/************************************************************** * * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. * *************************************************************/ #include #include #include "cppdef.h" #include "cpp.h" /* * Evaluate an #if expression. */ static char *opname[] = { /* For debug and error messages */ "end of expression", "val", "id", "+", "-", "*", "/", "%", "<<", ">>", "&", "|", "^", "==", "!=", "<", "<=", ">=", ">", "&&", "||", "?", ":", ",", "unary +", "unary -", "~", "!", "(", ")", "(none)", }; /* * opdope[] has the operator precedence: * Bits * 7 Unused (so the value is always positive) * 6-2 Precedence (000x .. 017x) * 1-0 Binary op. flags: * 01 The binop flag should be set/cleared when this op is seen. * 10 The new value of the binop flag. * Note: Expected, New binop * constant 0 1 Binop, end, or ) should follow constants * End of line 1 0 End may not be preceded by an operator * binary 1 0 Binary op follows a value, value follows. * unary 0 0 Unary op doesn't follow a value, value follows * ( 0 0 Doesn't follow value, value or unop follows * ) 1 1 Follows value. Op follows. */ static char opdope[OP_MAX] = { 0001, /* End of expression */ 0002, /* Digit */ 0000, /* Letter (identifier) */ 0141, 0141, 0151, 0151, 0151, /* ADD, SUB, MUL, DIV, MOD */ 0131, 0131, 0101, 0071, 0071, /* ASL, ASR, AND, OR, XOR */ 0111, 0111, 0121, 0121, 0121, 0121, /* EQ, NE, LT, LE, GE, GT */ 0061, 0051, 0041, 0041, 0031, /* ANA, ORO, QUE, COL, CMA */ /* * Unary op's follow */ 0160, 0160, 0160, 0160, /* NEG, PLU, COM, NOT */ 0170, 0013, 0023, /* LPA, RPA, END */ }; /* * OP_QUE and OP_RPA have alternate precedences: */ #define OP_RPA_PREC 0013 #define OP_QUE_PREC 0034 /* * S_ANDOR and S_QUEST signal "short-circuit" boolean evaluation, so that * #if FOO != 0 && 10 / FOO ... * doesn't generate an error message. They are stored in optab.skip. */ #define S_ANDOR 2 #define S_QUEST 1 typedef struct optab { char op; /* Operator */ char prec; /* Its precedence */ char skip; /* Short-circuit: TRUE to skip */ } OPTAB; static int evalue; /* Current value from evallex() */ #ifdef nomacargs FILE_LOCAL int isbinary(op) register int op; { return (op >= FIRST_BINOP && op <= LAST_BINOP); } FILE_LOCAL int isunary(op) register int op; { return (op >= FIRST_UNOP && op <= LAST_UNOP); } #else #define isbinary(op) (op >= FIRST_BINOP && op <= LAST_BINOP) #define isunary(op) (op >= FIRST_UNOP && op <= LAST_UNOP) #endif /* * The following definitions are used to specify basic variable sizes. */ #ifndef S_CHAR #define S_CHAR (sizeof (char)) #endif #ifndef S_SINT #define S_SINT (sizeof (short int)) #endif #ifndef S_INT #define S_INT (sizeof (int)) #endif #ifndef S_LINT #define S_LINT (sizeof (long int)) #endif #ifndef S_FLOAT #define S_FLOAT (sizeof (float)) #endif #ifndef S_DOUBLE #define S_DOUBLE (sizeof (double)) #endif #ifndef S_PCHAR #define S_PCHAR (sizeof (char *)) #endif #ifndef S_PSINT #define S_PSINT (sizeof (short int *)) #endif #ifndef S_PINT #define S_PINT (sizeof (int *)) #endif #ifndef S_PLINT #define S_PLINT (sizeof (long int *)) #endif #ifndef S_PFLOAT #define S_PFLOAT (sizeof (float *)) #endif #ifndef S_PDOUBLE #define S_PDOUBLE (sizeof (double *)) #endif #ifndef S_PFPTR #define S_PFPTR (sizeof (int (*)())) #endif typedef struct types { short type; /* This is the bit if */ char *name; /* this is the token word */ } TYPES; static TYPES basic_types[] = { { T_CHAR, "char", }, { T_INT, "int", }, { T_FLOAT, "float", }, { T_DOUBLE, "double", }, { T_SHORT, "short", }, { T_LONG, "long", }, { T_SIGNED, "signed", }, { T_UNSIGNED, "unsigned", }, { 0, NULL, }, /* Signal end */ }; /* * Test_table[] is used to test for illegal combinations. */ static short test_table[] = { T_FLOAT | T_DOUBLE | T_LONG | T_SHORT, T_FLOAT | T_DOUBLE | T_CHAR | T_INT, T_FLOAT | T_DOUBLE | T_SIGNED | T_UNSIGNED, T_LONG | T_SHORT | T_CHAR, 0 /* end marker */ }; /* * The order of this table is important -- it is also referenced by * the command line processor to allow run-time overriding of the * built-in size values. The order must not be changed: * char, short, int, long, float, double (func pointer) */ SIZES size_table[] = { { T_CHAR, S_CHAR, S_PCHAR }, /* char */ { T_SHORT, S_SINT, S_PSINT }, /* short int */ { T_INT, S_INT, S_PINT }, /* int */ { T_LONG, S_LINT, S_PLINT }, /* long */ { T_FLOAT, S_FLOAT, S_PFLOAT }, /* float */ { T_DOUBLE, S_DOUBLE, S_PDOUBLE }, /* double */ { T_FPTR, 0, S_PFPTR }, /* int (*()) */ { 0, 0, 0 }, /* End of table */ }; void InitCpp5() { } int eval() /* * Evaluate an expression. Straight-forward operator precedence. * This is called from control() on encountering an #if statement. * It calls the following routines: * evallex Lexical analyser -- returns the type and value of * the next input token. * evaleval Evaluate the current operator, given the values on * the value stack. Returns a pointer to the (new) * value stack. * For compatibility with older cpp's, this return returns 1 (TRUE) * if a syntax error is detected. */ { register int op; /* Current operator */ register int *valp; /* -> value vector */ register OPTAB *opp; /* Operator stack */ int prec; /* Op precedence */ int binop; /* Set if binary op. needed */ int op1; /* Operand from stack */ int skip; /* For short-circuit testing */ int value[NEXP]; /* Value stack */ OPTAB opstack[NEXP]; /* Operand stack */ #ifndef ZTC /* BP */ extern int *evaleval(); /* Does actual evaluation */ #endif valp = value; opp = opstack; opp->op = OP_END; /* Mark bottom of stack */ opp->prec = opdope[OP_END]; /* And its precedence */ opp->skip = 0; /* Not skipping now */ binop = 0; again: ; #ifdef DEBUG_EVAL fprintf( pCppOut, "In #if at again: skip = %d, binop = %d, line is: %s", opp->skip, binop, infile->bptr); #endif if ((op = evallex(opp->skip)) == OP_SUB && binop == 0) op = OP_NEG; /* Unary minus */ else if (op == OP_ADD && binop == 0) op = OP_PLU; /* Unary plus */ else if (op == OP_FAIL) return (1); /* Error in evallex */ #ifdef DEBUG_EVAL fprintf( pCppOut, "op = %s, opdope = %03o, binop = %d, skip = %d\n", opname[op], opdope[op], binop, opp->skip); #endif if (op == DIG) { /* Value? */ if (binop != 0) { cerror("misplaced constant in #if", NULLST); return (1); } else if (valp >= &value[NEXP-1]) { cerror("#if value stack overflow", NULLST); return (1); } else { #ifdef DEBUG_EVAL fprintf( pCppOut, "pushing %d onto value