/* RUN: %clang_cc1 -std=c89 -fsyntax-only -verify=expected,c89only -pedantic -Wno-c11-extensions %s RUN: %clang_cc1 -std=c99 -triple x86_64-unknown-linux -fsyntax-only -verify=expected,c99untilc2x -pedantic -Wno-c11-extensions %s RUN: %clang_cc1 -std=c99 -triple x86_64-unknown-win32 -fms-compatibility -fsyntax-only -verify=expected,c99untilc2x -pedantic -Wno-c11-extensions %s RUN: %clang_cc1 -std=c11 -fsyntax-only -verify=expected,c99untilc2x -pedantic %s RUN: %clang_cc1 -std=c17 -fsyntax-only -verify=expected,c99untilc2x -pedantic %s RUN: %clang_cc1 -std=c2x -fsyntax-only -verify=expected,c2xandup -pedantic %s */ /* The following are DRs which do not require tests to demonstrate * conformance or nonconformance. * * WG14 DR201: yes * Integer types longer than long * * WG14 DR211: yes * Accuracy of decimal string to/from "binary" (non-decimal) floating-point conversions * * WG14 DR215: yes * Equality operators * * WG14 DR218: yes * Signs of non-numeric floating point values * * WG14 DR219: yes * Effective types * * WG14 DR221: yes * Lacuna in pointer arithmetic * * WG14 DR222: yes * Partially initialized structures * * WG14 DR234: yes * Miscellaneous Typos * * WG14 DR245: yes * Missing paragraph numbers * * WG14 DR247: yes * Are values a form of behaviour? * * WG14 DR248: yes * Limits are required for optional types * * WG14 DR255: yes * Non-prototyped function calls and argument mismatches * * WG14 DR267: yes * Typos in 5.1.2.3, 7.24.4.4.5, 7.24.6.1, 7.24.6.1 * * WG14 DR273: yes * Meaning of __STDC_ISO_10646__ * * WG14 DR278: yes * Lacuna in character encodings * * WG14 DR279: yes * Wide character code values for members of the basic character set * * WG14 DR282: yes * Flexible array members & struct padding * * WG14 DR292: yes * Use of the word variable */ /* WG14 DR204: yes * size_t and ptrdiff_t as a long long type */ void dr204(void) { __typeof__(sizeof(0)) s; __typeof__((int *)0 - (int *)0) p; signed long sl; #if __LLONG_WIDTH__ > __LONG_WIDTH__ /* If the implementation supports a standard integer type larger than signed * long, it's okay for size_t and ptrdiff_t to have a greater integer * conversion rank than signed long. * * Note, it's not required that the implementation use that larger conversion * rank; it's acceptable to use an unsigned long or unsigned int for the size * type (those ranks are not greater than that of signed long). */ (void)_Generic(s + sl, unsigned long long : 1, unsigned long : 1, unsigned int : 1); /* c89only-warning {{'long long' is an extension when C99 mode is not enabled}} */ (void)_Generic(p + sl, signed long long : 1, signed long : 1, signed int : 1); /* c89only-warning {{'long long' is an extension when C99 mode is not enabled}} */ #elif __LLONG_WIDTH__ == __LONG_WIDTH__ /* But if the implementation doesn't support a larger standard integer type * than signed long, the conversion rank should prefer signed long if the type * is signed (ptrdiff_t) or unsigned long if the type is unsigned (size_t). * * Note, as above, unsigned/signed int is also acceptable due to having a * lesser integer conversion rank. */ (void)_Generic(s + sl, unsigned long : 1, unsigned int : 1); (void)_Generic(p + sl, signed long : 1, signed int : 1); #else #error "Something has gone off the rails" #endif } /* WG14 DR207: partial * Handling of imaginary types * * FIXME: Clang recognizes the _Imaginary keyword but does not support the data * type. */ void dr207(void) { _Imaginary float f; /* expected-error {{imaginary types are not supported}} c89only-warning {{'_Imaginary' is a C99 extension}} */ } /* WG14 DR216: yes * Source character encodings */ void dr216(void) { #define A(x) _Static_assert((char)x >= 0, "no") A('A'); A('B'); A('C'); A('D'); A('E'); A('F'); A('G'); A('H'); A('I'); A('J'); A('K'); A('L'); A('M'); A('N'); A('O'); A('P'); A('Q'); A('R'); A('S'); A('T'); A('U'); A('V'); A('W'); A('X'); A('Y'); A('Z'); A('a'); A('b'); A('c'); A('d'); A('e'); A('f'); A('g'); A('h'); A('i'); A('j'); A('k'); A('l'); A('m'); A('n'); A('o'); A('p'); A('q'); A('r'); A('s'); A('t'); A('u'); A('v'); A('w'); A('x'); A('y'); A('z'); A('0'); A('1'); A('2'); A('3'); A('4'); A('5'); A('6'); A('7'); A('8'); A('9'); A('!'); A('"'); A('#'); A('%'); A('&'); A('\''); A('('); A(')'); A('*'); A('+'); A(','); A('-'); A('.'); A('/'); A(':'); A(';'); A('<'); A('='); A('>'); A('?'); A('['); A('\\'); A(']'); A('^'); A('_'); A('{'); A('|'); A('}'); A('~'); #undef