add quad repersentation

Signed-off-by: szdytom <szdytom@163.com>

include/acir.h

@@ -6,16 +6,21 @@ enum {
 	IR_ADD, IR_SUB, IR_MUL, IR_DIV,
 	IR_EQ, IR_NE, IR_LT, IR_GT, IR_LE, IR_GE,
 	IR_NEG,
-	IR_LIT,
+	IR_LIT32, IR_LIT64,
 };
 
+struct IRblock {
+	
+}
+
 struct IRinstruction {
 	int op;
 	union {
-		struct { IRinstruction *left, *right; };
+		struct { int left, right; };
-		int val;
+		int val_i32;
+		int val_i64;
 	};
 };
 
 
-#endif
+#endif

include/ast.h

@@ -19,28 +19,32 @@ enum {
 
 extern const char *ast_opname[31];
 
+#ifndef ACC_ASTnode_SHARED_FIELDS
+
 // AST structure field shared by all types 
-// llist_node *n	: for linklist
+// llist_node *n	: linklist header
 // int op		: node operation
-#define ASTnode_SHARED_FIELDS \
+#define ACC_ASTnode_SHARED_FIELDS \
 	struct llist_node n; \
 	int op;
 
+#endif
+
 // AST structure (common)
 struct ASTnode {
-	ASTnode_SHARED_FIELDS 
+	ACC_ASTnode_SHARED_FIELDS 
 };
 
 // AST binary operation node
 struct ASTbinnode {
-	ASTnode_SHARED_FIELDS 
+	ACC_ASTnode_SHARED_FIELDS 
 	struct ASTnode *left;
 	struct ASTnode *right;
 };
 
 // AST if statement node
 struct ASTifnode {
-	ASTnode_SHARED_FIELDS 
+	ACC_ASTnode_SHARED_FIELDS 
 	struct ASTnode *left;	// condition true branch
 	struct ASTnode *right;	// condition false branch
 	struct ASTnode *cond;
@@ -48,41 +52,51 @@ struct ASTifnode {
 
 // AST unary operation node
 struct ASTunnode {
-	ASTnode_SHARED_FIELDS 
+	ACC_ASTnode_SHARED_FIELDS 
 	struct ASTnode *left;
 };
 
 // AST block node
 struct ASTblocknode {
-	ASTnode_SHARED_FIELDS 
+	ACC_ASTnode_SHARED_FIELDS 
 	struct linklist st; // statements linklist
 };
 
 // AST integer literal (32bit) node
 struct ASTi32node {
-	ASTnode_SHARED_FIELDS 
+	ACC_ASTnode_SHARED_FIELDS 
 	int32_t val;
 };
 
 // AST integer literal (64bit) node
 struct ASTi64node {
-	ASTnode_SHARED_FIELDS 
+	ACC_ASTnode_SHARED_FIELDS 
 	int64_t val;
 };
 
 // AST assign literal node
 struct ASTassignnode {
-	ASTnode_SHARED_FIELDS 
+	ACC_ASTnode_SHARED_FIELDS 
 	struct ASTnode* left;
 	struct ASTnode* right;
 };
 
 // AST variable value node
 struct ASTvarnode {
-	ASTnode_SHARED_FIELDS 
+	ACC_ASTnode_SHARED_FIELDS 
 	int id;
 };
 
+// A function with its AST root.
+// TODO: parameters
+struct Afunction {
+	struct llist_node n;	// linklist header
+	char *name;		// function name
+	struct ASTnode *rt;	// AST root
+};
+
+struct Afunction* afunc_make();
+
 struct ASTnode* ast_make_binary(int op, struct ASTnode *left, struct ASTnode *right);
 struct ASTnode* ast_make_lit_i32(int32_t x);
 struct ASTnode* ast_make_lit_i64(int64_t x);
@@ -91,6 +105,11 @@ struct ASTnode* ast_make_block();
 struct ASTnode* ast_make_var(int id);
 struct ASTnode* ast_make_assign(int op, struct ASTnode *left, struct ASTnode *right);
 struct ASTnode* ast_make_if(struct ASTnode *left, struct ASTnode *right, struct ASTnode *cond);
+
+void ast_debug_print(FILE *Outfile, struct ASTnode *rt);
+void afunc_debug_print(FILE *Outfile, struct Afunction *f);
+
+void afunc_free(struct Afunction *f);
 void ast_free(struct ASTnode *x);
 
