Implicitly cast unadorned floating point constants

Floating point constants without f or d adornments will automatically
cast, without warnings, to the type appropriate to the rest of the
expression.

tools/qfcc/include/expr.h

@@ -197,6 +197,7 @@ typedef struct expr_s {
 	int         printid;		///< avoid duplicate output when printing
 	unsigned    paren:1;		///< the expression is enclosed in ()
 	unsigned    rvalue:1;		///< the expression is on the right side of =
+	unsigned    implicit:1;		///< don't warn for implicit casts
 	union {
 		ex_label_t  label;				///< label expression
 		ex_labelref_t labelref;			///< label reference expression (&)

tools/qfcc/source/def.c

@@ -609,7 +609,8 @@ initialize_def (symbol_t *sym, expr_t *init, defspace_t *space,
 					reloc_def_field (init->e.value->v.pointer.def, sym->s.def);
 			} else {
 				ex_value_t *v = init->e.value;
-				if (is_double (init_type)
+				if (!init->implicit
+					&& is_double (init_type)
 					&& (is_integral (sym->type) || is_float (sym->type))) {
 					warning (init, "assigning double to %s in initializer "
 							 "(use a cast)", sym->type->name);

tools/qfcc/source/expr_assign.c

@@ -151,9 +151,11 @@ check_types_compatible (expr_t *dst, expr_t *src)
 
 	if (type_assignable (dst_type, src_type)) {
 		if (is_scalar (dst_type) && is_scalar (src_type)) {
-			if (is_double (src_type)) {
+			if (!src->implicit) {
-				warning (dst, "assignment of double to %s (use a cast)\n",
+				if (is_double (src_type)) {
-						 dst_type->name);
+					warning (dst, "assignment of double to %s (use a cast)\n",
+							 dst_type->name);
+				}
 			}
 			// the types are different but cast-compatible
 			expr_t     *new = cast_expr (dst_type, src);

tools/qfcc/source/expr_binary.c

@@ -954,6 +954,15 @@ binary_expr (int op, expr_t *e1, expr_t *e2)
 	et1 = low_level_type (t1);
 	et2 = low_level_type (t2);
 
+	if (is_constant (e1) && is_double (t1) && e1->implicit && is_float (t2)) {
+		t1 = &type_float;
+		convert_double (e1);
+	}
+	if (is_constant (e2) && is_double (t2) && e2->implicit && is_float (t1)) {
+		t2 = &type_float;
+		convert_double (e2);
+	}
+
 	if (et1 >= ev_type_count || !binary_expr_types[et1])
 		return invalid_binary_expr(op, e1, e2);
 	if (et2 >= ev_type_count || !binary_expr_types[et1][et2])

tools/qfcc/source/qc-lex.l

@@ -143,6 +143,7 @@ STRING		\"(\\.|[^"\\])*\"
 						if (options.traditional < 1) {
 							double      d = strtod (yytext, 0);
 							qc_yylval.expr = new_double_expr (d);
+							qc_yylval.expr->implicit = 1;
 						} else {
 							float       f = strtof (yytext, 0);
 							qc_yylval.expr = new_float_expr (f);