A } /* WG14 DR230: yes * Enumerated type rank */ void dr230(void) { enum E { Value = __INT_MAX__ } e; /* The enumeration type has a compatible type that is a signed or unsigned * integer type, or char. But it has to be large enough to hold all of the * values of the enumerators. So it needs to be at least int or unsigned int. * * The integer conversion rank for an enumeration is the same as its * compatible type (C99 6.3.1.1p1), so it's eligible for integer promotions * to either int or unsigned int, depending on the compatible type * (C99 6.3.1.1p2). */ (void)_Generic(e, int : 1, unsigned int : 1); (void)_Generic((enum E)Value, int : 1, unsigned int : 1); /* The enumerators themselves have type int (C99 6.7.2.2p3). */ (void)_Generic(Value, int : 1); } /* WG14 DR231: no * Semantics of text-line and non-directive * * One of the preprocessing groups to support is # non-directive (C99 6.10p1), * which is defined as pp-tokens followed by a newline. However, we fail to * translate the program if we don't recognize the directive, and we don't take * note when what follows the # is not a valid preprocessing token. */ /* FIXME: this should not fail. */ # nope /* expected-error {{invalid preprocessing directive}} */ /* FIXME: this should fail, but not because of the unknown directive; it should * fail because of the invalid preprocessing-token. */ # 'a /* expected-error@-1 {{invalid preprocessing directive}} \ expected-warning@-1 {{missing terminating ' character}} */ /* WG14 DR237: no * Declarations using [static] */ void dr237_f(int array[static 10]); /* c89only-warning {{static array size is a C99 feature}} expected-note {{callee declares array parameter as static here}} */ void dr237_1(void) { int array[4]; dr237_f(array); /* expected-warning {{array argument is too small; contains 4 elements, callee requires at least 10}} */ } /* FIXME: the composite type for this declaration should retain the static * array extent instead of losing it. */ void dr237_f(int array[]); void dr237_2(void) { int array[4]; /* FIXME: this should diagnose the same as above. */ dr237_f(array); } /* WG14 DR246: yes * Completion of declarators */ void dr246(void) { int i[i]; /* expected-error {{use of undeclared identifier 'i'}} */ } /* WG14 DR250: yes * Non-directives within macro arguments */ void dr250(void) { #define dr250_nothing(x) /* FIXME: See DR231 regarding the error about an invalid preprocessing * directive. */ dr250_nothing( #nondirective /* expected-error {{invalid preprocessing directive}} expected-warning {{embedding a directive within macro arguments has undefined behavior}} */ ) #undef dr250_nothing } /* WG14 DR251: yes * Are struct fred and union fred the same type? */ union dr251_fred { int a; }; /* expected-note {{previous use is here}} */ void dr251(void) { struct dr251_fred *ptr; /* expected-error {{use of 'dr251_fred' with tag type that does not match previous declaration}} */ } #if __STDC_VERSION__ < 202311L /* WG14 DR252: yes * Incomplete argument types when calling non-prototyped functions */ void dr252_no_proto(); /* expected-warning {{a function declaration without a prototype is deprecated in all versions of C}} */ void dr252_proto(void); /* expected-note {{'dr252_proto' declared here}} */ void dr252(void) { /* It's a constraint violation to pass an argument to a function with a * prototype that specifies a void parameter. */ dr252_proto(dr252_no_proto()); /* expected-error {{too many arguments to function call, expected 0, have 1}} */ /* It's technically UB to pass an incomplete type to a function without a * prototype, but Clang treats it as an error. */ dr252_no_proto(dr252_proto()); /* expected-error {{argument type 'void' is incomplete}} expected-warning {{passing