builtin_types_compatible_p(__typeof__(dr423_const), __typeof__(dr423_nonconst)), "fail"); /* expected-error {{fail}} */ void dr423_func(void) { const int i = 12; __typeof__(i) v1 = 12; /* expected-note {{variable 'v1' declared const here}} */ __typeof__((const int)12) v2 = 12; v1 = 100; /* expected-error {{cannot assign to variable 'v1' with const-qualified type 'typeof (i)' (aka 'const int')}} */ v2 = 100; /* Not an error; the qualifier was stripped. */ } /* WG14 DR432: yes * Possible defect report: Is 0.0 required to be a representable value? * * We're going to lean on the fpclassify builtin to tell us whether 0.0 * represents the value 0, and we'll test that adding and subtracting 0.0 does * not change the value, and we'll hope that's enough to validate this DR. */ _Static_assert(__builtin_fpclassify(0, 1, 2, 3, 4, 0.0f) == 4, ""); _Static_assert((1.0 / 3.0) + 0.0 == (1.0 / 3.0) - 0.0, ""); /* expected-warning {{expression is not an integer constant expression; folding it to a constant is a GNU extension}} */ /* WG14 DR444: partial * Issues with alignment in C11, part 1 */ void dr444(void) { _Alignas(int) int i; _Alignas(int) struct S { _Alignas(int) int i; } s; /* FIXME: This should be accepted as per this DR. */ int j = (_Alignas(int) int){12}; /* expected-error {{expected expression}} */ _Alignas(int) struct T { /* expected-warning {{'_Alignas' attribute ignored}} */ int i; }; struct U { _Alignas(int) int bit : 1; /* expected-error {{'_Alignas' attribute cannot be applied to a bit-field}} */ }; _Alignas(int) typedef int foo; /* expected-error {{'_Alignas' attribute only applies to variables and fields}} */ _Alignas(int) register int bar; /* expected-error {{'_Alignas' attribute cannot be applied to a variable with 'register' storage class}} */ _Alignas(int) void func(void); /* expected-error {{'_Alignas' attribute only applies to variables and fields}} */ /* FIXME: it is correct for us to accept this per 6.7.3p5, but it seems like * a situation we'd want to diagnose because the alignments are different and * the user probably doesn't know which one "wins". */ _Alignas(int) _Alignas(double) int k; } /* WG14 DR447: yes * Boolean from complex * * Ensure that the imaginary part contributes to the conversion to bool, not * just the real part. */ _Static_assert((_Bool)0.0 + 3.0 * (__extension__ 1.0iF), ""); /* c89only-warning {{'_Bool' is a C99 extension}} expected-warning {{expression is not an integer constant expression; folding it to a constant is a GNU extension}} */ _Static_assert(!(_Bool)0.0 + 0.0 * (__extension__ 1.0iF), ""); /* c89only-warning {{'_Bool' is a C99 extension}} expected-warning {{expression is not an integer constant expression; folding it to a constant is a GNU extension}} */ /* WG14 DR463: yes * Left-shifting into the sign bit * * This DR was NAD and leaves shifting a bit into the high bit of a signed * integer type undefined behavior, unlike in C++. Note, the diagnostic is also * issued in C++ for shifting into that bit despite being well-defined because * the code is questionable and should be validated by the programmer. */ void dr463(void) { (void)(1 << (__CHAR_BIT__ * sizeof(int))); /* expected-warning {{shift count >= width of type}} */ (void)(1 << ((__CHAR_BIT__ * sizeof(int)) - 1)); } /* WG14 DR478: yes * Valid uses of the main function */ int main(void) { /* This DR clarifies that C explicitly allows you to call main() in a hosted * environment; it is not special as it is in C++, so recursive calls are * fine as well as nonrecursive direct calls. */ main(); /* ok */ } void dr478(void) { int (*fp)(void) = main; /* ok */ main(); /* ok */ } /* WG14 DR481: yes * Controlling expression of _Generic primary expression */ void dr481(void) { /* The controlling expression undergoes lvalue to rvalue conversion, and that * performs array decay and strips qualifiers. */ (void)_Generic("bla", char *: "blu"); (void)_Generic((int const){ 0 }, int: "blu"); /* c89only-warning {{compound literals are a C99-specific feature}} */ (void)_Generic(+(int const){ 0 }, int: "blu"); /* c89only-warning {{compound literals are a C99-specific feature}} */ (void)_Generic("bla", /* expected-error {{controlling expression type 'char *' not compatible with any generic association type}} */ char[4]: "blu"); /* expected-warning {{due to lvalue conversion of the controlling expression, association of type 'char[4]' will never be selected because it is of array type}} */ (void)_Generic((int const){ 0 }, /* expected-error {{controlling expression type 'int' not compatible with any generic association type}} c89only-warning {{compound literals are a C99-specific feature}} */ int const: "blu"); /* expected-warning {{due to lvalue conversion of the controlling