[Impeller] Validation logs indicate where in code the validation error happened. (#53784)

Earlier, all validation logs originated from validation.cc which was not
useful at all since you had to find the string in the source.

Author: chinmaygarde

impeller/base/validation.cc

@@ -33,31 +33,30 @@ ScopedValidationFatal::~ScopedValidationFatal() {
   sValidationLogsAreFatal--;
 }
 
-ValidationLog::ValidationLog() = default;
+ValidationLog::ValidationLog(const char* file, int line)
+    : file_(file), line_(line) {}
 
 ValidationLog::~ValidationLog() {
   if (sValidationLogsDisabledCount <= 0) {
-    ImpellerValidationBreak(stream_.str().c_str());
+    ImpellerValidationBreak(stream_.str().c_str(), file_, line_);
   }
 }
 
 std::ostream& ValidationLog::GetStream() {
   return stream_;
 }
 
-void ImpellerValidationBreak(const char* message) {
-  std::stringstream stream;
+void ImpellerValidationBreak(const char* message, const char* file, int line) {
+  const auto severity =
+      ImpellerValidationErrorsAreFatal() ? fml::LOG_FATAL : fml::LOG_ERROR;
+  auto fml_log = fml::LogMessage{severity, file, line, nullptr};
+  fml_log.stream() <<
 #if FLUTTER_RELEASE
-  stream << "Impeller validation: " << message;
-#else
-  stream << "Break on '" << __FUNCTION__
-         << "' to inspect point of failure: " << message;
-#endif
-  if (sValidationLogsAreFatal > 0) {
-    FML_LOG(FATAL) << stream.str();
-  } else {
-    FML_LOG(ERROR) << stream.str();
-  }
+      "Impeller validation: " << message;
+#else   // FLUTTER_RELEASE
+      "Break on '" << __FUNCTION__
+                   << "' to inspect point of failure: " << message;
+#endif  // FLUTTER_RELEASE
 }
 
 bool ImpellerValidationErrorsAreFatal() {

impeller/base/validation.h

@@ -11,13 +11,15 @@ namespace impeller {
 
 class ValidationLog {
  public:
-  ValidationLog();
+  ValidationLog(const char* file, int line);
 
   ~ValidationLog();
 
   std::ostream& GetStream();
 
  private:
+  const char* file_ = nullptr;
+  int line_ = 0;
   std::ostringstream stream_;
 
   ValidationLog(const ValidationLog&) = delete;
@@ -29,7 +31,7 @@ class ValidationLog {
   ValidationLog& operator=(ValidationLog&&) = delete;
 };
 
-void ImpellerValidationBreak(const char* message);
+void ImpellerValidationBreak(const char* message, const char* file, int line);
 
 void ImpellerValidationErrorsSetFatal(bool fatal);
 
@@ -70,6 +72,6 @@ struct ScopedValidationFatal {
 ///   are fatal. The runtime-mode restriction still applies. This usually
 ///   happens in test environments.
 ///
-#define VALIDATION_LOG ::impeller::ValidationLog{}.GetStream()
+#define VALIDATION_LOG ::impeller::ValidationLog{__FILE__, __LINE__}.GetStream()
 
 #endif  // FLUTTER_IMPELLER_BASE_VALIDATION_H_