refactor: Add clang-tidy checks and simplify codebase

.clang-tidy

@@ -0,0 +1,30 @@
+Checks: |
+  -*,
+  abseil-*,
+  bugprone-*,
+  clang-analyzer-*,
+  misc-*,
+  modernize-*,
+  performance-*,
+  portability-*,
+  readability-*,
+  llvm-*,
+  -bugprone-easily-swappable-parameters,
+  -readability-avoid-const-params-in-decls,
+  -readability-identifier-length
+
+CheckOptions:
+  - key: readability-inconsistent-declaration-parameter-name.Strict
+    value: true
+  - key: readability-identifier-naming.StructCase
+    value: lower_case
+  - key: readability-identifier-naming.FunctionCase
+    value: lower_case
+  - key: readability-identifier-naming.VariableCase
+    value: lower_case
+  - key: readability-identifier-naming.EnumConstantCase
+    value: UPPER_CASE
+  - key: readability-identifier-naming.MacroDefinitionCase
+    value: UPPER_CASE
+  - key: readability-function-cognitive-complexity.Threshold
+    value: 15

config.h

@@ -1,4 +1,5 @@
-#pragma once
+#ifndef CONFIG_H
+#define CONFIG_H
 
 // String used to delimit block outputs in the status.
 #define DELIMITER "  "
@@ -27,3 +28,5 @@
     X("sb-volume", 0, 8)  \
     X("sb-battery", 5, 9) \
     X("sb-date", 1, 10)
+
+#endif  // CONFIG_H

include/block.h

@@ -1,4 +1,5 @@
-#pragma once
+#ifndef BLOCK_H
+#define BLOCK_H
 
 #include <bits/stdint-uintn.h>
 #include <stdbool.h>
@@ -24,3 +25,5 @@ int block_deinit(block *const block);
 int block_execute(block *const block, const uint8_t button);
 int block_update(block *const block);
 bool block_must_run(const block *const block, const unsigned int time);
+
+#endif  // BLOCK_H

include/cli.h

@@ -1,4 +1,5 @@
-#pragma once
+#ifndef CLI_H
+#define CLI_H
 
 #include <stdbool.h>
 
@@ -8,3 +9,5 @@ typedef struct {
 
 int cli_init(cli_arguments* const args, const char* const argv[],
              const int argc);
+
+#endif  // CLI_H

include/main.h

@@ -1,4 +1,5 @@
-#pragma once
+#ifndef MAIN_H
+#define MAIN_H
 
 #include <signal.h>
 
@@ -11,3 +12,5 @@
 #define X(...) "."
 enum { BLOCK_COUNT = LEN(BLOCKS(X)) - 1 };
 #undef X
+
+#endif  // MAIN_H

include/signal-handler.h

@@ -1,4 +1,5 @@
-#pragma once
+#ifndef SIGNAL_HANDLER_H
+#define SIGNAL_HANDLER_H
 
 #include <bits/types/sigset_t.h>
 
@@ -28,3 +29,5 @@ signal_handler signal_handler_new(
 int signal_handler_init(signal_handler* const handler);
 int signal_handler_deinit(signal_handler* const handler);
 int signal_handler_process(signal_handler* const handler, timer* const timer);
+
+#endif  // SIGNAL_HANDLER_H

include/status.h

@@ -1,4 +1,5 @@
-#pragma once
+#ifndef STATUS_H
+#define STATUS_H
 
 #include <stdbool.h>
 
@@ -26,3 +27,5 @@ status status_new(const block* const blocks, const unsigned short block_count);
 bool status_update(status* const status);
 int status_write(const status* const status, const bool is_debug_mode,
                  x11_connection* const connection);
+
+#endif  // STATUS_H

include/timer.h

@@ -1,4 +1,5 @@
-#pragma once
+#ifndef TIMER_H
+#define TIMER_H
 
 #include <signal.h>
 
@@ -14,3 +15,5 @@ typedef struct {
 
 timer timer_new(const block *const blocks, const unsigned short block_count);
 int timer_arm(timer *const timer);
+
+#endif  // TIMER_H

include/util.h

@@ -1,13 +1,17 @@
-#pragma once
+#ifndef UTIL_H
+#define UTIL_H
 
 #include <stddef.h>
 
 #define MAX(a, b) ((a) > (b) ? (a) : (b))
-#define LEN(arr)                  (sizeof(arr) / sizeof(arr[0]))
+#define LEN(arr)  (sizeof(arr) / sizeof((arr)[0]))
 #define BIT(n)    (1 << (n))
+
+// NOLINTBEGIN(bugprone-macro-parentheses)
 #define MEMBER_SIZE(type, member) sizeof(((type*)NULL)->member)
 #define MEMBER_LENGTH(type, member) \
     (MEMBER_SIZE(type, member) / MEMBER_SIZE(type, member[0]))
+// NOLINTEND(bugprone-macro-parentheses)
 
