Turn the style guide into a clang-format file

[LemonBoy]

Note that his has been written with clang-format 3.8 in mind since that's what Debian ships, see here for the docs.

I'm not too fond of the tabs + 100 columns combo since my laptop has a tiny screen, but that's not much of a problem.

So, I hereby declare the style-related bikeshed season open!

[ailin-nemui]

I tried clang-format on all files but it does the wrong thing in several cases, for example odd column style initialisation of arrays and structs, enum {\n wrapping cannot be configured and it misdetects some casts like (SIGNAL_FUNC) (func) (removes space)

[ailin-nemui]

I suggest we merge this, but do not auto-run clang-format. It does screw up several structures like struct initializers and enum lists. We could selectively run it and revert those erroneous changes, and ponder whether we want to litter the code with /* clang-format off */ at those places

[LemonBoy]

It does screw up several structures like struct initializers and enum lists. We could selectively run it and revert those erroneous changes

We should double-check if those problems go away using a newer clang-format or more options

[ailin-nemui]

outstanding issues and changes that would happen:

- == original irssi
+ == clang-format

a. spaces around boolean fields:

-unsigned int chanop:1;
+unsigned int chanop : 1;

b. collapsation of #define functions:

-#define alias_runstack_push(alias) \
-       alias_runstack = g_slist_append(alias_runstack, alias)
+#define alias_runstack_push(alias) alias_runstack = g_slist_append(alias_runstack, alias)

c. odd folding of enum types:

-enum {
-       CMDERR_OPTION_UNKNOWN = -3,
+enum { CMDERR_OPTION_UNKNOWN = -3,

c.2. alternative here could be to use break on enum, which would look like this:

-    enum {
-           CMDERR_OPTION_UNKNOWN = -3,
+    enum
+    {
+          CMDERR_OPTION_UNKNOWN = -3,

(I would prefer the original style...)

d. unindent of preprocessor codes:

 #ifdef HAVE_SYS_RESOURCE_H
-#  include <sys/resource.h>
+#include <sys/resource.h>
 #endif

e. odd initializer wrapping:

-       static GOptionEntry options[] = {
-               { "config", 0, 0, G_OPTION_ARG_STRING, &irssi_config_file, "Configuration file location (~/.irssi/config)", "PATH" },
-               { "home", 0, 0, G_OPTION_ARG_STRING, &irssi_dir, "Irssi home dir location (~/.irssi)", "PATH" },
-               { NULL }
-       };
+       static GOptionEntry options[] = { { "config", 0, 0, G_OPTION_ARG_STRING, &irssi_config_file,
+                                           "Configuration file location (~/.irssi/config)", "PATH" },
+                                         { "home", 0, 0, G_OPTION_ARG_STRING, &irssi_dir,
+                                           "Irssi home dir location (~/.irssi)", "PATH" },
+                                         { NULL } };

f. non-helpful column wrapping of initializers:

-static const char *levels[] = {
-       "CRAP",
...
-       "HILIGHTS",
-       "NOHILIGHT",
-       "NO_ACT",
-       NULL
-};
+static const char *levels[] = { "CRAP",         "MSGS",     "PUBLICS", "NOTICES",       "SNOTES",
+                               "CTCPS",        "ACTIONS",  "JOINS",   "PARTS",         "QUITS",
+                               "KICKS",        "MODES",    "TOPICS",  "WALLOPS",       "INVITES",
+                               "NICKS",        "DCC",      "DCCMSGS", "CLIENTNOTICES", "CLIENTCRAP",
+                               "CLIENTERRORS", "HILIGHTS",
+                               "NOHILIGHT",    "NO_ACT",   NULL };

g. non-helpful un-wrapping of initializers:

-int mirc_colors[] = { 15, 0, 1, 2, 12, 4, 5, 6, 14, 10, 3, 11, 9, 13, 8, 7,
-        /* 16-27 */  52,  94, 100,  58,  22,  29,  23,  24,  17,  54,  53,  89,
...
+int mirc_colors[] = { 15,
+                     0,
+                     1,
+                     2,
...
+                     /* 16-27 */ 52,
+                     94,
+                     100,
...

h. non-helpful re-wrapping of initializers:

 int term_color256map[] = {
-        0, 4, 2, 6, 1, 5, 3, 7, 8,12,10,14, 9,13,11,15,
-        0, 0, 1, 1, 1, 1, 0, 0, 3, 1, 1, 9, 2, 2, 3, 3, 3, 3,
...
+       0, 4, 2, 6,  1,  5,  3, 7, 8,  12, 10, 14, 9,  13, 11, 15, 0, 0, 1,  1,  1,  1,  0, 0,  3,  1,
+       1, 9, 2, 2,  3,  3,  3, 3, 2,  2,  3,  3,  3,  3,  2,  2,  3, 3, 3,  11, 10, 10, 3, 3,  11, 11,
...

j. its own opinion about empty for loop parts:

-       for (ptr = str; ; str++) {
+       for (ptr = str;; str++) {

altogether, committing the clang-format changes would touch 14000 lines in 285 files, of which are 5000 lines of incorrect tab/space indentation fixes

[ailin-nemui]

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