From aff70aa24370712ac51c55ccc5a2590cb1a0c84c Mon Sep 17 00:00:00 2001
From: Bill Currie <bill@taniwha.org>
Date: Tue, 30 Apr 2024 11:32:20 +0900
Subject: [PATCH] [qfcc] Support static type expressions in declarations

This allows types in declarations to be based on other types:

    int foo[3];
    @vector(float,sizeof(foo)) bar;
---
 tools/qfcc/include/expr.h     |   2 +
 tools/qfcc/source/expr_type.c | 279 ++++++++++++++++++++++++++++++++--
 tools/qfcc/source/qc-parse.y  |  10 +-
 3 files changed, 276 insertions(+), 15 deletions(-)

diff --git a/tools/qfcc/include/expr.h b/tools/qfcc/include/expr.h
index e2ef252ca..cd2e39a85 100644
--- a/tools/qfcc/include/expr.h
+++ b/tools/qfcc/include/expr.h
@@ -857,6 +857,8 @@ expr_t *new_memset_expr (const expr_t *dst, const expr_t *val,
 expr_t *new_type_expr (const type_t *type);
 const expr_t *type_function (int op, const expr_t *params);
 symbol_t *type_parameter (symbol_t *sym, const expr_t *type);
+const type_t *resolve_type (const expr_t *te);
+const expr_t *evaluate_type (const expr_t *te);
 
 /**	Convert a name to an expression of the appropriate type.
 
diff --git a/tools/qfcc/source/expr_type.c b/tools/qfcc/source/expr_type.c
index 91369958a..4b95a7b7a 100644
--- a/tools/qfcc/source/expr_type.c
+++ b/tools/qfcc/source/expr_type.c
@@ -37,9 +37,13 @@
 
 typedef struct {
 	const char *name;
-	const char *(*check_params) (int count, const expr_t **args);
+	const char *(*check_params) (int arg_count, const expr_t **args);
+	const type_t *(*resolve) (int arg_count, const expr_t **args);
+	const expr_t *(*evaluate) (int arg_count, const expr_t **args);
 } type_func_t;
 
+static type_func_t type_funcs[];
+
 static bool
 check_type (const expr_t *arg)
 {
@@ -50,23 +54,37 @@ check_type (const expr_t *arg)
 	return true;
 }
 
-static bool
+static bool __attribute__((pure))
 check_int (const expr_t *arg)
 {
+	if (arg->type == ex_expr || arg->type == ex_uexpr) {
+		if (!is_int (arg->expr.type)) {
+			return false;
+		}
+		return check_int (arg->expr.e1)
+			&& arg->type == ex_expr && check_int (arg->expr.e2);
+	}
+	if (is_integral_val (arg)) {
+		return true;
+	}
 	if ((arg->type != ex_symbol || arg->symbol->sy_type != sy_type_param)
 		&& arg->type != ex_type) {
 		return false;
 	}
+	int op = arg->symbol->s.expr->typ.op;
+	if (op != QC_AT_WIDTH && op != QC_AT_ROWS && op != QC_AT_COLS) {
+		return false;
+	}
 	return true;
 }
 
 static const char *
-single_type (int count, const expr_t **args)
+single_type (int arg_count, const expr_t **args)
 {
-	if (count < 1) {
+	if (arg_count < 1) {
 		return "too few arguments";
 	}
-	if (count > 1) {
+	if (arg_count > 1) {
 		return "too many arguments";
 	}
 	if (!check_type (args[0])) {
@@ -76,96 +94,288 @@ single_type (int count, const expr_t **args)
 }
 
 static const char *
-single_type_opt_int (int count, const expr_t **args)
+single_type_opt_int (int arg_count, const expr_t **args)
 {
-	if (count < 1) {
+	if (arg_count < 1) {
 		return "too few arguments";
 	}
-	if (count > 2) {
+	if (arg_count > 2) {
 		return "too many arguments";
 	}
 	if (!check_type (args[0])) {
 		return "first parameter must be a type";
 	}
-	if (count > 1 && !check_int (args[1])) {
+	if (arg_count > 1 && !check_int (args[1])) {
 		return "second parameter must be int";
 	}
 	return nullptr;
 }
 
 static const char *
-single_type_opt_int_pair (int count, const expr_t **args)
+single_type_opt_int_pair (int arg_count, const expr_t **args)
 {
-	if (count < 1) {
+	if (arg_count < 1) {
 		return "too few arguments";
 	}
-	if (count > 3) {
+	if (arg_count > 3) {
 		return "too many arguments";
 	}
-	if (count == 2) {
+	if (arg_count == 2) {
 		return "must have one or three arguments";
 	}
 	if (!check_type (args[0])) {
 		return "first parameter must be a type";
 	}
-	if (count > 1 && (!check_int (args[1]) || !check_int (args[2]))) {
+	if (arg_count > 1 && (!check_int (args[1]) || !check_int (args[2]))) {
 		return "second and third parameters must be int";
 	}
 	return nullptr;
 }
 
