Parsing P4Info for Actions and type-checking params.

e2e_tests/action_restrictions_invalid.p4

@@ -0,0 +1,77 @@
+#include <v1model.p4>
+
+type bit<16> custom_type_t;
+
+struct headers {};
+struct metadata {
+  bit<16> foo;
+  custom_type_t bar;
+};
+
+#define MULTICAST_GROUP_ID_BITWIDTH 16
+typedef bit<MULTICAST_GROUP_ID_BITWIDTH> multicast_group_id_t;
+
+parser MyParser(packet_in packet,
+                out headers hdr,
+                inout metadata meta,
+                inout standard_metadata_t standard_metadata) {
+  state start {
+    transition accept;
+  }
+}
+
+control MyVerifyChecksum(inout headers hdr, inout metadata meta) {
+  apply {  }
+}
+
+control MyIngress(inout headers hdr,
+                  inout metadata meta,
+                  inout standard_metadata_t standard_metadata) {
+
+  @id(123)
+  @action_restriction("multicast_group_id != 0")
+  action act_1(multicast_group_id_t multicast_group_id) {
+    meta.foo = multicast_group_id;
+  }
+
+  @id(1234)
+  @action_restriction("custom_type_param != 0")
+  action act_2(custom_type_t custom_type_param) {
+    meta.bar = custom_type_param;
+  }
+
+  table tbl {
+    key = {  }
+    actions = {
+      act_1;
+      act_2;
+    }
+  }
+
+  apply {
+    tbl.apply();
+  }
+}
+
+control MyEgress(inout headers hdr,
+                 inout metadata meta,
+                 inout standard_metadata_t standard_metadata) {
+  apply {  }
+}
+
+control MyComputeChecksum(inout headers hdr, inout metadata meta) {
+  apply {  }
+}
+
+control MyDeparser(packet_out packet, in headers hdr) {
+  apply {  }
+}
+
+V1Switch(
+MyParser(),
+MyVerifyChecksum(),
+MyIngress(),
+MyEgress(),
+MyComputeChecksum(),
+MyDeparser()
+) main;

e2e_tests/action_restrictions_valid.p4

@@ -0,0 +1,67 @@
+#include <v1model.p4>
+
+struct headers {};
+struct metadata {
+  bit<16> foo;
+};
+
+#define MULTICAST_GROUP_ID_BITWIDTH 16
+typedef bit<MULTICAST_GROUP_ID_BITWIDTH> multicast_group_id_t;
+
+parser MyParser(packet_in packet,
+                out headers hdr,
+                inout metadata meta,
+                inout standard_metadata_t standard_metadata) {
+  state start {
+    transition accept;
+  }
+}
+
+control MyVerifyChecksum(inout headers hdr, inout metadata meta) {
+  apply {  }
+}
+
+control MyIngress(inout headers hdr,
+                  inout metadata meta,
+                  inout standard_metadata_t standard_metadata) {
+
+  @id(123)
+  @action_restriction("multicast_group_id != 0")
+  action act_1(multicast_group_id_t multicast_group_id) {
+    meta.foo = multicast_group_id;
+  }
+
+  table tbl {
+    key = {  }
+    actions = {
+      act_1;
+    }
+  }
+
+  apply {
+    tbl.apply();
+  }
+}
+
+control MyEgress(inout headers hdr,
+                 inout metadata meta,
+                 inout standard_metadata_t standard_metadata) {
+  apply {  }
+}
+
+control MyComputeChecksum(inout headers hdr, inout metadata meta) {
+  apply {  }
+}
+
+control MyDeparser(packet_out packet, in headers hdr) {
+  apply {  }
+}
+
+V1Switch(
+MyParser(),
+MyVerifyChecksum(),
+MyIngress(),
+MyEgress(),
+MyComputeChecksum(),
+MyDeparser()
+) main;

gutils/BUILD.bazel

@@ -36,7 +36,14 @@ cc_library(
         "proto.h",
     ],
     visibility = ["//visibility:public"],
-    deps = ["@com_google_protobuf//:protobuf"],
+    deps = [
+        ":source_location",
+        ":status",
+        "@com_google_absl//absl/status",
+        "@com_google_absl//absl/strings",
+        "@com_google_protobuf//:protobuf",
+        "@com_google_protobuf//src/google/protobuf/io:tokenizer",
+    ],
 )
 
 cc_library(

gutils/proto.cc

@@ -1,10 +1,48 @@
 #include "gutils/proto.h"
 