stack[%d]\n", evalue, valp - value); #endif *valp++ = evalue; binop = 1; } goto again; } else if (op > OP_END) { cerror("Illegal #if line", NULLST); return (1); } prec = opdope[op]; if (binop != (prec & 1)) { cerror("Operator %s in incorrect context", opname[op]); return (1); } binop = (prec & 2) >> 1; for (;;) { #ifdef DEBUG_EVAL fprintf( pCppOut, "op %s, prec %d., stacked op %s, prec %d, skip %d\n", opname[op], prec, opname[opp->op], opp->prec, opp->skip); #endif if (prec > opp->prec) { if (op == OP_LPA) prec = OP_RPA_PREC; else if (op == OP_QUE) prec = OP_QUE_PREC; op1 = opp->skip; /* Save skip for test */ /* * Push operator onto op. stack. */ opp++; if (opp >= &opstack[NEXP]) { cerror("expression stack overflow at op \"%s\"", opname[op]); return (1); } opp->op = (char)op; opp->prec = (char)prec; skip = (valp[-1] != 0); /* Short-circuit tester */ /* * Do the short-circuit stuff here. Short-circuiting * stops automagically when operators are evaluated. */ if ((op == OP_ANA && !skip) || (op == OP_ORO && skip)) opp->skip = S_ANDOR; /* And/or skip starts */ else if (op == OP_QUE) /* Start of ?: operator */ opp->skip = (char)((op1 & S_ANDOR) | ((!skip) ? S_QUEST : 0)); else if (op == OP_COL) { /* : inverts S_QUEST */ opp->skip = (char)((op1 & S_ANDOR) | (((op1 & S_QUEST) != 0) ? 0 : S_QUEST)); } else { /* Other ops leave */ opp->skip = (char)op1; /* skipping unchanged. */ } #ifdef DEBUG_EVAL fprintf( pCppOut, "stacking %s, valp[-1] == %d at %s", opname[op], valp[-1], infile->bptr); dumpstack(opstack, opp, value, valp); #endif goto again; } /* * Pop operator from op. stack and evaluate it. * End of stack and '(' are specials. */ skip = opp->skip; /* Remember skip value */ switch ((op1 = opp->op)) { /* Look at stacked op */ case OP_END: /* Stack end marker */ if (op == OP_EOE) return (valp[-1]); /* Finished ok. */ goto again; /* Read another op. */ case OP_LPA: /* ( on stack */ if (op != OP_RPA) { /* Matches ) on input */ cerror("unbalanced paren's, op is \"%s\"", opname[op]); return (1); } opp--; /* Unstack it */ /* goto again; -- Fall through */ case OP_QUE: goto again; /* Evaluate true expr. */ case OP_COL: /* : on stack. */ opp--; /* Unstack : */ if (opp->op != OP_QUE) { /* Matches ? on stack? */ cerror("Misplaced '?' or ':', previous operator is %s", opname[(int)opp->op]); return (1); } /* * Evaluate op1. */ default: /* Others: */ opp--; /* Unstack the operator */ #ifdef DEBUG_EVAL fprintf( pCppOut, "Stack before evaluation of %s\n", opname[op1]); dumpstack(opstack, opp, value, valp); #endif valp = evaleval(valp, op1, skip); #ifdef DEBUG_EVAL fprintf( pCppOut, "Stack after evaluation\n"); dumpstack(opstack, opp, value, valp); #endif } /* op1 switch end */ } /* Stack unwind loop */ } FILE_LOCAL int evallex(int skip) /* * Return next eval operator or value. Called from eval(). It * calls a special-purpose routines for 'char' strings and * numeric values: * evalchar called to evaluate 'x' * evalnum called to evaluate numbers. */ { register int c, c1, t; again: do { /* Collect the token */ c = skipws(); if ((c = macroid(c)) == EOF_CHAR || c == '\n') { unget(); return (OP_EOE); /* End of expression */ } } while ((t = type[c]) == LET && catenate()); if (t == INV) { /* Total nonsense */ if (!skip) { if (isascii(c) && isprint(c)) cierror("illegal character '%c' in #if", c); else cierror("illegal character (%d decimal) in #if", c); } return (OP_FAIL); } else if (t == QUO) { /* ' or " */ if (c == '\'') { /* Character constant */ evalue = evalchar(skip); /* Somewhat messy */ #ifdef DEBUG_EVAL fprintf( pCppOut, "evalchar returns %d.