+/*-
+ * Copyright (c) 1980 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * %sccs.include.redist.c%
+ *
+ * %W% (Berkeley) %G%
+ */
+
+/*
+ * The size of the display.
+ */
+#define DSPLYSZ 20
+
+/*
+ * The structure of the runtime display
+ */
+#ifdef OBJ
+struct dispsave {
+ char *locvars; /* pointer to local variables */
+ struct blockmark *stp; /* pointer to local stack frame */
+};
+ /*
+ * The following union allows fast access to
+ * precomputed display entries
+ */
+union display {
+ struct dispsave frame[DSPLYSZ];
+ char *raw[2*DSPLYSZ];
+} display;
+#endif OBJ
+#ifdef PC
+#ifdef vax
+ /*
+ * the display is made up of saved AP's and FP's.
+ * FP's are used to find locals,
+ * and AP's are used to find parameters.
+ * FP and AP are untyped pointers,
+ * but are used throughout as (char *).
+ * the display is used by adding AP_OFFSET or FP_OFFSET to the
+ * address of the approriate display entry.
+ */
+ struct dispsave {
+ char *savedAP;
+ char *savedFP;
+ } display[ DSPLYSZ ];
+
+# define AP_OFFSET ( 0 )
+# define FP_OFFSET ( sizeof (char *) )
+#endif vax
+#ifdef mc68000
+ /*
+ * the display is just the saved a6.
+ * arguments are at positive offsets,
+ * locals are at negative offsets.
+ * there are no offsets within the saved display structure.
+ */
+ struct dispsave {
+ char *saveda6;
+ } display[ DSPLYSZ ];
+
+# define AP_OFFSET (0)
+# define FP_OFFSET (0)
+#endif mc68000
+#ifdef tahoe
+ /*
+ * the display is just the saved FP.
+ * arguments are at positive offsets,
+ * locals are at negative offsets.
+ * there are no offsets within the saved display structure.
+ */
+ struct dispsave {
+ char *savedFP;
+ } display[ DSPLYSZ ];
+
+# define AP_OFFSET 0
+# define FP_OFFSET 0
+#endif tahoe
+#endif PC
+
+ /*
+ * the structure below describes the block mark used by the architecture.
+ * this is the space used by the machine between the arguments and the
+ * whatever is used to point to the arguments.
+ */
+#ifdef OBJ
+struct blockmark {
+ char *tos; /* pointer to top of stack frame */
+ struct iorec *file; /* pointer to active file name */
+ struct hdr {
+ long framesze; /* number of bytes of local vars */
+ long nargs; /* number of bytes of arguments */
+ long tests; /* TRUE => perform runtime tests */
+ short offset; /* offset of procedure in source file */
+ char name[1]; /* name of active procedure */
+ } *entry;
+ struct dispsave odisp; /* previous display value for this level */
+ struct dispsave *dp; /* pointer to active display entry */
+ char *pc; /* previous location counter */
+ long lino; /* previous line number */
+};
+#endif OBJ
+#ifdef PC
+#ifdef vax
+ /*
+ * since we have the ap pointing to the number of args:
+ */
+ struct blockmark {
+ long nargs;
+ };
+#endif vax
+#ifdef mc68000
+ /*
+ * there's the saved pc (from the jsr)
+ * and the saved a6 (from the link a6).
+ */
+ struct blockmark {
+ char *savedpc;
+ char *saveda6;
+ };
+#endif mc68000
+#ifdef tahoe
+ /*
+ * since we have the fp pointing to its predecessor
+ */
+ struct blockmark {
+ long savedfp;
+ };
+#endif tahoe
+#endif PC
+
+ /*
+ * formal routine structure:
+ */
+struct formalrtn {
+ long (*fentryaddr)(); /* formal entry point */
+ long fbn; /* block number of function */
+ struct dispsave fdisp[ DSPLYSZ ]; /* saved at first passing */
+};
+#ifndef PC
+#ifndef OBJ
+struct formalrtn frtn;
+#endif
+#endif
+
+#define FENTRYOFFSET 0
+#define FBNOFFSET ( FENTRYOFFSET + sizeof frtn.fentryaddr )
+#define FDISPOFFSET ( FBNOFFSET + sizeof frtn.fbn )
+
+#ifdef OBJ
+ /*
+ * the creation time, the size and the magic number of the obj file
+ */
+ struct pxhdr {
+ long maketime;
+ long objsize;
+ long symtabsize;
+ short magicnum;
+ };
+
+/*
+ * START defines the beginning of the text space.
