| /* expr.c -operands, expressions- |
| Copyright (C) 1987, 90, 91, 92, 93, 94, 95, 96, 97, 1998 |
| Free Software Foundation, Inc. |
| |
| This file is part of GAS, the GNU Assembler. |
| |
| GAS is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GAS is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GAS; see the file COPYING. If not, write to the Free |
| Software Foundation, 59 Temple Place - Suite 330, Boston, MA |
| 02111-1307, USA. */ |
| |
| /* |
| * This is really a branch office of as-read.c. I split it out to clearly |
| * distinguish the world of expressions from the world of statements. |
| * (It also gives smaller files to re-compile.) |
| * Here, "operand"s are of expressions, not instructions. |
| */ |
| |
| #include <ctype.h> |
| #include <string.h> |
| #define min(a, b) ((a) < (b) ? (a) : (b)) |
| |
| #include "as.h" |
| #include "obstack.h" |
| |
| static void floating_constant PARAMS ((expressionS * expressionP)); |
| static void integer_constant PARAMS ((int radix, expressionS * expressionP)); |
| static void mri_char_constant PARAMS ((expressionS *)); |
| static void current_location PARAMS ((expressionS *)); |
| static void clean_up_expression PARAMS ((expressionS * expressionP)); |
| static segT operand PARAMS ((expressionS *)); |
| static operatorT operator PARAMS ((void)); |
| |
| extern const char EXP_CHARS[], FLT_CHARS[]; |
| |
| /* We keep a mapping of expression symbols to file positions, so that |
| we can provide better error messages. */ |
| |
| struct expr_symbol_line |
| { |
| struct expr_symbol_line *next; |
| symbolS *sym; |
| char *file; |
| unsigned int line; |
| }; |
| |
| static struct expr_symbol_line *expr_symbol_lines; |
| |
| /* Build a dummy symbol to hold a complex expression. This is how we |
| build expressions up out of other expressions. The symbol is put |
| into the fake section expr_section. */ |
| |
| symbolS * |
| make_expr_symbol (expressionP) |
| expressionS *expressionP; |
| { |
| expressionS zero; |
| const char *fake; |
| symbolS *symbolP; |
| struct expr_symbol_line *n; |
| |
| if (expressionP->X_op == O_symbol |
| && expressionP->X_add_number == 0) |
| return expressionP->X_add_symbol; |
| |
| if (expressionP->X_op == O_big) |
| { |
| /* This won't work, because the actual value is stored in |
| generic_floating_point_number or generic_bignum, and we are |
| going to lose it if we haven't already. */ |
| if (expressionP->X_add_number > 0) |
| as_bad (_("bignum invalid; zero assumed")); |
| else |
| as_bad (_("floating point number invalid; zero assumed")); |
| zero.X_op = O_constant; |
| zero.X_add_number = 0; |
| zero.X_unsigned = 0; |
| clean_up_expression (&zero); |
| expressionP = &zero; |
| } |
| |
| fake = FAKE_LABEL_NAME; |
| |
| /* Putting constant symbols in absolute_section rather than |
| expr_section is convenient for the old a.out code, for which |
| S_GET_SEGMENT does not always retrieve the value put in by |
| S_SET_SEGMENT. */ |
| symbolP = symbol_create (fake, |
| (expressionP->X_op == O_constant |
| ? absolute_section |
| : expr_section), |
| 0, &zero_address_frag); |
| symbolP->sy_value = *expressionP; |
| |
| if (expressionP->X_op == O_constant) |
| resolve_symbol_value (symbolP, 1); |
| |
| n = (struct expr_symbol_line *) xmalloc (sizeof *n); |
| n->sym = symbolP; |
| as_where (&n->file, &n->line); |
| n->next = expr_symbol_lines; |
| expr_symbol_lines = n; |
| |
| return symbolP; |
| } |
| |
| /* Return the file and line number for an expr symbol. Return |
| non-zero if something was found, 0 if no information is known for |
| the symbol. */ |
| |
| int |
| expr_symbol_where (sym, pfile, pline) |
| symbolS *sym; |
| char **pfile; |
| unsigned int *pline; |
| { |
| register struct expr_symbol_line *l; |
| |
| for (l = expr_symbol_lines; l != NULL; l = l->next) |
| { |
| if (l->sym == sym) |
| { |
| *pfile = l->file; |
| *pline = l->line; |
| return 1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* Utilities for building expressions. |
| Since complex expressions are recorded as symbols for use in other |
| expressions these return a symbolS * and not an expressionS *. |
| These explicitly do not take an "add_number" argument. */ |
| /* ??? For completeness' sake one might want expr_build_symbol. |
| It would just return its argument. */ |
| |
| /* Build an expression for an unsigned constant. |
| The corresponding one for signed constants is missing because |
| there's currently no need for it. One could add an unsigned_p flag |
| but that seems more clumsy. */ |
| |
| symbolS * |
| expr_build_uconstant (value) |
| offsetT value; |
| { |
| expressionS e; |
| |
| e.X_op = O_constant; |
| e.X_add_number = value; |
| e.X_unsigned = 1; |
| return make_expr_symbol (&e); |
| } |
| |
| /* Build an expression for OP s1. */ |
| |
| symbolS * |
| expr_build_unary (op, s1) |
| operatorT op; |
| symbolS *s1; |
| { |
| expressionS e; |
| |
| e.X_op = op; |
| e.X_add_symbol = s1; |
| e.X_add_number = 0; |
| return make_expr_symbol (&e); |
| } |
| |
| /* Build an expression for s1 OP s2. */ |
| |
| symbolS * |
| expr_build_binary (op, s1, s2) |
| operatorT op; |
| symbolS *s1; |
| symbolS *s2; |
| { |
| expressionS e; |
| |
| e.X_op = op; |
| e.X_add_symbol = s1; |
| e.X_op_symbol = s2; |
| e.X_add_number = 0; |
| return make_expr_symbol (&e); |
| } |
| |
| /* Build an expression for the current location ('.'). */ |
| |
| symbolS * |
| expr_build_dot () |
| { |
| expressionS e; |
| |
| current_location (&e); |
| return make_expr_symbol (&e); |
| } |
| |
| /* |
| * Build any floating-point literal here. |
| * Also build any bignum literal here. |
| */ |
| |
| /* Seems atof_machine can backscan through generic_bignum and hit whatever |
| happens to be loaded before it in memory. And its way too complicated |
| for me to fix right. Thus a hack. JF: Just make generic_bignum bigger, |
| and never write into the early words, thus they'll always be zero. |
| I hate Dean's floating-point code. Bleh. */ |
| LITTLENUM_TYPE generic_bignum[SIZE_OF_LARGE_NUMBER + 6]; |
| FLONUM_TYPE generic_floating_point_number = |
| { |
| &generic_bignum[6], /* low (JF: Was 0) */ |