expression, association of type 'const int' will never be selected because it is qualified}} */ (void)_Generic(+(int const){ 0 }, /* expected-error {{controlling expression type 'int' not compatible with any generic association type}} c89only-warning {{compound literals are a C99-specific feature}} */ int const: "blu"); /* expected-warning {{due to lvalue conversion of the controlling expression, association of type 'const int' will never be selected because it is qualified}} */ } /* WG14 DR489: partial * Integer Constant Expression * * The DR is about whether unevaluated operands have to follow the same * restrictions as the rest of the expression in an ICE, and according to the * committee, they do. */ void dr489(void) { struct S { int bit : 12 || 1.0f; /* expected-warning {{expression is not an integer constant expression; folding it to a constant is a GNU extension}} */ }; enum E { Val = 0 && 1.0f /* expected-warning {{expression is not an integer constant expression; folding it to a constant is a GNU extension}} */ }; int i; /* FIXME: mentioning the 'aligned' attribute is confusing, but also, should * this be folded as an ICE as a GNU extension? GCC does not fold it. */ _Alignas(0 ? i++ : 8) char c; /* expected-error {{'aligned' attribute requires integer constant}} */ /* FIXME: this should get the constant folding diagnostic as this is not a * valid ICE because the floating-point constants are not the immediate * operand of a cast. It should then also get a diagnostic about trying to * declare a VLA with static storage duration and the C99 extension warning * for VLAs in C89. */ static int vla[sizeof(1.0f + 1.0f)]; int val[5] = { [1 ? 0 : i--] = 12 }; /* expected-warning {{expression is not an integer constant expression; folding it to a constant is a GNU extension}} c89only-warning {{designated initializers are a C99 feature}} */ /* FIXME: this should be the constant folding diagnostic as this is not a * valid ICE because of the / operator. */ _Static_assert(sizeof(0 / 0), ""); /* FIXME: this should also get the constant folding diagnostic as this is not * a valid ICE because of the = operator. */ (void)_Generic(i = 12, int : 0); /* expected-warning {{expression with side effects has no effect in an unevaluated context}} */ switch (i) { case (int)0.0f: break; /* okay, a valid ICE */ /* FIXME: this should be accepted in C23 and up without a diagnostic, as C23 * added compound literals to the allowed list of things in an ICE. The * diagnostic is correct for C17 and earlier though. */ case (int){ 2 }: break; /* expected-warning {{expression is not an integer constant expression; folding it to a constant is a GNU extension}} c89only-warning {{compound literals are a C99-specific feature}} */ case 12 || main(): break; /* expected-warning {{expression is not an integer constant expression; folding it to a constant is a GNU extension}} */ } } /* WG14 DR492: yes * Named Child struct-union with no Member */ struct dr492_t { union U11 { /* expected-warning {{declaration does not declare anything}} */ int m11; float m12; }; int m13; } dr492; /* WG14 DR496: yes * offsetof questions */ void dr496(void) { struct A { int n, a [2]; }; struct B { struct A a; }; struct C { struct A a[1]; }; /* Array access & member access expressions are now valid. */ _Static_assert(__builtin_offsetof(struct B, a.n) == 0, ""); /* First int below is for 'n' and the second int is for 'a[0]'; this presumes * there is no padding involved. */ _Static_assert(__builtin_offsetof(struct B, a.a[1]) == sizeof(int) + sizeof(int), ""); /* However, we do not support using the -> operator to access a member, even * if that would be a valid expression. FIXME: GCC accepts this, perhaps we * should as well. */ (void)__builtin_offsetof(struct C, a->n); /* expected-error {{expected ')'}} \ expected-note {{to match this '('}} */ /* The DR asked a question about whether defining a new type within offsetof * is allowed. C2x N2350 made this explicitly undefined behavior, but GCC and * Clang both support it as an extension. */ (void)__builtin_offsetof(struct S { int a; }, a); /* expected-warning{{defining a type within '__builtin_offsetof' is a Clang extension}} */ } /* WG14 DR499: yes * Anonymous structure in union behavior */ void dr499(void) { union U { struct { char B1; char B2; char B3; char B4; }; int word; } u; /* Validate that B1, B2, B3, and B4 do not have overlapping storage, only the * anonymous structure and 'word' overlap. */ _Static_assert(__builtin_offsetof(union U, B1) == 0, ""); _Static_assert(__builtin_offsetof(union U, B2) == 1, ""); _Static_assert(__builtin_offsetof(union U, B3) == 2, ""); _Static_assert(__builtin_offsetof(union U, B4) == 3, ""); _Static_assert(__builtin_offsetof(union U, word) == 0, ""); }