| /* Distributed under the OSI-approved BSD 3-Clause License. See accompanying |
| file Copyright.txt or https://cmake.org/licensing for details. */ |
| #include "cmPlaceholderExpander.h" |
| |
| #include <cctype> |
| |
| std::string& cmPlaceholderExpander::ExpandVariables(std::string& s) |
| { |
| std::string::size_type start = s.find('<'); |
| // no variables to expand |
| if (start == std::string::npos) { |
| return s; |
| } |
| std::string::size_type pos = 0; |
| std::string expandedInput; |
| while (start != std::string::npos && start < s.size() - 2) { |
| std::string::size_type end = s.find('>', start); |
| // if we find a < with no > we are done |
| if (end == std::string::npos) { |
| s = expandedInput; |
| return s; |
| } |
| char c = s[start + 1]; |
| // if the next char after the < is not A-Za-z then |
| // skip it and try to find the next < in the string |
| if (!isalpha(c)) { |
| start = s.find('<', start + 1); |
| } else { |
| // extract the var |
| std::string var = s.substr(start + 1, end - start - 1); |
| std::string replace = this->ExpandVariable(var); |
| expandedInput += s.substr(pos, start - pos); |
| |
| // Prevent consecutive whitespace in the output if the rule variable |
| // expands to an empty string. |
| bool consecutive = replace.empty() && start > 0 && s[start - 1] == ' ' && |
| end + 1 < s.size() && s[end + 1] == ' '; |
| if (consecutive) { |
| expandedInput.pop_back(); |
| } |
| |
| expandedInput += replace; |
| |
| // move to next one |
| start = s.find('<', start + var.size() + 2); |
| pos = end + 1; |
| } |
| } |
| // add the rest of the input |
| expandedInput += s.substr(pos, s.size() - pos); |
| // remove trailing whitespace |
| if (!expandedInput.empty() && expandedInput.back() == ' ') { |
| expandedInput.pop_back(); |
| } |
| s = expandedInput; |
| |
| return s; |
| } |