From 6c6b91f9a6bc5ae203e99ac7abb3a70215488a6f Mon Sep 17 00:00:00 2001
From: Bobby Bingham <koorogi@koorogi.info>
Date: Wed, 18 Jan 2017 19:40:18 -0600
Subject: nqasm: support unary operators in immediate expressions

---
 lexer.l  |  6 +++++-
 nqasm.c  | 19 +++++++++++++++++--
 nqasm.h  | 16 +++++++++++++---
 parser.y | 10 ++++++++++
 4 files changed, 45 insertions(+), 6 deletions(-)

diff --git a/lexer.l b/lexer.l
index 053ac4e..324c3da 100644
--- a/lexer.l
+++ b/lexer.l
@@ -76,7 +76,11 @@ HEX        [0-9a-f]
 
 <args>\.                 { return T_DOT; }
 <args>@                  { return T_DEREF; }
-<args>[-+]?{DEC}+        { return intlit(yytext,   10, &yylval.lval); }
+<args>\+                 { return T_OPERATOR_ADD; }
+<args>-                  { return T_OPERATOR_SUB; }
+<args>!                  { return T_OPERATOR_NOT; }
+<args>~                  { return T_OPERATOR_INV; }
+<args>{DEC}+             { return intlit(yytext,   10, &yylval.lval); }
 <args>0x{HEX}+           { return intlit(yytext+2, 16, &yylval.lval); }
 <args>{SP}*,{SP}*        { return T_COMMA; }
 
diff --git a/nqasm.c b/nqasm.c
index ee3010a..49b4ec6 100644
--- a/nqasm.c
+++ b/nqasm.c
@@ -56,12 +56,27 @@ void add_instruction(const struct instruction *inst)
 	addr += 2;
 }
 
+struct argument *argdup(const struct argument *arg)
+{
+	struct argument *ret = malloc(sizeof *ret);
+	if (!ret) {
+		fprintf(stderr, "unable to allocate argument\n");
+		exit(1);
+	}
+	*ret = *arg;
+	return ret;
+}
+
 static long eval_argument(const struct argument *arg, uint16_t pc)
 {
 	struct label *l;
 	switch (arg->type) {
-	case ARG_INTEGER: return arg->value;
-	case ARG_PC:      return pc;
+	case ARG_INTEGER:   return  arg->value;
+	case ARG_PC:        return  pc;
+	case ARG_UNARY_ADD: return  eval_argument(arg->children[0], pc);
+	case ARG_UNARY_SUB: return -eval_argument(arg->children[0], pc);
+	case ARG_UNARY_NOT: return !eval_argument(arg->children[0], pc);
+	case ARG_UNARY_INV: return ~eval_argument(arg->children[0], pc);
 
 	case ARG_LABEL:
 		l = vector_search(&labels->v, &(struct label) { .name = arg->label }, cmp_label);
diff --git a/nqasm.h b/nqasm.h
index 0bc51f7..e5a7452 100644
--- a/nqasm.h
+++ b/nqasm.h
@@ -1,15 +1,23 @@
 #ifndef NQ_NQASM_H
 #define NQ_NQASM_H
 
-#define ARG_INTEGER   0
-#define ARG_LABEL     1
-#define ARG_PC        2
+enum {
+	ARG_INTEGER,
+	ARG_LABEL,
+	ARG_PC,
+
+	ARG_UNARY_ADD,
+	ARG_UNARY_SUB,
+	ARG_UNARY_NOT,
+	ARG_UNARY_INV,
+};
 
 struct argument {
 	int type;
 	union {
 		long value;
 		char *label;
+		const struct argument *children[1];
 	};
 };
 
@@ -25,5 +33,7 @@ struct instruction {
 void add_instruction(const struct instruction *);
 void add_label(const char *);
 
+struct argument *argdup(const struct argument *);
+
 #endif
 
diff --git a/parser.y b/parser.y
index 2ec2264..cb1343f 100644
--- a/parser.y
+++ b/parser.y
@@ -16,6 +16,7 @@ void yyerror(const char *msg)
 #define MKARGVALUE(v)         (struct argument)    { .type = ARG_INTEGER, .value = (v) }
 #define MKARGLABEL(l)         (struct argument)    { .type = ARG_LABEL,   .label = (l) }
 #define MKARGTYPE(t)          (struct argument)    { .type = (t) }
+#define MKARGEXPR(op,c)       (struct argument)    { .type = (op), .children = c }
 
 %}
 
@@ -84,6 +85,11 @@ void yyerror(const char *msg)
 %token       T_DOT      "."
 %token       T_DEREF    "@"
 
+%token       T_OPERATOR_ADD  "+"
+%token       T_OPERATOR_SUB  "-"
+%token       T_OPERATOR_NOT  "!"
+%token       T_OPERATOR_INV  "~"
+
 %type <inst> inst
 %type <arg>  reg
 %type <arg>  regp
@@ -181,6 +187,10 @@ expr:
 		intlit         { $$ = MKARGVALUE($1); }
 	|	T_LABEL        { $$ = MKARGLABEL($1); }
 	|	"."            { $$ = MKARGTYPE(ARG_PC); }
+	|	"+" expr       { $$ = MKARGEXPR(ARG_UNARY_ADD, { argdup(&$2) }); }
+	|	"-" expr       { $$ = MKARGEXPR(ARG_UNARY_SUB, { argdup(&$2) }); }
+	|	"!" expr       { $$ = MKARGEXPR(ARG_UNARY_NOT, { argdup(&$2) }); }
+	|	"~" expr       { $$ = MKARGEXPR(ARG_UNARY_INV, { argdup(&$2) }); }
 	;
 
 intlit:	T_INT
-- 
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