| &generic_bignum[SIZE_OF_LARGE_NUMBER + 6 - 1], /* high JF: (added +6) */ |
| 0, /* leader */ |
| 0, /* exponent */ |
| 0 /* sign */ |
| }; |
| /* If nonzero, we've been asked to assemble nan, +inf or -inf */ |
| int generic_floating_point_magic; |
| |
| static void |
| floating_constant (expressionP) |
| expressionS *expressionP; |
| { |
| /* input_line_pointer->*/ |
| /* floating-point constant. */ |
| int error_code; |
| |
| error_code = atof_generic (&input_line_pointer, ".", EXP_CHARS, |
| &generic_floating_point_number); |
| |
| if (error_code) |
| { |
| if (error_code == ERROR_EXPONENT_OVERFLOW) |
| { |
| as_bad (_("bad floating-point constant: exponent overflow, probably assembling junk")); |
| } |
| else |
| { |
| as_bad (_("bad floating-point constant: unknown error code=%d."), error_code); |
| } |
| } |
| expressionP->X_op = O_big; |
| /* input_line_pointer->just after constant, */ |
| /* which may point to whitespace. */ |
| expressionP->X_add_number = -1; |
| } |
| |
| static valueT |
| generic_bignum_to_int32 () |
| { |
| valueT number = |
| ((generic_bignum[1] & LITTLENUM_MASK) << LITTLENUM_NUMBER_OF_BITS) |
| | (generic_bignum[0] & LITTLENUM_MASK); |
| number &= 0xffffffff; |
| return number; |
| } |
| |
| #ifdef BFD64 |
| static valueT |
| generic_bignum_to_int64 () |
| { |
| valueT number = |
| ((((((((valueT) generic_bignum[3] & LITTLENUM_MASK) |
| << LITTLENUM_NUMBER_OF_BITS) |
| | ((valueT) generic_bignum[2] & LITTLENUM_MASK)) |
| << LITTLENUM_NUMBER_OF_BITS) |
| | ((valueT) generic_bignum[1] & LITTLENUM_MASK)) |
| << LITTLENUM_NUMBER_OF_BITS) |
| | ((valueT) generic_bignum[0] & LITTLENUM_MASK)); |
| return number; |
| } |
| #endif |
| |
| static void |
| integer_constant (radix, expressionP) |
| int radix; |
| expressionS *expressionP; |
| { |
| char *start; /* start of number. */ |
| char *suffix = NULL; |
| char c; |
| valueT number; /* offset or (absolute) value */ |
| short int digit; /* value of next digit in current radix */ |
| short int maxdig = 0;/* highest permitted digit value. */ |
| int too_many_digits = 0; /* if we see >= this number of */ |
| char *name; /* points to name of symbol */ |
| symbolS *symbolP; /* points to symbol */ |
| |
| int small; /* true if fits in 32 bits. */ |
| |
| /* May be bignum, or may fit in 32 bits. */ |
| /* Most numbers fit into 32 bits, and we want this case to be fast. |
| so we pretend it will fit into 32 bits. If, after making up a 32 |
| bit number, we realise that we have scanned more digits than |
| comfortably fit into 32 bits, we re-scan the digits coding them |
| into a bignum. For decimal and octal numbers we are |
| conservative: Some numbers may be assumed bignums when in fact |
| they do fit into 32 bits. Numbers of any radix can have excess |
| leading zeros: We strive to recognise this and cast them back |
| into 32 bits. We must check that the bignum really is more than |
| 32 bits, and change it back to a 32-bit number if it fits. The |
| number we are looking for is expected to be positive, but if it |
| fits into 32 bits as an unsigned number, we let it be a 32-bit |
| number. The cavalier approach is for speed in ordinary cases. */ |
| /* This has been extended for 64 bits. We blindly assume that if |
| you're compiling in 64-bit mode, the target is a 64-bit machine. |
| This should be cleaned up. */ |
| |
| #ifdef BFD64 |
| #define valuesize 64 |
| #else /* includes non-bfd case, mostly */ |
| #define valuesize 32 |
| #endif |
| |
| if (flag_m68k_mri && radix == 0) |
| { |
| int flt = 0; |
| |
| /* In MRI mode, the number may have a suffix indicating the |
| radix. For that matter, it might actually be a floating |
| point constant. */ |
| for (suffix = input_line_pointer; |
| isalnum ((unsigned char) *suffix); |
| suffix++) |
| { |
| if (*suffix == 'e' || *suffix == 'E') |
| flt = 1; |
| } |
| |
| if (suffix == input_line_pointer) |
| { |
| radix = 10; |
| suffix = NULL; |
| } |
| else |
| { |
| c = *--suffix; |
| if (islower ((unsigned char) c)) |
| c = toupper (c); |
| if (c == 'B') |
| radix = 2; |
| else if (c == 'D') |
| radix = 10; |
| else if (c == 'O' || c == 'Q') |
| radix = 8; |
| else if (c == 'H') |
| radix = 16; |
| else if (suffix[1] == '.' || c == 'E' || flt) |
| { |
| floating_constant (expressionP); |
| return; |
| } |
| else |
| { |
| radix = 10; |
| suffix = NULL; |
| } |
| } |
| } |
| |
| switch (radix) |
| { |
| case 2: |
| maxdig = 2; |
| too_many_digits = valuesize + 1; |
| break; |
| case 8: |
| maxdig = radix = 8; |
| too_many_digits = (valuesize + 2) / 3 + 1; |
| break; |
| case 16: |
| maxdig = radix = 16; |
| too_many_digits = (valuesize + 3) / 4 + 1; |
| break; |
| case 10: |
| maxdig = radix = 10; |
| too_many_digits = (valuesize + 12) / 4; /* very rough */ |
| } |
| #undef valuesize |
| start = input_line_pointer; |
| c = *input_line_pointer++; |
| for (number = 0; |
| (digit = hex_value (c)) < maxdig; |
| c = *input_line_pointer++) |
| { |
| number = number * radix + digit; |
| } |
| /* c contains character after number. */ |
| /* input_line_pointer->char after c. */ |
| small = (input_line_pointer - start - 1) < too_many_digits; |
| |
| if (radix == 16 && c == '_') |
| { |
| /* This is literal of the form 0x333_0_12345678_1. |
| This example is equivalent to 0x00000333000000001234567800000001. */ |
| |
| int num_little_digits = 0; |
| int i; |
| input_line_pointer = start; /*->1st digit. */ |
| |
| know (LITTLENUM_NUMBER_OF_BITS == 16); |
| |
| for (c = '_'; c == '_'; num_little_digits+=2) |
| { |
| |
| /* Convert one 64-bit word. */ |
| int ndigit = 0; |
| number = 0; |
| for (c = *input_line_pointer++; |
| (digit = hex_value (c)) < maxdig; |
| c = *(input_line_pointer++)) |
| { |
| number = number * radix + digit; |
| ndigit++; |
| } |
| |
| /* Check for 8 digit per word max. */ |
| if (ndigit > 8) |
| as_bad (_("A bignum with underscores may not have more than 8 hex digits in any word.")); |
| |
| /* Add this chunk to the bignum. Shift things down 2 little digits.*/ |
| know (LITTLENUM_NUMBER_OF_BITS == 16); |
| for (i = min (num_little_digits + 1, SIZE_OF_LARGE_NUMBER - 1); i >= 2; i--) |
| generic_bignum[i] = generic_bignum[i-2]; |
| |
| /* Add the new digits as the least significant new ones. */ |
