unary operators

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

include/ast.h

@@ -7,8 +7,10 @@
 // AST operation types
 enum {
 	A_ASSIGN,
-	A_ADD, A_SUB, A_MUL, A_DIV,
+	A_NEG, A_ADD, A_SUB, A_MUL, A_DIV,
 	A_EQ, A_NE, A_LT, A_GT, A_LE, A_GE,
+	A_LNOT, A_LAND, A_LOR,
+	A_BNOT,
 	A_LIT_I32, A_LIT_I64,
 	A_VAR,
 	A_BLOCK,

include/quad.h

@@ -11,6 +11,11 @@ enum {
 	// Loading immediates
 	Q_IMM_I32,	// integer (32bits)
 
+	// Arithmetic operations
+	Q_NEG,		// negation
+	Q_NOT,		// bitwise not
+	Q_CMP_EQ,	// compare whether equal
+
 	// Terminates
 	Q_RET,		// return 
 	Q_BR_ALWAYS,	// conditional goto: always goto true branch.

include/token.h

@@ -23,7 +23,9 @@ enum {
 	T_SEMI,					// ;
 	T_LB, T_RB, T_LP, T_RP,			// { } ( )
 	T_ASSIGN,				// =
-	T_PLUS, T_MINUS, T_STAR, T_SLASH,	// + - * /
+	T_PLUS, T_MINUS, T_STAR, T_SLASH,	// - + - * /
+	T_LNOT, T_LAND, T_LOR,			// ! && ||
+	T_BNOT,					// ~
 	T_EQ, T_NE, T_LT, T_GT, T_LE, T_GE,	// == != < > <= >=
 	T_INT, T_VOID, T_CHAR, T_LONG,		// int void char long
 	T_SHORT,				// short

src/ast.c

@@ -6,8 +6,10 @@
 
 const char *ast_opname[] = {
 	"=",
-	"+", "-", "*", "/",
+	"neg", "add", "sub", "mul", "div",
 	"==", "!=", "<", ">", "<=", ">=",
+	"not", "and", "or",
+	"~",
 	"int32", "int64",
 	"var",
 	"block",
@@ -188,7 +190,8 @@ void ast_free(struct ASTnode *x) {
 			ast_free(t->right);
 		}	break;
 
-		case A_PRINT: case A_RETURN: {
+		case A_PRINT: case A_RETURN:
+		case A_LNOT: case A_BNOT: case A_NEG: {
 			struct ASTunnode *t = (struct ASTunnode*)x;
 			ast_free(t->left);
 		}	break;

src/parse.c

@@ -10,7 +10,7 @@
 static struct linklist Tokens;	// current token for parsing
 
 // Check that we have a binary operator and return its precedence.
-// operators with larger precedence value will be evaluated first
+// Operators with larger precedence value will be evaluated first.
 static int op_precedence(struct token *t) {
 	switch (t->type) {
 		case T_ASSIGN:
@@ -28,8 +28,8 @@ static int op_precedence(struct token *t) {
 	}
 }
 
-// Convert a arithmetic token into an AST operation.
-static int arithop(struct token *t) {
+// Converts a binary arithmetic token into an AST operation.
+static int binary_arithop(struct token *t) {
 	static const int map[][2] = {
 		{T_PLUS,	A_ADD},
 		{T_MINUS,	A_SUB},
@@ -42,6 +42,8 @@ static int arithop(struct token *t) {
 		{T_GT,		A_GT},
 		{T_GE,		A_GE},
 		{T_ASSIGN,	A_ASSIGN},
+		{T_LAND,	A_LAND},
+		{T_LOR,		A_LOR},
 		{-1}
 	};
 
@@ -53,7 +55,25 @@ static int arithop(struct token *t) {
 	fail_ce_expect(t->line, "an binary operator", token_typename[t->type]);
 }
 
-// operator ssociativity direction
+// Converts a unary arithmetic token into an AST operation.
+static int unary_arithop(struct token *t) {
+	static const int map[][2] = {
+		{T_MINUS,	A_NEG},
+		{T_LNOT,	A_LNOT},
+		{T_BNOT,	A_BNOT},
+		{-1}
+	};
+
+	for (int i = 0; map[i][0] != -1; ++i) {
+		if (t->type == map[i][0]) {
+			return map[i][1];
+		}
+	}
+
+	fail_ce_expect(t->line, "an unary operator", token_typename[t->type]);
+}
+
+// Operator associativity direction
 // Returns	false if left to right, e.g. +
 // 		true if right to left, e.g. =
 static bool direction_rtl(int t) {
@@ -114,6 +134,7 @@ static struct ASTnode* expression(void);
 static struct ASTnode* primary(void) {
 	struct ASTnode *res;
 	struct token *t = current();
+
 	if (t->type == T_LP) {
 		// ( expr ) considered as primary
 		next();
@@ -143,16 +164,50 @@ static struct ASTnode* primary(void) {
 	return (res);
 }
 
