5 files changed, 401 insertions, 0 deletions

diff --git a/works/life/compile-principle-experiment/4/lex.l b/works/life/compile-principle-experiment/4/lex.l
new file mode 100644
index 0000000..e7731ca
--- /dev/null
+++ b/works/life/compile-principle-experiment/4/lex.l
@@ -0,0 +1,20 @@
+%{
+#include "main.h"
+#include "syn.h"
+%}
+%option noyywrap
+%%
+[ \t]	{ ; }	/* skip blanks and tabs */
+[0-9]+\.?|[0-9]*\.[0-9]+ {
+	Symbol *s = cru_symbol_install("", UNDEF, (SymbolValue)0.0);
+	sscanf(yytext, "%lf", &s->value.val);
+	yylval.sym = s;
+	return NUMBER; }
+[a-zA-Z][a-zA-Z0-9]* {
+	Symbol *s;
+	if ((s=cru_symbol_lookup(yytext)) == 0)
+		s = cru_symbol_install(yytext, UNDEF, (SymbolValue)0.0);
+	yylval.sym = s;
+	return s->type == UNDEF ? VAR : s->type; }
+\n	{ lineno++; return '\n'; }   /* everything else */
+.	{ return yytext[0]; }
diff --git a/works/life/compile-principle-experiment/4/main.c b/works/life/compile-principle-experiment/4/main.c
new file mode 100644
index 0000000..258ccc7
--- /dev/null
+++ b/works/life/compile-principle-experiment/4/main.c
@@ -0,0 +1,279 @@
+#include "main.h"
+
+#include "syn.h"
+
+#include <errno.h>
+#include <math.h>
+#include <setjmp.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static Symbol *symlist = 0; /* symbol table: linked list */
+
+void *emalloc(size_t n) /* check return from malloc */
+{
+  void *p = malloc(n);
+  if (p == 0)
+    execerror("out of memory", (char *)0);
+  return p;
+}
+
+Symbol *cru_symbol_lookup(const char *name) {
+  for (Symbol *sp = symlist; sp != NULL; sp = sp->next)
+    if (strcmp(sp->name, name) == 0)
+      return sp;
+  return NULL;
+}
+
+Symbol *cru_symbol_install(const char *name, int type, SymbolValue value) {
+  Symbol *sp = (Symbol *)emalloc(sizeof(Symbol));
+  sp->name = emalloc(strlen(name) + 1);
+  strcpy(sp->name, name);
+  sp->type = type;
+  sp->value = value;
+  sp->next = symlist;
+  symlist = sp;
+  return sp;
+}
+
+jmp_buf begin;
+int lineno;
+
+void warning(const char *s, const char *t) {
+  fprintf(stderr, "%s", s);
+  if (t)
+    fprintf(stderr, " %s", t);
+  fprintf(stderr, " near line %d\n", lineno);
+}
+
+void yyerror(const char *s) { warning(s, NULL); }
+
+void execerror(const char *s, const char *t) {
+  warning(s, t);
+  longjmp(begin, 0);
+}
+
+double errcheck(double result, const char *name) {
+  if (errno == EDOM) {
+    errno = 0;
+    execerror(name, "argument out of domain");
+  } else if (errno == ERANGE) {
+    errno = 0;
+    execerror(name, "result out of range");
+  }
+  return result;
+}
+
+double Log(double x) { return errcheck(log(x), "log"); }
+double Log10(double x) { return errcheck(log10(x), "log10"); }
+double Sqrt(double x) { return errcheck(sqrt(x), "sqrt"); }
+double Exp(double x) { return errcheck(exp(x), "exp"); }
+double Pow(double x, double y) { return errcheck(pow(x, y), "exponentiation"); }
+double integer(double x) { return (double)(long)x; }
+
+static struct { /* Constants */
+  char *name;
+  double cval;
+} consts[] = {
+    {"PI", 3.14159265358979323846},    {"E", 2.71828182845904523536},
+    {"GAMMA", 0.57721566490153286060}, {"DEG", 57.29577951308232087680},
+    {"PHI", 1.61803398874989484820},
+};
+
+static struct { /* Built-ins */
+  char *name;
+  double (*func)();
+} builtins[] = {
+    {"sin", sin},   {"cos", cos},     {"atan", atan},