+ * This should be the defined external label "start",
+ * however there is no way to access externals from C
+ * whose names do not begin with an "_".
+ */
+#ifdef vax
+# define HEADER_BYTES 2048 /* the size of px_header */
+# define START 0x0 /* beginning of text */
+#endif vax
+#ifdef tahoe
+# define HEADER_BYTES 2048 /* the size of px_header */
+# define START 0x0 /* beginning of text */
+#endif tahoe
+#ifdef mc68000
+# define HEADER_BYTES 3072 /* the size of px_header */
+# define START 0x8000 /* beginning of text */
+#endif mc68000
+# define INDX 1 /* amt to shift display index */
+# define A_OBJSTACK 2 /* interpreter stack alignment */
+#endif OBJ
+
+ /*
+ * these are because of varying sizes of pointers
+ */
+#ifdef ADDR16
+# define PTR_AS O_AS2
+# define PTR_RV O_RV2
+# define PTR_IND O_IND2
+# define PTR_CON O_CON2
+# define PTR_DUP O_SDUP2
+# define CON_INT O_CON2
+# define INT_TYP (nl + T2INT)
+# define PTR_DCL char *
+# define TOOMUCH 50000
+# define SHORTADDR 65536
+# define MAXSET 65536 /* maximum set size */
+#endif ADDR16
+#ifdef ADDR32
+# define PTR_AS O_AS4
+# define PTR_RV O_RV4
+# define PTR_IND O_IND4
+# define PTR_CON O_CON4
+# define PTR_DUP O_SDUP4
+# define CON_INT O_CON24
+# define INT_TYP (nl + T4INT)
+# define PTR_DCL unsigned long /* for pointer variables */
+# define SHORTADDR 32768 /* maximum short address */
+# define TOOMUCH 65536 /* maximum variable size */
+# define MAXSET 65536 /* maximum set size */
+#endif ADDR32
+ /*
+ * 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.
+ * since locals are allocated negative offsets,
+ * -DPOFF1 is the last used implicit local offset.
+ * DPOFF2 is the size of the block mark.
+ * since arguments are allocated positive offsets,
+ * DPOFF2 is the end of the implicit arguments.
+ * for obj, the first argument has the highest offset
+ * from the stackpointer. and the block mark is an
+ * implicit last parameter.
+ * for pc, the first argument has the lowest offset
+ * from the argumentpointer. and the block mark is an
+ * implicit first parameter.
+ */
+# ifdef OBJ
+# ifdef ADDR32
+# define MAGICNUM 0403 /* obj magic number */
+# define DPOFF1 0
+# define DPOFF2 (sizeof (struct blockmark))
+# define INPUT_OFF -8 /* offset of `input' */
+# define OUTPUT_OFF -4 /* offset of `output' */
+# endif ADDR32
+# ifdef ADDR16
+# define MAGICNUM 0404
+# define DPOFF1 0
+# define DPOFF2 (sizeof (struct blockmark))
+# define INPUT_OFF -2
+# define OUTPUT_OFF -4
+# endif ADDR16
+# endif OBJ
+# ifdef PC
+# define DPOFF1 ( sizeof (struct rtlocals) )
+# define DPOFF2 ( sizeof (struct blockmark) )
+# define INPUT_OFF 0
+# define OUTPUT_OFF 0
+# endif PC
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