-// Check if it is binary operator
-static int is_binop(int t) {
-	return (T_ASSIGN <= t && t <= T_GE);
+// Returns whether the given token type can be a prefix operator (negation, logical not, bitwise not)
+static bool is_prefix_op(int op) {
+	switch (op) {
+		case T_MINUS: case T_LNOT: case T_BNOT:
+			return (true);
+
+		default:
+			return (false);
+	}
+}
+
+// Parses a primary expression with prefixes, e.g. ~10
+static struct ASTnode* prefixed_primary(void) {
+	struct token *t = current();
+
+	if (is_prefix_op(t->type)) {
+		next();
+		struct ASTnode *child = prefixed_primary();
+		return (ast_make_unary(unary_arithop(t), child));
+	}
+
+	return (primary());
+}
+
+// Returns whether the given token type can be a binary operator.
+static bool is_binop(int t) {
+	switch (t) {
+		case T_ASSIGN:
+		case T_PLUS: case T_MINUS: case T_STAR: case T_SLASH:
+		case T_LAND: case T_LOR:
+		case T_EQ: case T_NE: case T_LT:
+		case T_GT: case T_LE: case T_GE:
+			return (true);
+
+		default:
+			return (false);
+	}
 }
 
 // Return an AST tree whose root is a binary operator
 static struct ASTnode* binexpr(int precedence) {
 	struct ASTnode *left, *right;
 
-	left = primary();
+	left = prefixed_primary();
 	struct token *op = current();
 	if (!is_binop(op->type)) {
 		return (left);
@@ -164,10 +219,10 @@ static struct ASTnode* binexpr(int precedence) {
 
 		if (direction_rtl(op->type)) {
 			right = binexpr(precedence);
-			left = ast_make_assign(arithop(op), left, right);
+			left = ast_make_assign(binary_arithop(op), left, right);
 		} else {
 			right = binexpr(tp);
-			left = ast_make_binary(arithop(op), left, right); // join right into left
+			left = ast_make_binary(binary_arithop(op), left, right); // join right into left
 		}
 
 		op = current();
@@ -304,7 +359,7 @@ static struct ASTnode* for_statement(void) {
 	return ((struct ASTnode*)container);
 }
 
-static struct ASTnode* return_statement() {
+static struct ASTnode* return_statement(void) {
 	match(T_RETURN);
 	struct ASTnode *res = expression();
 	match(T_SEMI);
@@ -347,7 +402,7 @@ static struct ASTnode* statement(void) {
 
 // Parse one top-level function
 // Sets the func_name param.
-static struct Afunction* function() {
+static struct Afunction* function(void) {
 	struct Afunction *res = afunc_make();
 
 	match(T_INT);

src/quad.c

@@ -84,7 +84,20 @@ struct Qvar* qfunc_new_var(struct Qfunction *f) {
 	return (res);
 }
 
+// Translate an AST unary arithmetic opcode to a Quad opcode.
+static int unary_arithop(int op) {
+	switch (op) {
+		case A_NEG:	return (Q_NEG);
+		case A_BNOT:	return (Q_NOT);
+		default:	fail_quad_op(op, __FUNCTION__);
+	}
+}
+
 static struct Qvar* qcg_dfs(struct ASTnode *x, struct Qfunction *f, struct Qblock *b) {
+	if (x == NULL) {
+		return (NULL);
+	}
+
 	switch (x->op) {
 		case A_RETURN: {
 			struct ASTunnode *t = (void*)x;
@@ -94,13 +107,6 @@ static struct Qvar* qcg_dfs(struct ASTnode *x, struct Qfunction *f, struct Qbloc
 			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;
@@ -111,6 +117,31 @@ static struct Qvar* qcg_dfs(struct ASTnode *x, struct Qfunction *f, struct Qbloc
 			return (NULL);
 		}
 
