/* Parse C expressions for cpplib.
- Copyright (C) 1987, 1992, 1994, 1995, 1997, 1998, 1999, 2000, 2001
- Free Software Foundation.
+ Copyright (C) 1987, 1992, 1994, 1995, 1997, 1998, 1999, 2000, 2001,
+ 2002 Free Software Foundation.
Contributed by Per Bothner, 1994.
This program is free software; you can redistribute it and/or modify it
#include "cpplib.h"
#include "cpphash.h"
-/* Yield nonzero if adding two numbers with A's and B's signs can yield a
- number with SUM's sign, where A, B, and SUM are all C integers. */
-#define possible_sum_sign(a, b, sum) ((((a) ^ (b)) | ~ ((a) ^ (sum))) < 0)
-
-static void integer_overflow PARAMS ((cpp_reader *));
-static HOST_WIDEST_INT left_shift PARAMS ((cpp_reader *, HOST_WIDEST_INT,
- unsigned int,
- unsigned HOST_WIDEST_INT));
-static HOST_WIDEST_INT right_shift PARAMS ((cpp_reader *, HOST_WIDEST_INT,
- unsigned int,
- unsigned HOST_WIDEST_INT));
-static struct op parse_number PARAMS ((cpp_reader *, const cpp_token *));
-static struct op parse_defined PARAMS ((cpp_reader *));
-static struct op lex PARAMS ((cpp_reader *, int));
-static const unsigned char *op_as_text PARAMS ((cpp_reader *, enum cpp_ttype));
+typedef struct cpp_num cpp_num;
+
+#define PART_PRECISION (sizeof (cpp_num_part) * CHAR_BIT)
+#define HALF_MASK (~(cpp_num_part) 0 >> (PART_PRECISION / 2))
+#define LOW_PART(num_part) (num_part & HALF_MASK)
+#define HIGH_PART(num_part) (num_part >> (PART_PRECISION / 2))
+
+/* A preprocessing number. Code assumes that any unused high bits of
+ the double integer are set to zero. */
+struct cpp_num
+{
+ cpp_num_part high;
+ cpp_num_part low;
+ bool unsignedp; /* True if value should be treated as unsigned. */
+ bool overflow; /* True if the most recent calculation overflowed. */
+};
struct op
{
+ cpp_num value; /* The value logically "right" of op. */
enum cpp_ttype op;
- U_CHAR prio; /* Priority of op. */
- U_CHAR flags;
- U_CHAR unsignedp; /* True if value should be treated as unsigned. */
- HOST_WIDEST_INT value; /* The value logically "right" of op. */
};
-/* There is no "error" token, but we can't get comments in #if, so we can
- abuse that token type. */
+/* Some simple utility routines on double integers. */
+#define num_zerop(num) ((num.low | num.high) == 0)
+#define num_eq(num1, num2) (num1.low == num2.low && num1.high == num2.high)
+static bool num_positive PARAMS ((cpp_num, size_t));
+static bool num_greater_eq PARAMS ((cpp_num, cpp_num, size_t));
+static cpp_num num_trim PARAMS ((cpp_num, size_t));
+static cpp_num num_part_mul PARAMS ((cpp_num_part, cpp_num_part));
+
+static cpp_num num_unary_op PARAMS ((cpp_reader *, cpp_num, enum cpp_ttype));
+static cpp_num num_binary_op PARAMS ((cpp_reader *, cpp_num, cpp_num,
+ enum cpp_ttype));
+static cpp_num num_negate PARAMS ((cpp_num, size_t));
+static cpp_num num_bitwise_op PARAMS ((cpp_reader *, cpp_num, cpp_num,
+ enum cpp_ttype));
+static cpp_num num_inequality_op PARAMS ((cpp_reader *, cpp_num, cpp_num,
+ enum cpp_ttype));
+static cpp_num num_equality_op PARAMS ((cpp_reader *, cpp_num, cpp_num,
+ enum cpp_ttype));
+static cpp_num num_mul PARAMS ((cpp_reader *, cpp_num, cpp_num,
+ enum cpp_ttype));
+static cpp_num num_div_op PARAMS ((cpp_reader *, cpp_num, cpp_num,
+ enum cpp_ttype));
+static cpp_num num_lshift PARAMS ((cpp_num, size_t, size_t));
+static cpp_num num_rshift PARAMS ((cpp_num, size_t, size_t));
+
+static cpp_num append_digit PARAMS ((cpp_num, int, int, size_t));
+static cpp_num interpret_number PARAMS ((cpp_reader *, const cpp_token *));
+static cpp_num parse_defined PARAMS ((cpp_reader *));
+static cpp_num eval_token PARAMS ((cpp_reader *, const cpp_token *));
+static struct op *reduce PARAMS ((cpp_reader *, struct op *, enum cpp_ttype));
+
+/* Token type abuse. There is no "error" token, but we can't get
+ comments in #if, so we can abuse that token type. Similarly,
+ create unary plus and minus operators. */
#define CPP_ERROR CPP_COMMENT
+#define CPP_UPLUS (CPP_LAST_CPP_OP + 1)
+#define CPP_UMINUS (CPP_LAST_CPP_OP + 2)
/* With -O2, gcc appears to produce nice code, moving the error
message load and subsequent jump completely out of the main path. */
-#define CPP_ICE(msgid) \
- do { cpp_ice (pfile, msgid); goto syntax_error; } while(0)
#define SYNTAX_ERROR(msgid) \
- do { cpp_error (pfile, msgid); goto syntax_error; } while(0)
+ do { cpp_error (pfile, DL_ERROR, msgid); goto syntax_error; } while(0)
#define SYNTAX_ERROR2(msgid, arg) \
- do { cpp_error (pfile, msgid, arg); goto syntax_error; } while(0)
+ do { cpp_error (pfile, DL_ERROR, msgid, arg); goto syntax_error; } while(0)
struct suffix
{
{ "ull", 1, 2 }, { "ULL", 1, 2 }, { "uLL", 1, 2 }, { "Ull", 1, 2 },
{ "llu", 1, 2 }, { "LLU", 1, 2 }, { "LLu", 1, 2 }, { "llU", 1, 2 }
};
-#define Nsuff(tab) (sizeof tab / sizeof (struct suffix))
-/* Parse and convert an integer for #if. Accepts decimal, hex, or
- octal with or without size suffixes. Returned op is CPP_ERROR on
- error, otherwise it is a CPP_NUMBER. */
+/* Append DIGIT to NUM, a number of PRECISION bits being read in base
+ BASE. */
+static cpp_num
+append_digit (num, digit, base, precision)
+ cpp_num num;
+ int digit, base;
+ size_t precision;
+{
+ cpp_num result;
+ unsigned int shift = 3 + (base == 16);
+ bool overflow;
+ cpp_num_part add_high, add_low;
+
+ /* Multiply by 8 or 16. Catching this overflow here means we don't
+ need to worry about add_high overflowing. */
+ overflow = num.high >> (PART_PRECISION - shift);
+ result.high = num.high << shift;
+ result.low = num.low << shift;
+ result.high |= num.low >> (PART_PRECISION - shift);
+
+ if (base == 10)
+ {
+ add_low = num.low << 1;
+ add_high = (num.high << 1) + (num.low >> (PART_PRECISION - 1));
+ }
+ else
+ add_high = add_low = 0;
+
+ if (add_low + digit < add_low)
+ add_high++;
+ add_low += digit;
+
+ if (result.low + add_low < result.low)
+ add_high++;
+ if (result.high + add_high < result.high)
+ overflow = true;
+
+ result.low += add_low;
+ result.high += add_high;
+
+ /* The above code catches overflow of a cpp_num type. This catches
+ overflow of the (possibly shorter) target precision. */
+ num.low = result.low;
+ num.high = result.high;
+ result = num_trim (result, precision);
+ if (!num_eq (result, num))
+ overflow = true;
+
+ result.unsignedp = num.unsignedp;
+ result.overflow = overflow;
+ return result;
+}
-static struct op
-parse_number (pfile, tok)
+/* Parse and convert what is presumably an integer in TOK. Accepts
+ decimal, hex, or octal with or without size suffixes. Returned op
+ is CPP_ERROR on error, otherwise it is a CPP_NUMBER. */
+static cpp_num
+interpret_number (pfile, tok)
cpp_reader *pfile;
const cpp_token *tok;
{
- struct op op;
- const U_CHAR *start = tok->val.str.text;
- const U_CHAR *end = start + tok->val.str.len;
- const U_CHAR *p = start;
- int c = 0, i, nsuff;
- unsigned HOST_WIDEST_INT n = 0, nd, MAX_over_base;
- int base = 10;
- int overflow = 0;
- int digit, largest_digit = 0;
+ cpp_num result;
+ const uchar *start = tok->val.str.text;
+ const uchar *end = start + tok->val.str.len;
+ const uchar *p = start;
const struct suffix *sufftab;
+ size_t precision = CPP_OPTION (pfile, precision);
+ unsigned int i, nsuff, base = 10, c = 0, largest_digit = 0;
+ bool overflow = false;
- op.unsignedp = 0;
+ result.low = result.high = 0;
+ result.unsignedp = 0;
+ result.overflow = 0;
if (p[0] == '0')
{
}
}
- /* Some buggy compilers (e.g. MPW C) seem to need both casts. */
- MAX_over_base = (((unsigned HOST_WIDEST_INT) -1)
- / ((unsigned HOST_WIDEST_INT) base));
-
for(; p < end; p++)
{
c = *p;
- if (c >= '0' && c <= '9')
- digit = c - '0';
- /* We believe that in all live character sets, a-f are
- consecutive, and so are A-F. */
- else if (base == 16 && c >= 'a' && c <= 'f')
- digit = c - 'a' + 10;
- else if (base == 16 && c >= 'A' && c <= 'F')
- digit = c - 'A' + 10;
+ if (ISDIGIT (c) || (base == 16 && ISXDIGIT (c)))
+ c = hex_value (c);
else
break;
- if (largest_digit < digit)
- largest_digit = digit;
- nd = n * base + digit;
- overflow |= MAX_over_base < n || nd < n;
- n = nd;
+ result = append_digit (result, c, base, precision);
+ overflow |= result.overflow;
+ if (largest_digit < c)
+ largest_digit = c;
}
if (p < end)
|| (base == 16 && (c == 'P' || c == 'p')
&& p+1 < end && (p[1] == '+' || p[1] == '-')))
SYNTAX_ERROR ("floating point numbers are not valid in #if");
-
+
/* Determine the suffix. l means long, and u means unsigned.
