quakeforge/ruamoko/scheme/Compiler.r

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#include "Compiler.h"
#include "Instruction.h"
#include "Nil.h"
#include "Void.h"
#include "Boolean.h"
#include "Cons.h"
#include "defs.h"
Symbol lambdaSym;
Symbol quoteSym;
Symbol defineSym;
Symbol ifSym;
Symbol letrecSym;
Symbol beginSym;
@implementation Compiler
+ (void) initialize
{
lambdaSym = [Symbol forString: "lambda"];
[lambdaSym retain];
quoteSym = [Symbol forString: "quote"];
[quoteSym retain];
defineSym = [Symbol forString: "define"];
[defineSym retain];
ifSym = [Symbol forString: "if"];
[ifSym retain];
letrecSym = symbol("letrec");
[letrecSym retain];
beginSym = symbol("begin");
[beginSym retain];
}
+ (id) newWithLambda: (SchemeObject) xp scope: (Scope) sc
{
return [[self alloc] initWithLambda: xp scope: sc];
}
- (id) initWithLambda: (SchemeObject) xp scope: (Scope) sc
{
self = [super init];
sexpr = xp;
scope = sc;
code = [CompiledCode new];
err = NIL;
return self;
}
- (void) emitBuildEnvironment: (SchemeObject) arguments
{
local integer count, index;
local SchemeObject cur;
scope = [Scope newWithOuter: scope];
count = 0;
for (cur = arguments; [cur isKindOfClass: [Cons class]]; cur = [cur cdr]) {
count++;
}
[code minimumArguments: count];
if (cur != [Nil nil]) {
count++;
}
[code addInstruction: [Instruction opcode: MAKEENV operand: count]];
[code addInstruction: [Instruction opcode: LOADENV]];
cur = arguments;
for (index = 0; index < count; cur = [cur cdr]) {
if ([cur isKindOfClass: [Cons class]]) {
[scope addName: (Symbol) [cur car]];
[code addInstruction: [Instruction opcode: SET operand: index]];
} else if ([cur isKindOfClass: [Symbol class]]) {
[scope addName: (Symbol) cur];
[code addInstruction:
[Instruction opcode: SETREST operand: index]];
break;
} else {
err = [Error type: "syntax"
message: "Invalid entry in argument list"
by: arguments];
return;
}
index++;
}
}
- (void) emitSequence: (SchemeObject) expressions flags: (integer) fl
{
local SchemeObject cur;
for (cur = expressions; cur != [Nil nil]; cur = [cur cdr]) {
if ([cur cdr] == [Nil nil] && (fl & TAIL)) {
[self emitExpression: [cur car] flags: fl];
} else {
[self emitExpression: [cur car] flags: fl & ~TAIL];
}
if (err) return;
}
}
- (void) emitVariable: (Symbol) sym
{
local integer depth = [scope depthOf: sym];
local integer index = [scope indexOf: sym];
[code addInstruction: [Instruction opcode: LOADENV]];
if (depth != -1) {
for (; depth; depth--) {
[code addInstruction: [Instruction opcode: GETLINK]];
}
[code addInstruction: [Instruction opcode: GET operand: index]];
} else {
index = [code addConstant: sym];
[code addInstruction: [Instruction opcode: LOADLITS]];
[code addInstruction: [Instruction opcode: GET operand: index]];
[code addInstruction: [Instruction opcode: GETGLOBAL]];
}
}
- (void) emitDefine: (SchemeObject) expression
{
local integer index = 0;
if (![expression isKindOfClass: [Cons class]] ||
![[expression cdr] isKindOfClass: [Cons class]]) {
err = [Error type: "syntax"
message: "Malformed define statement"
by: expression];
return;
}
if ([[expression car] isKindOfClass: [Cons class]]) {
index = [code addConstant: [[expression car] car]];
[self emitLambda: cons(lambdaSym,
cons([[expression car] cdr],
[expression cdr]))];
if (err) return;
} else if ([[expression car] isKindOfClass: [Symbol class]]) {
index = [code addConstant: [expression car]];
[self emitExpression: [[expression cdr] car] flags: 0];
if (err) return;
} else {
err = [Error type: "syntax"
message: "Malformed define statement"
by: expression];
return;
}
[code addInstruction: [Instruction opcode: PUSH]];
[code addInstruction: [Instruction opcode: LOADLITS]];
[code addInstruction: [Instruction opcode: GET operand: index]];
[code addInstruction: [Instruction opcode: SETGLOBAL]];
}
- (void) emitIf: (SchemeObject) expression flags: (integer) fl
{
local Instruction falseLabel, endLabel;
local integer index;
if (![expression isKindOfClass: [Cons class]] ||
![[expression cdr] isKindOfClass: [Cons class]]) {
err = [Error type: "syntax"
message: "Malformed if expression"
by: expression];
}
falseLabel = [Instruction opcode: LABEL];
endLabel = [Instruction opcode: LABEL];
[self emitExpression: [expression car] flags: fl & ~TAIL];
if (err) return;
[code addInstruction: [Instruction opcode: IFFALSE label: falseLabel]];
[self emitExpression: [[expression cdr] car] flags: fl];
if (err) return;
