[flang-commits] [flang] [flang] Fix execute_command_line cmdstat is not set when error occurs (PR #93023)

[Yi Wu via flang-commits]

================
@@ -64,22 +64,40 @@ void CheckAndStoreIntToDescriptor(
 // the CMDSTAT variable is not present, error termination is initiated.
 int TerminationCheck(int status, const Descriptor *cmdstat,
     const Descriptor *cmdmsg, Terminator &terminator) {
-  if (status == -1) {
-    if (!cmdstat) {
-      terminator.Crash("Execution error with system status code: %d", status);
-    } else {
-      StoreIntToDescriptor(cmdstat, EXECL_ERR, terminator);
-      CheckAndCopyCharsToDescriptor(cmdmsg, "Execution error");
-    }
-  }
 #ifdef _WIN32
   // On WIN32 API std::system returns exit status directly
   int exitStatusVal{status};
-  if (exitStatusVal == 1) {
 #else
   int exitStatusVal{WEXITSTATUS(status)};
-  if (exitStatusVal == 127 || exitStatusVal == 126) {
+  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");
+    }
+  } else
 #endif
+  if (exitStatusVal != 0) {
----------------
yi-wu-arm wrote:

I don't know if there is a prettier way to write this logic:
On Linux (remember the !=0 covers all other error exit code)
```
if exit ==1
else if exit == 126
else if exit == 127
else if exit != 0
```
On Windows
```
if exit != 0
```

So in my code it becomes:
```
#ifdef Linux
  if exit ==1
  else if exit == 126
  else if exit == 127
  else (connect to the following if to beocome a else-if)
#endif 
if exit != 0

```

https://github.com/llvm/llvm-project/pull/93023