\n", evalue); #endif return (DIG); /* Return a value */ } cerror("Can't use a string in an #if", NULLST); return (OP_FAIL); } else if (t == LET) { /* ID must be a macro */ if (streq(token, "defined")) { /* Or defined name */ c1 = c = skipws(); if (c == '(') /* Allow defined(name) */ c = skipws(); if (type[c] == LET) { evalue = (lookid(c) != NULL); if (c1 != '(' /* Need to balance */ || skipws() == ')') /* Did we balance? */ return (DIG); /* Parsed ok */ } cerror("Bad #if ... defined() syntax", NULLST); return (OP_FAIL); } else if (streq(token, "sizeof")) /* New sizeof hackery */ return (dosizeof()); /* Gets own routine */ /* * The Draft ANSI C Standard says that an undefined symbol * in an #if has the value zero. We are a bit pickier, * warning except where the programmer was careful to write * #if defined(foo) ? foo : 0 */ #ifdef STRICT_UNDEF if (!skip) cwarn("undefined symbol \"%s\" in #if, 0 used", token); #endif evalue = 0; return (DIG); } else if (t == DIG) { /* Numbers are harder */ evalue = evalnum(c); #ifdef DEBUG_EVAL fprintf( pCppOut, "evalnum returns %d.\n", evalue); #endif } else if (strchr("!=<>&|\\", c) != NULL) { /* * Process a possible multi-byte lexeme. */ c1 = cget(); /* Peek at next char */ switch (c) { case '!': if (c1 == '=') return (OP_NE); break; case '=': if (c1 != '=') { /* Can't say a=b in #if */ unget(); cerror("= not allowed in #if", NULLST); return (OP_FAIL); } return (OP_EQ); case '>': case '<': if (c1 == c) return ((c == '<') ? OP_ASL : OP_ASR); else if (c1 == '=') return ((c == '<') ? OP_LE : OP_GE); break; case '|': case '&': if (c1 == c) return ((c == '|') ? OP_ORO : OP_ANA); break; case '\\': if (c1 == '\n') /* Multi-line if */ goto again; cerror("Unexpected \\ in #if", NULLST); return (OP_FAIL); } unget(); } return (t); } FILE_LOCAL int dosizeof() /* * Process the sizeof (basic type) operation in an #if string. * Sets evalue to the size and returns * DIG success * OP_FAIL bad parse or something. */ { register int c; register TYPES *tp; register SIZES *sizp; register short *testp; short typecode; if ((c = skipws()) != '(') goto nogood; /* * Scan off the tokens. */ typecode = 0; while (0 != (c = skipws())) { if ((c = macroid(c)) == EOF_CHAR || c == '\n') goto nogood; /* End of line is a bug */ else if (c == '(') { /* thing (*)() func ptr */ if (skipws() == '*' && skipws() == ')') { /* We found (*) */ if (skipws() != '(') /* Let () be optional */ unget(); else if (skipws() != ')') goto nogood; typecode |= T_FPTR; /* Function pointer */ } else { /* Junk is a bug */ goto nogood; } } else if (type[c] != LET) /* Exit if not a type */ break; else if (!catenate()) { /* Maybe combine tokens */ /* * Look for this unexpandable token in basic_types. * The code accepts "int long" as well as "long int" * which is a minor bug as bugs go (and one