/* $NetBSD: lang_level_c99.c,v 1.6 2024/11/05 04:53:28 rillig Exp $ */ # 3 "lang_level_c99.c" /* * Tests that are specific to the C99 language level, in particular: * * * syntax elements that were added in C99 * * lint diagnostics that differ between the C90 and C99 language levels * * lint diagnostics that differ between the C99 and C11 language levels */ /* lint1-flags: -S -w -X 351 */ /* * Features that were added in the C99 standard, as listed in the C99 foreword. * * In the below comments, [-] means unsupported and [x] means supported. */ // [-] restricted character set support via digraphs and // // Lint neither parses digraphs nor trigraphs. // [x] wide character library support in and // // On all supported platforms, 'wchar_t' == 'int'. const int wide_string[] = L"wide"; // [x] more precise aliasing rules via effective type // // Irrelevant, as lint does not check the runtime behavior. // [x] restricted pointers // // Can be parsed, are otherwise ignored. // [-] variable length arrays // // Variable length arrays are handled as if the number of elements in the array // were always 1. /* FIXME: Parameter 'n' _is_ actually used. */ /* expect+2: warning: parameter 'n' unused in function 'variable_length_arrays' [231] */ unsigned long long variable_length_arrays(int n) { int vla[n]; /* FIXME: The array dimension is not constant, but still negative. */ /* expect+1: error: negative array dimension (-4) [20] */ typedef int sizeof_vla[-(int)sizeof(vla)]; return sizeof(vla); } // [x] flexible array members // // Flexible array members are parsed but not validated thoroughly. void flexible_array_members(void) { struct { int regular; int flexible[]; } s = { 0, // Flexible array member must not be initialized. Lint does // not detect this, leaving the job to the C99 compiler. { 1, 3, 4, } }; /* expect+1: error: negative array dimension (-4) [20] */ typedef int sizeof_s[-(int)sizeof(s)]; } // [x] static and type qualifiers in parameter array declarators // // Can be parsed, are otherwise ignored. // [-] complex (and imaginary) support in // // Lint does not keep track of which parts of a complex object are initialized. // // Lint does not support '_Imaginary'. // [x] type-generic math macros in // // Irrelevant, as lint only sees the preprocessed source code. // [x] the long long int type and library functions // // On all platforms supported by lint, 'long long' is 64 bits wide. The other // fixed-width types are 'char', 'short', 'int' and (only on 64-bit platforms) // '__int128_t'. // // The lint standard libraries -lstdc and -lposix do not contain the // functions added in C99. /* expect+1: error: negative array dimension (-1) [20] */ typedef int sizeof_char[-(int)sizeof(char)]; /* expect+1: error: negative array dimension (-2) [20] */ typedef int sizeof_short[-(int)sizeof(short)]; /* expect+1: error: negative array dimension (-4) [20] */ typedef int sizeof_int[-(int)sizeof(int)]; /* expect+1: error: negative array dimension (-8) [20] */ typedef int sizeof_long_long[-(int)sizeof(long long)]; // [x] increased minimum translation limits // // Irrelevant, as lint does not have any hard-coded limits. // [x] additional floating-point characteristics in // // Lint has very limited support for floating point numbers, as it fully relies // on the host platform. This is noticeable when cross-compiling between // platforms with different size or representation of 'long double'. // [x] remove implicit int // // Lint parses old-style declarations and marks them as errors. // [x] reliable integer division // // The lint source code requires a C99 compiler, so when mapping the integer // operations to those from the host platform, lint uses these. // [-] universal character names (\u and \U) // // No, as nothing in the NetBSD source tree uses this feature. // [-] extended identifiers // // No, as nothing in the NetBSD source tree uses this feature. // [x] hexadecimal floating-point constants and %a and %A printf/scanf // conversion specifiers void pf(); /* no prototype parameters */ void hexadecimal_floating_point_constants(void) { double hex = 0x1.0p34; pf("%s %a\n", "hex", hex); } // [x] compound literals // // See d_c99_compound_literal_comma.c. struct short_rect { short top, left, bottom, right; }; struct short_rect *rect_location(void); void compound_literal(void) { struct short_rect me = (struct short_rect){ 1, 2, 3, 4 }; me.left = me.left; *rect_location() = (struct short_rect){ 1, 2, 3, 4 }; } // [x] designated initializers // // See init_c99.c. // [x] // comments // // Also supported in GCC mode. // [?] extended integer types and library functions in and // // // TODO // [x] remove