1BSD/pi/0.h
/*define DEBUG */
#define CHAR
#define STATIC
/*
* pi - Pascal interpreter code translator
*
* Charles Haley, Bill Joy
* University of California, Berkeley (UCB)
* Version 1.0 August, 1977
*/
/*
* Option flags
*
* The following options are recognized in the text of the program
* and also on the command line:
*
* b block buffer the file output
*
* i make a listing of the procedures and functions in
* the following include files
*
* l make a listing of the program
*
* n place each include file on a new page with a header
*
* p disable post mortem and statement limit counting
*
* t disable run-time tests
*
* u card image mode; only first 72 chars of input count
*
* w suppress special diagnostic warnings
*
* z generate counters for an execution profile
*/
#ifdef DEBUG
char fulltrace, errtrace, testtrace, yyunique;
#endif
/*
* Each option has a stack of 17 option values, with opts giving
* the current, top value, and optstk the value beneath it.
* One refers to option `l' as, e.g., opt('l') in the text for clarity.
*/
char opts[26];
int optstk[26];
#define opt(c) opts[c-'a']
/*
* Monflg is set when we are generating
* a profile
*/
char monflg;
/*
* NOTES ON THE DYNAMIC NATURE OF THE DATA STRUCTURES
*
* Pi uses expandable tables for
* its namelist (symbol table), string table
* hash table, and parse tree space. The following
* definitions specify the size of the increments
* for these items in fundamental units so that
* each uses approximately 1024 bytes.
*/
#define STRINC 1024 /* string space increment */
#define TRINC 512 /* tree space increment */
#define HASHINC 509 /* hash table size in words, each increment */
#define NLINC 56 /* namelist increment size in nl structs */
/*
* The initial sizes of the structures.
* These should be large enough to compile
* an "average" sized program so as to minimize
* storage requests.
* On a small system or and 11/34 or 11/40
* these numbers can be trimmed to make the
* compiler smaller.
*/
#define ITREE 2000
#define INL 200
#define IHASH 509
/*
* The following limits on hash and tree tables currently
* allow approximately 1200 symbols and 20k words of tree
* space. The fundamental limit of 64k total data space
* should be exceeded well before these are full.
*/
#define MAXHASH 4
#define MAXNL 12
#define MAXTREE 30
#define MAXDEPTH 150
/*
* ERROR RELATED DEFINITIONS
*/
/*
* Exit statuses to pexit
*
* AOK
* ERRS Compilation errors inhibit obj productin
* NOSTART Errors before we ever got started
* DIED We ran out of memory or some such
*/
#define AOK 0
#define ERRS 1
#define NOSTART 2
#define DIED 3
char Recovery;
#define eholdnl() Eholdnl = 1
#define nocascade() Enocascade = 1
char Eholdnl, Enocascade;
/*
* The flag eflg is set whenever we have a hard error.
* The character in errpfx will precede the next error message.
* When cgenflg is set code generation is suppressed.
* This happens whenver we have an error (i.e. if eflg is set)
* and when we are walking the tree to determine types only.
*/
int eflg;
char errpfx;
#define setpfx(x) errpfx = x
#define standard() setpfx('s')
#define warning() setpfx('w')
#define recovered() setpfx('e')
int cgenflg;
/*
* The flag syneflg is used to suppress the diagnostics of the form
* E 10 a, defined in someprocedure, is neither used nor set
* when there were syntax errors in "someprocedure".
* In this case, it is likely that these warinings would be spurious.
*/
char syneflg;
/*
* The compiler keeps its error messages in a file.
* The variable efil is the unit number on which
* this file is open for reading of error message text.
* Similarly, the file ofil is the unit of the file
* "obj" where we write the interpreter code.
*/
char efil, ofil;
int obuf[259];
#define elineoff() Enoline++
#define elineon() Enoline = 0
char Enoline;
/*
* SYMBOL TABLE STRUCTURE DEFINITIONS
*
* The symbol table is henceforth referred to as the "namelist".
* It consists of a number of structures of the form "nl" below.
* These are contained in a number of segments of the symbol
* table which are dynamically allocated as needed.
* The major namelist manipulation routines are contained in the
* file "nl.c".
*
* The major components of a namelist entry are the "symbol", giving
* a pointer into the string table for the string associated with this
* entry and the "class" which tells which of the (currently 19)
* possible types of structure this is.
*
* Many of the classes use the "type" field for a pointer to the type
* which the entry has.
*
* Other pieces of information in more than one class include the block
* in which the symbol is defined, flags indicating whether the symbol
* has been used and whether it has been assigned to, etc.
*
* A more complete discussion of the features of the namelist is impossible
* here as it would be too voluminous. Refer to the "PI 1.0 Implementation
* Notes" for more details.
*/
/*
* The basic namelist structure.
* There are also two other variants, defining the real
* field as longs or integers given below.
*
* The array disptab defines the hash header for the symbol table.
