move and use CopyAndPad from character.h

The compiler must have access to the implementations
of templated functions at the points where they're instantiated.

Author: yiwu0b11

flang/include/flang/Runtime/character.h

@@ -6,6 +6,36 @@
 //
 //===----------------------------------------------------------------------===//
 
+// character.h
+#ifndef CHARACTER_H
+#define CHARACTER_H
+
+#include <cstddef>
+#include <algorithm>
+
+template <typename TO, typename FROM>
+void CopyAndPad(
+    TO *to, const FROM *from, std::size_t toChars, std::size_t fromChars) {
+  if constexpr (sizeof(TO) != sizeof(FROM)) {
+    std::size_t copyChars{std::min(toChars, fromChars)};
+    for (std::size_t j{0}; j < copyChars; ++j) {
+      to[j] = from[j];
+    }
+    for (std::size_t j{copyChars}; j < toChars; ++j) {
+      to[j] = static_cast<TO>(' ');
+    }
+  } else if (toChars <= fromChars) {
+    std::memcpy(to, from, toChars * sizeof(TO));
+  } else {
+    std::memcpy(to, from, fromChars * sizeof(TO));
+    for (std::size_t j{fromChars}; j < toChars; ++j) {
+      to[j] = static_cast<TO>(' ');
+    }
+  }
+}
+
+#endif // CHARACTER_H
+
 // Defines API between compiled code and the CHARACTER
 // support functions in the runtime library.
 

flang/runtime/character.cpp

@@ -11,6 +11,7 @@
 #include "tools.h"
 #include "flang/Common/bit-population-count.h"
 #include "flang/Common/uint128.h"
+#include "flang/Runtime/character.h"
 #include "flang/Runtime/cpp-type.h"
 #include "flang/Runtime/descriptor.h"
 #include <algorithm>
@@ -461,27 +462,6 @@ static void GeneralCharFuncKind(Descriptor &result, const Descriptor &string,
   }
 }
 
-template <typename TO, typename FROM>
-static void CopyAndPad(
-    TO *to, const FROM *from, std::size_t toChars, std::size_t fromChars) {
-  if constexpr (sizeof(TO) != sizeof(FROM)) {
-    std::size_t copyChars{std::min(toChars, fromChars)};
-    for (std::size_t j{0}; j < copyChars; ++j) {
-      to[j] = from[j];
-    }
-    for (std::size_t j{copyChars}; j < toChars; ++j) {
-      to[j] = static_cast<TO>(' ');
-    }
-  } else if (toChars <= fromChars) {
-    std::memcpy(to, from, toChars * sizeof(TO));
-  } else {
-    std::memcpy(to, from, fromChars * sizeof(TO));
-    for (std::size_t j{fromChars}; j < toChars; ++j) {
-      to[j] = static_cast<TO>(' ');
-    }
-  }
-}
-
 template <typename CHAR, bool ISMIN>
 static void MaxMinHelper(Descriptor &accumulator, const Descriptor &x,
     const Terminator &terminator) {

flang/runtime/extensions.cpp

@@ -11,10 +11,10 @@
 
 #include "flang/Runtime/extensions.h"
 #include "terminator.h"
+#include "flang/Runtime/character.h"
 #include "flang/Runtime/command.h"
 #include "flang/Runtime/descriptor.h"
 #include "flang/Runtime/io-api.h"
-#include <cstring>
 
 #ifdef _WIN32
 #define WIN32_LEAN_AND_MEAN
@@ -81,14 +81,15 @@ void FORTRAN_PROCEDURE_NAME(getarg)(
 }
 
 void FORTRAN_PROCEDURE_NAME(getlog)(std::int8_t *arg, std::int64_t length) {
-  int charLen{LOGIN_NAME_MAX + 1};
-  char str[charLen];
+  const int nameMaxLen = LOGIN_NAME_MAX + 1;
+  char str[nameMaxLen];
 
-  int error{getlogin_r(*str, charLen)};
+  int error{getlogin_r(str, nameMaxLen)};
   Terminator terminator{__FILE__, __LINE__};
   RUNTIME_CHECK(terminator, error == 0);
 
-  CopyBufferAndPad(reinterpret_cast<char *>(arg), length, *str, charLen);
+  // find first \0 in string then pad from there
+  CopyAndPad(reinterpret_cast<char *>(arg), str, length, std::strlen(str));
 }
 
 } // namespace Fortran::runtime