See the suffix tables, above. */
switch (end - p)
{
- case 1: sufftab = vsuf_1; nsuff = Nsuff(vsuf_1); break;
- case 2: sufftab = vsuf_2; nsuff = Nsuff(vsuf_2); break;
- case 3: sufftab = vsuf_3; nsuff = Nsuff(vsuf_3); break;
+ case 1: sufftab = vsuf_1; nsuff = ARRAY_SIZE (vsuf_1); break;
+ case 2: sufftab = vsuf_2; nsuff = ARRAY_SIZE (vsuf_2); break;
+ case 3: sufftab = vsuf_3; nsuff = ARRAY_SIZE (vsuf_3); break;
default: goto invalid_suffix;
}
break;
if (i == nsuff)
goto invalid_suffix;
- op.unsignedp = sufftab[i].u;
+ result.unsignedp = sufftab[i].u;
if (CPP_WTRADITIONAL (pfile)
&& sufftab[i].u
&& ! cpp_sys_macro_p (pfile))
- cpp_warning (pfile, "traditional C rejects the `U' suffix");
+ cpp_error (pfile, DL_WARNING, "traditional C rejects the `U' suffix");
if (sufftab[i].l == 2 && CPP_OPTION (pfile, pedantic)
&& ! CPP_OPTION (pfile, c99))
- cpp_pedwarn (pfile, "too many 'l' suffixes in integer constant");
+ cpp_error (pfile, DL_PEDWARN,
+ "too many 'l' suffixes in integer constant");
}
-
+
if (base <= largest_digit)
- cpp_pedwarn (pfile, "integer constant contains digits beyond the radix");
+ cpp_error (pfile, DL_PEDWARN,
+ "integer constant contains digits beyond the radix");
if (overflow)
- cpp_pedwarn (pfile, "integer constant out of range");
-
+ cpp_error (pfile, DL_PEDWARN, "integer constant too large for its type");
/* If too big to be signed, consider it unsigned. */
- else if ((HOST_WIDEST_INT) n < 0 && ! op.unsignedp)
+ else if (!result.unsignedp && !num_positive (result, precision))
{
if (base == 10)
- cpp_warning (pfile, "integer constant is so large that it is unsigned");
- op.unsignedp = 1;
+ cpp_error (pfile, DL_WARNING,
+ "integer constant is so large that it is unsigned");
+ result.unsignedp = 1;
}
- op.value = n;
- op.op = CPP_NUMBER;
- return op;
+ return result;
invalid_suffix:
- cpp_error (pfile, "invalid suffix '%.*s' on integer constant",
+ cpp_error (pfile, DL_ERROR, "invalid suffix '%.*s' on integer constant",
(int) (end - p), p);
syntax_error:
- op.op = CPP_ERROR;
- return op;
+ return result;
}
-static struct op
+/* Handle meeting "defined" in a preprocessor expression. */
+static cpp_num
parse_defined (pfile)
cpp_reader *pfile;
{
+ cpp_num result;
int paren = 0;
cpp_hashnode *node = 0;
const cpp_token *token;
- struct op op;
+ cpp_context *initial_context = pfile->context;
/* Don't expand macros. */
pfile->state.prevent_expansion++;
node = token->val.node;
if (paren && cpp_get_token (pfile)->type != CPP_CLOSE_PAREN)
{
- cpp_error (pfile, "missing ')' after \"defined\"");
+ cpp_error (pfile, DL_ERROR, "missing ')' after \"defined\"");
node = 0;
}
}
else
{
- cpp_error (pfile, "operator \"defined\" requires an identifier");
+ cpp_error (pfile, DL_ERROR,
+ "operator \"defined\" requires an identifier");
if (token->flags & NAMED_OP)
{
cpp_token op;
op.flags = 0;
op.type = token->type;
- cpp_error (pfile,
+ cpp_error (pfile, DL_ERROR,
"(\"%s\" is an alternative token for \"%s\" in C++)",
cpp_token_as_text (pfile, token),
cpp_token_as_text (pfile, &op));
}
}
- if (!node)
- op.op = CPP_ERROR;
- else
+ if (node)
{
- op.value = node->type == NT_MACRO;
- op.unsignedp = 0;
- op.op = CPP_NUMBER;
+ if (pfile->context != initial_context)
+ cpp_error (pfile, DL_WARNING,
+ "this use of \"defined\" may not be portable");
/* A possible controlling macro of the form #if !defined ().