+    {"log", Log},   {"log10", Log10}, {"exp", Exp},
+    {"sqrt", Sqrt}, {"int", integer}, {"abs", fabs},
+};
+
+int initcode();
+int execute(Inst *p);
+
+void init() {
+  initcode();
+  for (int i = 0; i < sizeof(consts) / sizeof(*consts); i++)
+    cru_symbol_install(consts[i].name, VAR, (SymbolValue)consts[i].cval);
+  for (int i = 0; i < sizeof(builtins) / sizeof(*builtins); i++) {
+    cru_symbol_install(builtins[i].name, BLTIN, (SymbolValue)builtins->func);
+  }
+}
+
+int main(int argc, char **argv) {
+  init();
+  (void)setjmp(begin);
+  yyparse();
+  execute(prog);
+
+  return 0;
+}
+
+#define NSTACK 256
+static Datum stack[NSTACK]; /* the stack */
+static Datum *stackp;       /* next free spot on stack */
+
+#define NPROG 2000
+Inst prog[NPROG]; /* the machine */
+Inst *progp;      /* next free spot for code generation */
+Inst *pc;         /* program counter during execution */
+
+int initcode() /* initialize for code generation */
+{
+  stackp = stack;
+  progp = prog;
+  return 0;
+}
+
+int push(Datum d) /* push d onto stack */
+{
+  if (stackp >= &stack[NSTACK])
+    execerror("stack overflow", (char *)0);
+  *stackp++ = d;
+  return 0;
+}
+
+Datum pop() /* pop and return top elem from stack */
+{
+  if (stackp <= stack)
+    execerror("stack underflow", (char *)0);
+  return *--stackp;
+}
+
+int constpush() /* push constant onto stack */
+{
+  Datum d;
+  d.val = ((Symbol *)*pc++)->value.val;
+  push(d);
+  return 0;
+}
+
+int varpush() /* push variable onto stack */
+{
+  Datum d;
+  d.sym = (Symbol *)(*pc++);
+  push(d);
+  return 0;
+}
+
+int bltin() /* evaluate built-in on top of stack */
+{
+  Datum d;
+  d = pop();
+  d.val = (*(double (*)())(*pc++))(d.val);
+  push(d);
+  return 0;
+}
+
+int eval() /* evaluate variable on stack */
+{
+  Datum d;
+  d = pop();
+  if (d.sym->type == UNDEF)
+    execerror("undefined variable", d.sym->name);
+  d.val = d.sym->value.val;
+  push(d);
+  return 0;
+}
+
+int add() /* add top two elems on stack */
+{
+  Datum d1, d2;
+  d2 = pop();
+  d1 = pop();
+  d1.val += d2.val;
+  push(d1);
+  return 0;
+}
+
+int sub() /* subtract top of stack from next */
+{
+  Datum d1, d2;
+  d2 = pop();
+  d1 = pop();
+  d1.val -= d2.val;
+  push(d1);
+  return 0;
+}
+
+int mul() {
+  Datum d1, d2;
+  d2 = pop();
+  d1 = pop();
+  d1.val *= d2.val;
+  push(d1);
+  return 0;
+}
+
+int mydiv() {
+  Datum d1, d2;
+  d2 = pop();
+  if (d2.val == 0.0)
+    execerror("division by zero", (char *)0);
+  d1 = pop();
+  d1.val /= d2.val;
+  push(d1);
+  return 0;
+}
+
+int negate() {
+  Datum d;
+  d = pop();
+  d.val = -d.val;
+  push(d);
+  return 0;
+}
+
+int power() {
+  Datum d1, d2;
+  extern double Pow();
+  d2 = pop();
+  d1 = pop();
+  d1.val = Pow(d1.val, d2.val);
+  push(d1);
+  return 0;
+}
+
+int assign() /* assign top value to next value */
+{
+  Datum d1, d2;
+  d1 = pop();
+  d2 = pop();
+  if (d1.sym->type != VAR && d1.sym->type != UNDEF)
+    execerror("assignment to non-variable", d1.sym->name);
+  d1.sym->value.val = d2.val;
+  d1.sym->type = VAR;
+  push(d2);
+  return 0;
+}
+
+int print() /* pop top value from stack, print it */
+{
+  Datum d;
+  d = pop();
+  printf("\t%.8g\n", d.val);
+  return 0;
+}
+
+Inst *code(Inst f) /* install one instruction or operand */
+{
+  Inst *oprogp = progp;