implicit function declaration void call_implicitly_declared_function(void) { /* expect+1: error: function 'implicitly_declared_function' implicitly declared to return int [215] */ implicitly_declared_function(0); } // [x] preprocessor arithmetic done in intmax_t/uintmax_t // // Irrelevant, as lint only sees the preprocessed source code. // [x] mixed declarations and code // [x] new block scopes for selection and iteration statements void for_scope(void) { // A for loop may have a declaration in its first part. for (int i = 0; i < 10; i++) continue; // Test that the scope of the previous i has ended. for (int i = 0; i < 10; i++) continue; } // [?] integer constant type rules // // TODO // [?] integer promotion rules // // TODO // [x] macros with a variable number of arguments // // Irrelevant, as lint only sees the preprocessed source code. // [x] the vscanf family of functions in and // // Irrelevant, as typical C99 compilers already check these. // [x] additional math library functions in // // Irrelevant, as lint does not check arithmetic expressions. // // Lint also does not generate its own standard library definition for libm. // [x] treatment of error conditions by math library functions // (math_errhandling) // // Irrelevant, as lint does not check for error handling. // [x] floating-point environment access in // // TODO // [x] IEC 60559 (also known as IEC 559 or IEEE arithmetic) support // // On platforms that conform to IEC 60559, lint performs the arithmetic // operations accordingly. When cross-compiling on a vax host for other target // platforms, no such support is available. // [x] trailing comma allowed in enum declaration // // Yes, see the grammar rule 'enums_with_opt_comma'. // [-] %lf conversion specifier allowed in printf // // TODO: see tests/lint2/msg_013.exp. // [x] inline functions // // Yes, also allowed in GCC mode. // [x] the snprintf family of functions in // // The snprintf functions are treated like all other functions. The checks for // matching format strings targets traditional C only and thus does not apply // to these functions, as they have a prototype definition. // [x] boolean type in // // Yes. Conversion to and from boolean follows 6.3.1.2. See also the -T flag, // which enables 'strict bool mode'. // [x] idempotent type qualifiers // // Lint warns about duplicate type qualifiers but accepts them otherwise. /* expect+1: warning: duplicate 'const' [10] */ const const int duplicate_type_qualifier = 2; // [x] empty macro arguments // // Irrelevant, as lint only sees the preprocessed source code. // [?] new structure type compatibility rules (tag compatibility) // // TODO // [x] additional predefined macro names // // Irrelevant, as lint only sees the preprocessed source code. // [-] _Pragma preprocessing operator // // No, not yet asked for. // [-] standard pragmas // // No, not yet asked for. // [x] __func__ predefined identifier // // Yes, see 'fallback_symbol'. const char * function_name(void) { /* expect+1: error: negative array dimension (-14) [20] */ typedef int reveal_size[-(int)sizeof(__func__)]; return __func__; } // Since tree.c 1.504 from 2023-01-29 and before tree.c 1.591 from 2024-01-07, // lint crashed because there was no "current function", even though the // "block level" was not 0. /* expect+1: error: '__func__' undefined [99] */ typedef int func_outside_function(int[sizeof(__func__)]); // [x] va_copy macro // // Irrelevant, as lint only sees the preprocessed source code. // [x] additional strftime conversion specifiers // // Irrelevant, as lint does not check strftime in depth. // [?] LIA compatibility annex // // TODO // [x] deprecate ungetc at the beginning of a binary file // // Irrelevant, as lint's analysis is not that deep into the runtime behavior. // [x] remove deprecation of aliased array parameters // // Irrelevant, as lint does not check for aliasing. // [?] conversion of array to pointer not limited to lvalues // // TODO // [x] relaxed constraints on aggregate and union initialization // // Yes, struct and union members can be initialized with non-constant // expressions. Members that have struct or union type can be initialized with // an expression of the same type. // [x] relaxed restrictions on portable header names // // Irrelevant, as lint only sees the preprocessed source code. // [x] return without expression not permitted in function that returns a value // (and vice versa) void return_no_expr(int x) { x++; /* expect+1: error: void function 'return_no_expr' cannot return value [213] */ return x; } int return_expr(void) { /* expect+1: error: function 'return_expr' expects to return value [214] */ return; }