 #endif

include/fatals.h

@@ -7,6 +7,7 @@
 void* malloc_or_fail(size_t s, const char *func_name);
 noreturn void fail_target(const char *target_name);
 noreturn void fail_malloc(const char *func_name);
+noreturn void fail_quad_op(int op, const char *func_name);
 noreturn void fail_ast_op(int op, const char *func_name);
 noreturn void fail_ce_expect(int line, const char *expected, const char *got);
 noreturn void fail_ce(int line, const char *reason);

include/parse.h

@@ -1,6 +1,6 @@
 #ifndef ACC_PARSE_H
 #define ACC_PARSE_H
 
-struct ASTnode* parse(const char *name);
+struct Afunction* parse_source(const char *filename);
 
 #endif

include/print_ast.h

@@ -1,7 +0,0 @@
-#ifndef ACC_DEBUG_PRINT_AST
-#define ACC_DEBUG_PRINT_AST
-
-void debug_ast_print(FILE *Outfile, struct ASTnode *rt);
-
-#endif
-

include/quad.h

@@ -0,0 +1,96 @@
+#ifndef ACC_QUAD_H
+#define ACC_QUAD_H
+
+#include <stdint.h>
+#include <stdbool.h>
+#include "ast.h"
+#include "util/linklist.h"
+
+// Operation code definations
+enum {
+	// Loading immediates
+	Q_IMM_I32,	// integer (32bits)
+
+	// Terminates
+	Q_RET,		// return 
+	Q_BR_ALWAYS,	// conditional goto: always goto true branch.
+
+	// Guard
+	Q_NULL,
+};
+
+// Local(in function) variable.
+struct Qvar {
+	struct llist_node n;	// linklist header
+	int id;			// variable id
+};
+
+// Quad instruction.
+struct Quad {
+	struct llist_node n;	// linklist header
+	int op;			// operation code
+	struct Qvar *dest;	// operation destination
+	union {
+		struct { struct Qvar *left, *right; };	// left/right operands for calculations
+		struct { struct Qblock *bt, *bf; };	// true branch & false branch for conditional goto
+		int32_t val_i32;			// immediate: integer (32bits)
+	};
+};
+
+// Basic block consist of Quad instructions.
+struct Qblock {
+	struct llist_node n;	// linklist header
+	int id;			// block id
+	struct linklist ins;	// instruction Quads
+	bool is_complete;	// whether the block is properly ended with a terminate
+};
+
+// Function containing Quad instructions.
+// TODO: paramaters
+struct Qfunction {
+	struct llist_node n;	// linklist header
+	char *name;		// function name
+	struct linklist bs;	// basic blocks
+	struct linklist vars;	// local variables
+};
+
+// Constructs a Quad with an operator, a destination and two operands.
+struct Quad* quad_make(int op, struct Qvar *dest, struct Qvar *left, struct Qvar *right);
+
+// Constructs a Quad with a loads an integer immediate (32bits).
+struct Quad* quad_make_i32(struct Qvar *dest, int32_t v);
+
+// Constructs a Quad with instruction Q_BR_XXX (conditional goto).
+struct Quad* quad_make_br(int op, struct Qblock *bt, struct Qblock *bf);
+
+// Returns whether the given opcode is a opcode from a terminate.
+bool quad_is_terminate(int op);
+
+// Constructs a Qblock.
+struct Qblock* qblock_make();
+
+// Allocates a new basic block in the give function.
+struct Qblock* qfunc_new_block(struct Qfunction *f);
+
+// Appends an instruction to a block.
+void qblock_add_ins(struct Qblock *b, struct Quad *x);
+
+// Constructs a new Qvar.
+struct Qvar* qvar_make(int id);
+
+// Allocates a new variable in the given function.
+struct Qvar* qfunc_new_var(struct Qfunction *f);
+
+// Generates Quad Repersentation from an AST
+struct Qfunction* qfunc_cgenerate(struct Afunction *afunc);
+
+// Frees a Qblock and all its components.
+void qblock_free(struct Qblock *b);
+
+// Frees a Qfunction and all its components.
+void qfunc_free(struct Qfunction *f);
+
+// Prints the contents of a Qfunction for debugging.
+void qfunc_debug_print(struct Qfunction *self, FILE *Outfile);
+
+#endif

include/scan.h

@@ -3,6 +3,6 @@
 
 #include "util/linklist.h"
 