_cpp_parse_expr checks there was no other junk on the line. */
}
pfile->state.prevent_expansion--;
- return op;
-}
-/* Read a token. The returned type is CPP_NUMBER for a valid number
- (an interpreted preprocessing number or character constant, or the
- result of the "defined" or "#" operators), CPP_ERROR on error,
- CPP_EOF, or the type of an operator token. */
+ result.unsignedp = 0;
+ result.high = 0;
+ result.overflow = 0;
+ result.low = node && node->type == NT_MACRO;
+ return result;
+}
-static struct op
-lex (pfile, skip_evaluation)
+/* Convert a token into a CPP_NUMBER (an interpreted preprocessing
+ number or character constant, or the result of the "defined" or "#"
+ operators), or CPP_ERROR on error. */
+static cpp_num
+eval_token (pfile, token)
cpp_reader *pfile;
- int skip_evaluation;
+ const cpp_token *token;
{
- struct op op;
- const cpp_token *token = cpp_get_token (pfile);
+ cpp_num result;
+ unsigned int temp;
+ int unsignedp = 0;
switch (token->type)
{
case CPP_NUMBER:
- return parse_number (pfile, token);
+ return interpret_number (pfile, token);
- case CPP_CHAR:
case CPP_WCHAR:
+ case CPP_CHAR:
{
- unsigned int chars_seen;
+ cppchar_t cc = cpp_interpret_charconst (pfile, token,
+ &temp, &unsignedp);
- /* This is always a signed type. */
- op.unsignedp = 0;
- op.op = CPP_NUMBER;
- op.value = cpp_interpret_charconst (pfile, token, 1, 0, &chars_seen);
- return op;
+ result.high = 0;
+ result.low = cc;
+ /* Sign-extend the result if necessary. */
+ if (!unsignedp && (cppchar_signed_t) cc < 0)
+ {
+ if (PART_PRECISION > BITS_PER_CPPCHAR_T)
+ result.low |= ~(~(cpp_num_part) 0
+ >> (PART_PRECISION - BITS_PER_CPPCHAR_T));
+ result.high = ~(cpp_num_part) 0;
+ result = num_trim (result, CPP_OPTION (pfile, precision));
+ }
}
-
- case CPP_STRING:
- case CPP_WSTRING:
- SYNTAX_ERROR ("string constants are not valid in #if");
-
- case CPP_OTHER:
- if (ISGRAPH (token->val.c))
- SYNTAX_ERROR2 ("invalid character '%c' in #if", token->val.c);
- else
- SYNTAX_ERROR2 ("invalid character '\\%03o' in #if", token->val.c);
+ break;
case CPP_NAME:
if (token->val.node == pfile->spec_nodes.n_defined)
- {
- if (pfile->context->prev && CPP_PEDANTIC (pfile))
- cpp_pedwarn (pfile, "\"defined\" operator appears during macro expansion");
-
- return parse_defined (pfile);
- }
+ return parse_defined (pfile);
else if (CPP_OPTION (pfile, cplusplus)
&& (token->val.node == pfile->spec_nodes.n_true
|| token->val.node == pfile->spec_nodes.n_false))
{
- op.op = CPP_NUMBER;
- op.unsignedp = 0;
- op.value = (token->val.node == pfile->spec_nodes.n_true);
+ result.high = 0;
+ result.low = (token->val.node == pfile->spec_nodes.n_true);
/* Warn about use of true or false in #if when pedantic
and stdbool.h has not been included. */
if (CPP_PEDANTIC (pfile)
&& ! cpp_defined (pfile, DSC("__bool_true_false_are_defined")))
- cpp_pedwarn (pfile, "ISO C++ does not permit \"%s\" in #if",
- NODE_NAME (token->val.node));
- return op;
+ cpp_error (pfile, DL_PEDWARN,
+ "ISO C++ does not permit \"%s\" in #if",
+ NODE_NAME (token->val.node));
}
else
{
- op.op = CPP_NUMBER;
- op.unsignedp = 0;
- op.value = 0;
-
- if (CPP_OPTION (pfile, warn_undef) && !skip_evaluation)
- cpp_warning (pfile, "\"%s\" is not defined",
- NODE_NAME (token->val.node));
- return op;
+ result.high = 0;
+ result.low = 0;
+ if (CPP_OPTION (pfile, warn_undef) && !pfile->state.skip_eval)
+ cpp_error (pfile, DL_WARNING, "\"%s\" is not defined",
+ NODE_NAME (token->val.node));
}
+ break;
- case CPP_HASH:
- {
- int temp;
-
- op.op = CPP_NUMBER;
- if (_cpp_test_assertion (pfile, &temp))
- op.op = CPP_ERROR;
- op.unsignedp = 0;
- op.value = temp;
- return op;
- }
-
- default:
- if (((int) token->type > (int) CPP_EQ
- && (int) token->type < (int) CPP_PLUS_EQ)
- || token->type == CPP_EOF)
- {
- op.op = token->type;
- return op;
- }
-
- SYNTAX_ERROR2 ("\"%s\" is not valid in #if expressions",
- cpp_token_as_text (pfile, token));
- }
-
- syntax_error:
- op.op = CPP_ERROR;
- return op;
-}
-
-static void
-integer_overflow (pfile)
- cpp_reader *pfile;
-{
- if (CPP_PEDANTIC (pfile))
- cpp_pedwarn (pfile, "integer overflow in preprocessor expression");
-}
-
-static HOST_WIDEST_INT
-left_shift (pfile, a, unsignedp, b)
- cpp_reader *pfile;
- HOST_WIDEST_INT a;
- unsigned int unsignedp;
- unsigned HOST_WIDEST_INT b;
-{
- if (b >= HOST_BITS_PER_WIDEST_INT)
- {
- if (! unsignedp && a != 0)
- integer_overflow (pfile);
- return 0;
+ default: /* CPP_HASH */
+ _cpp_test_assertion (pfile, &temp);
+ result.high = 0;
+ result.low = temp;
}
- else if (unsignedp)
- return (unsigned HOST_WIDEST_INT) a << b;
- else
- {
- HOST_WIDEST_INT l = a << b;
- if (l >> b != a)
- integer_overflow (pfile);
- return l;
- }
-}
-static HOST_WIDEST_INT
-right_shift (pfile, a, unsignedp, b)
- cpp_reader *pfile ATTRIBUTE_UNUSED;
- HOST_WIDEST_INT a;
- unsigned int unsignedp;
- unsigned HOST_WIDEST_INT b;
-{
- if (b >= HOST_BITS_PER_WIDEST_INT)
- return unsignedp ? 0 : a >> (HOST_BITS_PER_WIDEST_INT - 1);
- else if (unsignedp)
- return (unsigned HOST_WIDEST_INT) a >> b;
- else
- return a >> b;
+ result.unsignedp = unsignedp;
+ result.overflow = 0;
+ return result;
}
\f
/* Operator precedence and flags table.
After an operator is returned from the lexer, if it has priority less
-than or equal to the operator on the top of the stack, we reduce the
-stack by one operator and repeat the test. Since equal priorities
-reduce, this is naturally left-associative.
-
-We handle right-associative operators by clearing the lower bit of all
-left-associative operators, and setting it for right-associative ones.
-After the reduction phase of a new operator, just before it is pushed
-onto the stack, its RIGHT_ASSOC bit is cleared. The effect is that
-during the reduction phase, the current right-associative operator has
-a priority one greater than any other operator of otherwise equal
-precedence that has been pushed on the top of the stack. This avoids
-a reduction pass, and effectively makes the logic right-associative.
+than the operator on the top of the stack, we reduce the stack by one
+operator and repeat the test. Since equal priorities do not reduce,
+this is naturally right-associative.
+
+We handle left-associative operators by decrementing the priority of
+just-lexed operators by one, but retaining the priority of operators
+already on the stack.
The remaining cases are '(' and ')'. We handle '(' by skipping the
reduction phase completely. ')' is given lower priority than
everything else, including '(', effectively forcing a reduction of the
-parenthesised expression. If there is no matching '(', the stack will
-be reduced all the way to the beginning, exiting the parser in the
-same way as the ultra-low priority end-of-expression dummy operator.
-The exit code checks to see if the operator that caused it is ')', and
-if so outputs an appropriate error message.
-
-The parser assumes all shifted operators require a right operand
-unless the flag NO_R_OPERAND is set, and similarly for NO_L_OPERAND.
-These semantics are automatically checked, any extra semantics need to
-be handled with operator-specific code. */
-
-#define FLAG_BITS 8
-#define FLAG_MASK ((1 << FLAG_BITS) - 1)
-#define PRIO_SHIFT (FLAG_BITS + 1)
-#define EXTRACT_PRIO(CNST) ((CNST) >> FLAG_BITS)
-#define EXTRACT_FLAGS(CNST) ((CNST) & FLAG_MASK)
+parenthesised expression. If there is a matching '(', the routine
+reduce() exits immediately. If the normal exit route sees a ')', then
+there cannot have been a matching '(' and an error message is output.
