use cstring not string.h, add terminator, fill buffer with space

take copyBufferAndPad() out of anonymous namespace,
so it can be called in other places.

Author: yiwu0b11

flang/include/flang/Runtime/time-intrinsic.h

@@ -9,6 +9,17 @@
 // Defines the API between compiled code and the implementations of time-related
 // intrinsic subroutines in the runtime library.
 
+// time-intrinsic.h
+#ifndef TIME_INTRINSIC_H
+#define TIME_INTRINSIC_H
+
+#include <cstddef>
+
+void copyBufferAndPad(
+    char *dest, std::size_t destChars, char *buffer, std::size_t len);
+
+#endif // TIME_INTRINSIC_H
+
 #ifndef FORTRAN_RUNTIME_TIME_INTRINSIC_H_
 #define FORTRAN_RUNTIME_TIME_INTRINSIC_H_
 

flang/runtime/extensions.cpp

@@ -10,18 +10,20 @@
 // extensions that will eventually be implemented in Fortran.
 
 #include "flang/Runtime/extensions.h"
+#include "terminator.h"
 #include "flang/Runtime/command.h"
 #include "flang/Runtime/descriptor.h"
 #include "flang/Runtime/io-api.h"
-#include <string.h>
+#include "flang/Runtime/time-intrinsic.h" // copyBufferAndPad
+#include <cstring>
 
 #ifdef _WIN32
 #define WIN32_LEAN_AND_MEAN
 #define NOMINMAX
 #include <windows.h>
 
+#include <cstdlib> // wcstombs_s
 #include <lmcons.h> // UNLEN=256
-#include <stdlib.h> // wcstombs_s
 #include <wchar.h> // wchar_t cast to LPWSTR
 #pragma comment(lib, "Advapi32.lib") // Link Advapi32.lib for GetUserName
 #define LOGIN_NAME_MAX UNLEN
@@ -30,10 +32,9 @@ inline int getlogin_r(char *buf, size_t bufSize) {
   wchar_t w_username[UNLEN + 1];
   DWORD nameLen = UNLEN + 1;
 
-  if (GetUserNameW(w_username, &nameLen)) {
+  if (GetUserName(w_username, &nameLen)) {
     // Convert the wchar_t string to a regular C string using wcstombs_s
-    if (wcstombs_s(nullptr, buf, sizeof(w_username), w_username, _TRUNCATE) !=
-        0) {
+    if (wcstombs_s(nullptr, buf, bufSize, w_username, _TRUNCATE) != 0) {
       // Conversion failed
       return -1;
     }
@@ -49,7 +50,11 @@ inline int getlogin_r(char *buf, size_t bufSize) {
 #include <unistd.h>
 #else
 // System is not posix-compliant
-inline int getlogin_r(char *buf, size_t bufsize) { return -1; }
+inline int getlogin_r(char *buf, size_t bufSize) {
+  std::memset(buf, ' ', bufSize - 1);
+  buf[bufSize - 1] = '\0';
+  return 0;
+}
 #endif
 
 extern "C" {
@@ -78,15 +83,13 @@ void FORTRAN_PROCEDURE_NAME(getarg)(
 
 void FORTRAN_PROCEDURE_NAME(getlog)(std::int8_t *arg, std::int64_t length) {
   std::array<char, LOGIN_NAME_MAX + 1> str;
+
   int error = getlogin_r(str.data(), str.size());
-  assert(error == 0 && "getlogin_r returned an error");
+  Terminator terminator{__FILE__, __LINE__};
+  RUNTIME_CHECK(terminator, error == 0);
 
-  // Trim space from right/end
-  int i = str.size();
-  while (' ' == str[--i]) {
-    str[i] = 0;
-  }
-  strncpy(reinterpret_cast<char *>(arg), str.data(), length);
+  copyBufferAndPad(
+      reinterpret_cast<char *>(arg), length, str.data(), str.size());
 }
 
 } // namespace Fortran::runtime

flang/runtime/time-intrinsic.cpp

@@ -39,6 +39,17 @@
 // overload will have a dummy parameter whose type indicates whether or not it
 // should be preferred. Any other parameters required for SFINAE should have
 // default values provided.
+
+// outside anonymous namespace, function reused
+void copyBufferAndPad(
+    char *dest, std::size_t destChars, char *buffer, std::size_t len) {
+  auto copyLen{std::min(len, destChars)};
+  std::memcpy(dest, buffer, copyLen);
+  for (auto i{copyLen}; i < destChars; ++i) {
+    dest[i] = ' ';
+  }
+}
+
 namespace {
 // Types for the dummy parameter indicating the priority of a given overload.
 // We will invoke our helper with an integer literal argument, so the overload
@@ -279,29 +290,22 @@ static void GetDateAndTime(Fortran::runtime::Terminator &terminator, char *date,
 
   static constexpr std::size_t buffSize{16};
   char buffer[buffSize];
-  auto copyBufferAndPad{
-      [&](char *dest, std::size_t destChars, std::size_t len) {
-        auto copyLen{std::min(len, destChars)};
-        std::memcpy(dest, buffer, copyLen);
-        for (auto i{copyLen}; i < destChars; ++i) {
-          dest[i] = ' ';
-        }
-      }};
+
   if (date) {
     auto len = std::strftime(buffer, buffSize, "%Y%m%d", &localTime);
-    copyBufferAndPad(date, dateChars, len);
+    copyBufferAndPad(date, dateChars, buffer, len);
   }
   if (time) {
     auto len{std::snprintf(buffer, buffSize, "%02d%02d%02d.%03jd",
         localTime.tm_hour, localTime.tm_min, localTime.tm_sec, ms)};
-    copyBufferAndPad(time, timeChars, len);
+    copyBufferAndPad(time, timeChars, buffer, len);
   }
   if (zone) {
     // Note: this may leave the buffer empty on many platforms. Classic flang
     // has a much more complex way of doing this (see __io_timezone in classic
     // flang).
     auto len{std::strftime(buffer, buffSize, "%z", &localTime)};
-    copyBufferAndPad(zone, zoneChars, len);
+    copyBufferAndPad(zone, zoneChars, buffer, len);
   }
   if (values) {
     auto typeCode{values->type().GetCategoryAndKind()};