* Symbols are hashed based on the low 6 bits of their pointer into
* the string table; see the routines in the file "lookup.c" and also "fdec.c"
* especially "funcend".
*/
struct nl {
char *symbol;
char class, nl_flags;
struct nl *type;
struct nl *chain, *nl_next;
double real;
} nl[], *nlp, *disptab[077+1];
struct {
char *symbol;
char class, nl_block;
struct nl *type;
struct nl *chain, *nl_next;
long range[2];
};
struct {
char *symbol;
char class, nl_flags;
struct nl *type;
struct nl *chain, *nl_next;
int value[4];
};
/*
* NL FLAGS BITS
*
* Definitions of the usage of the bits in
* the nl_flags byte. Note that the low 5 bits of the
* byte are the "nl_block" and that some classes make use
* of this byte as a "width".
*
* The only non-obvious bit definition here is "NFILES"
* which records whether a structure contains any files.
* Such structures are not allowed to be dynamically allocated.
*/
#define NPACKED 0200
#define NUSED 0100
#define NMOD 0040
#define NFORWD 0200
#define NFILES 0200
/*
* Definition of the commonly used "value" fields.
* The most important ones are NL_LOC which gives the location
* in the code of a label or procedure, and NL_OFFS which gives
* the offset of a variable in its stack mark.
*/
#define NL_OFFS 0
#define NL_LOC 1
#define NL_FVAR 3
#define NL_GOLEV 2
#define NL_GOLINE 3
#define NL_FORV 1
#define NL_FLDSZ 1
#define NL_VARNT 2
#define NL_VTOREC 2
#define NL_TAG 3
/*
* For BADUSE nl structures, NL_KINDS is a bit vector
* indicating the kinds of illegal usages complained about
* so far. For kind of bad use "kind", "1 << kind" is set.
* The low bit is reserved as ISUNDEF to indicate whether
* this identifier is totally undefined.
*/
#define NL_KINDS 0
#define ISUNDEF 1
/*
* NAMELIST CLASSES
*
* The following are the namelist classes.
* Different classes make use of the value fields
* of the namelist in different ways.
*
* The namelist should be redesigned by providing
* a number of structure definitions with one corresponding
* to each namelist class, ala a variant record in Pascal.
*/
#define BADUSE 0
#define CONST 1
#define TYPE 2
#define VAR 3
#define ARRAY 4
#define PTRFILE 5
#define RECORD 6
#define FIELD 7
#define PROC 8
#define FUNC 9
#define FVAR 10
#define REF 11
#define PTR 12
#define FILE 13
#define SET 14
#define RANGE 15
#define LABEL 16
#define WITHPTR 17
#define SCAL 18
#define STR 19
#define PROG 20
#define IMPROPER 21
#define VARNT 22
/*
* Clnames points to an array of names for the
* namelist classes.
*/
char **clnames;
/*
* PRE-DEFINED NAMELIST OFFSETS
*
* The following are the namelist offsets for the
* primitive types. The ones which are negative
* don't actually exist, but are generated and tested
* internally. These definitions are sensitive to the
* initializations in nl.c.
*/
#define TFIRST -7
#define TFILE -7
#define TREC -6
#define TARY -5
#define TSCAL -4
#define TPTR -3
#define TSET -2
#define TSTR -1
#define NIL 0
#define TBOOL 1
#define TCHAR 2
#define TINT 3
#define TDOUBLE 4
#define TNIL 5
#define T1INT 6
#define T2INT 7
#define T4INT 8
#define T1CHAR 9
#define T1BOOL 10
#define T8REAL 11
#define TLAST 11
/*
* SEMANTIC DEFINITIONS
*/
/*
* NOCON and SAWCON are flags in the tree telling whether
* a constant set is part of an expression.
*/
#define NOCON 0
#define SAWCON 1
/*
* The variable cbn gives the current block number,
* the variable bn is set as a side effect of a call to
* lookup, and is the block number of the variable which
* was found.
*/
int bn, cbn;
/*
* The variable line is the current semantic
* line and is set in stat.c from the numbers
* embedded in statement type tree nodes.
*/
int line;
/*
* The size of the display
* which defines the maximum nesting
* of procedures and functions allowed.
* Because of the flags in the current namelist
* this must be no greater than 32.
*/
#define DSPLYSZ 20
/*
* The following structure is used
* to keep track of the amount of variable
* storage required by each block.
* "Max" is the high water mark, "off"
* the current need. Temporaries for "for"
* loops and "with" statements are allocated
* in the local variable area and these
* numbers are thereby changed if necessary.
*/
struct om {
long om_off;
long om_max;
} sizes[DSPLYSZ];
/*
* Structure recording information about a constant
* declaration. It is actually the return value from
* the routine "gconst", but since C doesn't support
* record valued functions, this is more convenient.
*/
struct {
int ctype;
int cival;
double crval;
} con;
/*
* The set structure records the lower bound
* and upper bound with the lower bound normalized
* to zero when working with a set. It is set by
* the routine setran in var.c.
