From e59ec59b027f921a6bfbe5014b15c2a802445ada Mon Sep 17 00:00:00 2001
From: Aleksandr Nogikh <nogikh@google.com>
Date: Wed, 29 Nov 2023 16:01:41 +0100
Subject: pkg/ast: support expressions with ast.Type

So far they have the following grammar:

OP = "==", "!=", "&"

value-expr = value-expr OP value-expr
           | factor

factor = "(" and-expr ")"
         | integer
	 | identifier
         | string

Operators are left associative, e.g. A & B & C is the same as
(A & B) & C.

Further restrictions will be imposed in pkg/compiler.

This will help implement conditionally included fields.
---
 pkg/ast/testdata/all.txt    | 19 +++++++++++++++++++
 pkg/ast/testdata/errors.txt | 10 +++++++++-
 2 files changed, 28 insertions(+), 1 deletion(-)

(limited to 'pkg/ast/testdata')

diff --git a/pkg/ast/testdata/all.txt b/pkg/ast/testdata/all.txt
index c9569840c..d04fd4992 100644
--- a/pkg/ast/testdata/all.txt
+++ b/pkg/ast/testdata/all.txt
@@ -8,3 +8,22 @@ incdir <some/path>
 
 strflags0 = "foo", strflags1
 strflags1 = "bar"
+
+expressions {
+	f0	int8	(if[value[X] & Y])
+	f1	int8	(if[X & Y == Z])
+	f2	int8	(if[X & Y & Z == value[X] & A])
+	f3	int8	(if[X & (A == B) & Z != C])
+}
+
+condFields {
+	mask	int8
+# Simple expressions work.
+	f0	int16	(if[val[mask] == SOME_CONST])
+# Conditions and other attributes work together.
+	f1	int16	(out, if[val[mask] == SOME_CONST])
+# Test some more complex expressions.
+	f2	int16	(out, if[val[mask] & SOME_CONST == OTHER_CONST])
+	f3	int16	(out, if[val[mask] & SOME_CONST & OTHER_CONST == val[mask] & CONST_X])
+	f4	int16	(out, if[val[mask] & SOME_CONST])
+}
diff --git a/pkg/ast/testdata/errors.txt b/pkg/ast/testdata/errors.txt
index 266babf8f..b3d9e7f52 100644
--- a/pkg/ast/testdata/errors.txt
+++ b/pkg/ast/testdata/errors.txt
@@ -11,7 +11,7 @@ meta foo, bar	### unexpected ',', expecting '\n'
 
 int_flags0 = 0, 0x1, 0xab
 int_flags1 = 123ab0x			### bad integer "123ab0x"
-int_flags1 == 0, 1			### unexpected '=', expecting int, identifier, string
+int_flags1 == 0, 1			### unexpected ==, expecting '(', '{', '[', '='
 int_flags = 0, "foo"			### unexpected string, expecting int, identifier
 int_flags2 = '				### char literal is not terminated
 int_flags3 = 'a				### char literal is not terminated
@@ -67,6 +67,14 @@ s3 {
 	f1	int8
 } [attribute[1, "foo"], another[and[another]]]
 
+sCondFieldsError1 {
+	f0	int16 (out, if[val[mask] SOME_CONST == val[mask]]) ### unexpected identifier, expecting ']'
+} ### unexpected '}', expecting comment, define, include, resource, identifier
+
+sCondFieldsError2 {
+	f5	int16 (out, if[val[mask] & == val[mask]]) ### unexpected ==, expecting int, identifier, string
+} ### unexpected '}', expecting comment, define, include, resource, identifier
+
 type mybool8 int8
 type net_port proc[1, 2, int16be]
 type mybool16				### unexpected '\n', expecting '[', identifier
-- 
cgit mrf-deployment