+
+The parser assumes all shifted operators require a left operand unless
+the flag NO_L_OPERAND is set. These semantics are automatic; any
+extra semantics need to be handled with operator-specific code. */
/* Flags. */
-#define HAVE_VALUE (1 << 0)
-#define NO_L_OPERAND (1 << 1)
-#define NO_R_OPERAND (1 << 2)
-#define SHORT_CIRCUIT (1 << 3)
-
-/* Priority and flag combinations. */
-#define RIGHT_ASSOC (1 << FLAG_BITS)
-#define FORCE_REDUCE_PRIO (0 << PRIO_SHIFT)
-#define CLOSE_PAREN_PRIO (1 << PRIO_SHIFT)
-#define OPEN_PAREN_PRIO ((2 << PRIO_SHIFT) | NO_L_OPERAND)
-#define COMMA_PRIO (3 << PRIO_SHIFT)
-#define COND_PRIO ((4 << PRIO_SHIFT) | RIGHT_ASSOC | SHORT_CIRCUIT)
-#define COLON_PRIO ((5 << PRIO_SHIFT) | SHORT_CIRCUIT)
-#define OROR_PRIO ((6 << PRIO_SHIFT) | SHORT_CIRCUIT)
-#define ANDAND_PRIO ((7 << PRIO_SHIFT) | SHORT_CIRCUIT)
-#define OR_PRIO (8 << PRIO_SHIFT)
-#define XOR_PRIO (9 << PRIO_SHIFT)
-#define AND_PRIO (10 << PRIO_SHIFT)
-#define MINMAX_PRIO (11 << PRIO_SHIFT)
-#define EQUAL_PRIO (12 << PRIO_SHIFT)
-#define LESS_PRIO (13 << PRIO_SHIFT)
-#define SHIFT_PRIO (14 << PRIO_SHIFT)
-#define PLUS_PRIO (15 << PRIO_SHIFT)
-#define MUL_PRIO (16 << PRIO_SHIFT)
-#define UNARY_PRIO ((17 << PRIO_SHIFT) | RIGHT_ASSOC | NO_L_OPERAND)
+#define NO_L_OPERAND (1 << 0)
+#define LEFT_ASSOC (1 << 1)
+/* Arity. */
+#define UNARY (1 << 0)
+#define BINARY (1 << 1)
+#define OTHER (1 << 2)
+
+typedef cpp_num (*binary_handler) PARAMS ((cpp_reader *, cpp_num, cpp_num,
+ enum cpp_ttype));
/* Operator to priority map. Must be in the same order as the first
N entries of enum cpp_ttype. */
-static const short
-op_to_prio[] =
+static const struct operator
+{
+ uchar prio;
+ uchar flags;
+ uchar arity;
+ binary_handler handler;
+} optab[] =
{
- /* EQ */ 0, /* dummy entry - can't happen */
- /* NOT */ UNARY_PRIO,
- /* GREATER */ LESS_PRIO,
- /* LESS */ LESS_PRIO,
- /* PLUS */ UNARY_PRIO, /* note these two can be unary */
- /* MINUS */ UNARY_PRIO, /* or binary */
- /* MULT */ MUL_PRIO,
- /* DIV */ MUL_PRIO,
- /* MOD */ MUL_PRIO,
- /* AND */ AND_PRIO,
- /* OR */ OR_PRIO,
- /* XOR */ XOR_PRIO,
- /* RSHIFT */ SHIFT_PRIO,
- /* LSHIFT */ SHIFT_PRIO,
- /* MIN */ MINMAX_PRIO, /* C++ specific */
- /* MAX */ MINMAX_PRIO, /* extensions */
-
- /* COMPL */ UNARY_PRIO,
- /* AND_AND */ ANDAND_PRIO,
- /* OR_OR */ OROR_PRIO,
- /* QUERY */ COND_PRIO,
- /* COLON */ COLON_PRIO,
- /* COMMA */ COMMA_PRIO,
- /* OPEN_PAREN */ OPEN_PAREN_PRIO,
- /* CLOSE_PAREN */ CLOSE_PAREN_PRIO,
- /* EQ_EQ */ EQUAL_PRIO,
- /* NOT_EQ */ EQUAL_PRIO,
- /* GREATER_EQ */ LESS_PRIO,
- /* LESS_EQ */ LESS_PRIO
+ /* EQ */ {0, 0, OTHER, NULL}, /* Shouldn't happen. */
+ /* NOT */ {16, NO_L_OPERAND, UNARY, NULL},
+ /* GREATER */ {12, LEFT_ASSOC, BINARY, num_inequality_op},
+ /* LESS */ {12, LEFT_ASSOC, BINARY, num_inequality_op},
+ /* PLUS */ {14, LEFT_ASSOC, BINARY, num_binary_op},
+ /* MINUS */ {14, LEFT_ASSOC, BINARY, num_binary_op},
+ /* MULT */ {15, LEFT_ASSOC, BINARY, num_mul},
+ /* DIV */ {15, LEFT_ASSOC, BINARY, num_div_op},
+ /* MOD */ {15, LEFT_ASSOC, BINARY, num_div_op},
+ /* AND */ {9, LEFT_ASSOC, BINARY, num_bitwise_op},
+ /* OR */ {7, LEFT_ASSOC, BINARY, num_bitwise_op},
+ /* XOR */ {8, LEFT_ASSOC, BINARY, num_bitwise_op},
+ /* RSHIFT */ {13, LEFT_ASSOC, BINARY, num_binary_op},
+ /* LSHIFT */ {13, LEFT_ASSOC, BINARY, num_binary_op},
+
+ /* MIN */ {10, LEFT_ASSOC, BINARY, num_binary_op},
+ /* MAX */ {10, LEFT_ASSOC, BINARY, num_binary_op},
+
+ /* COMPL */ {16, NO_L_OPERAND, UNARY, NULL},
+ /* AND_AND */ {6, LEFT_ASSOC, OTHER, NULL},
+ /* OR_OR */ {5, LEFT_ASSOC, OTHER, NULL},
+ /* QUERY */ {3, 0, OTHER, NULL},
+ /* COLON */ {4, LEFT_ASSOC, OTHER, NULL},
+ /* COMMA */ {2, LEFT_ASSOC, BINARY, num_binary_op},
+ /* OPEN_PAREN */ {1, NO_L_OPERAND, OTHER, NULL},
+ /* CLOSE_PAREN */ {0, 0, OTHER, NULL},
+ /* EOF */ {0, 0, OTHER, NULL},
+ /* EQ_EQ */ {11, LEFT_ASSOC, BINARY, num_equality_op},
+ /* NOT_EQ */ {11, LEFT_ASSOC, BINARY, num_equality_op},
+ /* GREATER_EQ */ {12, LEFT_ASSOC, BINARY, num_inequality_op},
+ /* LESS_EQ */ {12, LEFT_ASSOC, BINARY, num_inequality_op},
+ /* UPLUS */ {16, NO_L_OPERAND, UNARY, NULL},
+ /* UMINUS */ {16, NO_L_OPERAND, UNARY, NULL}
};
-#define COMPARE(OP) \
- top->unsignedp = 0; \
- top->value = (unsigned1 | unsigned2) \
- ? (unsigned HOST_WIDEST_INT) v1 OP (unsigned HOST_WIDEST_INT) v2 \
- : (v1 OP v2)
-#define EQUALITY(OP) \
- top->value = v1 OP v2; \
- top->unsignedp = 0;
-#define BITWISE(OP) \
- top->value = v1 OP v2; \
- top->unsignedp = unsigned1 | unsigned2;
-#define MINMAX(OP) \
- top->value = (v1 OP v2) ? v1 : v2; \
- top->unsignedp = unsigned1 | unsigned2;
-#define UNARY(OP) \
- top->value = OP v2; \
- top->unsignedp = unsigned2; \
- top->flags |= HAVE_VALUE;
-#define SHIFT(PSH, MSH) \
- if (skip_evaluation) \
- break; \
- top->unsignedp = unsigned1; \
- if (v2 < 0 && ! unsigned2) \
- top->value = MSH (pfile, v1, unsigned1, -v2); \
- else \
- top->value = PSH (pfile, v1, unsigned1, v2);
-
/* Parse and evaluate a C expression, reading from PFILE.
- Returns the truth value of the expression. */
+ Returns the truth value of the expression.
-int
+ The implementation is an operator precedence parser, i.e. a
+ bottom-up parser, using a stack for not-yet-reduced tokens.
+
+ The stack base is op_stack, and the current stack pointer is 'top'.
+ There is a stack element for each operator (only), and the most
+ recently pushed operator is 'top->op'. An operand (value) is
+ stored in the 'value' field of the stack element of the operator
+ that precedes it. */
+bool
_cpp_parse_expr (pfile)
cpp_reader *pfile;
{
- /* The implementation is an operator precedence parser, i.e. a
- bottom-up parser, using a stack for not-yet-reduced tokens.
-
- The stack base is 'stack', and the current stack pointer is 'top'.
- There is a stack element for each operator (only),
- and the most recently pushed operator is 'top->op'.
- An operand (value) is stored in the 'value' field of the stack
- element of the operator that precedes it.
