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__
IsDirSep(char c)28 inline bool IsDirSep (char c)
29 {
30 return c == '/' || c == '\\';
31 }
IsAbsPath(char const * str)32 inline 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
IsDirSep(char c)41 inline bool IsDirSep (char c)
42 {
43 return c == '/';
44 }
IsAbsPath(char const * str)45 inline bool IsAbsPath (char const *str)
46 {
47 return IsDirSep (str[0]);
48 }
49 #endif
50
51 constexpr char DIR_SEPARATOR = '/';
52
53 constexpr char DOT_REPLACE = ','; // Replace . directories
54 constexpr char COLON_REPLACE = '-'; // Replace : (partition char)
55 constexpr char const REPO_DIR[] = "cmi.cache";
56
57 namespace Cody {
58
~Resolver()59 Resolver::~Resolver ()
60 {
61 }
62
GetCMISuffix()63 char const *Resolver::GetCMISuffix ()
64 {
65 return "cmi";
66 }
67
GetCMIName(std::string const & module)68 std::string Resolver::GetCMIName (std::string const &module)
69 {
70 std::string result;
71
72 result.reserve (module.size () + 8);
73 bool is_header = false;
74 bool is_abs = false;
75
76 if (IsAbsPath (module.c_str ()))
77 is_header = is_abs = true;
78 else if (module.front () == '.' && IsDirSep (module.c_str ()[1]))
79 is_header = true;
80
81 if (is_abs)
82 {
83 result.push_back ('.');
84 result.append (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 ('.', 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 (result[ix - 1]))
105 continue;
106 if (!IsDirSep (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 (':');
116 if (colon != result.npos)
117 result[colon] = COLON_REPLACE;
118 }
119
120 if (char const *suffix = GetCMISuffix ())
121 {
122 result.push_back ('.');
123 result.append (suffix);
124 }
125
126 return result;
127 }
128
WaitUntilReady(Server *)129 void Resolver::WaitUntilReady (Server *)
130 {
131 }
132
ConnectRequest(Server * s,unsigned version,std::string &,std::string &)133 Resolver *Resolver::ConnectRequest (Server *s, unsigned version,
134 std::string &, std::string &)
135 {
136 if (version > Version)
137 s->ErrorResponse ("version mismatch");
138 else
139 s->ConnectResponse ("default");
140
141 return this;
142 }
143
ModuleRepoRequest(Server * s)144 int Resolver::ModuleRepoRequest (Server *s)
145 {
146 s->PathnameResponse (REPO_DIR);
147 return 0;
148 }
149
150 // Deprecated resolver functions
ModuleExportRequest(Server * s,Flags,std::string & module)151 int Resolver::ModuleExportRequest (Server *s, Flags, std::string &module)
152 {
153 auto cmi = GetCMIName (module);
154 s->PathnameResponse (cmi);
155 return 0;
156 }
157
ModuleImportRequest(Server * s,Flags,std::string & module)158 int Resolver::ModuleImportRequest (Server *s, Flags, std::string &module)
159 {
160 auto cmi = GetCMIName (module);
161 s->PathnameResponse (cmi);
162 return 0;
163 }
164
ModuleCompiledRequest(Server * s,Flags,std::string &)165 int Resolver::ModuleCompiledRequest (Server *s, Flags, std::string &)
166 {
167 s->OKResponse ();
168 return 0;
169 }
170
IncludeTranslateRequest(Server * s,Flags,std::string & include)171 int 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 (include);
177 struct stat statbuf;
178
179 #if HAVE_FSTATAT
180 int fd_dir = open (REPO_DIR, O_RDONLY | O_CLOEXEC | O_DIRECTORY);
181 if (fd_dir >= 0
182 && fstatat (fd_dir, cmi.c_str (), &statbuf, 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_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 (cmi);
200 else
201 s->BoolResponse (false);
202
203 return 0;
204 }
205
ErrorResponse(Server * server,std::string && msg)206 void Resolver::ErrorResponse (Server *server, std::string &&msg)
207 {
208 server->ErrorResponse (msg);
209 }
210
211 }
212