SERVER-52604 normalize log.h inclusion semantics

1 files changed, 92 insertions, 119 deletions

diff --git a/src/mongo/logv2/log.h b/src/mongo/logv2/log.h
index 27e8f9f52fe..d887e6ea351 100644
--- a/src/mongo/logv2/log.h
+++ b/src/mongo/logv2/log.h
@@ -27,22 +27,7 @@
  *    it in the license file.
  */
 
-// #pragma once is not used in this header.
-// This header attempts to enforce the rule that no logging should be done in
-// an inline function defined in a header.
-// To enforce this "no logging in header" rule, we use #include guards with a validating #else
-// clause.
-// Also, this header relies on a preprocessor macro to determine the default component for the
-// unconditional logging functions severe(), error(), warning() and log(). Disallowing multiple
-// inclusion of log.h will ensure that the default component will be set correctly.
-
-#if defined(MONGO_UTIL_LOGV2_H_)
-#error \
-    "mongo/logv2/log.h cannot be included multiple times. " \
-       "This may occur when log.h is included in a header. " \
-       "Please check your #include's."
-#else  // MONGO_UTIL_LOGV2_H_
-#define MONGO_UTIL_LOGV2_H_
+#pragma once
 
 #include "mongo/base/status.h"
 #include "mongo/bson/util/builder.h"
@@ -56,26 +41,16 @@
 #include "mongo/logv2/redaction.h"
 #include "mongo/util/errno_util.h"
 
-namespace {
-#if defined(MONGO_LOGV2_DEFAULT_COMPONENT)
-// Provide log component in global scope so that MONGO_LOG will always have a valid component.
-// Global log component will be kDefault unless overridden by MONGO_LOGV2_DEFAULT_COMPONENT.
-const mongo::logv2::LogComponent MongoLogV2DefaultComponent_component =
-    MONGO_LOGV2_DEFAULT_COMPONENT;
-#else
-#error \
-    "mongo/logv2/log.h requires MONGO_LOGV2_DEFAULT_COMPONENT to be defined. " \
-       "Please see https://github.com/mongodb/mongo/blob/master/docs/logging.md "
-#endif  // MONGO_LOGV2_DEFAULT_COMPONENT
-}  // namespace
-
 // The logging macros below are documented in detail under docs/logging.md
-namespace mongo {
-// Internal helper to be able to create LogOptions with two arguments from other macros
-#define MAKE_OPTIONS_ARG2(ARG0, ARG1) \
-    ::mongo::logv2::LogOptions {      \
-        ARG0, ARG1                    \
-    }
+//
+// They all (except LOGV2_IMPL) require a `MONGO_LOGV2_DEFAULT_COMPONENT` macro.
+// This configuration macro must expand at their point of use to a
+// `LogComponent` expression. For example:
+//
+//     #define MONGO_LOGV2_DEFAULT_COMPONENT ::mongo::logv2::LogComponent::kDefault
+//
+//     LOGV2(1234500, "Something interesting happened");
+//
 
 // Internal helper to perform the logging where it requires the MESSAGE to be a compile time string.
 #define LOGV2_IMPL(ID, SEVERITY, OPTIONS, FMTSTR_MESSAGE, ...) \
@@ -98,11 +73,11 @@ namespace mongo {
  * DYNAMIC_ATTRIBUTES single argument DynamicAttributes object
  *   no attributes may be passed with "name"_attr=value when this is used
  */
-#define LOGV2(ID, FMTSTR_MESSAGE, ...)                                           \
-    LOGV2_IMPL(ID,                                                               \
-               ::mongo::logv2::LogSeverity::Log(),                               \
-               ::mongo::logv2::LogOptions{MongoLogV2DefaultComponent_component}, \
-               FMTSTR_MESSAGE,                                                   \
+#define LOGV2(ID, FMTSTR_MESSAGE, ...)                                    \
+    LOGV2_IMPL(ID,                                                        \
+               ::mongo::logv2::LogSeverity::Log(),                        \
+               ::mongo::logv2::LogOptions{MONGO_LOGV2_DEFAULT_COMPONENT}, \
+               FMTSTR_MESSAGE,                                            \
                ##__VA_ARGS__)
 