- In that case the 'flags' field has the HAVE_VALUE flag set. */
-
-#define INIT_STACK_SIZE 20
- struct op init_stack[INIT_STACK_SIZE];
- struct op *stack = init_stack;
- struct op *limit = stack + INIT_STACK_SIZE;
- struct op *top = stack + 1;
- int skip_evaluation = 0;
- int result;
- unsigned int lex_count, saw_leading_not;
+ struct op *top = pfile->op_stack;
+ const cpp_token *token = NULL, *prev_token;
+ unsigned int lex_count;
+ bool saw_leading_not, want_value = true;
+
+ pfile->state.skip_eval = 0;
/* Set up detection of #if ! defined(). */
pfile->mi_ind_cmacro = 0;
- saw_leading_not = 0;
+ saw_leading_not = false;
lex_count = 0;
- /* We've finished when we try to reduce this. */
+ /* Lowest priority operator prevents further reductions. */
top->op = CPP_EOF;
- /* Nifty way to catch missing '('. */
- top->prio = EXTRACT_PRIO(CLOSE_PAREN_PRIO);
- /* Avoid missing right operand checks. */
- top->flags = NO_R_OPERAND;
for (;;)
{
- unsigned int prio;
- unsigned int flags;
struct op op;
- /* Read a token */
- op = lex (pfile, skip_evaluation);
+ prev_token = token;
+ token = cpp_get_token (pfile);
lex_count++;
+ op.op = token->type;
- /* If the token is an operand, push its value and get next
- token. If it is an operator, get its priority and flags, and
- try to reduce the expression on the stack. */
switch (op.op)
{
- case CPP_ERROR:
- goto syntax_error;
- push_immediate:
+ /* These tokens convert into values. */
case CPP_NUMBER:
- /* Push a value onto the stack. */
- if (top->flags & HAVE_VALUE)
- SYNTAX_ERROR ("missing binary operator");
- top->value = op.value;
- top->unsignedp = op.unsignedp;
- top->flags |= HAVE_VALUE;
+ case CPP_CHAR:
+ case CPP_WCHAR:
+ case CPP_NAME:
+ case CPP_HASH:
+ if (!want_value)
+ SYNTAX_ERROR2 ("missing binary operator before token \"%s\"",
+ cpp_token_as_text (pfile, token));
+ want_value = false;
+ top->value = eval_token (pfile, token);
continue;
- case CPP_EOF: prio = FORCE_REDUCE_PRIO; break;
-
case CPP_NOT:
saw_leading_not = lex_count == 1;
- prio = op_to_prio[op.op];
break;
case CPP_PLUS:
- case CPP_MINUS: prio = PLUS_PRIO; if (top->flags & HAVE_VALUE) break;
- /* else unary; fall through */
- default: prio = op_to_prio[op.op]; break;
- }
+ if (want_value)
+ op.op = CPP_UPLUS;
+ break;
+ case CPP_MINUS:
+ if (want_value)
+ op.op = CPP_UMINUS;
+ break;
+ case CPP_OTHER:
+ if (ISGRAPH (token->val.c))
+ SYNTAX_ERROR2 ("invalid character '%c' in #if", token->val.c);
+ else
+ SYNTAX_ERROR2 ("invalid character '\\%03o' in #if", token->val.c);
- /* Separate the operator's code into priority and flags. */
- flags = EXTRACT_FLAGS(prio);
- prio = EXTRACT_PRIO(prio);
- if (prio == EXTRACT_PRIO(OPEN_PAREN_PRIO))
- goto skip_reduction;
+ default:
+ if ((int) op.op <= (int) CPP_EQ || (int) op.op >= (int) CPP_PLUS_EQ)
+ SYNTAX_ERROR2 ("token \"%s\" is not valid in #if expressions",
+ cpp_token_as_text (pfile, token));
+ break;
+ }
- /* Check for reductions. Then push the operator. */
- while (prio <= top->prio)
+ /* Check we have a value or operator as appropriate. */
+ if (optab[op.op].flags & NO_L_OPERAND)
+ {
+ if (!want_value)
+ SYNTAX_ERROR2 ("missing binary operator before token \"%s\"",
+ cpp_token_as_text (pfile, token));
+ }
+ else if (want_value)
{
- HOST_WIDEST_INT v1, v2;
- unsigned int unsigned1, unsigned2;
-
- /* Most operators that can appear on the stack require a
- right operand. Check this before trying to reduce. */
- if ((top->flags & (HAVE_VALUE | NO_R_OPERAND)) == 0)
+ /* Ordering here is subtle and intended to favour the
+ missing parenthesis diagnostics over alternatives. */
+ if (op.op == CPP_CLOSE_PAREN)
{
if (top->op == CPP_OPEN_PAREN)
SYNTAX_ERROR ("void expression between '(' and ')'");
- else
- SYNTAX_ERROR2 ("operator '%s' has no right operand",
- op_as_text (pfile, top->op));
}
+ else if (top->op == CPP_EOF)
+ SYNTAX_ERROR ("#if with no expression");
+ if (top->op != CPP_EOF && top->op != CPP_OPEN_PAREN)
+ SYNTAX_ERROR2 ("operator '%s' has no right operand",
+ cpp_token_as_text (pfile, prev_token));
+ }
+
+ top = reduce (pfile, top, op.op);
+ if (!top)
+ goto syntax_error;
+
+ if (op.op == CPP_EOF)
+ break;
- unsigned2 = top->unsignedp, v2 = top->value;
+ switch (op.op)
+ {
+ case CPP_CLOSE_PAREN:
+ continue;
+ case CPP_OR_OR:
+ if (!num_zerop (top->value))
+ pfile->state.skip_eval++;
+ break;
+ case CPP_AND_AND:
+ case CPP_QUERY:
+ if (num_zerop (top->value))
+ pfile->state.skip_eval++;
+ break;
+ case CPP_COLON:
+ if (top->op != CPP_QUERY)
+ SYNTAX_ERROR (" ':' without preceding '?'");
+ if (!num_zerop (top[-1].value)) /* Was '?' condition true? */
+ pfile->state.skip_eval++;
+ else
+ pfile->state.skip_eval--;
+ default:
+ break;
+ }
+
+ want_value = true;
+
+ /* Check for and handle stack overflow. */
+ if (++top == pfile->op_limit)
+ top = _cpp_expand_op_stack (pfile);
+
+ top->op = op.op;
+ }
+
+ /* The controlling macro expression is only valid if we called lex 3
+ times: <!> <defined expression> and <EOF>. push_conditional ()
+ checks that we are at top-of-file. */
+ if (pfile->mi_ind_cmacro && !(saw_leading_not && lex_count == 3))
+ pfile->mi_ind_cmacro = 0;
+
+ if (top != pfile->op_stack)
+ {
+ cpp_error (pfile, DL_ICE, "unbalanced stack in #if");
+ syntax_error:
+ return false; /* Return false on syntax error. */
+ }
+
+ return !num_zerop (top->value);
+}
+
+/* Reduce the operator / value stack if possible, in preparation for
+ pushing operator OP. Returns NULL on error, otherwise the top of
+ the stack. */
+static struct op *
+reduce (pfile, top, op)
+ cpp_reader *pfile;
+ struct op *top;
+ enum cpp_ttype op;
+{
+ unsigned int prio;
+
+ if (top->op <= CPP_EQ || top->op > CPP_LAST_CPP_OP + 2)
+ {
+ bad_op:
+ cpp_error (pfile, DL_ICE, "impossible operator '%u'", top->op);
+ return 0;
+ }
+
+ if (op == CPP_OPEN_PAREN)
+ return top;
+
+ /* Decrement the priority of left-associative operators to force a
+ reduction with operators of otherwise equal priority. */
+ prio = optab[op].prio - ((optab[op].flags & LEFT_ASSOC) != 0);
+ while (prio < optab[top->op].prio)
+ {
+ if (optab[top->op].arity == UNARY)
+ {
+ if (!pfile->state.skip_eval)
+ top[-1].value = num_unary_op (pfile, top->value, top->op);
+ top--;
+ }
+ else if (optab[top->op].arity == BINARY)
+ {
+ if (!pfile->state.skip_eval)
+ top[-1].value = (* (binary_handler) optab[top->op].handler)
+ (pfile, top[-1].value, top->value, top->op);
top--;
- unsigned1 = top->unsignedp, v1 = top->value;