+#include <fcntl.h>
+
+#include <string>
+#include <string_view>
+
+#include "absl/status/status.h"
+#include "absl/strings/substitute.h"
+#include "google/protobuf/io/tokenizer.h"
 #include "google/protobuf/message.h"
+#include "google/protobuf/text_format.h"
 #include "google/protobuf/util/message_differencer.h"
+#include "gutils/source_location.h"
+#include "gutils/status_builder.h"
 
 namespace gutils {
 
+// Collects errors by appending them to a given string.
+class StringErrorCollector : public google::protobuf::io::ErrorCollector {
+ public:
+  // String error_text is unowned and must remain valid during the use of
+  // StringErrorCollector.
+  explicit StringErrorCollector(std::string *error_text)
+      : error_text_{error_text} {};
+  StringErrorCollector(const StringErrorCollector &) = delete;
+  StringErrorCollector &operator=(const StringErrorCollector &) = delete;
+
+  // Implementation of protobuf::io::ErrorCollector::AddError.
+  void AddError(int line, int column, const std::string &message) override {
+    if (error_text_ != nullptr) {
+      absl::SubstituteAndAppend(error_text_, "$0($1): $2\n", line, column,
+                                message);
+    }
+  }
+
+  // Implementation of protobuf::io::ErrorCollector::AddWarning.
+  void AddWarning(int line, int column, const std::string &message) override {
+    AddError(line, column, message);
+  }
+
+ private:
+  std::string *const error_text_;
+};
+
 bool ProtoEqual(const google::protobuf::Message &message1,
                 const google::protobuf::Message &message2,
                 google::protobuf::util::MessageDifferencer &differ) {
@@ -22,4 +60,27 @@ bool ProtoEqual(const google::protobuf::Message &message1,
   return ProtoEqual(message1, message2, differ);
 }
 
+absl::Status ReadProtoFromString(std::string_view proto_string,
+                                 google::protobuf::Message *message) {
+  // Verifies that the version of the library that we linked against is
+  // compatible with the version of the headers we compiled against.
+  /* copybara:insert(not needed nor possible in google3, as it is a mono repo)
+  GOOGLE_PROTOBUF_VERIFY_VERSION;
+  */
+
+  google::protobuf::TextFormat::Parser parser;
+  std::string all_errors;
+  StringErrorCollector collector(&all_errors);
+  parser.RecordErrorsTo(&collector);
+
+  if (!parser.ParseFromString(std::string(proto_string), message)) {
+    return InvalidArgumentErrorBuilder(GUTILS_LOC)
+           << "string <" << proto_string << "> did not parse as a"
+           << message->GetTypeName() << ":\n"
+           << all_errors;
+  }
+
+  return absl::OkStatus();
+}
+
 }  // namespace gutils

gutils/proto.h

@@ -1,6 +1,9 @@
 #ifndef THIRD_PARTY_P4LANG_P4_CONSTRAINTS_GUTILS_PROTO_H_
 #define THIRD_PARTY_P4LANG_P4_CONSTRAINTS_GUTILS_PROTO_H_
 
+#include <string_view>
+
+#include "absl/status/status.h"
 #include "google/protobuf/message.h"
 #include "google/protobuf/util/message_differencer.h"
 
@@ -14,6 +17,10 @@ bool ProtoEqual(const google::protobuf::Message &message1,
 bool ProtoEqual(const google::protobuf::Message &message1,
                 const google::protobuf::Message &message2);
 
+// Read the contents of the string into a protobuf.
+absl::Status ReadProtoFromString(std::string_view proto_string,
+                                 google::protobuf::Message *message);
+
 }  //  namespace gutils
 
 #endif  // THIRD_PARTY_P4LANG_P4_CONSTRAINTS_GUTILS_PROTO_H_

p4_constraints/ast.proto

@@ -184,5 +184,10 @@ message SourceLocation {
     // If present, `line` and `column` are relative to an @entry_restriction
     // annotation attached to a table of the given name.
     string table_name = 4;
+
+    // P4 action name. Prefer `file_path` whenever possible.
+    // If present, `line` and `column` are relative to an @action_restriction
+    // annotation attached to an action of the given name.
+    string action_name = 5;
   }
 }

p4_constraints/backend/BUILD.bazel

@@ -83,6 +83,7 @@ cc_library(
         "//p4_constraints/frontend:constraint_kind",
         "//p4_constraints/frontend:parser",
         "@com_github_p4lang_p4runtime//:p4info_cc_proto",
+        "@com_github_p4lang_p4runtime//:p4types_cc_proto",
         "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/log",
         "@com_google_absl//absl/log:check",
@@ -208,3 +209,18 @@ cc_test(
         "@com_google_googletest//:gtest_main",
     ],
 )
+
+cc_test(
+    name = "constraint_info_test",
+    srcs = ["constraint_info_test.cc"],
+    deps = [
+        ":constraint_info",
+        "//gutils:proto",
+        "//gutils:status_matchers",
+        "@com_github_p4lang_p4runtime//:p4info_cc_proto",
+        "@com_google_absl//absl/container:flat_hash_map",
+        "@com_google_absl//absl/log:check",
+        "@com_google_absl//absl/status:statusor",
+        "@com_google_googletest//:gtest_main",
+    ],
+)