[code addInstruction: [Instruction opcode: GOTO label: endLabel]];
[code addInstruction: falseLabel];
if ([[expression cdr] cdr] == [Nil nil]) {
index = [code addConstant: [Void voidConstant]];
[code addInstruction: [Instruction opcode: LOADLITS]];
[code addInstruction: [Instruction opcode: GET operand: index]];
} else {
[self emitExpression: [[[expression cdr] cdr] car] flags: fl];
if (err) return;
}
[code addInstruction: endLabel];
}
- (void) emitLetrec: (SchemeObject) expression flags: (integer) fl
{
local SchemeObject bindings;
local integer count;
if (!isList(expression) ||
!isList([expression car]) ||
![[expression cdr] isKindOfClass: [Cons class]]) {
err = [Error type: "syntax"
message: "Malformed letrec expression"
by: expression];
}
scope = [Scope newWithOuter: scope];
count = 0;
for (bindings = [expression car]; bindings != [Nil nil]; bindings = [bindings cdr]) {
[scope addName: (Symbol) [[bindings car] car]];
count++;
}
[code addInstruction: [Instruction opcode: MAKEENV operand: count]];
count = 0;
for (bindings = [expression car]; bindings != [Nil nil]; bindings = [bindings cdr]) {
[self emitSequence: [[bindings car] cdr] flags: fl & ~TAIL];
[code addInstruction: [Instruction opcode: PUSH]];
[code addInstruction: [Instruction opcode: LOADENV]];
[code addInstruction: [Instruction opcode: SET operand: count]];
count++;
}
[self emitSequence: [expression cdr] flags: fl];
[code addInstruction: [Instruction opcode: POPENV]];
scope = [scope outer];
}
- (void) emitExpression: (SchemeObject) expression flags: (integer) fl
{
if ([expression isKindOfClass: [Cons class]]) {
[code source: [expression source]];
[code line: [expression line]];
if ([expression car] == lambdaSym) {
[self emitLambda: expression];
} else if ([expression car] == quoteSym) {
[self emitConstant: [[expression cdr] car]];
} else if ([expression car] == defineSym) {
[self emitDefine: [expression cdr]];
} else if ([expression car] == ifSym) {
[self emitIf: [expression cdr] flags: fl];
} else if ([expression car] == letrecSym) {
[self emitLetrec: [expression cdr] flags: fl];
} else if ([expression car] == beginSym) {
[self emitSequence: [expression cdr] flags: fl];
} else {
[self emitApply: expression flags: fl];
}
} else if ([expression isKindOfClass: [Symbol class]]) {
[self emitVariable: (Symbol) expression];
} else {
[self emitConstant: expression];
}
}
- (void) emitArguments: (SchemeObject) expression
{
if (expression == [Nil nil]) {
return;
} else {
[self emitArguments: [expression cdr]];
if (err) return;
[self emitExpression: [expression car] flags: 0];
if (err) return;
[code addInstruction: [Instruction opcode: PUSH]];
}
}
- (void) emitApply: (SchemeObject) expression flags: (integer) fl
{
local Instruction label = [Instruction opcode: LABEL];
if (!(fl & TAIL)) {
[code addInstruction: [Instruction opcode: MAKECONT label: label]];
}
[self emitArguments: [expression cdr]];
if (err) return;
[self emitExpression: [expression car] flags: fl & ~TAIL];
if (err) return;
[code addInstruction: [Instruction opcode: CALL]];
[code addInstruction: label];
}
- (void) emitLambda: (SchemeObject) expression
{
local Compiler compiler = [Compiler newWithLambda: expression
scope: scope];
local SchemeObject res;
local integer index;
res = [compiler compile];
if ([res isError]) {
err = (Error) res;
return;
}
index = [code addConstant: res];
[code addInstruction: [Instruction opcode: LOADLITS]];
[code addInstruction: [Instruction opcode: GET operand: index]];
[code addInstruction: [Instruction opcode: MAKECLOSURE]];
}
- (void) emitConstant: (SchemeObject) expression
{
local integer index;
index = [code addConstant: expression];
[code addInstruction: [Instruction opcode: LOADLITS]];
[code addInstruction: [Instruction opcode: GET operand: index]];
}
- (void) checkLambdaSyntax: (SchemeObject) expression
{
if (![expression isKindOfClass: [Cons class]] ||
[expression car] != lambdaSym ||
[expression cdr] == [Nil nil] ||
[[expression cdr] cdr] == [Nil nil]) {
err = [Error type: "syntax"
message: "malformed lambda expression"
by: expression];
}
}
- (SchemeObject) compile
{
[self checkLambdaSyntax: sexpr];
if (err) {
return err;
}
[self emitBuildEnvironment: [[sexpr cdr] car]];
if (err) {
return err;
}
[self emitSequence: [[sexpr cdr] cdr] flags: TAIL];
if (err) {
return err;
}
[code addInstruction: [Instruction opcode: RETURN]];
[code compile];
return code;
}
- (void) markReachable
{
[code mark];
[sexpr mark];
[scope mark];
}
@end