| generic_bignum[0] = number & 0xffffffff; |
| generic_bignum[1] = number >> 16; |
| } |
| |
| /* Again, c is char after number, input_line_pointer->after c. */ |
| |
| if (num_little_digits > SIZE_OF_LARGE_NUMBER - 1) |
| num_little_digits = SIZE_OF_LARGE_NUMBER - 1; |
| |
| assert (num_little_digits >= 4); |
| |
| if (num_little_digits != 8) |
| as_bad (_("A bignum with underscores must have exactly 4 words.")); |
| |
| /* We might have some leading zeros. These can be trimmed to give |
| * us a change to fit this constant into a small number. |
| */ |
| while (generic_bignum[num_little_digits-1] == 0 && num_little_digits > 1) |
| num_little_digits--; |
| |
| if (num_little_digits <= 2) |
| { |
| /* will fit into 32 bits. */ |
| number = generic_bignum_to_int32 (); |
| small = 1; |
| } |
| #ifdef BFD64 |
| else if (num_little_digits <= 4) |
| { |
| /* Will fit into 64 bits. */ |
| number = generic_bignum_to_int64 (); |
| small = 1; |
| } |
| #endif |
| else |
| { |
| small = 0; |
| number = num_little_digits; /* number of littlenums in the bignum. */ |
| } |
| } |
| else if (!small) |
| { |
| /* |
| * we saw a lot of digits. manufacture a bignum the hard way. |
| */ |
| LITTLENUM_TYPE *leader; /*->high order littlenum of the bignum. */ |
| LITTLENUM_TYPE *pointer; /*->littlenum we are frobbing now. */ |
| long carry; |
| |
| leader = generic_bignum; |
| generic_bignum[0] = 0; |
| generic_bignum[1] = 0; |
| generic_bignum[2] = 0; |
| generic_bignum[3] = 0; |
| input_line_pointer = start; /*->1st digit. */ |
| c = *input_line_pointer++; |
| for (; |
| (carry = hex_value (c)) < maxdig; |
| c = *input_line_pointer++) |
| { |
| for (pointer = generic_bignum; |
| pointer <= leader; |
| pointer++) |
| { |
| long work; |
| |
| work = carry + radix * *pointer; |
| *pointer = work & LITTLENUM_MASK; |
| carry = work >> LITTLENUM_NUMBER_OF_BITS; |
| } |
| if (carry) |
| { |
| if (leader < generic_bignum + SIZE_OF_LARGE_NUMBER - 1) |
| { |
| /* room to grow a longer bignum. */ |
| *++leader = carry; |
| } |
| } |
| } |
| /* again, c is char after number, */ |
| /* input_line_pointer->after c. */ |
| know (LITTLENUM_NUMBER_OF_BITS == 16); |
| if (leader < generic_bignum + 2) |
| { |
| /* will fit into 32 bits. */ |
| number = generic_bignum_to_int32 (); |
| small = 1; |
| } |
| #ifdef BFD64 |
| else if (leader < generic_bignum + 4) |
| { |
| /* Will fit into 64 bits. */ |
| number = generic_bignum_to_int64 (); |
| small = 1; |
| } |
| #endif |
| else |
| { |
| number = leader - generic_bignum + 1; /* number of littlenums in the bignum. */ |
| } |
| } |
| |
| if (flag_m68k_mri && suffix != NULL && input_line_pointer - 1 == suffix) |
| c = *input_line_pointer++; |
| |
| if (small) |
| { |
| /* |
| * here with number, in correct radix. c is the next char. |
| * note that unlike un*x, we allow "011f" "0x9f" to |
| * both mean the same as the (conventional) "9f". this is simply easier |
| * than checking for strict canonical form. syntax sux! |
| */ |
| |
| if (LOCAL_LABELS_FB && c == 'b') |
| { |
| /* |
| * backward ref to local label. |
| * because it is backward, expect it to be defined. |
| */ |
| /* Construct a local label. */ |
| name = fb_label_name ((int) number, 0); |
| |
| /* seen before, or symbol is defined: ok */ |
| symbolP = symbol_find (name); |
| if ((symbolP != NULL) && (S_IS_DEFINED (symbolP))) |
| { |
| /* local labels are never absolute. don't waste time |
| checking absoluteness. */ |
| know (SEG_NORMAL (S_GET_SEGMENT (symbolP))); |
| |
| expressionP->X_op = O_symbol; |
| expressionP->X_add_symbol = symbolP; |
| } |
| else |
| { |
| /* either not seen or not defined. */ |
| /* @@ Should print out the original string instead of |
| the parsed number. */ |
| as_bad (_("backw. ref to unknown label \"%d:\", 0 assumed."), |
| (int) number); |
| expressionP->X_op = O_constant; |
| } |
| |
| expressionP->X_add_number = 0; |
| } /* case 'b' */ |
| else if (LOCAL_LABELS_FB && c == 'f') |
| { |
| /* |
| * forward reference. expect symbol to be undefined or |
| * unknown. undefined: seen it before. unknown: never seen |
| * it before. |
| * construct a local label name, then an undefined symbol. |
| * don't create a xseg frag for it: caller may do that. |
| * just return it as never seen before. |
| */ |
| name = fb_label_name ((int) number, 1); |
| symbolP = symbol_find_or_make (name); |
| /* we have no need to check symbol properties. */ |
| #ifndef many_segments |
| /* since "know" puts its arg into a "string", we |
| can't have newlines in the argument. */ |
| know (S_GET_SEGMENT (symbolP) == undefined_section || S_GET_SEGMENT (symbolP) == text_section || S_GET_SEGMENT (symbolP) == data_section); |
| #endif |
| expressionP->X_op = O_symbol; |
| expressionP->X_add_symbol = symbolP; |
| expressionP->X_add_number = 0; |
| } /* case 'f' */ |
| else if (LOCAL_LABELS_DOLLAR && c == '$') |
| { |
| /* If the dollar label is *currently* defined, then this is just |
| another reference to it. If it is not *currently* defined, |
| then this is a fresh instantiation of that number, so create |
| it. */ |
| |
| if (dollar_label_defined ((long) number)) |
| { |
| name = dollar_label_name ((long) number, 0); |
| symbolP = symbol_find (name); |
| know (symbolP != NULL); |
| } |
| else |
| { |
| name = dollar_label_name ((long) number, 1); |
| symbolP = symbol_find_or_make (name); |
| } |
| |
| expressionP->X_op = O_symbol; |
| expressionP->X_add_symbol = symbolP; |
| expressionP->X_add_number = 0; |
| } /* case '$' */ |
| else |
| { |
| expressionP->X_op = O_constant; |
| #ifdef TARGET_WORD_SIZE |
| /* Sign extend NUMBER. */ |
| number |= (-(number >> (TARGET_WORD_SIZE - 1))) << (TARGET_WORD_SIZE - 1); |
| #endif |
| expressionP->X_add_number = number; |
| input_line_pointer--; /* restore following character. */ |
| } /* really just a number */ |
| } |
| else |
| { |
| /* not a small number */ |
| expressionP->X_op = O_big; |
| expressionP->X_add_number = number; /* number of littlenums */ |
| input_line_pointer--; /*->char following number. */ |
| } |
| } |
| |
| /* Parse an MRI multi character constant. */ |
| |
| static void |
| mri_char_constant (expressionP) |
