diff options
Diffstat (limited to 'gcc/c-common.c')
| -rw-r--r-- | gcc/c-common.c | 303 |
1 files changed, 238 insertions, 65 deletions
diff --git a/gcc/c-common.c b/gcc/c-common.c index 404c3072ef3..490bc335ba3 100644 --- a/gcc/c-common.c +++ b/gcc/c-common.c @@ -1,5 +1,5 @@ /* Subroutines shared by all languages that are variants of C. - Copyright (C) 1992, 93, 94, 95, 96, 97, 1998 Free Software Foundation, Inc. + Copyright (C) 1992, 93-98, 1999 Free Software Foundation, Inc. This file is part of GNU CC. @@ -28,6 +28,7 @@ Boston, MA 02111-1307, USA. */ #include "toplev.h" #include "output.h" #include "c-pragma.h" +#include "rtl.h" #if USE_CPPLIB #include "cpplib.h" @@ -144,7 +145,7 @@ tree c_global_trees[50]; int skip_evaluation; enum attrs {A_PACKED, A_NOCOMMON, A_COMMON, A_NORETURN, A_CONST, A_T_UNION, - A_NO_INSTRUMENT_FUNCTION, + A_NO_CHECK_MEMORY_USAGE, A_NO_INSTRUMENT_FUNCTION, A_CONSTRUCTOR, A_DESTRUCTOR, A_MODE, A_SECTION, A_ALIGNED, A_UNUSED, A_FORMAT, A_FORMAT_ARG, A_WEAK, A_ALIAS, A_INIT_PRIORITY}; @@ -152,13 +153,14 @@ enum attrs {A_PACKED, A_NOCOMMON, A_COMMON, A_NORETURN, A_CONST, A_T_UNION, enum format_type { printf_format_type, scanf_format_type, strftime_format_type }; -static void declare_hidden_char_array PROTO((char *, char *)); -static void add_attribute PROTO((enum attrs, char *, +static void declare_hidden_char_array PROTO((const char *, const char *)); +static void add_attribute PROTO((enum attrs, const char *, int, int, int)); static void init_attributes PROTO((void)); static void record_function_format PROTO((tree, tree, enum format_type, int, int)); static void record_international_format PROTO((tree, tree, int)); +static tree c_find_base_decl PROTO((tree)); /* Keep a stack of if statements. We record the number of compound statements seen up to the if keyword, as well as the line number @@ -169,9 +171,10 @@ typedef struct { int compstmt_count; int line; - char *file; + const char *file; int needs_warning; } if_elt; +static void tfaff PROTO((void)); static if_elt *if_stack; @@ -250,12 +253,12 @@ c_expand_start_else () expand_start_else (); } -/* Make bindings for __FUNCTION__ and __PRETTY_FUNCTION__. */ +/* Make bindings for __FUNCTION__, __PRETTY_FUNCTION__, and __func__. */ void declare_function_name () { - char *name, *printable_name; + const char *name, *printable_name; if (current_function_decl == NULL) { @@ -274,11 +277,14 @@ declare_function_name () declare_hidden_char_array ("__FUNCTION__", name); declare_hidden_char_array ("__PRETTY_FUNCTION__", printable_name); + /* The ISO C people "of course" couldn't use __FUNCTION__ in the + ISO C 9x standard; instead a new variable is invented. */ + declare_hidden_char_array ("__func__", name); } static void declare_hidden_char_array (name, value) - char *name, *value; + const char *name, *value; { tree decl, type, init; int vlen; @@ -446,7 +452,7 @@ static int attrtab_idx = 0; static void add_attribute (id, string, min_len, max_len, decl_req) enum attrs id; - char *string; + const char *string; int min_len, max_len; int decl_req; { @@ -491,6 +497,7 @@ init_attributes () add_attribute (A_ALIAS, "alias", 1, 1, 1); add_attribute (A_INIT_PRIORITY, "init_priority", 0, 1, 0); add_attribute (A_NO_INSTRUMENT_FUNCTION, "no_instrument_function", 0, 0, 1); + add_attribute (A_NO_CHECK_MEMORY_USAGE, "no_check_memory_usage", 0, 0, 1); } /* Process the attributes listed in ATTRIBUTES and PREFIX_ATTRIBUTES @@ -612,7 +619,8 @@ decl_attributes (node, attributes, prefix_attributes) TREE_USED (type) = 1; else if (TREE_CODE (decl) == PARM_DECL || TREE_CODE (decl) == VAR_DECL - || TREE_CODE (decl) == FUNCTION_DECL) + || TREE_CODE (decl) == FUNCTION_DECL + || TREE_CODE (decl) == LABEL_DECL) TREE_USED (decl) = 1; else warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name)); @@ -676,7 +684,7 @@ decl_attributes (node, attributes, prefix_attributes) else { int j; - char *p = IDENTIFIER_POINTER (TREE_VALUE (args)); + const char *p = IDENTIFIER_POINTER (TREE_VALUE (args)); int len = strlen (p); enum machine_mode mode = VOIDmode; tree typefm; @@ -808,7 +816,7 @@ decl_attributes (node, attributes, prefix_attributes) } else { - char *p = IDENTIFIER_POINTER (format_type_id); + const char *p = IDENTIFIER_POINTER (format_type_id); if (!strcmp (p, "printf") || !strcmp (p, "__printf__")) format_type = printf_format_type; @@ -819,7 +827,7 @@ decl_attributes (node, attributes, prefix_attributes) format_type = strftime_format_type; else { - error ("`%s' is an unrecognized format function type", p); + warning ("`%s' is an unrecognized format function type", p); continue; } } @@ -986,6 +994,23 @@ decl_attributes (node, attributes, prefix_attributes) warning ("`%s' attribute ignored", IDENTIFIER_POINTER (name)); break; + case A_NO_CHECK_MEMORY_USAGE: + if (TREE_CODE (decl) != FUNCTION_DECL) + { + error_with_decl (decl, + "`%s' attribute applies only to functions", + IDENTIFIER_POINTER (name)); + } + else if (DECL_INITIAL (decl)) + { + error_with_decl (decl, + "can't set `%s' attribute after definition", + IDENTIFIER_POINTER (name)); + } + else + DECL_NO_CHECK_MEMORY_USAGE (decl) = 1; + break; + case A_INIT_PRIORITY: { tree initp_expr = (args ? TREE_VALUE (args): NULL_TREE); @@ -1017,24 +1042,18 @@ decl_attributes (node, attributes, prefix_attributes) continue; } - /* Check for init_priorities that are reserved for - implementation. Reserved for language and runtime - support implementations.*/ - if ((10 <= pri && pri <= 99) - /* Reserved for standard library implementations. */ - || (500 <= pri && pri <= 999) - /* Reserved for objects with no attributes. */ - || pri > (MAX_INIT_PRIORITY - 50)) + if (pri > MAX_INIT_PRIORITY || pri <= 0) { - warning - ("requested init_priority is reserved for internal use"); + error ("requested init_priority is out of range"); continue; } - if (pri > MAX_INIT_PRIORITY || pri <= 0) + /* Check for init_priorities that are reserved for + language and runtime support implementations.*/ + if (pri <= MAX_RESERVED_INIT_PRIORITY) { - error ("requested init_priority is out of range"); - continue; + warning + ("requested init_priority is reserved for internal use"); } static_aggregates_initp @@ -1177,7 +1196,7 @@ strip_attrs (specs_attrs) #define T_ST &sizetype typedef struct { - char *format_chars; + const char *format_chars; int pointer_count; /* Type of argument if no length modifier is used. */ tree *nolen; @@ -1200,7 +1219,7 @@ typedef struct { If NULL, then this modifier is not allowed. */ tree *zlen; /* List of other modifier characters allowed with these options. */ - char *flag_chars; + const char *flag_chars; } format_char_info; static format_char_info print_char_table[] = { @@ -1216,7 +1235,7 @@ static format_char_info print_char_table[] = { { "S", 1, T_W, NULL, NULL, NULL, NULL, NULL, NULL, "-wp" }, { "p", 1, T_V, NULL, NULL, NULL, NULL, NULL, NULL, "-w" }, { "n", 1, T_I, NULL, T_S, T_L, T_LL, NULL, NULL, "" }, - { NULL } + { NULL, 0, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL } }; static format_char_info scan_char_table[] = { @@ -1230,7 +1249,7 @@ static format_char_info scan_char_table[] = { { "S", 1, T_W, NULL, NULL, NULL, NULL, NULL, NULL, "*a" }, { "p", 2, T_V, NULL, NULL, NULL, NULL, NULL, NULL, "*" }, { "n", 1, T_I, T_C, T_S, T_L, T_LL, NULL, NULL, "" }, - { NULL } + { NULL, 0, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL } }; /* Handle format characters recognized by glibc's strftime.c. @@ -1255,7 +1274,7 @@ static format_char_info time_char_table[] = { { "p", 0, NULL, NULL, NULL, NULL, NULL, NULL, NULL, "#" }, { "bh", 0, NULL, NULL, NULL, NULL, NULL, NULL, NULL, "^" }, { "CY", 0, NULL, NULL, NULL, NULL, NULL, NULL, NULL, "-_0EOw" }, - { NULL } + { NULL, 0, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL } }; typedef struct function_format_info @@ -1400,7 +1419,11 @@ record_international_format (name, assembler_name, format_num) info->format_num = format_num; } -static char tfaff[] = "too few arguments for format"; +static void +tfaff () +{ + warning ("too few arguments for format"); +} /* Check the argument list of a call to printf, scanf, etc. NAME is the function identifier. @@ -1450,7 +1473,7 @@ check_format_info (info, params) tree cur_type; tree wanted_type; tree first_fillin_param; - char *format_chars; + const char *format_chars; format_char_info *fci = NULL; char flag_chars[8]; int has_operand_number = 0; @@ -1614,7 +1637,7 @@ check_format_info (info, params) it is an operand number, so set PARAMS to that operand. */ if (*format_chars >= '0' && *format_chars <= '9') { - char *p = format_chars; + const char *p = format_chars; while (*p >= '0' && *p++ <= '9') ; @@ -1667,7 +1690,7 @@ check_format_info (info, params) ++format_chars; if (params == 0) { - warning (tfaff); + tfaff (); return; } if (info->first_arg_num != 0) @@ -1710,7 +1733,7 @@ check_format_info (info, params) ++format_chars; if (params == 0) { - warning (tfaff); + tfaff (); return; } cur_param = TREE_VALUE (params); @@ -1880,7 +1903,7 @@ check_format_info (info, params) if (precise && index (flag_chars, '0') != 0 && (format_char == 'd' || format_char == 'i' || format_char == 'o' || format_char == 'u' - || format_char == 'x' || format_char == 'x')) + || format_char == 'x' || format_char == 'X')) warning ("`0' flag ignored with precision specifier and `%c' format", format_char); switch (length_char) @@ -1905,7 +1928,7 @@ check_format_info (info, params) continue; if (params == 0) { - warning (tfaff); + tfaff (); return; } cur_param = TREE_VALUE (params); @@ -1931,9 +1954,9 @@ check_format_info (info, params) continue; } if (TREE_CODE (cur_type) != ERROR_MARK) - warning ("format argument is not a %s (arg %d)", - ((fci->pointer_count + aflag == 1) - ? "pointer" : "pointer to a pointer"), + warning ((fci->pointer_count + aflag == 1 + ? "format argument is not a pointer (arg %d)" + : "format argument is not a pointer to a pointer (arg %d)"), arg_num); break; } @@ -1973,8 +1996,8 @@ check_format_info (info, params) && (TYPE_MAIN_VARIANT (cur_type) == signed_char_type_node || TYPE_MAIN_VARIANT (cur_type) == unsigned_char_type_node))) { - register char *this; - register char *that; + register const char *this; + register const char *that; this = IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (wanted_type))); that = 0; @@ -2243,8 +2266,10 @@ type_for_mode (mode, unsignedp) if (mode == TYPE_MODE (intDI_type_node)) return unsignedp ? unsigned_intDI_type_node : intDI_type_node; +#if HOST_BITS_PER_WIDE_INT >= 64 if (mode == TYPE_MODE (intTI_type_node)) return unsignedp ? unsigned_intTI_type_node : intTI_type_node; +#endif if (mode == TYPE_MODE (float_type_node)) return float_type_node; @@ -2302,7 +2327,7 @@ void binary_op_error (code) enum tree_code code; { - register char *opname; + register const char *opname; switch (code) { @@ -2478,6 +2503,12 @@ shorten_compare (op0_ptr, op1_ptr, restype_ptr, rescode_ptr) type = signed_or_unsigned_type (unsignedp0, TREE_TYPE (primop0)); + /* If TYPE is an enumeration, then we need to get its min/max + values from it's underlying integral type, not the enumerated + type itself. */ + if (TREE_CODE (type) == ENUMERAL_TYPE) + type = type_for_size (TYPE_PRECISION (type), unsignedp0); + maxval = TYPE_MAX_VALUE (type); minval = TYPE_MIN_VALUE (type); @@ -2587,18 +2618,18 @@ shorten_compare (op0_ptr, op1_ptr, restype_ptr, rescode_ptr) /* This is the case of (char)x >?