WIP LSP client

This contains the start of an LSP client.
Nothing (except starting the LSP server) works
at the moment and the feature is disabled by default.

1 files changed, 126 insertions, 0 deletions

diff --git a/src/dged/process-posix.c b/src/dged/process-posix.c
new file mode 100644
index 0000000..94ceb5f
--- /dev/null
+++ b/src/dged/process-posix.c
@@ -0,0 +1,126 @@
+#include "process.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <sys/types.h>
+#include <sys/wait.h>
+
+static int create_pipe(int *read_end, int *write_end, bool read_nonblock,
+                       bool write_nonblock) {
+  int pipes[2] = {0};
+  if (pipe(pipes) < 0) {
+    return -1;
+  }
+
+  if (write_nonblock) {
+    int flags = fcntl(pipes[1], F_GETFL, 0);
+    if (flags < 0) {
+      return -1;
+    }
+
+    flags |= O_NONBLOCK;
+    if (fcntl(pipes[1], F_SETFL, flags) < 0) {
+      return -1;
+    }
+  }
+
+  if (read_nonblock) {
+    int flags = fcntl(pipes[0], F_GETFL, 0);
+    if (flags < 0) {
+      return -1;
+    }
+
+    flags |= O_NONBLOCK;
+    if (fcntl(pipes[0], F_SETFL, flags) < 0) {
+      return -1;
+    }
+  }
+
+  *read_end = pipes[0];
+  *write_end = pipes[1];
+
+  return 0;
+}
+
+struct process_create_result process_create(char *const command[],
+                                            struct process *result) {
+
+  int stdin_read, stdin_write;
+  if (create_pipe(&stdin_read, &stdin_write, false, true) < 0) {
+    return (struct process_create_result){
+        .ok = false,
+        .error_message = strerror(errno),
+    };
+  }
+
+  int stdout_read, stdout_write;
+  if (create_pipe(&stdout_read, &stdout_write, true, false) < 0) {
+    return (struct process_create_result){
+        .ok = false,
+        .error_message = strerror(errno),
+    };
+  }
+
+  int stderr_read, stderr_write;
+  if (create_pipe(&stderr_read, &stderr_write, true, false) < 0) {
+    return (struct process_create_result){
+        .ok = false,
+        .error_message = strerror(errno),
+    };
+  }
+
+  pid_t pid = fork();
+  if (pid == -1) {
+    return (struct process_create_result){
+        .ok = false,
+        .error_message = strerror(errno),
+    };
+  } else if (pid == 0) {
+    close(stdin_write);
+    close(stdout_read);
+    close(stderr_read);
+
+    if (dup2(stdin_read, STDIN_FILENO) < 0) {
+      exit(16);
+    }
+
+    if (dup2(stdout_write, STDOUT_FILENO) < 0) {
+      exit(16);
+    }
+
+    if (dup2(stderr_write, STDERR_FILENO) < 0) {
+      exit(16);
+    }
+
+    if (execvp(command[0], command) < 0) {
+      exit(16);
+    }
+  } else {
+    close(stdin_read);
+    close(stdout_write);
+    close(stderr_write);
+
+    result->stdin = stdin_write;
+    result->stdout = stdout_read;
+    result->stderr = stderr_read;
+    result->id = (fd_t)pid;
+    result->impl = NULL;
+  }
+
+  return (struct process_create_result){
+      .ok = true,
+  };
+}
+
+void process_destroy(struct process *p) { (void)p; }
+
+bool process_running(const struct process *p) {
+  return waitpid(p->id, NULL, WNOHANG) == 0;
+}
+
+bool process_kill(const struct process *p) { return kill(p->id, SIGTERM) == 0; }