arguments to 'dr252_no_proto' without a prototype is deprecated in all versions of C and is not supported in C23}} */ } #endif /* __STDC_VERSION__ < 202311L */ /* WG14 DR258: yes * Ordering of "defined" and macro replacement */ void dr258(void) { /* We get the diagnostic twice because the argument is used twice in the * expansion. */ #define repeat(x) x && x #if repeat(defined fred) /* expected-warning 2 {{macro expansion producing 'defined' has undefined behavior}} */ #endif /* We get no diagnostic because the argument is unused. */ #define forget(x) 0 #if forget(defined fred) #endif #undef repeat #undef forget } /* WG14 DR261: yes * Constant expressions */ void dr261(void) { /* This is still an integer constant expression despite the overflow. */ enum e1 { ex1 = __INT_MAX__ + 1 /* expected-warning {{overflow in expression; result is -2147483648 with type 'int'}} */ }; /* This is not an integer constant expression, because of the comma operator, * but we fold it as a constant expression anyway as a GNU extension. */ enum e2 { ex2 = __INT_MAX__ + (0, 1) /* expected-warning {{expression is not an integer constant expression; folding it to a constant is a GNU extension}} expected-note {{value 2147483648 is outside the range of representable values of type 'int'}} expected-warning {{left operand of comma operator has no effect}} */ }; /* It's a bit weird that we issue a "congratulations, you did the thing" * diagnostic, but the diagnostic does help demonstrate that we correctly * treat it as a null pointer constant value. */ char *p1 = (1 - 1); /* expected-warning {{expression which evaluates to zero treated as a null pointer constant of type 'char *'}} */ /* This is an invalid initialization/assignment because the right-hand side * does not have pointer to void or pointer to char type and is not the null * pointer constant. */ char *p2 = (42, 1 - 1); /* expected-error {{incompatible integer to pointer conversion initializing 'char *' with an expression of type 'int'}} expected-warning {{left operand of comma operator has no effect}} */ p1 = (42, 1 - 1); /* expected-error {{incompatible integer to pointer conversion assigning to 'char *' from 'int'}} expected-warning {{left operand of comma operator has no effect}} */ /* These are both valid. The initialization doesn't require an integer * constant expression, nor does the assignment. */ short s1 = 42 + (0, 1); /* c89only-warning {{mixing declarations and code is a C99 extension}} expected-warning {{left operand of comma operator has no effect}} */ s1 = (42, 69); /* expected-warning {{left operand of comma operator has no effect}} */ /* These are both valid because they are constant expressions and the value * is the null pointer constant. */ p2 = 0; p2 = 1 - 1; /* expected-warning {{expression which evaluates to zero treated as a null pointer constant of type 'char *'}} */ } /* WG14 DR262: yes * Maximum size of bit fields */ void dr262(void) { _Static_assert(sizeof(short) == 2, "short is not two chars?"); struct S { short field : __CHAR_BIT__ * 2; /* ok */ short other_field : __CHAR_BIT__ * 2 + 1; /* expected-error-re {{width of bit-field 'other_field' ({{[0-9]+}} bits) exceeds the width of its type ({{[0-9]+}} bits)}} */ }; } /* WG14 DR263: yes * All-zero bits representations * * This tests that the integer value 0 is not comprised of any non-zero bits, * which demonstrates that a value with all zero bits will be treated as the * integer value zero. */ _Static_assert(__builtin_popcount(0) < 1, "zero is not all zero bits"); /* WG14 DR265: yes * Preprocessor arithmetic */ #if __UINT_MAX__ == 0xFFFFFFFF /* Ensure that the literal is interpreted as intptr_t instead of uintptr_t, * despite that being the phase 7 behavior being that the literal is unsigned. */ #if -0xFFFFFFFF >= 0 #error "Interpreting the literal incorrectly in the preprocessor" #endif #endif /* __UINT_MAX__ == 0xFFFFFFFF */ /* WG14 DR266: yes * Overflow of sizeof */ void dr266(void) { /* Some targets support a maximum size which cannot be represented by an * unsigned long, and so unsigned long long