xref: /aosp_15_r20/external/skia/src/sksl/SkSLString.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2017 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #include "src/base/SkStringView.h"
9 #include "src/sksl/SkSLDefines.h"
10 #include "src/sksl/SkSLString.h"
11 
12 #include <cerrno>
13 #include <cmath>
14 #include <cstdio>
15 #include <cstdlib>
16 #include <locale>
17 #include <memory>
18 #include <sstream>
19 #include <string>
20 #include <string_view>
21 
22 template <typename RoundtripType, int kFullPrecision>
to_string_impl(RoundtripType value)23 static std::string to_string_impl(RoundtripType value) {
24     std::stringstream buffer;
25     buffer.imbue(std::locale::classic());
26     buffer.precision(7);
27     buffer << value;
28     std::string text = buffer.str();
29 
30     double roundtripped;
31     buffer >> roundtripped;
32     if (value != (RoundtripType)roundtripped && std::isfinite(value)) {
33         buffer.str({});
34         buffer.clear();
35         buffer.precision(kFullPrecision);
36         buffer << value;
37         text = buffer.str();
38         SkASSERTF((buffer >> roundtripped, value == (RoundtripType)roundtripped),
39                   "%.17g -> %s -> %.17g", value, text.c_str(), roundtripped);
40     }
41 
42     // We need to emit a decimal point to distinguish floats from ints.
43     if (!skstd::contains(text, '.') && !skstd::contains(text, 'e')) {
44         text += ".0";
45     }
46 
47     return text;
48 }
49 
to_string(float value)50 std::string skstd::to_string(float value) {
51     return to_string_impl<float, 9>(value);
52 }
53 
to_string(double value)54 std::string skstd::to_string(double value) {
55     return to_string_impl<double, 17>(value);
56 }
57 
stod(std::string_view s,SKSL_FLOAT * value)58 bool SkSL::stod(std::string_view s, SKSL_FLOAT* value) {
59     std::string str(s.data(), s.size());
60     std::stringstream buffer(str);
61     buffer.imbue(std::locale::classic());
62     buffer >> *value;
63     return !buffer.fail() && std::isfinite(*value);
64 }
65 
stoi(std::string_view s,SKSL_INT * value)66 bool SkSL::stoi(std::string_view s, SKSL_INT* value) {
67     if (s.empty()) {
68         return false;
69     }
70     char suffix = s.back();
71     if (suffix == 'u' || suffix == 'U') {
72         s.remove_suffix(1);
73     }
74     std::string str(s);  // s is not null-terminated
75     const char* strEnd = str.data() + str.length();
76     char* p;
77     errno = 0;
78     unsigned long long result = strtoull(str.data(), &p, /*base=*/0);
79     *value = static_cast<SKSL_INT>(result);
80     return p == strEnd && errno == 0 && result <= 0xFFFFFFFF;
81 }
82 
printf(const char * fmt,...)83 std::string SkSL::String::printf(const char* fmt, ...) {
84     va_list args;
85     va_start(args, fmt);
86     std::string result;
87     vappendf(&result, fmt, args);
88     va_end(args);
89     return result;
90 }
91 
appendf(std::string * str,const char * fmt,...)92 void SkSL::String::appendf(std::string *str, const char* fmt, ...) {
93     va_list args;
94     va_start(args, fmt);
95     vappendf(str, fmt, args);
96     va_end(args);
97 }
98 
vappendf(std::string * str,const char * fmt,va_list args)99 void SkSL::String::vappendf(std::string *str, const char* fmt, va_list args) {
100     #define BUFFER_SIZE 256
101     char buffer[BUFFER_SIZE];
102     va_list reuse;
103     va_copy(reuse, args);
104     size_t size = vsnprintf(buffer, BUFFER_SIZE, fmt, args);
105     if (BUFFER_SIZE >= size + 1) {
106         str->append(buffer, size);
107     } else {
108         auto newBuffer = std::unique_ptr<char[]>(new char[size + 1]);
109         vsnprintf(newBuffer.get(), size + 1, fmt, reuse);
110         str->append(newBuffer.get(), size);
111     }
112     va_end(reuse);
113 }
114