| expressionS *expressionP; |
| { |
| int i; |
| |
| if (*input_line_pointer == '\'' |
| && input_line_pointer[1] != '\'') |
| { |
| expressionP->X_op = O_constant; |
| expressionP->X_add_number = 0; |
| return; |
| } |
| |
| /* In order to get the correct byte ordering, we must build the |
| number in reverse. */ |
| for (i = SIZE_OF_LARGE_NUMBER - 1; i >= 0; i--) |
| { |
| int j; |
| |
| generic_bignum[i] = 0; |
| for (j = 0; j < CHARS_PER_LITTLENUM; j++) |
| { |
| if (*input_line_pointer == '\'') |
| { |
| if (input_line_pointer[1] != '\'') |
| break; |
| ++input_line_pointer; |
| } |
| generic_bignum[i] <<= 8; |
| generic_bignum[i] += *input_line_pointer; |
| ++input_line_pointer; |
| } |
| |
| if (i < SIZE_OF_LARGE_NUMBER - 1) |
| { |
| /* If there is more than one littlenum, left justify the |
| last one to make it match the earlier ones. If there is |
| only one, we can just use the value directly. */ |
| for (; j < CHARS_PER_LITTLENUM; j++) |
| generic_bignum[i] <<= 8; |
| } |
| |
| if (*input_line_pointer == '\'' |
| && input_line_pointer[1] != '\'') |
| break; |
| } |
| |
| if (i < 0) |
| { |
| as_bad (_("Character constant too large")); |
| i = 0; |
| } |
| |
| if (i > 0) |
| { |
| int c; |
| int j; |
| |
| c = SIZE_OF_LARGE_NUMBER - i; |
| for (j = 0; j < c; j++) |
| generic_bignum[j] = generic_bignum[i + j]; |
| i = c; |
| } |
| |
| know (LITTLENUM_NUMBER_OF_BITS == 16); |
| if (i > 2) |
| { |
| expressionP->X_op = O_big; |
| expressionP->X_add_number = i; |
| } |
| else |
| { |
| expressionP->X_op = O_constant; |
| if (i < 2) |
| expressionP->X_add_number = generic_bignum[0] & LITTLENUM_MASK; |
| else |
| expressionP->X_add_number = |
| (((generic_bignum[1] & LITTLENUM_MASK) |
| << LITTLENUM_NUMBER_OF_BITS) |
| | (generic_bignum[0] & LITTLENUM_MASK)); |
| } |
| |
| /* Skip the final closing quote. */ |
| ++input_line_pointer; |
| } |
| |
| /* Return an expression representing the current location. This |
| handles the magic symbol `.'. */ |
| |
| static void |
| current_location (expressionp) |
| expressionS *expressionp; |
| { |
| if (now_seg == absolute_section) |
| { |
| expressionp->X_op = O_constant; |
| expressionp->X_add_number = abs_section_offset; |
| } |
| else |
| { |
| symbolS *symbolp; |
| |
| symbolp = symbol_new (FAKE_LABEL_NAME, now_seg, |
| (valueT) frag_now_fix (), |
| frag_now); |
| expressionp->X_op = O_symbol; |
| expressionp->X_add_symbol = symbolp; |
| expressionp->X_add_number = 0; |
| } |
| } |
| |
| /* |
| * Summary of operand(). |
| * |
| * in: Input_line_pointer points to 1st char of operand, which may |
| * be a space. |
| * |
| * out: A expressionS. |
| * The operand may have been empty: in this case X_op == O_absent. |
| * Input_line_pointer->(next non-blank) char after operand. |
| */ |
| |
| static segT |
| operand (expressionP) |
| expressionS *expressionP; |
| { |
| char c; |
| symbolS *symbolP; /* points to symbol */ |
| char *name; /* points to name of symbol */ |
| segT segment; |
| |
| /* All integers are regarded as unsigned unless they are negated. |
| This is because the only thing which cares whether a number is |
| unsigned is the code in emit_expr which extends constants into |
| bignums. It should only sign extend negative numbers, so that |
| something like ``.quad 0x80000000'' is not sign extended even |
| though it appears negative if valueT is 32 bits. */ |
| expressionP->X_unsigned = 1; |
| |
| /* digits, assume it is a bignum. */ |
| |
| SKIP_WHITESPACE (); /* leading whitespace is part of operand. */ |
| c = *input_line_pointer++; /* input_line_pointer->past char in c. */ |
| |
| switch (c) |
| { |
| case '1': |
| case '2': |
| case '3': |
| case '4': |
| case '5': |
| case '6': |
| case '7': |
| case '8': |
| case '9': |
| input_line_pointer--; |
| |
| integer_constant (flag_m68k_mri ? 0 : 10, expressionP); |
| break; |
| |
| case '0': |
| /* non-decimal radix */ |
| |
| if (flag_m68k_mri) |
| { |
| char *s; |
| |
| /* Check for a hex constant. */ |
| for (s = input_line_pointer; hex_p (*s); s++) |
| ; |
| if (*s == 'h' || *s == 'H') |
| { |
| --input_line_pointer; |
| integer_constant (0, expressionP); |
| break; |
| } |
| } |
| |
| c = *input_line_pointer; |
| switch (c) |
| { |
| case 'o': |
| case 'O': |
| case 'q': |
| case 'Q': |
| case '8': |
| case '9': |
| if (flag_m68k_mri) |
| { |
| integer_constant (0, expressionP); |
| break; |
| } |
| /* Fall through. */ |
| default: |
| default_case: |
| if (c && strchr (FLT_CHARS, c)) |
| { |
| input_line_pointer++; |
| floating_constant (expressionP); |
| expressionP->X_add_number = |
| - (isupper ((unsigned char) c) ? tolower (c) : c); |
| } |
| else |
| { |
| /* The string was only zero */ |
| expressionP->X_op = O_constant; |
| expressionP->X_add_number = 0; |
| } |
| |
| break; |
| |
| case 'x': |
| case 'X': |
| if (flag_m68k_mri) |
| goto default_case; |
| input_line_pointer++; |
| integer_constant (16, expressionP); |
| break; |
| |
| case 'b': |
| if (LOCAL_LABELS_FB && ! flag_m68k_mri) |
| { |
| /* This code used to check for '+' and '-' here, and, in |
| some conditions, fall through to call |
| integer_constant. However, that didn't make sense, |
| as integer_constant only accepts digits. */ |
| /* Some of our code elsewhere does permit digits greater |
| than the expected base; for consistency, do the same |
| here. */ |
| if (input_line_pointer[1] < '0' |
| || input_line_pointer[1] > '9') |
| { |
| /* Parse this as a back reference to label 0. */ |
| input_line_pointer--; |
| integer_constant (10, expressionP); |
| break; |
| } |
| /* Otherwise, parse this as a binary number. */ |
| } |
| /* Fall through. */ |
| case 'B': |
| input_line_pointer++; |
| if (flag_m68k_mri) |
| goto default_case; |
| integer_constant (2, expressionP); |
| break; |
| |
| case '0': |
| case '1': |
| case '2': |
| case '3': |
| case '4': |
| case '5': |
| case '6': |
| case '7': |
| integer_constant (flag_m68k_mri ? 0 : 8, expressionP); |
| break; |
| |
| case 'f': |
| if (LOCAL_LABELS_FB) |
| { |
| /* If it says "0f" and it could possibly be a floating point |
| number, make it one. Otherwise, make it a local label, |
| and try to deal with parsing the rest later. */ |