shared with * a lot of C compilers). */ for (tp = basic_types; tp->name != NULLST; tp++) { if (streq(token, tp->name)) break; } if (tp->name == NULLST) { cerror("#if sizeof, unknown type \"%s\"", token); return (OP_FAIL); } typecode |= tp->type; /* Or in the type bit */ } } /* * We are at the end of the type scan. Chew off '*' if necessary. */ if (c == '*') { typecode |= T_PTR; c = skipws(); } if (c == ')') { /* Last syntax check */ for (testp = test_table; *testp != 0; testp++) { if (!bittest(typecode & *testp)) { cerror("#if ... sizeof: illegal type combination", NULLST); return (OP_FAIL); } } /* * We assume that all function pointers are the same size: * sizeof (int (*)()) == sizeof (float (*)()) * We assume that signed and unsigned don't change the size: * sizeof (signed int) == (sizeof unsigned int) */ if ((typecode & T_FPTR) != 0) /* Function pointer */ typecode = T_FPTR | T_PTR; else { /* Var or var * datum */ typecode &= ~(T_SIGNED | T_UNSIGNED); if ((typecode & (T_SHORT | T_LONG)) != 0) typecode &= ~T_INT; } if ((typecode & ~T_PTR) == 0) { cerror("#if sizeof() error, no type specified", NULLST); return (OP_FAIL); } /* * Exactly one bit (and possibly T_PTR) may be set. */ for (sizp = size_table; sizp->bits != 0; sizp++) { if ((typecode & ~T_PTR) == sizp->bits) { evalue = ((typecode & T_PTR) != 0) ? sizp->psize : sizp->size; return (DIG); } } /* We shouldn't fail */ cierror("#if ... sizeof: bug, unknown type code 0x%x", typecode); return (OP_FAIL); } nogood: unget(); cerror("#if ... sizeof() syntax error", NULLST); return (OP_FAIL); } FILE_LOCAL int bittest(int value) /* * TRUE if value is zero or exactly one bit is set in value. */ { #if (4096 & ~(-4096)) == 0 return ((value & ~(-value)) == 0); #else /* * Do it the hard way (for non 2's complement machines) */ return (value == 0 || value ^ (value - 1) == (value * 2 - 1)); #endif } FILE_LOCAL int evalnum(int c) /* * Expand number for #if lexical analysis. Note: evalnum recognizes * the unsigned suffix, but only returns a signed int value. */ { register int value; register int base; register int c1; if (c != '0') base = 10; else if ((c = cget()) == 'x' || c == 'X') { base = 16; c = cget(); } else base = 8; value = 0; for (;;) { c1 = c; if (isascii(c) && isupper(c1)) c1 = tolower(c1); #ifdef EBCDIC if (c1 <= 'f') #else if (c1 >= 'a') #endif c1 -= ('a' - 10); else c1 -= '0'; if (c1 < 0 || c1 >= base) break; value *= base; value += c1; c = cget(); } if (c == 'u' || c == 'U') /* Unsigned nonsense */ c = cget(); unget(); return (value); } FILE_LOCAL int evalchar(int skip) /* * Get a character constant */ { register int c; register int value; register int count; instring = TRUE; if ((c = cget()) == '\\') { switch ((c = cget())) { case 'a': /* New in Standard */ #if ('a' == '\a' || '\a' == ALERT) value = ALERT; /* Use predefined value */ #else value = '\a'; /* Use compiler's value */ #endif break; case 'b': value = '\b'; break; case 'f': value = '\f'; break; case 'n': value = '\n'; break; case 'r': value = '\r'; break; case 't': value = '\t'; break; case 'v': /* New in Standard */ #if ('v' == '\v' || '\v' == VT) value = VT; /* Use predefined value */ #else value = '\v'; /* Use compiler's