-struct linklist scan_tokens(const char *name);
+struct linklist scan_tokens(const char *filename);
 
 #endif

include/target.h

@@ -3,7 +3,9 @@
 
 // Target types
 enum {
-	TARGET_AST
+	TARGET_AST,
+	TARGET_QUAD,
+	TARGET_NULL,
 };
 
 int target_parse(const char *target_string);

include/util/misc.h

@@ -3,7 +3,9 @@
 
 #include <stdbool.h>
 
+#define ACC_ARRAY_LENGTH(a) (sizeof((a))/sizeof(*(a)))
+
 bool strequal(const char *s1, const char *s2);
-char *strclone(const char *s);
+char* strclone(const char *s);
 
 #endif

main.c

@@ -5,7 +5,7 @@
 #include "parse.h"
 #include "ast.h"
 #include "target.h"
-#include "print_ast.h"
+#include "quad.h"
 
 // Print out a usage if started incorrectly
 static void usage(char *prog) {
@@ -14,8 +14,13 @@ static void usage(char *prog) {
 	exit(1);
 }
 
+static FILE *Outfile;
+
 // Do clean up job
 void unload(void) {
+	if (Outfile && Outfile != stdout) {
+		fclose(Outfile);
+	}
 }
 
 int main(int argc, char *argv[]) {
@@ -24,19 +29,21 @@ int main(int argc, char *argv[]) {
 		usage(argv[0]);
 	}
 
-	FILE *Outfile;
 	if (argc >= 4) {
 		Outfile = fopen(argv[3], "w");
 	} else {
-		Outfile = fopen("out.txt", "w");
+		Outfile = stdout;
 	}
 
 	int target = target_parse(argv[1]);
-	struct ASTnode *rt = parse(argv[2]);
+	struct Afunction *afunc = parse_source(argv[2]);
 	if (target == TARGET_AST) {
-		debug_ast_print(Outfile, rt);
+		afunc_debug_print(Outfile, afunc);
+	} else if (target == TARGET_QUAD) {
+		struct Qfunction *qfunc = qfunc_cgenerate(afunc);
+		qfunc_debug_print(qfunc, Outfile);
+		qfunc_free(qfunc);
 	}
-	ast_free(rt);
+	afunc_free(afunc);
-	fclose(Outfile);
 	return (0);
 }

src/ast.c

@@ -16,7 +16,7 @@ const char *ast_opname[] = {
 	NULL
 };
 
-// Build and return a binary AST node
+// Constructs a binary AST node
 struct ASTnode* ast_make_binary(int op, struct ASTnode *left, struct ASTnode *right) {
 	struct ASTbinnode *x = malloc_or_fail(sizeof(struct ASTbinnode), __FUNCTION__);
 
@@ -26,7 +26,7 @@ struct ASTnode* ast_make_binary(int op, struct ASTnode *left, struct ASTnode *ri
 	return ((struct ASTnode*)x);
 }
 
-// Make an AST integer literal (32bit) node
+// Make an AST integer literal (32bits) node
 struct ASTnode* ast_make_lit_i32(int32_t v) {
 	struct ASTi32node *x = malloc_or_fail(sizeof(struct ASTi32node), __FUNCTION__);
 
@@ -35,7 +35,7 @@ struct ASTnode* ast_make_lit_i32(int32_t v) {
 	return ((struct ASTnode*)x);
 }
 