+static const expr_t *
+evaluate_int (const expr_t *expr)
+{
+	if (expr->type == ex_expr || expr->type == ex_uexpr) {
+		auto e = new_expr ();
+		*e = *expr;
+		e->expr.e1 = evaluate_int (expr->expr.e1);
+		if (expr->type == ex_uexpr) {
+			e->expr.e2 = evaluate_int (expr->expr.e2);
+		}
+		return fold_constants (e);
+	}
+	if (is_integral_val (expr)) {
+		return expr;
+	}
+	int op = expr->typ.op;
+	int ind = op - QC_GENERIC;
+	auto type = expr->typ.type;
+	if (!type) {
+		return error (expr, "invalid type passed to %s", type_funcs[ind].name);
+	}
+	if (op == QC_AT_WIDTH) {
+		return new_int_expr (type_width (type), false);
+	}
+	if (op == QC_AT_ROWS) {
+		return new_int_expr (type_rows (type), false);
+	}
+	if (op == QC_AT_COLS) {
+		return new_int_expr (type_cols (type), false);
+	}
+	internal_error (expr, "invalid type op");
+}
+
+static const expr_t *
+evaluate_int_op (int arg_count, const expr_t **args)
+{
+	return evaluate_int (args[0]);
+}
+
+static const type_t *
+resolve_field (int arg_count, const expr_t **args)
+{
+	auto type = resolve_type (args[0]);
+	if (type) {
+		type = field_type (type);
+		type = find_type (type);
+	}
+	return type;
+}
+
+static const type_t *
+resolve_pointer (int arg_count, const expr_t **args)
+{
+	auto type = resolve_type (args[0]);
+	if (type) {
+		type = pointer_type (type);
+		type = find_type (type);
+	}
+	return type;
+}
+
+static const type_t *
+resolve_array (int arg_count, const expr_t **args)
+{
+	auto type = resolve_type (args[0]);
+	if (type) {
+		int count = 0;
+		if (arg_count > 1) {
+			auto count_expr = evaluate_int (args[1]);
+			if (is_error (count_expr)) {
+				return nullptr;
+			}
+			count = expr_int (count_expr);
+		}
+		type = array_type (type, count);
+	}
+	return type;
+}
+
+static const type_t *
+resolve_base (int arg_count, const expr_t **args)
+{
+	auto type = resolve_type (args[0]);
+	if (type) {
+		type = base_type (type);
+	}
+	return type;
+}
+
+static const type_t *
+resolve_vector (int arg_count, const expr_t **args)
+{
+	auto type = resolve_type (args[0]);
+	if (type) {
+		int width = 0;
+		if (arg_count > 1) {
+			auto width_expr = evaluate_int (args[1]);
+			if (is_error (width_expr)) {
+				return nullptr;
+			}
+			width = expr_integral (width_expr);
+		} else {
+			width = type_width (type);
+		}
+		type = vector_type (type, width);
+		if (!type) {
+			error (args[0], "invalid @vector");
+		}
+	}
+	return type;
+}
+
+static const type_t *
+resolve_matrix (int arg_count, const expr_t **args)
+{
+	auto type = resolve_type (args[0]);
+	if (type) {
+		int rows = 0;
+		int cols = 0;
+		if (arg_count > 1) {
+			auto rows_expr = evaluate_int (args[2]);
+			auto cols_expr = evaluate_int (args[1]);
+			if (is_error (rows_expr) || is_error (cols_expr)) {
+				return nullptr;
+			}
+			rows = expr_integral (rows_expr);
+			cols = expr_integral (cols_expr);
+		} else {
+			cols = type_cols (type);
+			rows = type_rows (type);
+		}
+		type = matrix_type (type, cols, rows);
+		if (!type) {
+			error (args[0], "invalid @matrix");
+		}
+	}
+	return type;
+}
+
+static const type_t *
+resolve_int (int arg_count, const expr_t **args)
+{
+	auto type = resolve_type (args[0]);
+	if (type) {
+		type = int_type (type);
+	}
+	return type;
+}
+
+static const type_t *
+resolve_uint (int arg_count, const expr_t **args)
+{
+	auto type = resolve_type (args[0]);
+	if (type) {
+		type = uint_type (type);
+	}
+	return type;
+}
+
+static const type_t *
+resolve_bool (int arg_count, const expr_t **args)
+{
+	auto type = resolve_type (args[0]);
+	if (type) {
+		type = bool_type (type);
+	}
+	return type;
+}
+
+static const type_t *
+resolve_float (int arg_count, const expr_t **args)
+{
+	auto type = resolve_type (args[0]);
+	if (type) {
+		type = float_type (type);
+	}
+	return type;
+}
+
 static type_func_t type_funcs[] = {
 	[QC_AT_FIELD - QC_GENERIC] = {
 		.name = "@field",
 		.check_params = single_type,
+		.resolve = resolve_field,
 	},
 	[QC_AT_POINTER - QC_GENERIC] = {
 		.name = "@pointer",
 		.check_params = single_type,
+		.resolve = resolve_pointer,
 	},
 	[QC_AT_ARRAY - QC_GENERIC] = {
 		.name = "@array",
 		.check_params = single_type_opt_int,
+		.resolve = resolve_array,
 	},
 	[QC_AT_BASE - QC_GENERIC] = {
 		.name = "@base",
 		.check_params = single_type,
+		.resolve = resolve_base,
 	},
 	[QC_AT_WIDTH - QC_GENERIC] = {
 		.name = "@width",
 		.check_params = single_type,
+		.evaluate = evaluate_int_op,
 	},
 	[QC_AT_VECTOR - QC_GENERIC] = {
 		.name = "@vector",
 		.check_params = single_type_opt_int,
+		.resolve = resolve_vector,
 	},
 	[QC_AT_ROWS - QC_GENERIC] = {
 		.name = "@rows",
 		.check_params = single_type,
+		.evaluate = evaluate_int_op,
 	},
 	[QC_AT_COLS - QC_GENERIC] = {
 		.name = "@cols",
 		.check_params = single_type,
+		.evaluate = evaluate_int_op,
 	},
 	[QC_AT_MATRIX - QC_GENERIC] = {
 		.name = "@matrix",
 		.check_params = single_type_opt_int_pair,
+		.resolve = resolve_matrix,
 	},
 	[QC_AT_INT - QC_GENERIC] = {
 		.name = "@int",
 		.check_params = single_type,
+		.resolve = resolve_int,
 	},
 	[QC_AT_UINT - QC_GENERIC] = {
 		.name = "@uint",
 		.check_params = single_type,
+		.resolve = resolve_uint,
 	},
 	[QC_AT_BOOL - QC_GENERIC] = {
 		.name = "@bool",
 		.check_params = single_type,
+		.resolve = resolve_bool,
 	},
 	[QC_AT_FLOAT - QC_GENERIC] = {
 		.name = "@float",
 		.check_params = single_type,
+		.resolve = resolve_float,
 	},
 };
 