value */ #endif break; case 'x': /* '\xFF' */ count = 3; value = 0; while ((((c = get()) >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F')) && (--count >= 0)) { value *= 16; #ifdef EBCDIC value += (c <= '9') ? (c - '0') : ((c & 0xF) + 9); #else value += (c >= '0') ? (c - '0') : ((c & 0xF) + 9); #endif } unget(); break; default: if (c >= '0' && c <= '7') { count = 3; value = 0; while (c >= '0' && c <= '7' && --count >= 0) { value *= 8; value += (c - '0'); c = get(); } unget(); } else value = c; break; } } else if (c == '\'') value = 0; else value = c; /* * We warn on multi-byte constants and try to hack * (big|little)endian machines. */ #if BIG_ENDIAN count = 0; #endif while ((c = get()) != '\'' && c != EOF_CHAR && c != '\n') { if (!skip) ciwarn("multi-byte constant '%c' isn't portable", c); #if BIG_ENDIAN count += BITS_CHAR; value += (c << count); #else value <<= BITS_CHAR; value += c; #endif } instring = FALSE; return (value); } FILE_LOCAL int * evaleval(int* valp, int op, int skip) /* * Apply the argument operator to the data on the value stack. * One or two values are popped from the value stack and the result * is pushed onto the value stack. * * OP_COL is a special case. * * evaleval() returns the new pointer to the top of the value stack. */ { register int v1, v2 = 0; if (isbinary(op)) v2 = *--valp; v1 = *--valp; #ifdef DEBUG_EVAL fprintf( pCppOut, "%s op %s", (isbinary(op)) ? "binary" : "unary", opname[op]); if (isbinary(op)) fprintf( pCppOut, ", v2 = %d.", v2); fprintf( pCppOut, ", v1 = %d.\n", v1); #endif switch (op) { case OP_EOE: break; case OP_ADD: v1 += v2; break; case OP_SUB: v1 -= v2; break; case OP_MUL: v1 *= v2; break; case OP_DIV: case OP_MOD: if (v2 == 0) { if (!skip) { cwarn("%s by zero in #if, zero result assumed", (op == OP_DIV) ? "divide" : "mod"); } v1 = 0; } else if (op == OP_DIV) v1 /= v2; else v1 %= v2; break; case OP_ASL: v1 <<= v2; break; case OP_ASR: v1 >>= v2; break; case OP_AND: v1 &= v2; break; case OP_OR: v1 |= v2; break; case OP_XOR: v1 ^= v2; break; case OP_EQ: v1 = (v1 == v2); break; case OP_NE: v1 = (v1 != v2); break; case OP_LT: v1 = (v1 < v2); break; case OP_LE: v1 = (v1 <= v2); break; case OP_GE: v1 = (v1 >= v2); break; case OP_GT: v1 = (v1 > v2); break; case OP_ANA: v1 = (v1 && v2); break; case OP_ORO: v1 = (v1 || v2); break; case OP_COL: /* * v1 has the "true" value, v2 the "false" value. * The top of the value stack has the test. */ v1 = (*--valp) ? v1 : v2; break; case OP_NEG: v1 = (-v1); break; case OP_PLU: break; case OP_COM: v1 = ~v1; break; case OP_NOT: v1 = !v1; break; default: cierror("#if bug, operand = %d.", op); v1 = 0; } *valp++ = v1; return (valp); } #ifdef DEBUG_EVAL dumpstack(opstack, opp, value, valp) OPTAB opstack[NEXP]; /* Operand stack */ register OPTAB *opp; /* Operator stack */ int value[NEXP]; /* Value stack */ register int *valp; /* -> value vector */ { fprintf( pCppOut, "index op prec skip name -- op stack at %s", infile->bptr); while (opp > opstack) { fprintf( pCppOut, " [%2d] %2d %03o %d %s\n", opp - opstack, opp->op, opp->prec, opp->skip, opname[opp->op]); opp--; } while (--valp >= value) { fprintf( pCppOut, "value[%d] = %d\n", (valp - value), *valp); } } #endif