Separate I2CAddr from I2CExplorer

Summary:
Problem:
I2CExplore can't include Utils because it'll cause circular dependency as below:
I2CExplorer -> ConfigValidator -> Utils -> I2CExplorer

To avoid this, move I2CAddr as a separate library, the graph more or less becomes:

I2CAddr -> ConfigValidator -> Utils -> I2CExplorer

Reviewed By: somasun

Differential Revision: D62396774

fbshipit-source-id: d54f56cd0080b868b4568ad1cf90d315737c0f52

fboss/platform/platform_manager/BUCK

@@ -46,7 +46,7 @@ cpp_library(
         "ConfigValidator.cpp",
     ],
     exported_deps = [
-        ":i2c_explorer",
+        ":i2c_misc",
         ":platform_manager_config-cpp2-types",
         "//folly/logging:logging",
     ],
@@ -61,13 +61,14 @@ cpp_library(
         "I2cExplorer.cpp",
     ],
     exported_deps = [
+        "fbcode//fboss/lib/i2c:i2c_ctrl",
+        "fbcode//fboss/platform/helpers:platform_utils",
+        "fbcode//folly:file_util",
+        "fbcode//folly:string",
+        "fbcode//folly/logging:logging",
         "fbsource//third-party/fmt:fmt",
+        ":i2c_misc",
         ":platform_manager_config-cpp2-types",
-        "//fboss/lib/i2c:i2c_ctrl",
-        "//fboss/platform/helpers:platform_utils",
-        "//folly:file_util",
-        "//folly:string",
-        "//folly/logging:logging",
     ],
     exported_external_deps = [
         "re2",
@@ -159,7 +160,9 @@ cpp_library(
 
 cpp_library(
     name = "utils",
-    srcs = ["Utils.cpp"],
+    srcs = [
+        "Utils.cpp",
+    ],
     exported_deps = [
         ":config_validator",
         ":platform_manager_config-cpp2-types",
@@ -176,6 +179,19 @@ cpp_library(
     ],
 )
 
+cpp_library(
+    name = "i2c_misc",
+    headers = [
+        "I2cAddr.h",
+    ],
+    exported_deps = [
+        "fbsource//third-party/fmt:fmt",
+    ],
+    exported_external_deps = [
+        "re2",
+    ],
+)
+
 cpp_library(
     name = "data_store",
     srcs = ["DataStore.cpp"],

fboss/platform/platform_manager/ConfigValidator.cpp

@@ -5,8 +5,7 @@
 #include <folly/logging/xlog.h>
 #include <re2/re2.h>
 
-#include "fboss/platform/platform_manager/I2cExplorer.h"
-#include "fboss/platform/platform_manager/gen-cpp2/platform_manager_config_constants.h"
+#include "fboss/platform/platform_manager/I2cAddr.h"
 
 namespace {
 const re2::RE2 kRpmVersionRegex{"^[0-9]+\\.[0-9]+\\.[0-9]+\\-[0-9]+$"};

fboss/platform/platform_manager/I2cAddr.h

@@ -0,0 +1,43 @@
+// (c) Meta Platforms, Inc. and affiliates. Confidential and proprietary.
+
+#pragma once
+
+#include <string>
+
+#include <fmt/format.h>
+#include <re2/re2.h>
+
+namespace facebook::fboss::platform::platform_manager {
+
+inline const re2::RE2 kI2cAddrRe{"0x[0-9a-f]{2}"};
+
+struct I2cAddr {
+ public:
+  explicit I2cAddr(uint16_t addr) : addr_(addr) {}
+  explicit I2cAddr(const std::string& addr)
+      : addr_(std::stoi(addr, nullptr, 16 /* base */)) {
+    if (!re2::RE2::FullMatch(addr, kI2cAddrRe)) {
+      throw std::invalid_argument("Invalid i2c addr: " + addr);
+    }
+  }
+  bool operator==(const I2cAddr& b) const {
+    return addr_ == b.addr_;
+  }
+  // Returns string in the format 0x0f
+  std::string hex2Str() const {
+    return fmt::format("{:#04x}", addr_);
+  }
+  // Returns string in the format 000f
+  std::string hex4Str() const {
+    return fmt::format("{:04x}", addr_);
+  }
+  // Returns integer
+  uint16_t raw() const {
+    return addr_;
+  }
+
+ private:
+  uint16_t addr_{0};
+};
+
+} // namespace facebook::fboss::platform::platform_manager

fboss/platform/platform_manager/I2cExplorer.h

@@ -6,7 +6,6 @@
 #include <map>
 #include <memory>
 #include <optional>
-#include <stdexcept>
 #include <vector>
 
 #include <fmt/format.h>
@@ -15,39 +14,11 @@
 #include <re2/re2.h>
 
 #include "fboss/platform/helpers/PlatformUtils.h"
+#include "fboss/platform/platform_manager/I2cAddr.h"
 #include "fboss/platform/platform_manager/gen-cpp2/platform_manager_config_types.h"
 
 namespace facebook::fboss::platform::platform_manager {
 
-struct I2cAddr {
- public:
-  explicit I2cAddr(uint16_t addr) : addr_(addr) {}
-  explicit I2cAddr(const std::string& addr)
-      : addr_(std::stoi(addr, nullptr, 16 /* base */)) {
-    if (!re2::RE2::FullMatch(addr, re2::RE2{"0x[0-9a-f]{2}"})) {
-      throw std::invalid_argument("Invalid i2c addr: " + addr);
-    }
-  }
-  bool operator==(const I2cAddr& b) const {
-    return addr_ == b.addr_;
-  }
-  // Returns string in the format 0x0f
-  std::string hex2Str() const {
-    return fmt::format("{:#04x}", addr_);
-  }
-  // Returns string in the format 000f
-  std::string hex4Str() const {
-    return fmt::format("{:04x}", addr_);
-  }
-  // Returns integer
-  uint16_t raw() const {
-    return addr_;
-  }
-
- private:
-  uint16_t addr_{0};
-};
-
 class I2cExplorer {
  public:
   virtual ~I2cExplorer() = default;