1 // go-diagnostics.cc -- Go error/warning diagnostics utilities.
2
3 // Copyright 2016 The Go Authors. All rights reserved.
4 // Use of this source code is governed by a BSD-style
5 // license that can be found in the LICENSE file.
6
7 #include "go-diagnostics.h"
8
9 static std::string
mformat_value()10 mformat_value()
11 {
12 return std::string(xstrerror(errno));
13 }
14
15 // Rewrite a format string to expand any extensions not
16 // supported by sprintf(). See comments in go-diagnostics.h
17 // for list of supported format specifiers.
18
19 static std::string
expand_format(const char * fmt)20 expand_format(const char* fmt)
21 {
22 std::stringstream ss;
23 for (const char* c = fmt; *c; ++c)
24 {
25 if (*c != '%')
26 {
27 ss << *c;
28 continue;
29 }
30 c++;
31 switch (*c)
32 {
33 case '\0':
34 {
35 // malformed format string
36 go_unreachable();
37 }
38 case '%':
39 {
40 ss << "%";
41 break;
42 }
43 case 'm':
44 {
45 ss << mformat_value();
46 break;
47 }
48 case '<':
49 {
50 ss << go_open_quote();
51 break;
52 }
53 case '>':
54 {
55 ss << go_close_quote();
56 break;
57 }
58 case 'q':
59 {
60 ss << go_open_quote();
61 c++;
62 if (*c == 'm')
63 {
64 ss << mformat_value();
65 }
66 else
67 {
68 ss << "%" << *c;
69 }
70 ss << go_close_quote();
71 break;
72 }
73 default:
74 {
75 ss << "%" << *c;
76 }
77 }
78 }
79 return ss.str();
80 }
81
82 // Expand message format specifiers, using a combination of
83 // expand_format above to handle extensions (ex: %m, %q) and vasprintf()
84 // to handle regular printf-style formatting. A pragma is being used here to
85 // suppress this warning:
86 //
87 // warning: function ‘std::__cxx11::string expand_message(const char*, __va_list_tag*)’ might be a candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]
88 //
89 // What appears to be happening here is that the checker is deciding that
90 // because of the call to vasprintf() (which has attribute gnu_printf), the
91 // calling function must need to have attribute gnu_printf as well, even
92 // though there is already an attribute declaration for it.
93
94 static std::string
95 expand_message(const char* fmt, va_list ap) GO_ATTRIBUTE_GCC_DIAG(1,0);
96
97 #pragma GCC diagnostic push
98 #pragma GCC diagnostic ignored "-Wsuggest-attribute=format"
99
100 static std::string
expand_message(const char * fmt,va_list ap)101 expand_message(const char* fmt, va_list ap)
102 {
103 char* mbuf = 0;
104 std::string expanded_fmt = expand_format(fmt);
105 int nwr = vasprintf(&mbuf, expanded_fmt.c_str(), ap);
106 if (nwr == -1)
107 {
108 // memory allocation failed
109 go_be_error_at(Linemap::unknown_location(),
110 "memory allocation failed in vasprintf");
111 go_assert(0);
112 }
113 std::string rval = std::string(mbuf);
114 free(mbuf);
115 return rval;
116 }
117
118 #pragma GCC diagnostic pop
119
120 static const char* cached_open_quote = NULL;
121 static const char* cached_close_quote = NULL;
122
123 const char*
go_open_quote()124 go_open_quote()
125 {
126 if (cached_open_quote == NULL)
127 go_be_get_quotechars(&cached_open_quote, &cached_close_quote);
128 return cached_open_quote;
129 }
130
131 const char*
go_close_quote()132 go_close_quote()
133 {
134 if (cached_close_quote == NULL)
135 go_be_get_quotechars(&cached_open_quote, &cached_close_quote);
136 return cached_close_quote;
137 }
138
139 void
go_error_at(const Location location,const char * fmt,...)140 go_error_at(const Location location, const char* fmt, ...)
141 {
142 va_list ap;
143
144 va_start(ap, fmt);
145 go_be_error_at(location, expand_message(fmt, ap));
146 va_end(ap);
147 }
148
149 void
go_warning_at(const Location location,int opt,const char * fmt,...)150 go_warning_at(const Location location, int opt, const char* fmt, ...)
151 {
152 va_list ap;
153
154 va_start(ap, fmt);
155 go_be_warning_at(location, opt, expand_message(fmt, ap));
156 va_end(ap);
157 }
158
159 void
go_fatal_error(const Location location,const char * fmt,...)160 go_fatal_error(const Location location, const char* fmt, ...)
161 {
162 va_list ap;
163
164 va_start(ap, fmt);
165 go_be_fatal_error(location, expand_message(fmt, ap));
166 va_end(ap);
167 }
168
169 void
go_inform(const Location location,const char * fmt,...)170 go_inform(const Location location, const char* fmt, ...)
171 {
172 va_list ap;
173
174 va_start(ap, fmt);
175 go_be_inform(location, expand_message(fmt, ap));
176 va_end(ap);
177 }
178