-// Make an AST integer literal (64bit) node
+// Make an AST integer literal (64bits) node
 struct ASTnode* ast_make_lit_i64(int64_t v) {
 	struct ASTi64node *x = malloc_or_fail(sizeof(struct ASTi64node), __FUNCTION__);
 
@@ -92,7 +92,83 @@ struct ASTnode* ast_make_if(struct ASTnode *left, struct ASTnode *right, struct
 	return ((struct ASTnode*)x);
 }
 
-// free an AST's memory
+static void ast_print_dfs(FILE* Outfile, struct ASTnode *x, int tabs) {
+	for (int i = 0; i < tabs; ++i) {
+		fprintf(Outfile, "\t");
+	}
+
+	if (x == NULL) {
+		fprintf(Outfile, "--->NULL.\n");
+		return;
+	}
+
+	switch(x->op) {
+		case A_RETURN: case A_PRINT: {
+			struct ASTunnode *t = (struct ASTunnode*)x;
+			fprintf(Outfile, "--->UNOP(%s)\n", ast_opname[x->op]);
+			ast_print_dfs(Outfile, t->left, tabs + 1);
+		}	break;
+
+		case A_LIT_I32: {
+			struct ASTi32node *t = (struct ASTi32node*)x;
+			fprintf(Outfile, "--->INT32(%d)\n", t->val);
+		}	break;
+
+		case A_LIT_I64: {
+			struct ASTi64node *t = (struct ASTi64node*)x;
+			fprintf(Outfile, "--->INT64(%lld)\n", t->val);
+		}	break;
+
+		case A_BLOCK: {
+			struct ASTblocknode *t = (struct ASTblocknode*)x;
+			fprintf(Outfile, "--->BLOCK(%d statements)\n", t->st.length);
+			struct llist_node *p = t->st.head;
+			while (p) {
+				ast_print_dfs(Outfile, (struct ASTnode*)p, tabs + 1);
+				p = p->nxt;
+			}
+		}	break;
+
+		default: {
+			fail_ast_op(x->op, __FUNCTION__);
+		}	break;
+	}
+}
+
+// Prints the structure of a AST into Outfile.
+void ast_debug_print(FILE *Outfile, struct ASTnode *rt) {
+	ast_print_dfs(Outfile, rt, 0);
+}
+
+// Prints the structure of a Afunction into Outfile.
+void afunc_debug_print(FILE *Outfile, struct Afunction *f) {
+	fprintf(Outfile, "FUNCTION %s: \n", f->name);
+	ast_print_dfs(Outfile, f->rt, 0);
+}
+
+// Constructs a Afunction.
+struct Afunction* afunc_make() {
+	struct Afunction *res = (struct Afunction*)malloc_or_fail(sizeof(struct Afunction), __FUNCTION__);
+
+	res->rt = NULL;
+	res->name = NULL;
+	return res;
+}
+
+// Frees a Afunction and all its components.
+void afunc_free(struct Afunction *f) {
+	if (f->name) {
+		free(f->name);
+	}
+
+	if (f->rt) {
+		ast_free(f->rt);
+	}
+
+	free(f);
+}
+
+// Frees an AST's memory, including its childs.
 void ast_free(struct ASTnode *x) {
 	if (x == NULL) {
 		return;
@@ -125,10 +201,13 @@ void ast_free(struct ASTnode *x) {
 				ast_free((struct ASTnode*)p);
 				p = nxt;
 			}
-			llist_free(&t->st);
+		}	break;
+
+		case A_LIT_I32: case A_LIT_I64: {
 		}	break;
 
 		default: {
+			fail_ast_op(x->op, __FUNCTION__);
 		}	break;
 	}
 	free(x);

src/fatals.c

@@ -1,6 +1,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include "scan.h"
+#include "ast.h"
+#include "quad.h"
 
 void fail_target(const char *target_name) {
 	fprintf(stderr, "unknown target: %s.\n", target_name);
@@ -20,9 +22,24 @@ void* malloc_or_fail(size_t s, const char *func_name) {
 	return (res);
 }
 