is used instead. However, C89 * doesn't have the long long type, so we issue a pedantic warning about it. * Disable the warning momentarily so we don't have to add target triples to * the RUN lines pinning the targets down concretely. */ #pragma clang diagnostic push #pragma clang diagnostic ignored "-Wlong-long" (void)sizeof(int[__SIZE_MAX__ / 2][__SIZE_MAX__ / 2]); /* expected-error-re 2 {{array is too large ({{[0-9]+}} elements)}} */ #pragma clang diagnostic pop } /* WG14 DR272: yes * Type category */ void dr272(void) { /* The crux of this DR is to confirm that lvalue conversion of the rhs on an * assignment expression strips top-level qualifiers, and not all qualifiers, * from the resulting expression type. */ const int * volatile ptr; (void)_Generic(ptr = 0, const int * : 1); /* expected-warning {{expression with side effects has no effect in an unevaluated context}} */ } /* WG14 DR277: no * Declarations within iteration statements */ void dr277(void) { /* FIXME: it's a bit silly to issue both of these warnings at the same time * in pedantic mode given that they're both effectively the same root cause. * * C99 6.8.5p3: The declaration part of a for statement shall only declare * identifiers for objects having storage class auto or register. * * FIXME: we don't issue a pedantic warning below for the declaration of E, * and its enumerators, none of which declare an object with auto or register * storage classes. */ for (enum E { one, two } i = one; i < two; ++i) /* c89only-warning {{variable declaration in for loop is a C99-specific feature}} c89only-warning {{GCC does not allow variable declarations in for loop initializers before C99}} */ ; } #if __STDC_VERSION__ >= 199901L /* WG14 DR289: yes * Function prototype with [restrict] * * Ensure that we support [restrict] array syntax as an abstract declarator and * not just as a direct declarator. */ void dr289(int * restrict const [restrict]); #endif /* __STDC_VERSION__ >= 199901L */ /* WG14 DR295: yes * Incomplete types for function parameters */ struct NotCompleted; /* expected-note {{forward declaration of 'struct NotCompleted'}} */ void dr295_1(struct NotCompleted); void dr295_1(struct NotCompleted Val) { /* expected-error {{variable has incomplete type 'struct NotCompleted'}} */ } /* There's no reason to reject this code, but it's technically undefined * behavior, so diagnosing it is reasonable. * * FIXME: either downgrade this error into a warning or remove it entirely; it * doesn't add a whole lot of value as an error. */ void dr295_2(void param); /* expected-error {{argument may not have 'void' type}} */ /* WG14 DR298: partial * Validity of constant in unsigned long long range * * I'm giving this one a partial because we fail to pedantically diagnose the * use of 'long long' through a constant value. We correctly warn about the * type when spelled out and when using an explicit suffix, but we fail to warn * otherwise. */ #if __LLONG_WIDTH__ >= 64 && __LONG_WIDTH__ < 64 /* This test requires that long long be at least 64-bits and long be smaller * because the test is whether the integer literal which is too large to fit in * a constant of type long long. This is undefined behavior in C, which means * we're free to pick a different type so long as we diagnose the extension * appropriately. */ void dr298(void) { /* FIXME: These uses of the constants need a pedantic warning in C89 mode; * we've picked a type that does not exist in C89. */ (void)_Generic(9223372036854775808, /* expected-warning {{integer literal is too large to be represented in a signed integer type, interpreting as unsigned}} c89only-warning {{'long long' is an extension when C99 mode is not enabled}} */ unsigned long long : 1); /* c89only-warning {{'long long' is an extension when C99 mode is not enabled}} */ (void)_Generic(9223372036854775807, /* c89only-warning {{'long long' is an extension when C99 mode is not enabled}} */ long long : 1); /* c89only-warning {{'long long' is an extension when C99 mode is not enabled}} */ } #endif /* __LLONG_WIDTH__ == 64 && __LONG_WIDTH__ < 64 */