+ }
+ /* Anything changing skip_eval has to be handled here. */
+ else switch (top--->op)
+ {
+ case CPP_OR_OR:
+ if (!num_zerop (top->value))
+ pfile->state.skip_eval--;
+ top->value.low = !num_zerop (top->value) || !num_zerop (top[1].value);
+ top->value.high = 0;
+ top->value.unsignedp = false;
+ top->value.overflow = false;
+ break;
+
+ case CPP_AND_AND:
+ if (num_zerop (top->value))
+ pfile->state.skip_eval--;
+ top->value.low = !num_zerop (top->value) && !num_zerop (top[1].value);
+ top->value.high = 0;
+ top->value.unsignedp = false;
+ top->value.overflow = false;
+ break;
+
+ case CPP_OPEN_PAREN:
+ if (op != CPP_CLOSE_PAREN)
+ {
+ cpp_error (pfile, DL_ERROR, "missing ')' in expression");
+ return 0;
+ }
+ top->value = top[1].value;
+ return top;
- /* Now set top->value = (top[1].op)(v1, v2); */
- switch (top[1].op)
+ case CPP_COLON:
+ top--;
+ if (!num_zerop (top->value))
{
- default:
- cpp_ice (pfile, "impossible operator '%s'",
- op_as_text (pfile, top[1].op));
- goto syntax_error;
-
- case CPP_NOT: UNARY(!); break;
- case CPP_COMPL: UNARY(~); break;
- case CPP_LESS: COMPARE(<); break;
- case CPP_GREATER: COMPARE(>); break;
- case CPP_LESS_EQ: COMPARE(<=); break;
- case CPP_GREATER_EQ: COMPARE(>=); break;
- case CPP_EQ_EQ: EQUALITY(==); break;
- case CPP_NOT_EQ: EQUALITY(!=); break;
- case CPP_AND: BITWISE(&); break;
- case CPP_XOR: BITWISE(^); break;
- case CPP_OR: BITWISE(|); break;
- case CPP_LSHIFT: SHIFT(left_shift, right_shift); break;
- case CPP_RSHIFT: SHIFT(right_shift, left_shift); break;
- case CPP_MIN: MINMAX(<); break;
- case CPP_MAX: MINMAX(>); break;
-
- case CPP_PLUS:
- if (!(top->flags & HAVE_VALUE))
- {
- /* Can't use UNARY(+) because K+R C did not have unary
- plus. Can't use UNARY() because some compilers object
- to the empty argument. */
- top->value = v2;
- top->unsignedp = unsigned2;
- top->flags |= HAVE_VALUE;
-
- if (CPP_WTRADITIONAL (pfile))
- cpp_warning (pfile,
- "traditional C rejects the unary plus operator");
- }
- else
- {
- top->value = v1 + v2;
- top->unsignedp = unsigned1 | unsigned2;
- if (! top->unsignedp && ! skip_evaluation
- && ! possible_sum_sign (v1, v2, top->value))
- integer_overflow (pfile);
- }
- break;
- case CPP_MINUS:
- if (!(top->flags & HAVE_VALUE))
- {
- UNARY(-);
- if (!skip_evaluation && (top->value & v2) < 0 && !unsigned2)
- integer_overflow (pfile);
- }
- else
- { /* Binary '-' */
- top->value = v1 - v2;
- top->unsignedp = unsigned1 | unsigned2;
- if (! top->unsignedp && ! skip_evaluation
- && ! possible_sum_sign (top->value, v2, v1))
- integer_overflow (pfile);
- }
- break;
- case CPP_MULT:
- top->unsignedp = unsigned1 | unsigned2;
- if (top->unsignedp)
- top->value = (unsigned HOST_WIDEST_INT) v1 * v2;
- else if (!skip_evaluation)
- {
- top->value = v1 * v2;
- if (v1 && (top->value / v1 != v2
- || (top->value & v1 & v2) < 0))
- integer_overflow (pfile);
- }
- break;
- case CPP_DIV:
- case CPP_MOD:
- if (skip_evaluation)
- break;
- if (v2 == 0)
- SYNTAX_ERROR ("division by zero in #if");
- top->unsignedp = unsigned1 | unsigned2;
- if (top[1].op == CPP_DIV)
- {
- if (top->unsignedp)
- top->value = (unsigned HOST_WIDEST_INT) v1 / v2;
- else
- {
- top->value = v1 / v2;
- if ((top->value & v1 & v2) < 0)
- integer_overflow (pfile);
- }
- }
- else
- {
- if (top->unsignedp)
- top->value = (unsigned HOST_WIDEST_INT) v1 % v2;
- else
- top->value = v1 % v2;
- }
- break;
-
- case CPP_OR_OR:
- top->value = v1 || v2;
- top->unsignedp = 0;
- if (v1) skip_evaluation--;
- break;
- case CPP_AND_AND:
- top->value = v1 && v2;
- top->unsignedp = 0;
- if (!v1) skip_evaluation--;
- break;
- case CPP_COMMA:
- if (CPP_PEDANTIC (pfile))
- cpp_pedwarn (pfile, "comma operator in operand of #if");
- top->value = v2;
- top->unsignedp = unsigned2;
- break;
- case CPP_QUERY:
- SYNTAX_ERROR ("syntax error '?' without following ':'");
- case CPP_COLON:
- if (top[0].op != CPP_QUERY)
- SYNTAX_ERROR ("syntax error ':' without preceding '?'");
- top--;
- if (top->value) skip_evaluation--;
- top->value = top->value ? v1 : v2;
- top->unsignedp = unsigned1 | unsigned2;
- break;
- case CPP_OPEN_PAREN:
- if (op.op != CPP_CLOSE_PAREN)
- SYNTAX_ERROR ("missing ')' in expression");
- op.value = v2;
- op.unsignedp = unsigned2;
- goto push_immediate;
- case CPP_EOF:
- /* Reducing this dummy operator indicates we've finished. */
- if (op.op == CPP_CLOSE_PAREN)
- SYNTAX_ERROR ("missing '(' in expression");
- goto done;
+ pfile->state.skip_eval--;
+ top->value = top[1].value;
}
+ else
+ top->value = top[2].value;
+ top->value.unsignedp = (top[1].value.unsignedp
+ || top[2].value.unsignedp);
+ break;
+
+ case CPP_QUERY:
+ cpp_error (pfile, DL_ERROR, "'?' without following ':'");
+ return 0;
+
+ default:
+ goto bad_op;
}
- /* Handle short-circuit evaluations. */
- if (flags & SHORT_CIRCUIT)
- switch (op.op)
- {
- case CPP_OR_OR: if (top->value) skip_evaluation++; break;
- case CPP_AND_AND:
- case CPP_QUERY: if (!top->value) skip_evaluation++; break;
- case CPP_COLON:
- if (top[-1].value) /* Was '?' condition true? */
- skip_evaluation++;
- else
- skip_evaluation--;
- default:
- break;
- }
+ if (top->value.overflow && !pfile->state.skip_eval)
+ cpp_error (pfile, DL_PEDWARN,
+ "integer overflow in preprocessor expression");
+ }
+
+ if (op == CPP_CLOSE_PAREN)
+ {
+ cpp_error (pfile, DL_ERROR, "missing '(' in expression");
+ return 0;
+ }
+
+ return top;
+}
+
+/* Returns the position of the old top of stack after expansion. */
+struct op *
+_cpp_expand_op_stack (pfile)
+ cpp_reader *pfile;
+{
+ size_t old_size = (size_t) (pfile->op_limit - pfile->op_stack);
+ size_t new_size = old_size * 2 + 20;
+
+ pfile->op_stack = (struct op *) xrealloc (pfile->op_stack,
+ new_size * sizeof (struct op));
+ pfile->op_limit = pfile->op_stack + new_size;
+
+ return pfile->op_stack + old_size;
+}
+
+/* Clears the unused high order bits of the number pointed to by PNUM. */
+static cpp_num
+num_trim (num, precision)
+ cpp_num num;
+ size_t precision;
+{
+ if (precision > PART_PRECISION)
+ {
+ precision -= PART_PRECISION;
+ if (precision < PART_PRECISION)
+ num.high &= (1UL << precision) - 1;
+ }
+ else
+ {
+ if (precision < PART_PRECISION)
+ num.low &= (1UL << precision) - 1;
+ num.high = 0;
+ }
+
+ return num;
+}
- skip_reduction:
- /* Check we have a left operand iff we need one. */
- if (flags & NO_L_OPERAND)
+/* True iff A (presumed signed) >= 0. */
+static bool