+void fail_quad_op(int op, const char *func_name) {
+	if (op < Q_NULL) {
+		fprintf(stderr, "%s: unsupported Quad operator %s.\n", func_name, ast_opname[op]);
+		exit(1);
+	} else {
+		fprintf(stderr, "%s: unknown Quad operator %d.\n", func_name, op);
+		exit(1);
+	}
+}
+
 void fail_ast_op(int op, const char *func_name) {
-	fprintf(stderr, "%s: unknown ast operator %d.\n", func_name, op);
+	if (op < A_SOUL) {
-	exit(1);
+		fprintf(stderr, "%s: unsupported AST operator %s.\n", func_name, ast_opname[op]);
+		exit(1);
+	} else {
+		fprintf(stderr, "%s: unknown AST operator %d.\n", func_name, op);
+		exit(1);
+	}
 }
 
 void fail_ce_expect(int line, const char *expected, const char *got) {

src/parse.c

@@ -347,11 +347,13 @@ static struct ASTnode* statement(void) {
 
 // Parse one top-level function
 // Sets the func_name param.
-static struct ASTnode* function(char **func_name) {
+static struct Afunction* function() {
+	struct Afunction *res = afunc_make();
+
 	match(T_INT);
 	expect(T_ID);
-	*func_name = current()->val_s;	// transfer ownership of the identifier string to caller
+	res->name = current()->val_s;	// transfer ownership of the identifier string to caller
-	current()->val_s = NULL;	// prevent it from being freed in token_free() called by next.
+	current()->val_s = NULL;	// prevent it from being freed in token_free() called by next().
 	next();
 
 	match(T_LP);
@@ -359,20 +361,19 @@ static struct ASTnode* function(char **func_name) {
 		next();
 		goto END_PARAM_LIST;
 	}
-	// TODO: param list
+	// TODO: parameter list
 
 END_PARAM_LIST:
 	match(T_RP);
-	return (block());
+	res->rt = block();
+	return (res);
 }
 
 // Parse ans return the full ast
-struct ASTnode* parse(const char *name) {
+struct Afunction* parse_source(const char *filename) {
-	Tokens = scan_tokens(name);
+	Tokens = scan_tokens(filename);
-	char *func_name;
+	struct Afunction* res = function();
-	struct ASTnode* res = function(&func_name);
 
-	free(func_name);
 	while (Tokens.length > 0) {
 		token_free(llist_popfront(&Tokens));
 	}

src/print_ast.c

@@ -1,65 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include "ast.h"
-#include "print_ast.h"
-#include "symbol.h"
-#include "fatals.h"
-#include "util/array.h"
-
-static int tabs;
-
-static void print_tabs(FILE* Outfile) {
-	for (int i = 0; i < tabs; ++i) {
-		fprintf(Outfile, "\t");
-	}
-}
-
-static void ast_dfs(FILE* Outfile, struct ASTnode *x) {
-	print_tabs(Outfile);
-	if (x == NULL) {
-		fprintf(Outfile, "--->NULL.\n");
-		return;
-	}
-
-	switch(x->op) {
-		case A_RETURN: case A_PRINT: {
-			struct ASTunnode *t = (struct ASTunnode*)x;
-			fprintf(Outfile, "--->UNOP(%s)\n", ast_opname[x->op]);
-			tabs += 1;
-			ast_dfs(Outfile, t->left);
-			tabs -= 1;
-		}	break;
-
-		case A_LIT_I32: {
-			struct ASTi32node *t = (struct ASTi32node*)x;
-			fprintf(Outfile, "--->INT32(%d)\n", t->val);
-		}	break;
-
-		case A_LIT_I64: {
-			struct ASTi64node *t = (struct ASTi64node*)x;
-			fprintf(Outfile, "--->INT64(%lld)\n", t->val);
-		}	break;
-
-		case A_BLOCK: {
-			struct ASTblocknode *t = (struct ASTblocknode*)x;
-			fprintf(Outfile, "--->BLOCK(%d statements)\n", t->st.length);
-			tabs += 1;
-			struct llist_node *p = t->st.head;
-			while (p) {
-				ast_dfs(Outfile, (struct ASTnode*)p);
-				p = p->nxt;
-			}
-			tabs -= 1;
-		}	break;
-
-		default: {
-			fprintf(Outfile, "--->%s...\n", ast_opname[x->op]);
-		}	break;
-	}
-}
-
-void debug_ast_print(FILE *Outfile, struct ASTnode *rt) {
-	tabs = 0;
-	ast_dfs(Outfile, rt);
-}
-