 #define UTF8_MAX_BYTE_COUNT 4
 
@@ -20,3 +24,5 @@ enum pipe_fd_index {
 unsigned int gcd(unsigned int a, unsigned int b);
 size_t truncate_utf8_string(char* const buffer, const size_t size,
                             const size_t char_limit);
+
+#endif  // UTIL_H

include/watcher.h

@@ -1,4 +1,5 @@
-#pragma once
+#ifndef WATCHER_H
+#define WATCHER_H
 
 #include <stdbool.h>
 #include <sys/poll.h>
@@ -6,22 +7,22 @@
 #include "block.h"
 #include "main.h"
 
-typedef enum {
+enum watcher_fd_index {
     SIGNAL_FD = BLOCK_COUNT,
     WATCHER_FD_COUNT,
-} watcher_fd_index;
+};
 
 typedef struct pollfd watcher_fd;
 
 typedef struct {
     watcher_fd fds[WATCHER_FD_COUNT];
-
-    const block *const blocks;
-    const unsigned short block_count;
+    unsigned short active_blocks[BLOCK_COUNT];
+    unsigned short active_block_count;
+    bool got_signal;
 } watcher;
 
-watcher watcher_new(const block *const blocks,
-                    const unsigned short block_count);
-int watcher_init(watcher *const watcher, const int signal_fd);
+int watcher_init(watcher *const watcher, const block *const blocks,
+                 const unsigned short block_count, const int signal_fd);
 int watcher_poll(watcher *const watcher, const int timeout_ms);
-bool watcher_fd_is_readable(const watcher_fd *const watcher_fd);
+
+#endif  // WATCHER_H

include/x11.h

@@ -1,4 +1,5 @@
-#pragma once
+#ifndef X11_H
+#define X11_H
 
 #include <xcb/xcb.h>
 
@@ -8,3 +9,5 @@ x11_connection* x11_connection_open(void);
 void x11_connection_close(x11_connection* const connection);
 int x11_set_root_name(x11_connection* const connection,
                       const char* const name);
+
+#endif  // X11_H

src/block.c

@@ -141,7 +141,7 @@ int block_update(block *const block) {
         return 1;
     }
 
-    (void)strcpy(block->output, buffer);
+    (void)strncpy(block->output, buffer, LEN(buffer));
 
     return 0;
 }

src/main.c

@@ -86,48 +86,32 @@ static int event_loop(block *const blocks, const unsigned short block_count,
         return 1;
     }
 
-    watcher watcher = watcher_new(blocks, block_count);
-    if (watcher_init(&watcher, signal_handler->fd) != 0) {
+    watcher watcher;
+    if (watcher_init(&watcher, blocks, block_count, signal_handler->fd) != 0) {
         return 1;
     }
 
     status status = status_new(blocks, block_count);
     bool is_alive = true;
     while (is_alive) {
-        const int event_count = watcher_poll(&watcher, -1);
-        if (event_count == -1) {
+        if (watcher_poll(&watcher, -1) != 0) {
             return 1;
         }
 
-        int i = 0;
-        for (unsigned short j = 0; j < WATCHER_FD_COUNT; ++j) {
-            if (i == event_count) {
-                break;
-            }
-
-            const watcher_fd *const watcher_fd = &watcher.fds[j];
-            if (!watcher_fd_is_readable(watcher_fd)) {
-                continue;
-            }
-
-            ++i;
-
-            if (j == SIGNAL_FD) {
+        if (watcher.got_signal) {
             is_alive = signal_handler_process(signal_handler, &timer) == 0;
-                continue;
         }
 
-            block *const block = &blocks[j];
-            (void)block_update(block);
+        for (unsigned short i = 0; i < watcher.active_block_count; ++i) {
+            (void)block_update(&blocks[watcher.active_blocks[i]]);
         }
 
         const bool has_status_changed = status_update(&status);
-        if (has_status_changed) {
-            if (status_write(&status, is_debug_mode, connection) != 0) {
+        if (has_status_changed &&
+            status_write(&status, is_debug_mode, connection) != 0) {
             return 1;
         }
     }
-    }
 
     return 0;
 }

src/status.c

@@ -6,6 +6,7 @@
 
 #include "block.h"
 #include "config.h"
+#include "util.h"
 #include "x11.h"
 
 static bool has_status_changed(const status *const status) {
@@ -26,7 +27,7 @@ status status_new(const block *const blocks,
 }
 
 bool status_update(status *const status) {
-    (void)strcpy(status->previous, status->current);
+    (void)strncpy(status->previous, status->current, LEN(status->current));
     status->current[0] = '\0';
 
     for (unsigned short i = 0; i < status->block_count; ++i) {
@@ -34,27 +35,27 @@ bool status_update(status *const status) {
 
         if (strlen(block->output) > 0) {
 #if LEADING_DELIMITER
-            (void)strcat(status->current, DELIMITER);
+            (void)strncat(status->current, DELIMITER, LEN(DELIMITER));
 #else
             if (status->current[0] != '\0') {
-                (void)strcat(status->current, DELIMITER);
+                (void)strncat(status->current, DELIMITER, LEN(DELIMITER));
             }
 #endif
 
