Process error handling and process killing

src/basic/win32.cpp

@@ -283,7 +283,7 @@ struct Win32Process {
 };
 static_assert(sizeof(Win32Process) < sizeof(Process::platform));
 
-static String Win32GetPlatformError(String cmd) {
+static String Win32GetPlatformError(String msg, String cmd) {
     LPVOID lpMsgBuf;
     DWORD  dw = GetLastError();
     FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
@@ -296,7 +296,7 @@ static String Win32GetPlatformError(String cmd) {
     }
 
     // @warning: leak! but we don't care
-    String r = Format(GetSystemAllocator(), "Failed to create process using cmd: %.*s! %s", FmtString(cmd), (char *)lpMsgBuf);
+    String r = Format(GetSystemAllocator(), "%.*s: %.*s! %s", FmtString(msg), FmtString(cmd), (char *)lpMsgBuf);
     LocalFree(lpMsgBuf);
     return r;
 }
@@ -312,9 +312,9 @@ static void Win32CloseProcess(Process *process) {
     *p                = {};
 }
 
-static void Win32ProcessError(Process *process, String cmd) {
+static void Win32ProcessError(Process *process, String msg, String cmd) {
     Win32Process *p        = (Win32Process *)process->platform;
-    process->error_message = Win32GetPlatformError(cmd);
+    process->error_message = Win32GetPlatformError(msg, cmd);
     Win32CloseProcess(process);
 }
 
@@ -336,22 +336,22 @@ Process CreateCommandLineProcess(String command_line, String working_dir) {
     security_atrb.bInheritHandle      = TRUE;
 
     if (!CreatePipe(&p->child_stdout_read, &p->child_stdout_write, &security_atrb, 0)) {
-        Win32ProcessError(&process, command_line);
+        Win32ProcessError(&process, "Failed to create process at create pipe stage", command_line);
         return process;
     }
 
     if (!SetHandleInformation(p->child_stdout_read, HANDLE_FLAG_INHERIT, 0)) {
-        Win32ProcessError(&process, command_line);
+        Win32ProcessError(&process, "Failed to create process at create pipe stage", command_line);
         return process;
     }
 
     if (!CreatePipe(&p->child_stdin_read, &p->child_stdin_write, &security_atrb, 0)) {
-        Win32ProcessError(&process, command_line);
+        Win32ProcessError(&process, "Failed to create process at create pipe stage", command_line);
         return process;
     }
 
     if (!SetHandleInformation(p->child_stdin_write, HANDLE_FLAG_INHERIT, 0)) {
-        Win32ProcessError(&process, command_line);
+        Win32ProcessError(&process, "Failed to create process at create pipe stage", command_line);
         return process;
     }
 
@@ -369,7 +369,7 @@ Process CreateCommandLineProcess(String command_line, String working_dir) {
 
     PROCESS_INFORMATION info = {};
     if (!CreateProcessW(L"c:\\windows\\system32\\cmd.exe", cmd.data, 0, 0, TRUE, 0, env, cwd.data, &startup, &info)) {
-        Win32ProcessError(&process, command_line);
+        Win32ProcessError(&process, "failed to create process", command_line);
         return process;
     }
 
@@ -426,6 +426,7 @@ StdoutPollInfo PollStdout(Process *process, char *buffer, int64_t buffer_size) {
     StdoutPollInfo result     = {};
     bool           peek_error = PeekNamedPipe(p->child_stdout_read, NULL, 0, NULL, &bytes_avail, NULL) == 0;
     if (peek_error) {
+        process->error_message = Win32GetPlatformError("Failed to peek stdout of child process", "PeekNamedPipe");
         return result;
     }
 
@@ -436,6 +437,7 @@ StdoutPollInfo PollStdout(Process *process, char *buffer, int64_t buffer_size) {
     DWORD bytes_read = 0;
     bool  read_error = ReadFile(p->child_stdout_read, buffer, (DWORD)buffer_size, &bytes_read, 0) == 0;
     if (read_error) {
+        process->error_message = Win32GetPlatformError("Failed to read the stdout of child process", "ReadFile");
         return result;
     }