1// CODYlib -*- mode:c++ -*-
2// Copyright (C) 2020 Nathan Sidwell, nathan@acm.org
3// License: Apache v2.0
4
5// Cody
6#include "internal.hh"
7// OS
8#include <fcntl.h>
9#include <unistd.h>
10#include <sys/stat.h>
11#include <sys/types.h>
12
13#if ((defined (__unix__) \
14 && defined _POSIX_C_SOURCE \
15 && (_POSIX_C_SOURCE - 0) >= 200809L) \
16 || (defined (__Apple__) \
17 && defined (__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) \
18 && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 101000))
19// Autoconf test?
20#define HAVE_FSTATAT 1
21#else
22#define HAVE_FSTATAT 0
23#endif
24
25// Resolver code
26
27#if __windows__
28inline bool IsDirSep (char c)
29{
30 return c == '/' || c == '\\';
31}
32inline bool IsAbsPath (char const *str)
33{
34 // IIRC windows has the concept of per-drive current directories,
35 // which make drive-using paths confusing. Let's not get into that.
36 return IsDirSep (str)
37 || (((str[0] >= 'A' && str[0] <= 'Z')
38 || (str[0] >= 'a' && str[0] <= 'z'))&& str[1] == ':');
39}
40#else
41inline bool IsDirSep (char c)
42{
43 return c == '/';
44}
45inline bool IsAbsPath (char const *str)
46{
47 return IsDirSep (c: str[0]);
48}
49#endif
50
51constexpr char DIR_SEPARATOR = '/';
52
53constexpr char DOT_REPLACE = ','; // Replace . directories
54constexpr char COLON_REPLACE = '-'; // Replace : (partition char)
55constexpr char const REPO_DIR[] = "cmi.cache";
56
57namespace Cody {
58
59Resolver::~Resolver ()
60{
61}
62
63char const *Resolver::GetCMISuffix ()
64{
65 return "cmi";
66}
67
68std::string Resolver::GetCMIName (std::string const &module)
69{
70 std::string result;
71
72 result.reserve (res_arg: module.size () + 8);
73 bool is_header = false;
74 bool is_abs = false;
75
76 if (IsAbsPath (str: module.c_str ()))
77 is_header = is_abs = true;
78 else if (module.front () == '.' && IsDirSep (c: module.c_str ()[1]))
79 is_header = true;
80
81 if (is_abs)
82 {
83 result.push_back (c: '.');
84 result.append (str: module);
85 }
86 else
87 result = std::move (module);
88
89 if (is_header)
90 {
91 if (!is_abs)
92 result[0] = DOT_REPLACE;
93
94 /* Map .. to DOT_REPLACE, DOT_REPLACE. */
95 for (size_t ix = 1; ; ix++)
96 {
97 ix = result.find (c: '.', pos: ix);
98 if (ix == result.npos)
99 break;
100 if (ix + 2 > result.size ())
101 break;
102 if (result[ix + 1] != '.')
103 continue;
104 if (!IsDirSep (c: result[ix - 1]))
105 continue;
106 if (!IsDirSep (c: result[ix + 2]))
107 continue;
108 result[ix] = DOT_REPLACE;
109 result[ix + 1] = DOT_REPLACE;
110 }
111 }
112 else if (COLON_REPLACE != ':')
113 {
114 // There can only be one colon in a module name
115 auto colon = result.find (c: ':');
116 if (colon != result.npos)
117 result[colon] = COLON_REPLACE;
118 }
119
120 if (char const *suffix = GetCMISuffix ())
121 {
122 result.push_back (c: '.');
123 result.append (s: suffix);
124 }
125
126 return result;
127}
128
129void Resolver::WaitUntilReady (Server *)
130{
131}
132
133Resolver *Resolver::ConnectRequest (Server *s, unsigned version,
134 std::string &, std::string &)
135{
136 if (version > Version)
137 s->ErrorResponse (error: "version mismatch");
138 else
139 s->ConnectResponse (agent: "default");
140
141 return this;
142}
143
144int Resolver::ModuleRepoRequest (Server *s)
145{
146 s->PathnameResponse (path: REPO_DIR);
147 return 0;
148}
149
150// Deprecated resolver functions
151int Resolver::ModuleExportRequest (Server *s, Flags, std::string &module)
152{
153 auto cmi = GetCMIName (module);
154 s->PathnameResponse (path: cmi);
155 return 0;
156}
157
158int Resolver::ModuleImportRequest (Server *s, Flags, std::string &module)
159{
160 auto cmi = GetCMIName (module);
161 s->PathnameResponse (path: cmi);
162 return 0;
163}
164
165int Resolver::ModuleCompiledRequest (Server *s, Flags, std::string &)
166{
167 s->OKResponse ();
168 return 0;
169}
170
171int Resolver::IncludeTranslateRequest (Server *s, Flags, std::string &include)
172{
173 bool xlate = false;
174
175 // This is not the most efficient
176 auto cmi = GetCMIName (module: include);
177 struct stat statbuf;
178
179#if HAVE_FSTATAT
180 int fd_dir = open (file: REPO_DIR, O_RDONLY | O_CLOEXEC | O_DIRECTORY);
181 if (fd_dir >= 0
182 && fstatat (fd: fd_dir, file: cmi.c_str (), buf: &statbuf, flag: 0) == 0
183 && S_ISREG (statbuf.st_mode))
184 // Sadly can't easily check if this process has read access,
185 // except by trying to open it.
186 xlate = true;
187 if (fd_dir >= 0)
188 close (fd: fd_dir);
189#else
190 std::string append = REPO_DIR;
191 append.push_back (DIR_SEPARATOR);
192 append.append (cmi);
193 if (stat (append.c_str (), &statbuf) == 0
194 || S_ISREG (statbuf.st_mode))
195 xlate = true;
196#endif
197
198 if (xlate)
199 s->PathnameResponse (path: cmi);
200 else
201 s->BoolResponse (false);
202
203 return 0;
204}
205
206void Resolver::ErrorResponse (Server *server, std::string &&msg)
207{
208 server->ErrorResponse (error: msg);
209}
210
211}
212

source code of libcody/resolver.cc