 /**
@@ -113,24 +88,24 @@ namespace mongo {
  *
  * See LOGV2() for documentation of the other parameters
  */
-#define LOGV2_OPTIONS(ID, OPTIONS, FMTSTR_MESSAGE, ...)            \
-    LOGV2_IMPL(ID,                                                 \
-               ::mongo::logv2::LogSeverity::Log(),                 \
-               ::mongo::logv2::LogOptions::ensureValidComponent(   \
-                   OPTIONS, MongoLogV2DefaultComponent_component), \
-               FMTSTR_MESSAGE,                                     \
-               ##__VA_ARGS__)
+#define LOGV2_OPTIONS(ID, OPTIONS, FMTSTR_MESSAGE, ...)                                           \
+    LOGV2_IMPL(                                                                                   \
+        ID,                                                                                       \
+        ::mongo::logv2::LogSeverity::Log(),                                                       \
+        ::mongo::logv2::LogOptions::ensureValidComponent(OPTIONS, MONGO_LOGV2_DEFAULT_COMPONENT), \
+        FMTSTR_MESSAGE,                                                                           \
+        ##__VA_ARGS__)
 
 /**
  * Log with info severity.
  *
  * See LOGV2() for documentation of the parameters
  */
-#define LOGV2_INFO(ID, FMTSTR_MESSAGE, ...)                                      \
-    LOGV2_IMPL(ID,                                                               \
-               ::mongo::logv2::LogSeverity::Info(),                              \
-               ::mongo::logv2::LogOptions{MongoLogV2DefaultComponent_component}, \
-               FMTSTR_MESSAGE,                                                   \
+#define LOGV2_INFO(ID, FMTSTR_MESSAGE, ...)                               \
+    LOGV2_IMPL(ID,                                                        \
+               ::mongo::logv2::LogSeverity::Info(),                       \
+               ::mongo::logv2::LogOptions{MONGO_LOGV2_DEFAULT_COMPONENT}, \
+               FMTSTR_MESSAGE,                                            \
                ##__VA_ARGS__)
 
 /**
@@ -138,24 +113,24 @@ namespace mongo {
  *
  * See LOGV2_OPTIONS() for documentation of the parameters
  */
-#define LOGV2_INFO_OPTIONS(ID, OPTIONS, FMTSTR_MESSAGE, ...)       \
-    LOGV2_IMPL(ID,                                                 \
-               ::mongo::logv2::LogSeverity::Info(),                \
-               ::mongo::logv2::LogOptions::ensureValidComponent(   \
-                   OPTIONS, MongoLogV2DefaultComponent_component), \
-               FMTSTR_MESSAGE,                                     \
-               ##__VA_ARGS__)
+#define LOGV2_INFO_OPTIONS(ID, OPTIONS, FMTSTR_MESSAGE, ...)                                      \
+    LOGV2_IMPL(                                                                                   \
+        ID,                                                                                       \
+        ::mongo::logv2::LogSeverity::Info(),                                                      \
+        ::mongo::logv2::LogOptions::ensureValidComponent(OPTIONS, MONGO_LOGV2_DEFAULT_COMPONENT), \
+        FMTSTR_MESSAGE,                                                                           \
+        ##__VA_ARGS__)
 
 /**
  * Log with warning severity.
  *
  * See LOGV2() for documentation of the parameters
  */
-#define LOGV2_WARNING(ID, FMTSTR_MESSAGE, ...)                                   \
-    LOGV2_IMPL(ID,                                                               \
-               ::mongo::logv2::LogSeverity::Warning(),                           \
-               ::mongo::logv2::LogOptions{MongoLogV2DefaultComponent_component}, \
-               FMTSTR_MESSAGE,                                                   \
+#define LOGV2_WARNING(ID, FMTSTR_MESSAGE, ...)                            \
+    LOGV2_IMPL(ID,                                                        \
+               ::mongo::logv2::LogSeverity::Warning(),                    \
+               ::mongo::logv2::LogOptions{MONGO_LOGV2_DEFAULT_COMPONENT}, \
+               FMTSTR_MESSAGE,                                            \
                ##__VA_ARGS__)
 
 /**
@@ -163,24 +138,24 @@ namespace mongo {
  *
  * See LOGV2_OPTIONS() for documentation of the parameters
  */
-#define LOGV2_WARNING_OPTIONS(ID, OPTIONS, FMTSTR_MESSAGE, ...)    \
-    LOGV2_IMPL(ID,                                                 \
-               ::mongo::logv2::LogSeverity::Warning(),             \
-               ::mongo::logv2::LogOptions::ensureValidComponent(   \
-                   OPTIONS, MongoLogV2DefaultComponent_component), \
-               FMTSTR_MESSAGE,                                     \
-               ##__VA_ARGS__)
+#define LOGV2_WARNING_OPTIONS(ID, OPTIONS, FMTSTR_MESSAGE, ...)                                   \
+    LOGV2_IMPL(                                                                                   \
+        ID,                                                                                       \
+        ::mongo::logv2::LogSeverity::Warning(),                                                   \
+        ::mongo::logv2::LogOptions::ensureValidComponent(OPTIONS, MONGO_LOGV2_DEFAULT_COMPONENT), \
+        FMTSTR_MESSAGE,                                                                           \
+        ##__VA_ARGS__)
 