| if (!input_line_pointer[1] |
| || (is_end_of_line[0xff & input_line_pointer[1]])) |
| goto is_0f_label; |
| { |
| char *cp = input_line_pointer + 1; |
| int r = atof_generic (&cp, ".", EXP_CHARS, |
| &generic_floating_point_number); |
| switch (r) |
| { |
| case 0: |
| case ERROR_EXPONENT_OVERFLOW: |
| if (*cp == 'f' || *cp == 'b') |
| /* looks like a difference expression */ |
| goto is_0f_label; |
| else if (cp == input_line_pointer + 1) |
| /* No characters has been accepted -- looks like |
| end of operand. */ |
| goto is_0f_label; |
| else |
| goto is_0f_float; |
| default: |
| as_fatal (_("expr.c(operand): bad atof_generic return val %d"), |
| r); |
| } |
| } |
| |
| /* Okay, now we've sorted it out. We resume at one of these |
| two labels, depending on what we've decided we're probably |
| looking at. */ |
| is_0f_label: |
| input_line_pointer--; |
| integer_constant (10, expressionP); |
| break; |
| |
| is_0f_float: |
| /* fall through */ |
| ; |
| } |
| |
| case 'd': |
| case 'D': |
| if (flag_m68k_mri) |
| { |
| integer_constant (0, expressionP); |
| break; |
| } |
| /* Fall through. */ |
| case 'F': |
| case 'r': |
| case 'e': |
| case 'E': |
| case 'g': |
| case 'G': |
| input_line_pointer++; |
| floating_constant (expressionP); |
| expressionP->X_add_number = |
| - (isupper ((unsigned char) c) ? tolower (c) : c); |
| break; |
| |
| case '$': |
| if (LOCAL_LABELS_DOLLAR) |
| { |
| integer_constant (10, expressionP); |
| break; |
| } |
| else |
| goto default_case; |
| } |
| |
| break; |
| |
| case '(': |
| case '[': |
| /* didn't begin with digit & not a name */ |
| segment = expression (expressionP); |
| /* Expression() will pass trailing whitespace */ |
| if ((c == '(' && *input_line_pointer++ != ')') |
| || (c == '[' && *input_line_pointer++ != ']')) |
| { |
| as_bad (_("Missing ')' assumed")); |
| input_line_pointer--; |
| } |
| SKIP_WHITESPACE (); |
| /* here with input_line_pointer->char after "(...)" */ |
| return segment; |
| |
| case 'E': |
| if (! flag_m68k_mri || *input_line_pointer != '\'') |
| goto de_fault; |
| as_bad (_("EBCDIC constants are not supported")); |
| /* Fall through. */ |
| case 'A': |
| if (! flag_m68k_mri || *input_line_pointer != '\'') |
| goto de_fault; |
| ++input_line_pointer; |
| /* Fall through. */ |
| case '\'': |
| if (! flag_m68k_mri) |
| { |
| /* Warning: to conform to other people's assemblers NO |
| ESCAPEMENT is permitted for a single quote. The next |
| character, parity errors and all, is taken as the value |
| of the operand. VERY KINKY. */ |
| expressionP->X_op = O_constant; |
| expressionP->X_add_number = *input_line_pointer++; |
| break; |
| } |
| |
| mri_char_constant (expressionP); |
| break; |
| |
| case '+': |
| (void) operand (expressionP); |
| break; |
| |
| case '"': |
| /* Double quote is the bitwise not operator in MRI mode. */ |
| if (! flag_m68k_mri) |
| goto de_fault; |
| /* Fall through. */ |
| case '~': |
| /* ~ is permitted to start a label on the Delta. */ |
| if (is_name_beginner (c)) |
| goto isname; |
| case '!': |
| case '-': |
| { |
| operand (expressionP); |
| if (expressionP->X_op == O_constant) |
| { |
| /* input_line_pointer -> char after operand */ |
| if (c == '-') |
| { |
| expressionP->X_add_number = - expressionP->X_add_number; |
| /* Notice: '-' may overflow: no warning is given. This is |
| compatible with other people's assemblers. Sigh. */ |
| expressionP->X_unsigned = 0; |
| } |
| else if (c == '~' || c == '"') |
| expressionP->X_add_number = ~ expressionP->X_add_number; |
| else |
| expressionP->X_add_number = ! expressionP->X_add_number; |
| } |
| else if (expressionP->X_op != O_illegal |
| && expressionP->X_op != O_absent) |
| { |
| expressionP->X_add_symbol = make_expr_symbol (expressionP); |
| if (c == '-') |
| expressionP->X_op = O_uminus; |
| else if (c == '~' || c == '"') |
| expressionP->X_op = O_bit_not; |
| else |
| expressionP->X_op = O_logical_not; |
| expressionP->X_add_number = 0; |
| } |
| else |
| as_warn (_("Unary operator %c ignored because bad operand follows"), |
| c); |
| } |
| break; |
| |
| case '$': |
| /* $ is the program counter when in MRI mode, or when DOLLAR_DOT |
| is defined. */ |
| #ifndef DOLLAR_DOT |
| if (! flag_m68k_mri) |
| goto de_fault; |
| #endif |
| if (flag_m68k_mri && hex_p (*input_line_pointer)) |
| { |
| /* In MRI mode, $ is also used as the prefix for a |
| hexadecimal constant. */ |
| integer_constant (16, expressionP); |
| break; |
| } |
| |
| if (is_part_of_name (*input_line_pointer)) |
| goto isname; |
| |
| current_location (expressionP); |
| break; |
| |
| case '.': |
| if (!is_part_of_name (*input_line_pointer)) |
| { |
| current_location (expressionP); |
| break; |
| } |
| else if ((strncasecmp (input_line_pointer, "startof.", 8) == 0 |
| && ! is_part_of_name (input_line_pointer[8])) |
| || (strncasecmp (input_line_pointer, "sizeof.", 7) == 0 |
| && ! is_part_of_name (input_line_pointer[7]))) |
| { |
| int start; |
| |
| start = (input_line_pointer[1] == 't' |
| || input_line_pointer[1] == 'T'); |
| input_line_pointer += start ? 8 : 7; |
| SKIP_WHITESPACE (); |
| if (*input_line_pointer != '(') |
| as_bad (_("syntax error in .startof. or .sizeof.")); |
| else |
| { |
| char *buf; |
| |
| ++input_line_pointer; |
| SKIP_WHITESPACE (); |
| name = input_line_pointer; |
| c = get_symbol_end (); |
| |
| buf = (char *) xmalloc (strlen (name) + 10); |
| if (start) |
| sprintf (buf, ".startof.%s", name); |
| else |
| sprintf (buf, ".sizeof.%s", name); |
| symbolP = symbol_make (buf); |
| free (buf); |
| |
| expressionP->X_op = O_symbol; |
| expressionP->X_add_symbol = symbolP; |
| expressionP->X_add_number = 0; |
| |
| *input_line_pointer = c; |
| SKIP_WHITESPACE (); |
| if (*input_line_pointer != ')') |
| as_bad (_("syntax error in .startof. or .sizeof.")); |
| else |
| ++input_line_pointer; |
| } |
| break; |
| } |
| else |
| { |
| goto isname; |
| } |
| case ',': |
| case '\n': |
| case '\0': |
| eol: |
| /* can't imagine any other kind of operand */ |
| expressionP->X_op = O_absent; |
| input_line_pointer--; |
| break; |
| |
| case '%': |
| if (! flag_m68k_mri) |
| goto de_fault; |