src/quad.c

@@ -0,0 +1,193 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "quad.h"
+#include "fatals.h"
+
+// Constructs a Quad with an operator, a destination and two operands.
+struct Quad* quad_make(int op, struct Qvar *dest, struct Qvar *left, struct Qvar *right) {
+	struct Quad *x = malloc_or_fail(sizeof(struct Quad), __FUNCTION__);
+	
+	x->op = op;
+	x->dest = dest;
+	x->left = left;
+	x->right = right;
+	return (x);
+}
+
+// Constructs a Quad with a loads an integer immediate (32bits).
+struct Quad* quad_make_i32(struct Qvar *dest, int32_t v) {
+	struct Quad *x = malloc_or_fail(sizeof(struct Quad), __FUNCTION__);
+
+	x->op = Q_IMM_I32;
+	x->dest = dest;
+	x->val_i32 = v;
+	return (x);
+}
+
+// Constructs a Quad with instruction Q_BR_XXX (conditional goto).
+struct Quad* quad_make_br(int op, struct Qblock *bt, struct Qblock *bf) {
+	struct Quad *x = malloc_or_fail(sizeof(struct Quad), __FUNCTION__);
+	
+	x->op = op;
+	x->bt = bt;
+	x->bf = bf;
+	return (x);
+}
+
+// Returns whether the given opcode is a opcode from a terminate.
+bool quad_is_terminate(int op) {
+	switch (op) {
+		case Q_RET:
+		case Q_BR_ALWAYS:
+			return (true);
+
+		default:
+			return (false);
+	}
+}
+
+// Constructs a Qblock.
+struct Qblock* qblock_make(int id) {
+	struct Qblock *x = malloc_or_fail(sizeof(struct Qblock), __FUNCTION__);
+	llist_init(&x->ins);
+	x->id = id;
+	x->is_complete = false;
+	return (x);
+}
+
+// Allocates a new basic block in the give function.
+struct Qblock* qfunc_new_block(struct Qfunction *f) {
+	struct Qblock *x = qblock_make(f->bs.length);
+	llist_pushback(&f->bs, x);
+	return (x);
+}
+
+// Appends an instruction to a block.
+void qblock_add_ins(struct Qblock *b, struct Quad *x) {
+	if (b->is_complete) {
+		return;
+	}
+	llist_pushback(&b->ins, x);
+}
+
+// Constructs a new Qvar.
+struct Qvar* qvar_make(int id) {
+	struct Qvar *res = malloc_or_fail(sizeof(struct Qvar), __FUNCTION__);
+	res->id = id;
+	return (res);
+}
+
+// Allocates a new variable in the given function.
+struct Qvar* qfunc_new_var(struct Qfunction *f) {
+	struct Qvar *res = qvar_make(f->vars.length);
+	llist_pushback(&f->vars, res);
+	return (res);
+}
+
+static struct Qvar* qcg_dfs(struct ASTnode *x, struct Qfunction *f, struct Qblock *b) {
+	switch (x->op) {
+		case A_RETURN: {
+			struct ASTunnode *t = (void*)x;
+			struct Qvar *value = qcg_dfs(t->left, f, b);
+			qblock_add_ins(b, quad_make(Q_RET, NULL, value, NULL));
+			b->is_complete = true;
+			return (NULL);
+		}
+
+		case A_LIT_I32: {
+			struct ASTi32node *t = (void*)x;
+			struct Qvar *res = qfunc_new_var(f);
+			qblock_add_ins(b, quad_make_i32(res, t->val));
+			return (res);
+		}
+
+		case A_BLOCK: {
+			struct ASTblocknode *t = (void*)x;
+			struct llist_node *p = t->st.head;
+			while (p) {
+				qcg_dfs((struct ASTnode*)p, f, b);
+				p = p->nxt;
+			}
+			return (NULL);
+		}
+
+		default: {
+			fail_ast_op(x->op, __FUNCTION__);
+		}
+	}
+}
+
+// Generates Quad Repersentation from an AST
+struct Qfunction* qfunc_cgenerate(struct Afunction *afunc) {
+	struct Qfunction *self = malloc_or_fail(sizeof(struct Qfunction), __FUNCTION__);
+
+	self->name = afunc->name;	// transfer ownership of function name string
+	afunc->name = NULL;		// prevents the pointer being freed when freeing the Afunction
+
+	llist_init(&self->bs);
+	llist_init(&self->vars);
+
+	struct Qblock *entry = qfunc_new_block(self);
+	qcg_dfs(afunc->rt, self, entry);
+	return (self);
+}
+
+// Frees a Qblock and all its components.
+void qblock_free(struct Qblock *b) {
+	llist_free(&b->ins);
+	free(b);
+}
+
+// Frees a Qfunction and all its components.
+void qfunc_free(struct Qfunction *f) {
+	if (f->name) {
+		free(f->name);
+	}
+
+	struct llist_node *p = f->bs.head, *nxt;
+	while (p) {
+		nxt = p->nxt;
+		qblock_free((struct Qblock*)p);
+		p = nxt;
+	}
+
+	llist_free(&f->vars);
+	free(f);
+}
+
+// Prints the given instruction for debugging.
+static void quad_debug_print(struct Quad *self, FILE *Outfile) {
+	switch(self->op) {
+		case Q_IMM_I32: {
+			fprintf(Outfile, "\t$%d = i32 %d;\n", self->dest->id, self->val_i32);
+		}	break;
+
+		case Q_RET: {
+			fprintf(Outfile, "\tret $%d.\n", self->left->id);
+		}	break;
+
+		default: {
+			fail_quad_op(self->op, __FUNCTION__);
+		}
+	}
+}
+
+// Prints the contents of a Qblock for debugging.
+static void qblock_debug_print(struct Qblock *self, FILE *Outfile) {
+	fprintf(Outfile, "L%d:\n", self->id);
+	struct llist_node *p = self->ins.head;
+	while (p) {
+		quad_debug_print((struct Quad*)p, Outfile);
+		p = p->nxt;
+	}
+}
+
+// Prints the contents of a Qfunction for debugging.
+void qfunc_debug_print(struct Qfunction *self, FILE *Outfile) {
+	fprintf(Outfile, "%s:\n", self->name);
+	struct llist_node *p = self->bs.head;
+	while (p) {
+		qblock_debug_print((struct Qblock*)p, Outfile);
+		p = p->nxt;
+	}
+}