 /**
  * Log with error severity.
  *
  * See LOGV2() for documentation of the parameters
  */
-#define LOGV2_ERROR(ID, FMTSTR_MESSAGE, ...)                                     \
-    LOGV2_IMPL(ID,                                                               \
-               ::mongo::logv2::LogSeverity::Error(),                             \
-               ::mongo::logv2::LogOptions{MongoLogV2DefaultComponent_component}, \
-               FMTSTR_MESSAGE,                                                   \
+#define LOGV2_ERROR(ID, FMTSTR_MESSAGE, ...)                              \
+    LOGV2_IMPL(ID,                                                        \
+               ::mongo::logv2::LogSeverity::Error(),                      \
+               ::mongo::logv2::LogOptions{MONGO_LOGV2_DEFAULT_COMPONENT}, \
+               FMTSTR_MESSAGE,                                            \
                ##__VA_ARGS__)
 
 /**
@@ -188,27 +163,27 @@ namespace mongo {
  *
  * See LOGV2_OPTIONS() for documentation of the parameters
  */
-#define LOGV2_ERROR_OPTIONS(ID, OPTIONS, FMTSTR_MESSAGE, ...)      \
-    LOGV2_IMPL(ID,                                                 \
-               ::mongo::logv2::LogSeverity::Error(),               \
-               ::mongo::logv2::LogOptions::ensureValidComponent(   \
-                   OPTIONS, MongoLogV2DefaultComponent_component), \
-               FMTSTR_MESSAGE,                                     \
-               ##__VA_ARGS__)
+#define LOGV2_ERROR_OPTIONS(ID, OPTIONS, FMTSTR_MESSAGE, ...)                                     \
+    LOGV2_IMPL(                                                                                   \
+        ID,                                                                                       \
+        ::mongo::logv2::LogSeverity::Error(),                                                     \
+        ::mongo::logv2::LogOptions::ensureValidComponent(OPTIONS, MONGO_LOGV2_DEFAULT_COMPONENT), \
+        FMTSTR_MESSAGE,                                                                           \
+        ##__VA_ARGS__)
 
 /**
  * Log with fatal severity. fassertFailed(ID) will be performed after writing the log
  *
  * See LOGV2() for documentation of the parameters
  */
-#define LOGV2_FATAL(ID, FMTSTR_MESSAGE, ...)                                         \
-    do {                                                                             \
-        LOGV2_IMPL(ID,                                                               \
-                   ::mongo::logv2::LogSeverity::Severe(),                            \
-                   ::mongo::logv2::LogOptions{MongoLogV2DefaultComponent_component}, \
-                   FMTSTR_MESSAGE,                                                   \
-                   ##__VA_ARGS__);                                                   \
-        fassertFailed(ID);                                                           \
+#define LOGV2_FATAL(ID, FMTSTR_MESSAGE, ...)                                  \
+    do {                                                                      \
+        LOGV2_IMPL(ID,                                                        \
+                   ::mongo::logv2::LogSeverity::Severe(),                     \
+                   ::mongo::logv2::LogOptions{MONGO_LOGV2_DEFAULT_COMPONENT}, \
+                   FMTSTR_MESSAGE,                                            \
+                   ##__VA_ARGS__);                                            \
+        fassertFailed(ID);                                                    \
     } while (false)
 
 /**
@@ -216,15 +191,15 @@ namespace mongo {
  *
  * See LOGV2() for documentation of the parameters
  */
-#define LOGV2_FATAL_NOTRACE(ID, FMTSTR_MESSAGE, ...)                             \
-    do {                                                                         \
-        LOGV2_IMPL(ID,                                                           \
-                   ::mongo::logv2::LogSeverity::Severe(),                        \
-                   MAKE_OPTIONS_ARG2(MongoLogV2DefaultComponent_component,       \
-                                     ::mongo::logv2::FatalMode::kAssertNoTrace), \
-                   FMTSTR_MESSAGE,                                               \
-                   ##__VA_ARGS__);                                               \
-        fassertFailedNoTrace(ID);                                                \
+#define LOGV2_FATAL_NOTRACE(ID, FMTSTR_MESSAGE, ...)                                        \
+    do {                                                                                    \
+        LOGV2_IMPL(ID,                                                                      \
+                   ::mongo::logv2::LogSeverity::Severe(),                                   \
+                   (::mongo::logv2::LogOptions{MONGO_LOGV2_DEFAULT_COMPONENT,               \
+                                               ::mongo::logv2::FatalMode::kAssertNoTrace}), \
+                   FMTSTR_MESSAGE,                                                          \
+                   ##__VA_ARGS__);                                                          \
+        fassertFailedNoTrace(ID);                                                           \
     } while (false)
 