| integer_constant (2, expressionP); |
| break; |
| |
| case '@': |
| if (! flag_m68k_mri) |
| goto de_fault; |
| integer_constant (8, expressionP); |
| break; |
| |
| case ':': |
| if (! flag_m68k_mri) |
| goto de_fault; |
| |
| /* In MRI mode, this is a floating point constant represented |
| using hexadecimal digits. */ |
| |
| ++input_line_pointer; |
| integer_constant (16, expressionP); |
| break; |
| |
| case '*': |
| if (! flag_m68k_mri || is_part_of_name (*input_line_pointer)) |
| goto de_fault; |
| |
| current_location (expressionP); |
| break; |
| |
| default: |
| de_fault: |
| if (is_end_of_line[(unsigned char) c]) |
| goto eol; |
| if (is_name_beginner (c)) /* here if did not begin with a digit */ |
| { |
| /* |
| * Identifier begins here. |
| * This is kludged for speed, so code is repeated. |
| */ |
| isname: |
| name = --input_line_pointer; |
| c = get_symbol_end (); |
| |
| #ifdef md_parse_name |
| /* This is a hook for the backend to parse certain names |
| specially in certain contexts. If a name always has a |
| specific value, it can often be handled by simply |
| entering it in the symbol table. */ |
| if (md_parse_name (name, expressionP)) |
| { |
| *input_line_pointer = c; |
| break; |
| } |
| #endif |
| |
| #ifdef TC_I960 |
| /* The MRI i960 assembler permits |
| lda sizeof code,g13 |
| FIXME: This should use md_parse_name. */ |
| if (flag_mri |
| && (strcasecmp (name, "sizeof") == 0 |
| || strcasecmp (name, "startof") == 0)) |
| { |
| int start; |
| char *buf; |
| |
| start = (name[1] == 't' |
| || name[1] == 'T'); |
| |
| *input_line_pointer = c; |
| SKIP_WHITESPACE (); |
| |
| name = input_line_pointer; |
| c = get_symbol_end (); |
| |
| buf = (char *) xmalloc (strlen (name) + 10); |
| if (start) |
| sprintf (buf, ".startof.%s", name); |
| else |
| sprintf (buf, ".sizeof.%s", name); |
| symbolP = symbol_make (buf); |
| free (buf); |
| |
| expressionP->X_op = O_symbol; |
| expressionP->X_add_symbol = symbolP; |
| expressionP->X_add_number = 0; |
| |
| *input_line_pointer = c; |
| SKIP_WHITESPACE (); |
| |
| break; |
| } |
| #endif |
| |
| symbolP = symbol_find_or_make (name); |
| |
| /* If we have an absolute symbol or a reg, then we know its |
| value now. */ |
| segment = S_GET_SEGMENT (symbolP); |
| if (segment == absolute_section) |
| { |
| expressionP->X_op = O_constant; |
| expressionP->X_add_number = S_GET_VALUE (symbolP); |
| } |
| else if (segment == reg_section) |
| { |
| expressionP->X_op = O_register; |
| expressionP->X_add_number = S_GET_VALUE (symbolP); |
| } |
| else |
| { |
| expressionP->X_op = O_symbol; |
| expressionP->X_add_symbol = symbolP; |
| expressionP->X_add_number = 0; |
| } |
| *input_line_pointer = c; |
| } |
| else |
| { |
| /* Let the target try to parse it. Success is indicated by changing |
| the X_op field to something other than O_absent and pointing |
| input_line_pointer passed the expression. If it can't parse the |
| expression, X_op and input_line_pointer should be unchanged. */ |
| expressionP->X_op = O_absent; |
| --input_line_pointer; |
| md_operand (expressionP); |
| if (expressionP->X_op == O_absent) |
| { |
| ++input_line_pointer; |
| as_bad (_("Bad expression")); |
| expressionP->X_op = O_constant; |
| expressionP->X_add_number = 0; |
| } |
| } |
| break; |
| } |
| |
| /* |
| * It is more 'efficient' to clean up the expressionS when they are created. |
| * Doing it here saves lines of code. |
| */ |
| clean_up_expression (expressionP); |
| SKIP_WHITESPACE (); /*->1st char after operand. */ |
| know (*input_line_pointer != ' '); |
| |
| /* The PA port needs this information. */ |
| if (expressionP->X_add_symbol) |
| expressionP->X_add_symbol->sy_used = 1; |
| |
| switch (expressionP->X_op) |
| { |
| default: |
| return absolute_section; |
| case O_symbol: |
| return S_GET_SEGMENT (expressionP->X_add_symbol); |
| case O_register: |
| return reg_section; |
| } |
| } /* operand() */ |
| |
| /* Internal. Simplify a struct expression for use by expr() */ |
| |
| /* |
| * In: address of a expressionS. |
| * The X_op field of the expressionS may only take certain values. |
| * Elsewise we waste time special-case testing. Sigh. Ditto SEG_ABSENT. |
| * Out: expressionS may have been modified: |
| * 'foo-foo' symbol references cancelled to 0, |
| * which changes X_op from O_subtract to O_constant. |
| * Unused fields zeroed to help expr(). |
| */ |
| |
| static void |
| clean_up_expression (expressionP) |
| expressionS *expressionP; |
| { |
| switch (expressionP->X_op) |
| { |
| case O_illegal: |
| case O_absent: |
| expressionP->X_add_number = 0; |
| /* Fall through. */ |
| case O_big: |
| case O_constant: |
| case O_register: |
| expressionP->X_add_symbol = NULL; |
| /* Fall through. */ |
| case O_symbol: |
| case O_uminus: |
| case O_bit_not: |
| expressionP->X_op_symbol = NULL; |
| break; |
| case O_subtract: |
| if (expressionP->X_op_symbol == expressionP->X_add_symbol |
| || ((expressionP->X_op_symbol->sy_frag |
| == expressionP->X_add_symbol->sy_frag) |
| && SEG_NORMAL (S_GET_SEGMENT (expressionP->X_add_symbol)) |
| && (S_GET_VALUE (expressionP->X_op_symbol) |
| == S_GET_VALUE (expressionP->X_add_symbol)))) |
| { |
| addressT diff = (S_GET_VALUE (expressionP->X_add_symbol) |
| - S_GET_VALUE (expressionP->X_op_symbol)); |
| |
| expressionP->X_op = O_constant; |
| expressionP->X_add_symbol = NULL; |
| expressionP->X_op_symbol = NULL; |
| expressionP->X_add_number += diff; |
| } |
| break; |
| default: |
| break; |
| } |
| } |
| |
| /* Expression parser. */ |
| |
| /* |
| * We allow an empty expression, and just assume (absolute,0) silently. |
| * Unary operators and parenthetical expressions are treated as operands. |
| * As usual, Q==quantity==operand, O==operator, X==expression mnemonics. |
| * |
| * We used to do a aho/ullman shift-reduce parser, but the logic got so |
| * warped that I flushed it and wrote a recursive-descent parser instead. |
| * Now things are stable, would anybody like to write a fast parser? |
| * Most expressions are either register (which does not even reach here) |
| * or 1 symbol. Then "symbol+constant" and "symbol-symbol" are common. |
| * So I guess it doesn't really matter how inefficient more complex expressions |