+num_positive (num, precision)
+ cpp_num num;
+ size_t precision;
+{
+ if (precision > PART_PRECISION)
+ {
+ precision -= PART_PRECISION;
+ return (num.high & (1UL << (precision - 1))) == 0;
+ }
+
+ return (num.low & (1UL << (precision - 1))) == 0;
+}
+
+/* Returns the negative of NUM. */
+static cpp_num
+num_negate (num, precision)
+ cpp_num num;
+ size_t precision;
+{
+ cpp_num copy;
+
+ copy = num;
+ num.high = ~num.high;
+ num.low = ~num.low;
+ if (++num.low == 0)
+ num.high++;
+ num = num_trim (num, precision);
+ num.overflow = (!num.unsignedp && num_eq (num, copy) && !num_zerop (num));
+
+ return num;
+}
+
+/* Returns true if A >= B. */
+static bool
+num_greater_eq (pa, pb, precision)
+ cpp_num pa, pb;
+ size_t precision;
+{
+ bool unsignedp;
+
+ unsignedp = pa.unsignedp || pb.unsignedp;
+
+ if (!unsignedp)
+ {
+ /* Both numbers have signed type. If they are of different
+ sign, the answer is the sign of A. */
+ unsignedp = num_positive (pa, precision);
+
+ if (unsignedp != num_positive (pb, precision))
+ return unsignedp;
+
+ /* Otherwise we can do an unsigned comparison. */
+ }
+
+ return (pa.high > pb.high) || (pa.high == pb.high && pa.low >= pb.low);
+}
+
+/* Returns LHS OP RHS, where OP is a bit-wise operation. */
+static cpp_num
+num_bitwise_op (pfile, lhs, rhs, op)
+ cpp_reader *pfile ATTRIBUTE_UNUSED;
+ cpp_num lhs, rhs;
+ enum cpp_ttype op;
+{
+ lhs.overflow = false;
+ lhs.unsignedp = lhs.unsignedp || rhs.unsignedp;
+
+ /* As excess precision is zeroed, there is no need to num_trim () as
+ these operations cannot introduce a set bit there. */
+ if (op == CPP_AND)
+ {
+ lhs.low &= rhs.low;
+ lhs.high &= rhs.high;
+ }
+ else if (op == CPP_OR)
+ {
+ lhs.low |= rhs.low;
+ lhs.high |= rhs.high;
+ }
+ else
+ {
+ lhs.low ^= rhs.low;
+ lhs.high ^= rhs.high;
+ }
+
+ return lhs;
+}
+
+/* Returns LHS OP RHS, where OP is an inequality. */
+static cpp_num
+num_inequality_op (pfile, lhs, rhs, op)
+ cpp_reader *pfile;
+ cpp_num lhs, rhs;
+ enum cpp_ttype op;
+{
+ bool gte = num_greater_eq (lhs, rhs, CPP_OPTION (pfile, precision));
+
+ if (op == CPP_GREATER_EQ)
+ lhs.low = gte;
+ else if (op == CPP_LESS)
+ lhs.low = !gte;
+ else if (op == CPP_GREATER)
+ lhs.low = gte && !num_eq (lhs, rhs);
+ else /* CPP_LESS_EQ. */
+ lhs.low = !gte || num_eq (lhs, rhs);
+
+ lhs.high = 0;
+ lhs.overflow = false;
+ lhs.unsignedp = false;
+ return lhs;
+}
+
+/* Returns LHS OP RHS, where OP is == or !=. */
+static cpp_num
+num_equality_op (pfile, lhs, rhs, op)
+ cpp_reader *pfile ATTRIBUTE_UNUSED;
+ cpp_num lhs, rhs;
+ enum cpp_ttype op;
+{
+ lhs.low = num_eq (lhs, rhs);
+ if (op == CPP_NOT_EQ)
+ lhs.low = !lhs.low;
+ lhs.high = 0;
+ lhs.overflow = false;
+ lhs.unsignedp = false;
+ return lhs;
+}
+
+/* Shift NUM, of width PRECISION, right by N bits. */
+static cpp_num
+num_rshift (num, precision, n)
+ cpp_num num;
+ size_t precision, n;
+{
+ cpp_num_part sign_mask;
+
+ if (num.unsignedp || num_positive (num, precision))
+ sign_mask = 0;
+ else
+ sign_mask = ~(cpp_num_part) 0;
+
+ if (n >= precision)
+ num.high = num.low = sign_mask;
+ else
+ {
+ /* Sign-extend. */
+ if (precision < PART_PRECISION)
+ num.high = sign_mask, num.low |= sign_mask << precision;
+ else if (precision < 2 * PART_PRECISION)
+ num.high |= sign_mask << (precision - PART_PRECISION);
+
+ if (n >= PART_PRECISION)
+ {
+ n -= PART_PRECISION;
+ num.low = num.high;
+ num.high = sign_mask;
+ }
+
+ if (n)
{
- if (top->flags & HAVE_VALUE)
- SYNTAX_ERROR2 ("missing binary operator before '%s'",
- op_as_text (pfile, op.op));
+ num.low = (num.low >> n) | (num.high << (PART_PRECISION - n));
+ num.high = (num.high >> n) | (sign_mask << (PART_PRECISION - n));
}
+ }
+
+ num = num_trim (num, precision);
+ num.overflow = false;
+ return num;
+}
+
+/* Shift NUM, of width PRECISION, left by N bits. */
+static cpp_num
+num_lshift (num, precision, n)
+ cpp_num num;
+ size_t precision, n;
+{
+ if (n >= precision)
+ {
+ num.overflow = !num.unsignedp && !num_zerop (num);
+ num.high = num.low = 0;
+ }
+ else
+ {
+ cpp_num orig, maybe_orig;
+ size_t m = n;
+
+ orig = num;
+ if (m >= PART_PRECISION)
+ {
+ m -= PART_PRECISION;
+ num.high = num.low;
+ num.low = 0;
+ }
+ if (m)
+ {
+ num.high = (num.high << m) | (num.low >> (PART_PRECISION - m));
+ num.low <<= m;
+ }
+ num = num_trim (num, precision);
+
+ if (num.unsignedp)
+ num.overflow = false;
else
{
- if (!(top->flags & HAVE_VALUE))
- SYNTAX_ERROR2 ("operator '%s' has no left operand",
- op_as_text (pfile, op.op));
+ maybe_orig = num_rshift (num, precision, n);
+ num.overflow = !num_eq (orig, maybe_orig);
}
+ }
- /* Check for and handle stack overflow. */
- top++;
- if (top == limit)
+ return num;
+}
+
+/* The four unary operators: +, -, ! and ~. */
+static cpp_num
+num_unary_op (pfile, num, op)
+ cpp_reader *pfile;
+ cpp_num num;
+ enum cpp_ttype op;
+{
+ switch (op)
+ {
+ case CPP_UPLUS:
+ if (CPP_WTRADITIONAL (pfile))
+ cpp_error (pfile, DL_WARNING,
+ "traditional C rejects the unary plus operator");
+ num.overflow = false;
+ break;
+
+ case CPP_UMINUS:
+ num = num_negate (num, CPP_OPTION (pfile, precision));
+ break;
+
+ case CPP_COMPL:
+ num.high = ~num.high;
+ num.low = ~num.low;
+ num = num_trim (num, CPP_OPTION (pfile, precision));
+ num.overflow = false;
+ break;
+
+ default: /* case CPP_NOT: */
+ num.low = num_zerop (num);
+ num.high = 0;
+ num.overflow = false;
+ num.unsignedp = false;
+ break;
+ }
+
+ return num;
+}
+
+/* The various binary operators. */
+static cpp_num
+num_binary_op (pfile, lhs, rhs, op)
+ cpp_reader *pfile;
+ cpp_num lhs, rhs;
+ enum cpp_ttype op;
+{
+ cpp_num result;
+ size_t precision = CPP_OPTION (pfile, precision);
+ bool gte;
+ size_t n;
+
+ switch (op)
+ {
+ /* Shifts. */
+ case CPP_LSHIFT:
+ case CPP_RSHIFT:
+ if (!rhs.unsignedp && !num_positive (rhs, precision))
{
- struct op *new_stack;
- int old_size = (char *) limit - (char *) stack;
- int new_size = 2 * old_size;
- if (stack != init_stack)
- new_stack = (struct op *) xrealloc (stack, new_size);
+ /* A negative shift is a positive shift the other way. */
+ if (op == CPP_LSHIFT)
+ op = CPP_RSHIFT;
else
- {
- new_stack = (struct op *) xmalloc (new_size);
- memcpy (new_stack, stack, old_size);
- }
- stack = new_stack;
- top = (struct op *) ((char *) new_stack + old_size);
- limit = (struct op *) ((char *) new_stack + new_size);
+ op = CPP_LSHIFT;
+ rhs = num_negate (rhs, precision);
}
-
- top->flags = flags;
- top->prio = prio & ~EXTRACT_PRIO(RIGHT_ASSOC);