 /**
@@ -232,12 +207,12 @@ namespace mongo {
  *
  * See LOGV2() for documentation of the parameters
  */
-#define LOGV2_FATAL_CONTINUE(ID, FMTSTR_MESSAGE, ...)                   \
-    LOGV2_IMPL(ID,                                                      \
-               ::mongo::logv2::LogSeverity::Severe(),                   \
-               MAKE_OPTIONS_ARG2(MongoLogV2DefaultComponent_component,  \
-                                 ::mongo::logv2::FatalMode::kContinue), \
-               FMTSTR_MESSAGE,                                          \
+#define LOGV2_FATAL_CONTINUE(ID, FMTSTR_MESSAGE, ...)                              \
+    LOGV2_IMPL(ID,                                                                 \
+               ::mongo::logv2::LogSeverity::Severe(),                              \
+               (::mongo::logv2::LogOptions{MONGO_LOGV2_DEFAULT_COMPONENT,          \
+                                           ::mongo::logv2::FatalMode::kContinue}), \
+               FMTSTR_MESSAGE,                                                     \
                ##__VA_ARGS__)
 
 /**
@@ -250,7 +225,7 @@ namespace mongo {
 #define LOGV2_FATAL_OPTIONS(ID, OPTIONS, FMTSTR_MESSAGE, ...)                       \
     do {                                                                            \
         auto optionsMacroLocal_ = ::mongo::logv2::LogOptions::ensureValidComponent( \
-            OPTIONS, MongoLogV2DefaultComponent_component);                         \
+            OPTIONS, MONGO_LOGV2_DEFAULT_COMPONENT);                                \
         LOGV2_IMPL(ID,                                                              \
                    ::mongo::logv2::LogSeverity::Severe(),                           \
                    optionsMacroLocal_,                                              \
@@ -277,7 +252,7 @@ namespace mongo {
     do {                                                                                     \
         auto severityMacroLocal_ = ::mongo::logv2::LogSeverity::Debug(DLEVEL);               \
         auto optionsMacroLocal_ = ::mongo::logv2::LogOptions::ensureValidComponent(          \
-            OPTIONS, MongoLogV2DefaultComponent_component);                                  \
+            OPTIONS, MONGO_LOGV2_DEFAULT_COMPONENT);                                         \
         if (::mongo::logv2::LogManager::global().getGlobalSettings().shouldLog(              \
                 optionsMacroLocal_.component(), severityMacroLocal_)) {                      \
             LOGV2_IMPL(                                                                      \
@@ -292,17 +267,15 @@ namespace mongo {
  *
  * See LOGV2() for documentation of the other parameters
  */
-#define LOGV2_DEBUG(ID, DLEVEL, FMTSTR_MESSAGE, ...)                                      \
-    LOGV2_DEBUG_OPTIONS(ID,                                                               \
-                        DLEVEL,                                                           \
-                        ::mongo::logv2::LogOptions{MongoLogV2DefaultComponent_component}, \
-                        FMTSTR_MESSAGE,                                                   \
+#define LOGV2_DEBUG(ID, DLEVEL, FMTSTR_MESSAGE, ...)                               \
+    LOGV2_DEBUG_OPTIONS(ID,                                                        \
+                        DLEVEL,                                                    \
+                        ::mongo::logv2::LogOptions{MONGO_LOGV2_DEFAULT_COMPONENT}, \
+                        FMTSTR_MESSAGE,                                            \
                         ##__VA_ARGS__)
 
-inline bool shouldLog(logv2::LogComponent logComponent, logv2::LogSeverity severity) {
-    return logv2::LogManager::global().getGlobalSettings().shouldLog(logComponent, severity);
+namespace mongo::logv2 {
+inline bool shouldLog(LogComponent logComponent, LogSeverity severity) {
+    return LogManager::global().getGlobalSettings().shouldLog(logComponent, severity);
 }
-
-}  // namespace mongo
-
-#endif  // MONGO_UTIL_LOGV2_H_
+}  // namespace mongo::logv2