| * are parsed. |
| * |
| * After expr(RANK,resultP) input_line_pointer->operator of rank <= RANK. |
| * Also, we have consumed any leading or trailing spaces (operand does that) |
| * and done all intervening operators. |
| * |
| * This returns the segment of the result, which will be |
| * absolute_section or the segment of a symbol. |
| */ |
| |
| #undef __ |
| #define __ O_illegal |
| |
| static const operatorT op_encoding[256] = |
| { /* maps ASCII->operators */ |
| |
| __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| |
| __, O_bit_or_not, __, __, __, O_modulus, O_bit_and, __, |
| __, __, O_multiply, O_add, __, O_subtract, __, O_divide, |
| __, __, __, __, __, __, __, __, |
| __, __, __, __, O_lt, __, O_gt, __, |
| __, __, __, __, __, __, __, __, |
| __, __, __, __, __, __, __, __, |
| __, __, __, __, __, __, __, __, |
| __, __, __, __, __, __, O_bit_exclusive_or, __, |
| __, __, __, __, __, __, __, __, |
| __, __, __, __, __, __, __, __, |
| __, __, __, __, __, __, __, __, |
| __, __, __, __, O_bit_inclusive_or, __, __, __, |
| |
| __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, |
| __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __ |
| }; |
| |
| |
| /* |
| * Rank Examples |
| * 0 operand, (expression) |
| * 1 || |
| * 2 && |
| * 3 = <> < <= >= > |
| * 4 + - |
| * 5 used for * / % in MRI mode |
| * 6 & ^ ! | |
| * 7 * / % << >> |
| * 8 unary - unary ~ |
| */ |
| static operator_rankT op_rank[] = |
| { |
| 0, /* O_illegal */ |
| 0, /* O_absent */ |
| 0, /* O_constant */ |
| 0, /* O_symbol */ |
| 0, /* O_symbol_rva */ |
| 0, /* O_register */ |
| 0, /* O_bit */ |
| 8, /* O_uminus */ |
| 8, /* O_bit_not */ |
| 8, /* O_logical_not */ |
| 7, /* O_multiply */ |
| 7, /* O_divide */ |
| 7, /* O_modulus */ |
| 7, /* O_left_shift */ |
| 7, /* O_right_shift */ |
| 6, /* O_bit_inclusive_or */ |
| 6, /* O_bit_or_not */ |
| 6, /* O_bit_exclusive_or */ |
| 6, /* O_bit_and */ |
| 4, /* O_add */ |
| 4, /* O_subtract */ |
| 3, /* O_eq */ |
| 3, /* O_ne */ |
| 3, /* O_lt */ |
| 3, /* O_le */ |
| 3, /* O_ge */ |
| 3, /* O_gt */ |
| 2, /* O_logical_and */ |
| 1 /* O_logical_or */ |
| }; |
| |
| /* Unfortunately, in MRI mode for the m68k, multiplication and |
| division have lower precedence than the bit wise operators. This |
| function sets the operator precedences correctly for the current |
| mode. Also, MRI uses a different bit_not operator, and this fixes |
| that as well. */ |
| |
| #define STANDARD_MUL_PRECEDENCE (7) |
| #define MRI_MUL_PRECEDENCE (5) |
| |
| void |
| expr_set_precedence () |
| { |
| if (flag_m68k_mri) |
| { |
| op_rank[O_multiply] = MRI_MUL_PRECEDENCE; |
| op_rank[O_divide] = MRI_MUL_PRECEDENCE; |
| op_rank[O_modulus] = MRI_MUL_PRECEDENCE; |
| } |
| else |
| { |
| op_rank[O_multiply] = STANDARD_MUL_PRECEDENCE; |
| op_rank[O_divide] = STANDARD_MUL_PRECEDENCE; |
| op_rank[O_modulus] = STANDARD_MUL_PRECEDENCE; |
| } |
| } |
| |
| /* Initialize the expression parser. */ |
| |
| void |
| expr_begin () |
| { |
| expr_set_precedence (); |
| |
| /* Verify that X_op field is wide enough. */ |
| { |
| expressionS e; |
| e.X_op = O_max; |
| assert (e.X_op == O_max); |
| } |
| } |
| |
| /* Return the encoding for the operator at INPUT_LINE_POINTER. |
| Advance INPUT_LINE_POINTER to the last character in the operator |
| (i.e., don't change it for a single character operator). */ |
| |
| static inline operatorT |
| operator () |
| { |
| int c; |
| operatorT ret; |
| |
| c = *input_line_pointer & 0xff; |
| |
| switch (c) |
| { |
| default: |
| return op_encoding[c]; |
| |
| case '<': |
| switch (input_line_pointer[1]) |
| { |
| default: |
| return op_encoding[c]; |
| case '<': |
| ret = O_left_shift; |
| break; |
| case '>': |
| ret = O_ne; |
| break; |
| case '=': |
| ret = O_le; |
| break; |
| } |
| ++input_line_pointer; |
| return ret; |
| |
| case '=': |
| if (input_line_pointer[1] != '=') |
| return op_encoding[c]; |
| |
| ++input_line_pointer; |
| return O_eq; |
| |
| case '>': |
| switch (input_line_pointer[1]) |
| { |
| default: |
| return op_encoding[c]; |
| case '>': |
| ret = O_right_shift; |
| break; |
| case '=': |
| ret = O_ge; |
| break; |
| } |
| ++input_line_pointer; |
| return ret; |
| |
| case '!': |
| /* We accept !! as equivalent to ^ for MRI compatibility. */ |
| if (input_line_pointer[1] != '!') |
| { |
| if (flag_m68k_mri) |
| return O_bit_inclusive_or; |
| return op_encoding[c]; |
| } |
| ++input_line_pointer; |
| return O_bit_exclusive_or; |
| |
| case '|': |
| if (input_line_pointer[1] != '|') |
| return op_encoding[c]; |
| |
| ++input_line_pointer; |
| return O_logical_or; |
| |
| case '&': |
| if (input_line_pointer[1] != '&') |
| return op_encoding[c]; |
| |
| ++input_line_pointer; |
| return O_logical_and; |
| } |
| |
| /*NOTREACHED*/ |
| } |
| |
| /* Parse an expression. */ |
| |
| segT |
| expr (rank, resultP) |
| operator_rankT rank; /* Larger # is higher rank. */ |
| expressionS *resultP; /* Deliver result here. */ |
| { |
| segT retval; |
| expressionS right; |
| operatorT op_left; |
| operatorT op_right; |
| |
| know (rank >= 0); |
| |
| retval = operand (resultP); |
| |
| know (*input_line_pointer != ' '); /* Operand() gobbles spaces. */ |
| |
| op_left = operator (); |
| while (op_left != O_illegal && op_rank[(int) op_left] > rank) |
| { |
| segT rightseg; |
| |
| input_line_pointer++; /*->after 1st character of operator. */ |
| |
| rightseg = expr (op_rank[(int) op_left], &right); |
| if (right.X_op == O_absent) |
| { |
| as_warn (_("missing operand; zero assumed")); |
| right.X_op = O_constant; |
| right.X_add_number = 0; |
| right.X_add_symbol = NULL; |
| right.X_op_symbol = NULL; |
| } |
| |
| know (*input_line_pointer != ' '); |
| |
| if (retval == undefined_section) |
| { |
| if (SEG_NORMAL (rightseg)) |
| retval = rightseg; |
| } |
| else if (! SEG_NORMAL (retval)) |
| retval = rightseg; |
| else if (SEG_NORMAL (rightseg) |
| && retval != rightseg |
| #ifdef DIFF_EXPR_OK |
| && op_left != O_subtract |
| #endif |
| ) |
| as_bad (_("operation combines symbols in different segments")); |
| |
| op_right = operator (); |
| |
| know (op_right == O_illegal || op_rank[(int) op_right] <= op_rank[(int) op_left]); |