< 0x80, which people used to use expecting old C compilers to change the 0x80 into -0x80. */ if (val == boolean_false_node) - warning ("comparison is always 0 due to limited range of data type"); + warning ("comparison is always false due to limited range of data type"); if (val == boolean_true_node) - warning ("comparison is always 1 due to limited range of data type"); + warning ("comparison is always true due to limited range of data type"); } if (!min_lt && unsignedp0 && TREE_CODE (primop0) != INTEGER_CST) { /* This is the case of (unsigned char)x >?< -1 or < 0. */ if (val == boolean_false_node) - warning ("comparison is always 0 due to limited range of data type"); + warning ("comparison is always false due to limited range of data type"); if (val == boolean_true_node) - warning ("comparison is always 1 due to limited range of data type"); + warning ("comparison is always true due to limited range of data type"); } if (val != 0) @@ -2664,7 +2695,7 @@ shorten_compare (op0_ptr, op1_ptr, restype_ptr, rescode_ptr) && ! (TREE_CODE (primop0) == INTEGER_CST && ! TREE_OVERFLOW (convert (signed_type (type), primop0)))) - warning ("unsigned value >= 0 is always 1"); + warning ("comparison of unsigned expression >= 0 is always true"); value = boolean_true_node; break; @@ -2673,7 +2704,7 @@ shorten_compare (op0_ptr, op1_ptr, restype_ptr, rescode_ptr) && ! (TREE_CODE (primop0) == INTEGER_CST && ! TREE_OVERFLOW (convert (signed_type (type), primop0)))) - warning ("unsigned value < 0 is always 0"); + warning ("comparison of unsigned expression < 0 is always false"); value = boolean_false_node; break; @@ -2898,7 +2929,7 @@ truthvalue_conversion (expr) unsigned char *yy_cur, *yy_lim; #define GETC() (yy_cur < yy_lim ? *yy_cur++ : yy_get_token ()) -#define UNGETC(c) ((c), yy_cur--) +#define UNGETC(c) ((c) == EOF ? 0 : yy_cur--) int yy_get_token () @@ -3072,15 +3103,134 @@ get_directive_line (finput) down to the element type of an array. */ tree -c_build_type_variant (type, constp, volatilep) +c_build_qualified_type (type, type_quals) tree type; - int constp, volatilep; + int type_quals; { + /* A restrict-qualified pointer type must be a pointer to object or + incomplete type. Note that the use of POINTER_TYPE_P also allows + REFERENCE_TYPEs, which is appropriate for C++. Unfortunately, + the C++ front-end also use POINTER_TYPE for pointer-to-member + values, so even though it should be illegal to use `restrict' + with such an entity we don't flag that here. Thus, special case + code for that case is required in the C++ front-end. */ + if ((type_quals & TYPE_QUAL_RESTRICT) + && (!POINTER_TYPE_P (type) + || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type)))) + { + error ("invalid use of `restrict'"); + type_quals &= ~TYPE_QUAL_RESTRICT; + } + if (TREE_CODE (type) == ARRAY_TYPE) - return build_array_type (c_build_type_variant (TREE_TYPE (type), - constp, volatilep), + return build_array_type (c_build_qualified_type (TREE_TYPE (type), + type_quals), TYPE_DOMAIN (type)); - return build_type_variant (type, constp, volatilep); + return build_qualified_type (type, type_quals); +} + +/* Apply the TYPE_QUALS to the new DECL. */ + +void +c_apply_type_quals_to_decl (type_quals, decl) + int type_quals; + tree decl; +{ + if (type_quals & TYPE_QUAL_CONST) + TREE_READONLY (decl) = 1; + if (type_quals & TYPE_QUAL_VOLATILE) + { + TREE_SIDE_EFFECTS (decl) = 1; + TREE_THIS_VOLATILE (decl) = 1; + } + if (type_quals & TYPE_QUAL_RESTRICT) + { + if (!TREE_TYPE (decl) + || !POINTER_TYPE_P (TREE_TYPE (decl)) + || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (TREE_TYPE (decl)))) + error ("invalid use of `restrict'"); + else if (flag_strict_aliasing) + { + /* No two restricted pointers can point at the same thing. + However, a restricted pointer can point at the same thing + as an unrestricted pointer, if that unrestricted pointer + is based on the restricted pointer. So, we make the + alias set for the restricted pointer a subset of the + alias set for the type pointed to by the type of the + decl. */ + + int pointed_to_alias_set + = get_alias_set (TREE_TYPE (TREE_TYPE (decl))); + + if (!pointed_to_alias_set) + /* It's not legal to make a subset of alias set zero. */ + ; + else + { + DECL_POINTER_ALIAS_SET (decl) = new_alias_set (); + record_alias_subset (pointed_to_alias_set, + DECL_POINTER_ALIAS_SET (decl)); + } + } + } +} + +/* T is an expression with pointer type. Find the DECL on which this + expression is based. (For example, in `a[i]' this would be `a'.) + If there is no such DECL, or a unique decl cannot be determined, + NULL_TREE is retured. */ + +static tree +c_find_base_decl (t) + tree t; +{ + int i; + tree decl; + + if (t == NULL_TREE || t == error_mark_node) + return NULL_TREE; + + if (!POINTER_TYPE_P (TREE_TYPE (t))) + return NULL_TREE; + + decl = NULL_TREE; + + if (TREE_CODE (t) == FIELD_DECL + || TREE_CODE (t) == PARM_DECL + || TREE_CODE (t) == VAR_DECL) + /* Aha, we found a pointer-typed declaration. */ + return t; + + /* It would be nice to deal with COMPONENT_REFs here. If we could + tell that `a' and `b' were the same, then `a->f' and `b->f' are + also the same. */ + + /* Handle general expressions. */ + switch (TREE_CODE_CLASS (TREE_CODE (t))) + { + case '1': + case '2': + case '3': + for (i = tree_code_length [(int) TREE_CODE (t)]; --i >= 0;) + { + tree d = c_find_base_decl (TREE_OPERAND (t, i)); + if (d) + { + if (!decl) + decl = d; + else if (d && d != decl) + /* Two different declarations. That's confusing; let's + just assume we don't know what's going on. */ + decl = NULL_TREE; + } + } + break; + + default: + break; + } + + return decl; } /* Return the typed-based alias set for T, which may be an expression @@ -3091,6 +3241,7 @@ c_get_alias_set (t) tree t; { tree type; + tree u; if (t == error_mark_node) return 0; @@ -3111,18 +3262,40 @@ c_get_alias_set (t) the conservative assumption. */ return 0; - if (TREE_CODE (t) == COMPONENT_REF - && TREE_CODE (TREE_TYPE (TREE_OPERAND (t, 0))) == UNION_TYPE) - /* Permit type-punning when accessing a union, provided the - access is directly through the union. For example, this code does - not permit taking the address of a union member and then - storing through it. Even the type-punning allowed here is a - GCC extension, albeit a common and useful one; the C standard - says that such accesses have implementation-defined behavior. */ - return 0; + /* Permit type-punning when accessing a union, provided the access + is directly through the union. For example, this code does not + permit taking the address of a union member and then storing + through it. Even the type-punning allowed here is a GCC + extension, albeit a common and useful one; the C standard says + that such accesses have implementation-defined behavior. */ + for (u = t; + TREE_CODE (u) == COMPONENT_REF || TREE_CODE (u) == ARRAY_REF; + u = TREE_OPERAND (u, 0)) + if (TREE_CODE (u) == COMPONENT_REF + && TREE_CODE (TREE_TYPE (TREE_OPERAND (u, 0))) == UNION_TYPE) + return 0; + + if (TREE_CODE (t) == INDIRECT_REF) + { + /* Check for accesses through restrict-qualified pointers. */ + tree decl = c_find_base_decl (TREE_OPERAND (t, 0)); + + if (decl && DECL_POINTER_ALIAS_SET_KNOWN_P (decl)) + /* We use the alias set indicated in the declaration. */ + return DECL_POINTER_ALIAS_SET (decl); + } /* From here on, only the type matters. */ + if (TREE_CODE (t) == COMPONENT_REF + && DECL_BIT_FIELD_TYPE (TREE_OPERAND (t, 1))) + /* Since build_modify_expr calls get_unwidened for stores to + component references, the type of a bit field can be changed + from (say) `unsigned int : 16' to `unsigned short' or from + `enum E : 16' to `short'. We want the real type of the + bit-field in this case, not some the integral equivalent. */ + type = DECL_BIT_FIELD_TYPE (TREE_OPERAND (t, 1)); + if (TYPE_ALIAS_SET_KNOWN_P (type)) /* If we've already calculated the value, just return it. */ return TYPE_ALIAS_SET (type); |