*/
struct {
int lwrb, uprbp;
} set;
/*
* The following flags are passed on calls to lvalue
* to indicate how the reference is to affect the usage
* information for the variable being referenced.
* MOD is used to set the NMOD flag in the namelist
* entry for the variable, ASGN permits diagnostics
* to be formed when a for variable is assigned to in
* the range of the loop.
*/
#define NOMOD 0
#define MOD 01
#define ASGN 02
#define NOUSE 04
#define MAXINT 2147483647.
#define MININT -2147483648.
/*
* Variables for generation of profile information.
* Monflg is set when we want to generate a profile.
* Gocnt record the total number of goto's and
* cnts records the current counter for generating
* COUNT operators.
*/
int gocnt;
int cnts;
/*
* Most routines call "incompat" rather than asking "!compat"
* for historical reasons.
*/
#define incompat !compat
/*
* Parts records which declaration parts have been seen.
* The grammar allows the "const" "type" and "var"
* parts to be repeated and to be in any order, so that
* they can be detected semantically to give better
* error diagnostics.
*/
int parts;
#define LPRT 01
#define CPRT 02
#define TPRT 04
#define VPRT 08
/*
* Flags for the "you used / instead of div" diagnostic
*/
char divchk;
char divflg;
int errcnt[DSPLYSZ];
/*
* Forechain links those types which are
* ^ sometype
* so that they can be evaluated later, permitting
* circular, recursive list structures to be defined.
*/
struct nl *forechain;
/*
* Withlist links all the records which are currently
* opened scopes because of with statements.
*/
struct nl *withlist;
char *intset;
char *input, *output;
struct nl *program;
/*
* STRUCTURED STATEMENT GOTO CHECKING
*
* The variable level keeps track of the current
* "structured statement level" when processing the statement
* body of blocks. This is used in the detection of goto's into
* structured statements in a block.
*
* Each label's namelist entry contains two pieces of information
* related to this check. The first `NL_GOLEV' either contains
* the level at which the label was declared, `NOTYET' if the label
* has not yet been declared, or `DEAD' if the label is dead, i.e.
* if we have exited the level in which the label was defined.
*
* When we discover a "goto" statement, if the label has not
* been defined yet, then we record the current level and the current line
* for a later error check. If the label has been already become "DEAD"
* then a reference to it is an error. Now the compiler maintains,
* for each block, a linked list of the labels headed by "gotos[bn]".
* When we exit a structured level, we perform the routine
* ungoto in stat.c. It notices labels whose definition levels have been
* exited and makes them be dead. For labels which have not yet been
* defined, ungoto will maintain NL_GOLEV as the minimum structured level
* since the first usage of the label. It is not hard to see that the label
* must eventually be declared at this level or an outer level to this
* one or a goto into a structured statement will exist.
*/
int level;
struct nl *gotos[DSPLYSZ];
#define NOTYET 10000
#define DEAD 10000
/*
* Noreach is true when the next statement will
* be unreachable unless something happens along
* (like exiting a looping construct) to save
* the day.
*/
int noreach;
/*
* UNDEFINED VARIABLE REFERENCE STRUCTURES
*/
struct udinfo {
int ud_line;
struct udinfo *ud_next;
char nullch;
};
/*
* CODE GENERATION DEFINITIONS
*/
/*
* NSTAND is or'ed onto the abstract machine opcode
* for non-standard built-in procedures and functions.
*/
#define NSTAND 0400
#define codeon() cgenflg++
#define codeoff() --cgenflg
/*
* Offsets due to the structure of the runtime stack.
* DPOFF1 is the amount of fixed storage in each block allocated
* as local variables for the runtime system.
* DPOFF2 is the size of the block mark.
*/
#define DPOFF1 0
#define DPOFF2 16
/*
* Codeline is the last lino output in the code generator.
* It used to be used to suppress LINO operators but no
* more since we now count statements.
* Lc is the intepreter code location counter.
*
int codeline;
*/
char *lc;
/*
* Routines which need types
* other than "integer" to be
* assumed by the compiler.
*/
double atof();
long lwidth();
long aryconst();
long a8tol();
struct nl *lookup();
double atof();
int *tree();
int *hash();
char *alloc();
/*
* Funny structures to use
* pointers in wild and wooly ways
*/
struct {
char pchar;
};
struct {
int pint;
int pint2;
};
struct {
long plong;
};
struct {
double pdouble;
};
#define OCT 1
#define HEX 2
/*
* MAIN PROGRAM VARIABLES, MISCELLANY
*/
/*
* Variables forming a data base referencing
* the command line arguments with the "i" option, e.g.
* in "pi -i scanner.i compiler.p".
*/
char **pflist;
int pflstc;
int pfcnt;
char *filename; /* current source file name */
int tvec[2]; /* mod time of the source file */
char snark[]; /* SNARK */
char *classes[]; /* maps namelist classes to string names */