| know ((int) op_left >= (int) O_multiply |
| && (int) op_left <= (int) O_logical_or); |
| |
| /* input_line_pointer->after right-hand quantity. */ |
| /* left-hand quantity in resultP */ |
| /* right-hand quantity in right. */ |
| /* operator in op_left. */ |
| |
| if (resultP->X_op == O_big) |
| { |
| if (resultP->X_add_number > 0) |
| as_warn (_("left operand is a bignum; integer 0 assumed")); |
| else |
| as_warn (_("left operand is a float; integer 0 assumed")); |
| resultP->X_op = O_constant; |
| resultP->X_add_number = 0; |
| resultP->X_add_symbol = NULL; |
| resultP->X_op_symbol = NULL; |
| } |
| if (right.X_op == O_big) |
| { |
| if (right.X_add_number > 0) |
| as_warn (_("right operand is a bignum; integer 0 assumed")); |
| else |
| as_warn (_("right operand is a float; integer 0 assumed")); |
| right.X_op = O_constant; |
| right.X_add_number = 0; |
| right.X_add_symbol = NULL; |
| right.X_op_symbol = NULL; |
| } |
| |
| /* Optimize common cases. */ |
| if (op_left == O_add && right.X_op == O_constant) |
| { |
| /* X + constant. */ |
| resultP->X_add_number += right.X_add_number; |
| } |
| /* This case comes up in PIC code. */ |
| else if (op_left == O_subtract |
| && right.X_op == O_symbol |
| && resultP->X_op == O_symbol |
| && (right.X_add_symbol->sy_frag |
| == resultP->X_add_symbol->sy_frag) |
| && SEG_NORMAL (S_GET_SEGMENT (right.X_add_symbol))) |
| |
| { |
| resultP->X_add_number -= right.X_add_number; |
| resultP->X_add_number += (S_GET_VALUE (resultP->X_add_symbol) |
| - S_GET_VALUE (right.X_add_symbol)); |
| resultP->X_op = O_constant; |
| resultP->X_add_symbol = 0; |
| } |
| else if (op_left == O_subtract && right.X_op == O_constant) |
| { |
| /* X - constant. */ |
| resultP->X_add_number -= right.X_add_number; |
| } |
| else if (op_left == O_add && resultP->X_op == O_constant) |
| { |
| /* Constant + X. */ |
| resultP->X_op = right.X_op; |
| resultP->X_add_symbol = right.X_add_symbol; |
| resultP->X_op_symbol = right.X_op_symbol; |
| resultP->X_add_number += right.X_add_number; |
| retval = rightseg; |
| } |
| else if (resultP->X_op == O_constant && right.X_op == O_constant) |
| { |
| /* Constant OP constant. */ |
| offsetT v = right.X_add_number; |
| if (v == 0 && (op_left == O_divide || op_left == O_modulus)) |
| { |
| as_warn (_("division by zero")); |
| v = 1; |
| } |
| switch (op_left) |
| { |
| default: abort (); |
| case O_multiply: resultP->X_add_number *= v; break; |
| case O_divide: resultP->X_add_number /= v; break; |
| case O_modulus: resultP->X_add_number %= v; break; |
| case O_left_shift: resultP->X_add_number <<= v; break; |
| case O_right_shift: |
| /* We always use unsigned shifts, to avoid relying on |
| characteristics of the compiler used to compile gas. */ |
| resultP->X_add_number = |
| (offsetT) ((valueT) resultP->X_add_number >> (valueT) v); |
| break; |
| case O_bit_inclusive_or: resultP->X_add_number |= v; break; |
| case O_bit_or_not: resultP->X_add_number |= ~v; break; |
| case O_bit_exclusive_or: resultP->X_add_number ^= v; break; |
| case O_bit_and: resultP->X_add_number &= v; break; |
| case O_add: resultP->X_add_number += v; break; |
| case O_subtract: resultP->X_add_number -= v; break; |
| case O_eq: |
| resultP->X_add_number = |
| resultP->X_add_number == v ? ~ (offsetT) 0 : 0; |
| break; |
| case O_ne: |
| resultP->X_add_number = |
| resultP->X_add_number != v ? ~ (offsetT) 0 : 0; |
| break; |
| case O_lt: |
| resultP->X_add_number = |
| resultP->X_add_number < v ? ~ (offsetT) 0 : 0; |
| break; |
| case O_le: |
| resultP->X_add_number = |
| resultP->X_add_number <= v ? ~ (offsetT) 0 : 0; |
| break; |
| case O_ge: |
| resultP->X_add_number = |
| resultP->X_add_number >= v ? ~ (offsetT) 0 : 0; |
| break; |
| case O_gt: |
| resultP->X_add_number = |
| resultP->X_add_number > v ? ~ (offsetT) 0 : 0; |
| break; |
| case O_logical_and: |
| resultP->X_add_number = resultP->X_add_number && v; |
| break; |
| case O_logical_or: |
| resultP->X_add_number = resultP->X_add_number || v; |
| break; |
| } |
| } |
| else if (resultP->X_op == O_symbol |
| && right.X_op == O_symbol |
| && (op_left == O_add |
| || op_left == O_subtract |
| || (resultP->X_add_number == 0 |
| && right.X_add_number == 0))) |
| { |
| /* Symbol OP symbol. */ |
| resultP->X_op = op_left; |
| resultP->X_op_symbol = right.X_add_symbol; |
| if (op_left == O_add) |
| resultP->X_add_number += right.X_add_number; |
| else if (op_left == O_subtract) |
| resultP->X_add_number -= right.X_add_number; |
| } |
| else |
| { |
| /* The general case. */ |
| resultP->X_add_symbol = make_expr_symbol (resultP); |
| resultP->X_op_symbol = make_expr_symbol (&right); |
| resultP->X_op = op_left; |
| resultP->X_add_number = 0; |
| resultP->X_unsigned = 1; |
| } |
| |
| op_left = op_right; |
| } /* While next operator is >= this rank. */ |
| |
| /* The PA port needs this information. */ |
| if (resultP->X_add_symbol) |
| resultP->X_add_symbol->sy_used = 1; |
| |
| return resultP->X_op == O_constant ? absolute_section : retval; |
| } |
| |
| /* |
| * get_symbol_end() |
| * |
| * This lives here because it belongs equally in expr.c & read.c. |
| * Expr.c is just a branch office read.c anyway, and putting it |
| * here lessens the crowd at read.c. |
| * |
| * Assume input_line_pointer is at start of symbol name. |
| * Advance input_line_pointer past symbol name. |
| * Turn that character into a '\0', returning its former value. |
| * This allows a string compare (RMS wants symbol names to be strings) |
| * of the symbol name. |
| * There will always be a char following symbol name, because all good |
| * lines end in end-of-line. |
| */ |
| char |
| get_symbol_end () |
| { |
| char c; |
| |
| /* We accept \001 in a name in case this is being called with a |
| constructed string. */ |
| if (is_name_beginner (c = *input_line_pointer++) || c == '\001') |
| while (is_part_of_name (c = *input_line_pointer++) |
| || c == '\001') |
| ; |
| *--input_line_pointer = 0; |
| return (c); |
| } |
| |
| |
| unsigned int |
| get_single_number () |
| { |
| expressionS exp; |
| operand (&exp); |
| return exp.X_add_number; |
| |
| } |
| |
| /* end of expr.c */ |