move EnsureNullTerminated to tools.h, free memory after use.

On Linux, malloc is freed in parent, child process will be cleaned up on termination.
Same approach was taken on Windows as well, but does it work in the same way?

Author: yiwu0b11

flang/runtime/execute.cpp

@@ -147,28 +147,11 @@ int TerminationCheck(int status, const Descriptor *cmdstat,
   return exitStatusVal;
 }
 
-const char *ensureNullTerminated(
-    const char *str, size_t length, Terminator &terminator) {
-  if (length <= strlen(str)) {
-    char *newCmd{(char *)malloc(length + 1)};
-    if (newCmd == NULL) {
-      terminator.Crash("Command not null-terminated, memory allocation failed "
-                       "for null-terminated newCmd.");
-    }
-
-    strncpy(newCmd, str, length);
-    newCmd[length] = '\0';
-    return newCmd;
-  } else {
-    return str;
-  }
-}
-
 void RTNAME(ExecuteCommandLine)(const Descriptor &command, bool wait,
     const Descriptor *exitstat, const Descriptor *cmdstat,
     const Descriptor *cmdmsg, const char *sourceFile, int line) {
   Terminator terminator{sourceFile, line};
-  const char *newCmd{ensureNullTerminated(
+  const char *newCmd{EnsureNullTerminated(
       command.OffsetElement(), command.ElementBytes(), terminator)};
 
   if (exitstat) {
@@ -202,22 +185,18 @@ void RTNAME(ExecuteCommandLine)(const Descriptor &command, bool wait,
 
     // append "cmd.exe /c " to the beginning of command
     const char *prefix{"cmd.exe /c "};
-    char *newCmdWin{
-        (char *)malloc(std::strlen(prefix) + std::strlen(newCmd) + 1)};
-    if (newCmd != NULL) {
-      std::strcpy(newCmdWin, prefix);
-      std::strcat(newCmdWin, newCmd);
-    } else {
-      terminator.Crash("Memory allocation failed for newCmd");
-    }
+    char *newCmdWin{(char *)AllocateMemoryOrCrash(
+        terminator, std::strlen(prefix) + std::strlen(newCmd) + 1)};
+    std::strcpy(newCmdWin, prefix);
+    std::strcat(newCmdWin, newCmd);
 
     // Convert the char to wide char
     const size_t sizeNeeded{mbstowcs(NULL, newCmdWin, 0) + 1};
     wchar_t *wcmd{new wchar_t[sizeNeeded]};
     if (std::mbstowcs(wcmd, newCmdWin, sizeNeeded) == static_cast<size_t>(-1)) {
       terminator.Crash("Char to wide char failed for newCmd");
     }
-    free(newCmdWin);
+    FreeMemory((void *)newCmdWin);
 
     if (CreateProcess(nullptr, wcmd, nullptr, nullptr, FALSE, 0, nullptr,
             nullptr, &si, &pi)) {
@@ -233,7 +212,7 @@ void RTNAME(ExecuteCommandLine)(const Descriptor &command, bool wait,
         CheckAndCopyToDescriptor(cmdmsg, "CreateProcess failed.");
       }
     }
-    delete[] wcmd;
+    FreeMemory((void *)wcmd);
 #else
     // terminated children do not become zombies
     signal(SIGCHLD, SIG_IGN);
@@ -251,6 +230,7 @@ void RTNAME(ExecuteCommandLine)(const Descriptor &command, bool wait,
       exit(status);
     }
 #endif
+    FreeMemory((void *)newCmd);
   }
 }
 

flang/runtime/tools.h

@@ -411,5 +411,17 @@ RT_API_ATTRS void ShallowCopy(const Descriptor &to, const Descriptor &from,
     bool toIsContiguous, bool fromIsContiguous);
 RT_API_ATTRS void ShallowCopy(const Descriptor &to, const Descriptor &from);
 
+inline RT_API_ATTRS const char *EnsureNullTerminated(
+    const char *str, size_t length, Terminator &terminator) {
+  if (length <= std::strlen(str)) {
+    char *newCmd{(char *)AllocateMemoryOrCrash(terminator, length + 1)};
+    std::memcpy(newCmd, str, length);
+    newCmd[length] = '\0';
+    return newCmd;
+  } else {
+    return str;
+  }
+}
+
 } // namespace Fortran::runtime
 #endif // FORTRAN_RUNTIME_TOOLS_H_