Add explicit validation of string annotations

frontends/p4/frontend.cpp

@@ -74,6 +74,7 @@ limitations under the License.
 #include "uselessCasts.h"
 #include "validateMatchAnnotations.h"
 #include "validateParsedProgram.h"
+#include "validateStringAnnotations.h"
 #include "validateValueSets.h"
 
 namespace P4 {
@@ -174,6 +175,8 @@ const IR::P4Program *FrontEnd::run(const CompilerOptions &options, const IR::P4P
         // First pass of constant folding, before types are known --
         // may be needed to compute types.
         new ConstantFolding(constantFoldingPolicy),
+        // Validate @name/@deprecated/@noWarn. Should run after constant folding.
+        new ValidateStringAnnotations(),
         // Desugars direct parser and control applications
         // into instantiations followed by application
         new InstantiateDirectCalls(),

frontends/p4/validateStringAnnotations.h

@@ -0,0 +1,55 @@
+/*
+Copyright 2019 VMware, Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+#ifndef P4_VALIDATESTRINGANNOTATIONS_H_
+#define P4_VALIDATESTRINGANNOTATIONS_H_
+
+#include "frontends/p4/typeMap.h"
+#include "ir/ir.h"
+#include "lib/error.h"
+
+namespace P4 {
+
+/**
+ * Checks that the build-in string annotations (\@name, \@deprecated, \@noWarn) have string
+ * arguments.
+ */
+class ValidateStringAnnotations final : public Inspector {
+    TypeMap *typeMap;
+
+ public:
+    explicit ValidateStringAnnotations() {}
+
+    void postorder(const IR::Annotation *annotation) override {
+        const auto name = annotation->name;
+        if (name != IR::Annotation::nameAnnotation &&
+            name != IR::Annotation::deprecatedAnnotation &&
+            name != IR::Annotation::noWarnAnnotation) {
+            return;
+        }
+        if (annotation->expr.size() != 1)
+            ::error(ErrorType::ERR_INVALID, "%1%: annotation must have exactly 1 argument",
+                    annotation);
+        auto e0 = annotation->expr.at(0);
+        if (!e0->is<IR::StringLiteral>())
+            ::error(ErrorType::ERR_TYPE_ERROR, "%1%: @%2% annotation's value must be a string", e0,
+                    annotation->name.originalName);
+    }
+};
+
+}  // namespace P4
+
+#endif /* P4_VALIDATESTRINGANNOTATIONS_H_  */

testdata/p4_16_errors/spec-issue1297-string-cat-err-2-anno.p4

@@ -0,0 +1,4 @@
+// should not compile -- not a string
+@name(4)
+void fn() {
+}

testdata/p4_16_errors/spec-issue1297-string-cat-err-3-anno.p4

@@ -0,0 +1,4 @@
+// should not compile -- not valid string op
+@deprecated("a" | "b")
+void fn() {
+}

testdata/p4_16_errors_outputs/spec-issue1297-string-cat-err-2-anno.p4

@@ -0,0 +1,2 @@
+@name(4) void fn() {
+}

testdata/p4_16_errors_outputs/spec-issue1297-string-cat-err-2-anno.p4-stderr

@@ -0,0 +1,3 @@
+spec-issue1297-string-cat-err-2-anno.p4(2): [--Werror=type-error] error: 4: @name annotation's value must be a string
+@name(4)
+      ^

testdata/p4_16_errors_outputs/spec-issue1297-string-cat-err-3-anno.p4

@@ -0,0 +1,2 @@
+@deprecated("a" | "b") void fn() {
+}

testdata/p4_16_errors_outputs/spec-issue1297-string-cat-err-3-anno.p4-stderr

@@ -0,0 +1,3 @@
+spec-issue1297-string-cat-err-3-anno.p4(2): [--Werror=type-error] error: "a" | "b": @deprecated annotation's value must be a string
+@deprecated("a" | "b")
+              ^^^^^^^