+		case A_LIT_I32: {
+			struct Qvar *res = qfunc_new_var(f);
+			struct ASTi32node *t = (void*)x;
+			qblock_add_ins(b, quad_make_i32(res, t->val));
+			return (res);
+		}
+
+		case A_NEG: case A_BNOT: {
+			struct Qvar *res = qfunc_new_var(f);
+			struct ASTunnode *t = (void*)x;
+			struct Qvar *value = qcg_dfs(t->left, f, b);
+			qblock_add_ins(b, quad_make(unary_arithop(x->op), res, value, NULL));
+			return (res);
+		}
+
+		case A_LNOT: {
+			struct Qvar *res = qfunc_new_var(f);
+			struct ASTunnode *t = (void*)x;
+			struct Qvar *value = qcg_dfs(t->left, f, b);
+			struct Qvar *zero = qfunc_new_var(f);
+			qblock_add_ins(b, quad_make_i32(zero, 0));
+			qblock_add_ins(b, quad_make(Q_CMP_EQ, res, value, zero));
+			return (res);
+		}
+
 		default: {
 			fail_ast_op(x->op, __FUNCTION__);
 		}
@@ -163,7 +194,23 @@ static void quad_debug_print(struct Quad *self, FILE *Outfile) {
 		}	break;
 
 		case Q_RET: {
-			fprintf(Outfile, "\tret $%d.\n", self->left->id);
+			if (self->left) {
+				fprintf(Outfile, "\tret $%d.\n", self->left->id);
+			} else {
+				fputs("\tret.", Outfile);
+			}
+		}	break;
+
+		case Q_NEG: {
+			fprintf(Outfile, "\t$%d = neg $%d;\n", self->dest->id, self->left->id);
+		}	break;
+
+		case Q_NOT: {
+			fprintf(Outfile, "\t$%d = not $%d;\n", self->dest->id, self->left->id);
+		}	break;
+
+		case Q_CMP_EQ: {
+			fprintf(Outfile, "\t$%d = eq $%d, $%d;\n", self->dest->id, self->left->id, self->right->id);
 		}	break;
 
 		default: {

src/scan.c

@@ -185,8 +185,7 @@ static struct token* scan(void) {
 			t->type = T_NE;
 			next();
 		} else {
-			// TODO: the not operator
-			fail_char(t->line, c);
+			t->type = T_LNOT;
 		}
 	} else if (c == '<') {
 		t->type = T_LT;
@@ -204,6 +203,27 @@ static struct token* scan(void) {
 			t->type = T_GE;
 			next();
 		}
+	} else if (c == '~') {
+		t->type = T_BNOT;
+		next();
+	} else if (c == '&') {
+		next();
+		c = preview();
+		if (c == '&') {
+			t->type = T_LAND;
+		} else {
+			// TODO: bitwise and
+			fail_char(t->line, c);
+		}
+	} else if (c == '|') {
+		next();
+		c = preview();
+		if (c == '|') {
+			t->type = T_LOR;
+		} else {
+			// TODO: bitwise or
+			fail_char(t->line, c);
+		}
 	} else {
 		if (isdigit(c)) { // If it's a digit, scan the integer literal value in
 			scan_int(t);

src/token.c

@@ -7,6 +7,8 @@ const char *token_typename[63] = {
 	"{", "}", "(", ")",
 	"=",
 	"+", "-", "*", "/",
+	"!", "&&", "||",
+	"~",
 	"==", "!=", "<", ">", "<=", ">=",
 	"int", "void", "char", "long",
 	"short",

tests/invalid/missing_const.c

@@ -0,0 +1,3 @@
+int main() {
+    return !;
+}

tests/invalid/missing_semicolon.c

@@ -0,0 +1,3 @@
+int main() {
+    return !5
+}

tests/invalid/nested_missing_const.c

@@ -0,0 +1,3 @@
+int main() {
+    return !~;
+}

tests/invalid/wrong_order.c

@@ -0,0 +1,3 @@
+int main() {
+    return 4-;
+}

tests/valid/bitwise.c

@@ -0,0 +1,3 @@
+int main() {
+    return ~12;
+}

tests/valid/bitwise_zero.c

@@ -0,0 +1,3 @@
+int main() {
+    return ~0;
+}

tests/valid/neg.c

@@ -0,0 +1,3 @@
+int main() {
+    return -5;
+}

tests/valid/nested_ops.c

@@ -0,0 +1,3 @@
+int main() {
+    return !-3;
+}

tests/valid/nested_ops_2.c

@@ -0,0 +1,3 @@
+int main() {
+    return -------!!!----~0;
+}

tests/valid/not_five.c

@@ -0,0 +1,3 @@
+int main() {
+    return !5;
+}

tests/valid/not_zero.c

@@ -0,0 +1,3 @@
+int main() {
+    return !0;
+}