@@ -185,6 +395,7 @@ type_function (int op, const expr_t *params)
 	}
 	auto te = new_expr ();
 	te->type = ex_type;
+	te->nodag = 1;
 	te->typ = (ex_type_t) {
 		.op = op,
 		.params = params,
@@ -202,3 +413,43 @@ type_parameter (symbol_t *sym, const expr_t *type)
 	sym->s.expr = type;
 	return sym;
 }
+
+const type_t *
+resolve_type (const expr_t *te)
+{
+	if (te->type != ex_type) {
+		internal_error (te, "not a type expression");
+	}
+	if (!te->typ.op) {
+		if (!te->typ.type) {
+			internal_error (te, "no type in reference");
+		}
+		return te->typ.type;
+	}
+	int         op = te->typ.op;
+	unsigned    ind = op - QC_GENERIC;
+	if (ind >= sizeof (type_funcs) / sizeof (type_funcs[0])) {
+		internal_error (te, "invalid type op: %d", op);
+	}
+	int         arg_count = list_count (&te->typ.params->list);
+	const expr_t *args[arg_count];
+	list_scatter (&te->typ.params->list, args);
+	return type_funcs[ind].resolve (arg_count, args);
+}
+
+const expr_t *
+evaluate_type (const expr_t *te)
+{
+	if (te->type != ex_type) {
+		internal_error (te, "not a type expression");
+	}
+	int         op = te->typ.op;
+	unsigned    ind = op - QC_GENERIC;
+	if (ind >= sizeof (type_funcs) / sizeof (type_funcs[0])) {
+		internal_error (te, "invalid type op: %d", op);
+	}
+	int         arg_count = list_count (&te->typ.params->list);
+	const expr_t *args[arg_count];
+	list_scatter (&te->typ.params->list, args);
+	return type_funcs[ind].evaluate (arg_count, args);
+}
diff --git a/tools/qfcc/source/qc-parse.y b/tools/qfcc/source/qc-parse.y
index 5843324e7..0364d3256 100644
--- a/tools/qfcc/source/qc-parse.y
+++ b/tools/qfcc/source/qc-parse.y
@@ -418,6 +418,10 @@ make_ellipsis (void)
 static param_t *
 make_param (specifier_t spec)
 {
+	if (spec.type_expr) {
+		if (!(spec.type = resolve_type (spec.type_expr))) {
+		}
+	}
 	spec = default_type (spec, spec.sym);
 	spec.type = find_type (append_type (spec.sym->type, spec.type));
 	param_t    *param = new_param (0, spec.type, spec.sym->name);
@@ -916,7 +920,11 @@ typespec
 
 typespec_reserved
 	: TYPE_SPEC
-	| type_function					{ $$ = make_spec ($1->typ.type, 0, 0, 0); }
+	| type_function
+		{
+			auto type = resolve_type ($1);
+			$$ = make_spec (type, 0, 0, 0);
+		}
 	| algebra_specifier %prec LOW
 	| algebra_specifier '.' attribute
 		{