+  if (progp >= &prog[NPROG])
+    execerror("program too big", (char *)0);
+  *progp++ = f;
+  return oprogp;
+}
+
+int execute(Inst *p) /* run the machine */
+{
+  for (pc = p; *pc != STOP;)
+    (*(*pc++))();
+  return 0;
+}
+
+int mypop() {
+  pop();
+  return 0;
+}
diff --git a/works/life/compile-principle-experiment/4/main.h b/works/life/compile-principle-experiment/4/main.h
new file mode 100644
index 0000000..96bd9e7
--- /dev/null
+++ b/works/life/compile-principle-experiment/4/main.h
@@ -0,0 +1,41 @@
+#pragma once
+
+typedef union SymbolValue {
+  double val;
+  double (*ptr)();
+} SymbolValue;
+
+typedef struct Symbol {
+  char *name;
+  int type;
+  SymbolValue value;
+  struct Symbol *next;
+} Symbol;
+
+Symbol *cru_symbol_lookup(const char *name);
+Symbol *cru_symbol_install(const char *name, int type, SymbolValue value);
+
+double Pow(double x, double y);
+
+int yylex();
+int yyparse();
+void yyerror(const char *s);
+
+extern int lineno;
+void execerror(const char *s, const char *t);
+
+typedef union Datum { /* interpreter stack type */
+  double val;
+  Symbol *sym;
+} Datum;
+extern Datum pop();
+int mypop();
+
+typedef int (*Inst)(); /* machine instruction */
+#define STOP (Inst)0
+
+extern Inst prog[];
+extern int eval(), add(), sub(), mul(), mydiv(), negate(), power();
+extern int assign(), bltin(), varpush(), constpush(), print();
+
+extern Inst *code(Inst f);
diff --git a/works/life/compile-principle-experiment/4/makefile b/works/life/compile-principle-experiment/4/makefile
new file mode 100644
index 0000000..756cdcb
--- /dev/null
+++ b/works/life/compile-principle-experiment/4/makefile
@@ -0,0 +1,22 @@
+main: main.o lex.o syn.o
+	cc -g lex.o syn.o main.o -o main
+
+main.o: main.c main.h syn.h
+	cc -g -c -o main.o main.c
+
+lex.c: lex.l
+	flex  -o lex.c lex.l
+
+lex.o: lex.c syn.h main.h
+	cc -g -c -o lex.o lex.c
+
+syn.c syn.h: syn.y
+	bison syn.y -d -o syn.c
+
+syn.o: syn.c syn.h main.h
+	cc -g -c -o syn.o syn.c
+
+PHONY: clean
+
+clean:
+	rm -f *.o lex.c syn.c syn.h main
diff --git a/works/life/compile-principle-experiment/4/syn.y b/works/life/compile-principle-experiment/4/syn.y
new file mode 100644
index 0000000..ebe113f
--- /dev/null
+++ b/works/life/compile-principle-experiment/4/syn.y
@@ -0,0 +1,39 @@
+%{
+#include "main.h"
+#include <stdio.h>
+#define	code2(c1,c2)	code(c1); code(c2)
+#define	code3(c1,c2,c3)	code(c1); code(c2); code(c3)
+%}
+%union {
+	Symbol	*sym;	/* symbol table pointer */
+	double val;
+	Inst	*inst;	/* machine instruction */
+}
+%token	<sym>	NUMBER VAR BLTIN UNDEF
+%right	'='
+%left	'+' '-'
+%left	'*' '/'
+%left	UNARYMINUS
+%right	'^'	/* exponentiation */
+%%
+list:	  /* nothing */
+	| list '\n'
+	| list asgn '\n'  { code2(mypop, STOP); return 1; }
+	| list expr '\n'  { code2(print, STOP); return 1; }
+	| list error '\n' { yyerrok; }
+	;
+asgn:	  VAR '=' expr	{ code3(varpush,(Inst)$1,assign); }
+	;
+expr:	  NUMBER	{ code2(constpush, (Inst)$1); }
+	| VAR		{ code3(varpush, (Inst)$1, eval); }
+	| asgn
+	| BLTIN '(' expr ')' { code2(bltin, (Inst)$1->value.ptr); }
+	| '(' expr ')'
+	| expr '+' expr	{ code(add); }
+	| expr '-' expr	{ code(sub); }
+	| expr '*' expr	{ code(mul); }
+	| expr '/' expr	{ code(mydiv); }
+	| expr '^' expr	{ code(power); }
+	| '-' expr  %prec UNARYMINUS  { code(negate); }
+	;
+%%