add cmdmsg to common exit code 1, 126, 127 for Linux

for Windows, all three of them has a exit code of 1
so can't write cmdmsg for them

Author: yiwu0b11

flang/runtime/execute.cpp

@@ -79,6 +79,37 @@ int TerminationCheck(int status, const Descriptor *cmdstat,
       CheckAndCopyCharsToDescriptor(cmdmsg, "Invalid command line");
     }
   }
+
+#ifndef _WIN32
+  if (exitStatusVal == 1) {
+    if (!cmdstat) {
+      terminator.Crash("General Error with exit status code: 1");
+    } else {
+      StoreIntToDescriptor(cmdstat, INVALID_CL_ERR, terminator);
+      CheckAndCopyCharsToDescriptor(cmdmsg,
+          "General Error: a catch-all exit code for a variety of general "
+          "errors.");
+    }
+  } else if (exitStatusVal == 126) {
+    if (!cmdstat) {
+      terminator.Crash("Command cannot execute with exit status code: 126");
+    } else {
+      StoreIntToDescriptor(cmdstat, INVALID_CL_ERR, terminator);
+      CheckAndCopyCharsToDescriptor(cmdmsg,
+          "Command cannot execute: command was found, but it could not be "
+          "executed.");
+    }
+  } else if (exitStatusVal == 127) {
+    if (!cmdstat) {
+      terminator.Crash("Command not found with exit status code: 127");
+    } else {
+      StoreIntToDescriptor(cmdstat, INVALID_CL_ERR, terminator);
+      CheckAndCopyCharsToDescriptor(cmdmsg,
+          "Command not found: command was not found in the system's PATH");
+    }
+  }
+#endif
+
   if (status == -1) {
     if (!cmdstat) {
       terminator.Crash("Execution error with system status code: %d", status);

flang/unittests/Runtime/CommandTest.cpp

@@ -339,22 +339,64 @@ TEST_F(ZeroArguments, ECLValidCommandStatusSetSync) {
   CheckDescriptorEqStr(cmdMsg.get(), "No change");
 }
 
-TEST_F(ZeroArguments, ECLInvalidCommandErrorSync) {
-  OwningPtr<Descriptor> command{CharDescriptor("InvalidCommand")};
+TEST_F(ZeroArguments, ECLGeneralErrorCommandErrorSync) {
+  OwningPtr<Descriptor> command{CharDescriptor("cat general-error")};
+  bool wait{true};
+  OwningPtr<Descriptor> exitStat{IntDescriptor(404)};
+  OwningPtr<Descriptor> cmdStat{IntDescriptor(202)};
+  OwningPtr<Descriptor> cmdMsg{CharDescriptor("cmd msg buffer XXXXXXXX")};
+
+  RTNAME(ExecuteCommandLine)
+  (*command.get(), wait, exitStat.get(), cmdStat.get(), cmdMsg.get());
+#ifdef _WIN32
+  CheckDescriptorEqInt(exitStat.get(), 1);
+  CheckDescriptorEqStr(cmdMsg.get(), "Invalid command lineXXX");
+#else
+  CheckDescriptorEqInt<std::int64_t>(exitStat.get(), 1);
+  CheckDescriptorEqStr(cmdMsg.get(), "General Error: a catch-");
+#endif
+  CheckDescriptorEqInt<std::int64_t>(cmdStat.get(), 3);
+}
+
+TEST_F(ZeroArguments, ECLNotExecutedCommandErrorSync) {
+  OwningPtr<Descriptor> command{CharDescriptor("cd NotExecutedCommand")};
+  bool wait{true};
+  OwningPtr<Descriptor> exitStat{IntDescriptor(404)};
+  OwningPtr<Descriptor> cmdStat{IntDescriptor(202)};
+  OwningPtr<Descriptor> cmdMsg{CharDescriptor("cmd msg buffer XXXXXXXX")};
+
+  RTNAME(ExecuteCommandLine)
+  (*command.get(), wait, exitStat.get(), cmdStat.get(), cmdMsg.get());
+#ifdef _WIN32
+  CheckDescriptorEqInt(exitStat.get(), 1);
+  CheckDescriptorEqStr(cmdMsg.get(), "Invalid command lineXXX");
+#else
+  CheckDescriptorEqInt<std::int64_t>(exitStat.get(), 126);
+  CheckDescriptorEqStr(cmdMsg.get(), "Command cannot execute:");
+#endif
+  CheckDescriptorEqInt<std::int64_t>(cmdStat.get(), 3);
+}
+
+TEST_F(ZeroArguments, ECLNotFoundCommandErrorSync) {
+  OwningPtr<Descriptor> command{CharDescriptor("NotFoundCommand")};
   bool wait{true};
   OwningPtr<Descriptor> exitStat{IntDescriptor(404)};
   OwningPtr<Descriptor> cmdStat{IntDescriptor(202)};
-  OwningPtr<Descriptor> cmdMsg{CharDescriptor("Message ChangedXXXXXXXXX")};
+  OwningPtr<Descriptor> cmdMsg{CharDescriptor(
+      "cmdmsg will not modify the remaining buffer XXXXXXXXXXXXXXXXXXXX")};
 
   RTNAME(ExecuteCommandLine)
   (*command.get(), wait, exitStat.get(), cmdStat.get(), cmdMsg.get());
 #ifdef _WIN32
   CheckDescriptorEqInt(exitStat.get(), 1);
+  CheckDescriptorEqStr(cmdMsg.get(),
+      "Invalid command lineXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX");
 #else
   CheckDescriptorEqInt<std::int64_t>(exitStat.get(), 127);
+  CheckDescriptorEqStr(cmdMsg.get(),
+      "Command not found: command was not found in the system's PATHXXX");
 #endif
   CheckDescriptorEqInt<std::int64_t>(cmdStat.get(), 3);
-  CheckDescriptorEqStr(cmdMsg.get(), "Invalid command lineXXXX");
 }
 
 TEST_F(ZeroArguments, ECLInvalidCommandTerminatedSync) {