[flang-commits] [flang] c02abb6 - [flang][runtime] Enforce some limits on kP scale factors

[Peter Klausler via flang-commits]

Author: Peter Klausler
Date: 2022-04-22T16:51:36-07:00
New Revision: c02abb68cd88a9edbc5d4dd83de6f50766fb9ae8

URL: https://github.com/llvm/llvm-project/commit/c02abb68cd88a9edbc5d4dd83de6f50766fb9ae8
DIFF: https://github.com/llvm/llvm-project/commit/c02abb68cd88a9edbc5d4dd83de6f50766fb9ae8.diff

LOG: [flang][runtime] Enforce some limits on kP scale factors

Ew.d and Dw.d output edit descriptors should respect limitations from
the standard on the value of a kP scale factor with respect to the
digit count (d), at least for values of k other than zero.

Differential Revision: https://reviews.llvm.org/D124300

Added: 
    

Modified: 
    flang/include/flang/Runtime/iostat.h
    flang/runtime/edit-output.cpp
    flang/runtime/iostat.cpp

Removed: 
    


################################################################################
diff  --git a/flang/include/flang/Runtime/iostat.h b/flang/include/flang/Runtime/iostat.h
index 0303d3de16d09..f09f25a738e2e 100644
--- a/flang/include/flang/Runtime/iostat.h
+++ b/flang/include/flang/Runtime/iostat.h
@@ -69,6 +69,7 @@ enum Iostat {
   IostatUTF8Decoding,
   IostatUnitOverflow,
   IostatBadRealInput,
+  IostatBadScaleFactor,
 };
 
 const char *IostatErrorString(int);

diff  --git a/flang/runtime/edit-output.cpp b/flang/runtime/edit-output.cpp
index 95292ded777b6..ebdc62b78bb6b 100644
--- a/flang/runtime/edit-output.cpp
+++ b/flang/runtime/edit-output.cpp
@@ -196,9 +196,21 @@ bool RealOutputEditing<binaryPrecision>::EditEorDOutput(const DataEdit &edit) {
   int scale{isEN || isES ? 1 : edit.modes.scale}; // 'kP' value
   int zeroesAfterPoint{0};
   if (scale < 0) {
+    if (scale <= -editDigits) {
+      io_.GetIoErrorHandler().SignalError(IostatBadScaleFactor,
+          "Scale factor (kP) %d cannot be less than -d (%d)", scale,
+          -editDigits);
+      return false;
+    }
     zeroesAfterPoint = -scale;
     significantDigits = std::max(0, significantDigits - zeroesAfterPoint);
   } else if (scale > 0) {
+    if (scale >= editDigits + 2) {
+      io_.GetIoErrorHandler().SignalError(IostatBadScaleFactor,
+          "Scale factor (kP) %d cannot be greater than d+2 (%d)", scale,
+          editDigits + 2);
+      return false;
+    }
     ++significantDigits;
     scale = std::min(scale, significantDigits + 1);
   }

diff  --git a/flang/runtime/iostat.cpp b/flang/runtime/iostat.cpp
index e31fb83678301..e375b28a4c734 100644
--- a/flang/runtime/iostat.cpp
+++ b/flang/runtime/iostat.cpp
@@ -81,6 +81,8 @@ const char *IostatErrorString(int iostat) {
     return "UNIT number is out of range";
   case IostatBadRealInput:
     return "Bad REAL input value";
+  case IostatBadScaleFactor:
+    return "Bad REAL output scale factor (kP)";
   default:
     return nullptr;
   }