src/target.c

@@ -1,19 +1,23 @@
 #include <string.h>
+#include "util/misc.h"
 #include "fatals.h"
 #include "target.h"
 
+// Parse the target string
 int target_parse(const char *target_string) {
 	static const char *target_map_k[] = {
 		"ast",
+		"quad",
 		NULL
 	};
 
 	static const int target_map_v[] = {
 		TARGET_AST,
+		TARGET_QUAD,
 	};
 
 	for (int i = 0; target_map_k[i]; ++i) {
-		if (strcmp(target_map_k[i], target_string) == 0) {
+		if (strequal(target_map_k[i], target_string)) {
 			return (target_map_v[i]);
 		}
 	}

src/util/misc.c

@@ -2,13 +2,14 @@
 #include <stdlib.h>
 #include "util/misc.h"
 
-// check if two string are the same
+// This function does what you think it does :)
+// Returns whether the given strings are the same.
 bool strequal(const char *s1, const char *s2) {
 	return (strcmp(s1, s2) == 0);
 }
 
-// A impl of C23 strdup()
+// A impl of C23 strdup().
-// Clones the given string
+// Clones the given string and returns a pointer.
 char* strclone(const char *s) {
 	int n = strlen(s);
 	char *res = malloc(n + 1);
@@ -16,4 +17,3 @@ char* strclone(const char *s) {
 	res[n] = '\0';
 	return res;
 }
-