 #if CLICKABLE_BLOCKS
             if (block->signal > 0) {
                 const char signal[] = {(char)block->signal, '\0'};
-                (void)strcat(status->current, signal);
+                (void)strncat(status->current, signal, LEN(signal));
             }
 #endif
 
-            (void)strcat(status->current, block->output);
+            (void)strncat(status->current, block->output, LEN(block->output));
         }
     }
 
 #if TRAILING_DELIMITER
     if (status->current[0] != '\0') {
-        (void)strcat(status->current, DELIMITER);
+        (void)strcat(status->current, DELIMITER, LEN(DELIMITER));
     }
 #endif
 

src/util.c

@@ -24,7 +24,7 @@ size_t truncate_utf8_string(char* const buffer, const size_t size,
 
         unsigned short skip = 1;
 
-        // Multibyte unicode character
+        // Multibyte unicode character.
         if ((ch & UTF8_MULTIBYTE_BIT) != 0) {
             // Skip continuation bytes.
             ch <<= 1;

src/watcher.c

@@ -8,19 +8,15 @@
 #include "block.h"
 #include "util.h"
 
-watcher watcher_new(const block* const blocks,
-                    const unsigned short block_count) {
-    watcher watcher = {
-        .blocks = blocks,
-        .block_count = block_count,
-    };
-
-    return watcher;
+static bool watcher_fd_is_readable(const watcher_fd* const watcher_fd) {
+    return (watcher_fd->revents & POLLIN) != 0;
 }
 
-int watcher_init(watcher* const watcher, const int signal_fd) {
+int watcher_init(watcher* const watcher, const block* const blocks,
+                 const unsigned short block_count, const int signal_fd) {
     if (signal_fd == -1) {
-        fprintf(stderr,
+        (void)fprintf(
+            stderr,
             "error: invalid signal file descriptor passed to watcher\n");
         return 1;
     }
@@ -29,10 +25,10 @@ int watcher_init(watcher* const watcher, const int signal_fd) {
     fd->fd = signal_fd;
     fd->events = POLLIN;
 
-    for (unsigned short i = 0; i < watcher->block_count; ++i) {
-        const int block_fd = watcher->blocks[i].pipe[READ_END];
+    for (unsigned short i = 0; i < block_count; ++i) {
+        const int block_fd = blocks[i].pipe[READ_END];
         if (block_fd == -1) {
-            fprintf(
+            (void)fprintf(
                 stderr,
                 "error: invalid block file descriptors passed to watcher\n");
             return 1;
@@ -47,17 +43,27 @@ int watcher_init(watcher* const watcher, const int signal_fd) {
 }
 
 int watcher_poll(watcher* watcher, const int timeout_ms) {
-    const int event_count = poll(watcher->fds, LEN(watcher->fds), timeout_ms);
+    int event_count = poll(watcher->fds, LEN(watcher->fds), timeout_ms);
 
     // Don't return non-zero status for signal interruptions.
     if (event_count == -1 && errno != EINTR) {
         (void)fprintf(stderr, "error: watcher could not poll blocks\n");
-        return -1;
+        return 1;
     }
 
-    return event_count;
+    watcher->got_signal = watcher_fd_is_readable(&watcher->fds[SIGNAL_FD]);
+
+    watcher->active_block_count = event_count - (int)watcher->got_signal;
+    unsigned short i = 0;
+    unsigned short j = 0;
+    while (i < event_count && j < LEN(watcher->active_blocks)) {
+        if (watcher_fd_is_readable(&watcher->fds[j])) {
+            watcher->active_blocks[i] = j;
+            ++i;
         }
 
-bool watcher_fd_is_readable(const watcher_fd* const watcher_fd) {
-    return (watcher_fd->revents & POLLIN) != 0;
+        ++j;
+    }
+
+    return 0;
 }

src/x11.c

@@ -8,7 +8,7 @@
 x11_connection *x11_connection_open(void) {
     xcb_connection_t *const connection = xcb_connect(NULL, NULL);
     if (xcb_connection_has_error(connection)) {
-        (void)fprintf(stderr, "error: could not connect to the X server\n");
+        (void)fprintf(stderr, "error: could not connect to X server\n");
         return NULL;
     }