- top->op = op.op;
+ if (rhs.high)
+ n = ~0; /* Maximal. */
+ else
+ n = rhs.low;
+ if (op == CPP_LSHIFT)
+ lhs = num_lshift (lhs, precision, n);
+ else
+ lhs = num_rshift (lhs, precision, n);
+ break;
+
+ /* Min / Max. */
+ case CPP_MIN:
+ case CPP_MAX:
+ {
+ bool unsignedp = lhs.unsignedp || rhs.unsignedp;
+
+ gte = num_greater_eq (lhs, rhs, precision);
+ if (op == CPP_MIN)
+ gte = !gte;
+ if (!gte)
+ lhs = rhs;
+ lhs.unsignedp = unsignedp;
+ }
+ break;
+
+ /* Arithmetic. */
+ case CPP_MINUS:
+ rhs = num_negate (rhs, precision);
+ case CPP_PLUS:
+ result.low = lhs.low + rhs.low;
+ result.high = lhs.high + rhs.high;
+ if (result.low < lhs.low)
+ result.high++;
+
+ result = num_trim (result, precision);
+ result.unsignedp = lhs.unsignedp || rhs.unsignedp;
+ if (result.unsignedp)
+ result.overflow = false;
+ else
+ {
+ bool lhsp = num_positive (lhs, precision);
+ result.overflow = (lhsp == num_positive (rhs, precision)
+ && lhsp != num_positive (result, precision));
+ }
+ return result;
+
+ /* Comma. */
+ default: /* case CPP_COMMA: */
+ if (CPP_PEDANTIC (pfile))
+ cpp_error (pfile, DL_PEDWARN,
+ "comma operator in operand of #if");
+ lhs = rhs;
+ break;
}
- done:
- /* The controlling macro expression is only valid if we called lex 3
- times: <!> <defined expression> and <EOF>. push_conditional ()
- checks that we are at top-of-file. */
- if (pfile->mi_ind_cmacro && !(saw_leading_not && lex_count == 3))
- pfile->mi_ind_cmacro = 0;
+ return lhs;
+}
+
+/* Multiplies two unsigned cpp_num_parts to give a cpp_num. This
+ cannot overflow. */
+static cpp_num
+num_part_mul (lhs, rhs)
+ cpp_num_part lhs, rhs;
+{
+ cpp_num result;
+ cpp_num_part middle[2], temp;
+
+ result.low = LOW_PART (lhs) * LOW_PART (rhs);
+ result.high = HIGH_PART (lhs) * HIGH_PART (rhs);
+
+ middle[0] = LOW_PART (lhs) * HIGH_PART (rhs);
+ middle[1] = HIGH_PART (lhs) * LOW_PART (rhs);
- result = (top[1].value != 0);
+ temp = result.low;
+ result.low += LOW_PART (middle[0]) << (PART_PRECISION / 2);
+ if (result.low < temp)
+ result.high++;
- if (top != stack)
- CPP_ICE ("unbalanced stack in #if");
- else if (!(top[1].flags & HAVE_VALUE))
+ temp = result.low;
+ result.low += LOW_PART (middle[1]) << (PART_PRECISION / 2);
+ if (result.low < temp)
+ result.high++;
+
+ result.high += HIGH_PART (middle[0]);
+ result.high += HIGH_PART (middle[1]);
+
+ return result;
+}
+
+/* Multiply two preprocessing numbers. */
+static cpp_num
+num_mul (pfile, lhs, rhs, op)
+ cpp_reader *pfile;
+ cpp_num lhs, rhs;
+ enum cpp_ttype op ATTRIBUTE_UNUSED;
+{
+ cpp_num result, temp;
+ bool unsignedp = lhs.unsignedp || rhs.unsignedp;
+ bool overflow, negate = false;
+ size_t precision = CPP_OPTION (pfile, precision);
+
+ /* Prepare for unsigned multiplication. */
+ if (!unsignedp)
{
- SYNTAX_ERROR ("#if with no expression");
- syntax_error:
- result = 0; /* Return 0 on syntax error. */
+ if (!num_positive (lhs, precision))
+ negate = !negate, lhs = num_negate (lhs, precision);
+ if (!num_positive (rhs, precision))
+ negate = !negate, rhs = num_negate (rhs, precision);
}
- /* Free dynamic stack if we allocated one. */
- if (stack != init_stack)
- free (stack);
+ overflow = lhs.high && rhs.high;
+ result = num_part_mul (lhs.low, rhs.low);
+
+ temp = num_part_mul (lhs.high, rhs.low);
+ result.high += temp.low;
+ if (temp.high)
+ overflow = true;
+
+ temp = num_part_mul (lhs.low, rhs.high);
+ result.high += temp.low;
+ if (temp.high)
+ overflow = true;
+
+ temp.low = result.low, temp.high = result.high;
+ result = num_trim (result, precision);
+ if (!num_eq (result, temp))
+ overflow = true;
+
+ if (negate)
+ result = num_negate (result, precision);
+
+ if (unsignedp)
+ result.overflow = false;
+ else
+ result.overflow = overflow || (num_positive (result, precision) ^ !negate
+ && !num_zerop (result));
+ result.unsignedp = unsignedp;
+
return result;
}
-static const unsigned char *
-op_as_text (pfile, op)
+/* Divide two preprocessing numbers, returning the answer or the
+ remainder depending upon OP. */
+static cpp_num
+num_div_op (pfile, lhs, rhs, op)
cpp_reader *pfile;
+ cpp_num lhs, rhs;
enum cpp_ttype op;
{
- cpp_token token;
+ cpp_num result, sub;
+ cpp_num_part mask;
+ bool unsignedp = lhs.unsignedp || rhs.unsignedp;
+ bool negate = false, lhs_neg = false;
+ size_t i, precision = CPP_OPTION (pfile, precision);
+
+ /* Prepare for unsigned division. */
+ if (!unsignedp)
+ {
+ if (!num_positive (lhs, precision))
+ negate = !negate, lhs_neg = true, lhs = num_negate (lhs, precision);
+ if (!num_positive (rhs, precision))
+ negate = !negate, rhs = num_negate (rhs, precision);
+ }
+
+ /* Find the high bit. */
+ if (rhs.high)
+ {
+ i = precision - 1;
+ mask = 1UL << (i - PART_PRECISION);
+ for (; ; i--, mask >>= 1)
+ if (rhs.high & mask)
+ break;
+ }
+ else if (rhs.low)
+ {
+ if (precision > PART_PRECISION)
+ i = precision - PART_PRECISION - 1;
+ else
+ i = precision - 1;
+ mask = 1UL << i;
+ for (; ; i--, mask >>= 1)
+ if (rhs.low & mask)
+ break;
+ }
+ else
+ {
+ cpp_error (pfile, DL_ERROR, "division by zero in #if");
+ return lhs;
+ }
+
+ /* First non-zero bit of RHS is bit I. Do naive division by
+ shifting the RHS fully left, and subtracting from LHS if LHS is
+ at least as big, and then repeating but with one less shift.
+ This is not very efficient, but is easy to understand. */
+
+ rhs.unsignedp = true;
+ lhs.unsignedp = true;
+ i = precision - i - 1;
+ sub = num_lshift (rhs, precision, i);
+
+ result.high = result.low = 0;
+ for (;;)
+ {
+ if (num_greater_eq (lhs, sub, precision))
+ {
+ lhs = num_binary_op (pfile, lhs, sub, CPP_MINUS);
+ if (i >= PART_PRECISION)
+ result.high |= 1UL << (i - PART_PRECISION);
+ else
+ result.low |= 1UL << i;
+ }
+ if (i-- == 0)
+ break;
+ sub.low = (sub.low >> 1) | (sub.high << (PART_PRECISION - 1));
+ sub.high >>= 1;
+ }
+
+ /* We divide so that the remainder has the sign of the LHS. */
+ if (op == CPP_DIV)
+ {
+ result.unsignedp = unsignedp;
+ if (unsignedp)
+ result.overflow = false;
+ else
+ {
+ if (negate)
+ result = num_negate (result, precision);
+ result.overflow = num_positive (result, precision) ^ !negate;
+ }
+
+ return result;
+ }
+
+ /* CPP_MOD. */
+ lhs.unsignedp = unsignedp;
+ lhs.overflow = false;
+ if (lhs_neg)
+ lhs = num_negate (lhs, precision);
- token.type = op;
- token.flags = 0;
- return cpp_token_as_text (pfile, &token);
+ return lhs;
}
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