[flang][runtime] Correct handling of intentional I/O errors in pFLogger

At the end of an internal output statement, be sure to finish
any following control edit descriptors in the format (if any),
and (for output) advance to the next record.  Return the right
I/O error status code if output overruns the buffer.

Further, a signed integer in a format must have a digit, and can appear
only as the scale factor before a P control edit descriptor.

Author: klausler

flang/runtime/format-implementation.h

@@ -66,15 +66,6 @@ template <typename CONTEXT>
 int FormatControl<CONTEXT>::GetIntField(
     IoErrorHandler &handler, CharType firstCh, bool *hadError) {
   CharType ch{firstCh ? firstCh : PeekNext()};
-  if (ch != '-' && ch != '+' && (ch < '0' || ch > '9')) {
-    handler.SignalError(IostatErrorInFormat,
-        "Invalid FORMAT: integer expected at '%c'", static_cast<char>(ch));
-    if (hadError) {
-      *hadError = true;
-    }
-    return 0;
-  }
-  int result{0};
   bool negate{ch == '-'};
   if (negate || ch == '+') {
     if (firstCh) {
@@ -84,6 +75,15 @@ int FormatControl<CONTEXT>::GetIntField(
     }
     ch = PeekNext();
   }
+  if (ch < '0' || ch > '9') {
+    handler.SignalError(IostatErrorInFormat,
+        "Invalid FORMAT: integer expected at '%c'", static_cast<char>(ch));
+    if (hadError) {
+      *hadError = true;
+    }
+    return 0;
+  }
+  int result{0};
   while (ch >= '0' && ch <= '9') {
     constexpr int tenth{std::numeric_limits<int>::max() / 10};
     if (result > tenth ||
@@ -246,8 +246,15 @@ int FormatControl<CONTEXT>::CueUpNextDataEdit(Context &context, bool stop) {
       ch = GetNextChar(context);
     }
     if (ch == '-' || ch == '+' || (ch >= '0' && ch <= '9')) {
+      bool hadSign{ch == '-' || ch == '+'};
       repeat = GetIntField(context, ch);
       ch = GetNextChar(context);
+      if (hadSign && ch != 'p' && ch != 'P') {
+        ReportBadFormat(context,
+            "Invalid FORMAT: signed integer may appear only before 'P",
+            maybeReversionPoint);
+        return 0;
+      }
     } else if (ch == '*') {
       unlimited = true;
       ch = GetNextChar(context);

flang/runtime/internal-unit.cpp

@@ -109,7 +109,11 @@ std::size_t InternalDescriptorUnit<DIR>::GetNextInputBytes(
 template <Direction DIR>
 bool InternalDescriptorUnit<DIR>::AdvanceRecord(IoErrorHandler &handler) {
   if (currentRecordNumber >= endfileRecordNumber.value_or(0)) {
-    handler.SignalEnd();
+    if constexpr (DIR == Direction::Input) {
+      handler.SignalEnd();
+    } else {
+      handler.SignalError(IostatInternalWriteOverrun);
+    }
     return false;
   }
   if constexpr (DIR == Direction::Output) {

flang/runtime/io-stmt.cpp

@@ -118,6 +118,16 @@ template <Direction DIR> void InternalIoStatementState<DIR>::BackspaceRecord() {
   unit_.BackspaceRecord(*this);
 }
 
+template <Direction DIR>
+void InternalIoStatementState<DIR>::CompleteOperation() {
+  if (!this->completedOperation()) {
+    if constexpr (DIR == Direction::Output) {
+      unit_.AdvanceRecord(*this);
+    }
+    IoStatementBase::CompleteOperation();
+  }
+}
+
 template <Direction DIR> int InternalIoStatementState<DIR>::EndIoStatement() {
   if constexpr (DIR == Direction::Output) {
     unit_.EndIoStatement(); // fill
@@ -164,10 +174,8 @@ InternalFormattedIoStatementState<DIR, CHAR>::InternalFormattedIoStatementState(
 template <Direction DIR, typename CHAR>
 void InternalFormattedIoStatementState<DIR, CHAR>::CompleteOperation() {
   if (!this->completedOperation()) {
-    if constexpr (DIR == Direction::Output) {
-      format_.Finish(*this); // ignore any remaining input positioning actions
-    }
-    IoStatementBase::CompleteOperation();
+    format_.Finish(*this);
+    InternalIoStatementState<DIR>::CompleteOperation();
   }
 }
 

flang/runtime/io-stmt.h

@@ -346,6 +346,7 @@ class InternalIoStatementState : public IoStatementBase,
       const char *sourceFile = nullptr, int sourceLine = 0);
   InternalIoStatementState(
       const Descriptor &, const char *sourceFile = nullptr, int sourceLine = 0);
+  void CompleteOperation();
   int EndIoStatement();
 
   bool Emit(const char *data, std::size_t bytes, std::size_t elementBytes = 0);

flang/unittests/Runtime/NumericalFormatTest.cpp

@@ -104,7 +104,7 @@ TEST(IOApiTests, HelloWorldOutputTest) {
 
 TEST(IOApiTests, MultilineOutputTest) {
   // Allocate buffer for multiline output
-  static constexpr int numLines{5};
+  static constexpr int numLines{6};
   static constexpr int lineLength{32};
   char buffer[numLines][lineLength];
 
@@ -159,6 +159,7 @@ TEST(IOApiTests, MultilineOutputTest) {
                                   "                                "
                                   "789                 abcd 666 777"
                                   " 888 999                        "
+                                  "                                "
                                   "................................"};
   // Ensure formatted string matches expected output
   EXPECT_TRUE(