diff options
Diffstat (limited to 'src/regex__FFI.cc')
| -rw-r--r-- | src/regex__FFI.cc | 141 |
1 files changed, 47 insertions, 94 deletions
diff --git a/src/regex__FFI.cc b/src/regex__FFI.cc index e3ff601..619ea44 100644 --- a/src/regex__FFI.cc +++ b/src/regex__FFI.cc @@ -15,10 +15,9 @@ #include "src/regex__FFI.h" -#include <cstdio> -#include <cstring> -#include <string> #include <regex> // NOLINT(build/c++11) +#include <stdexcept> +#include <vector> #include <boost/numeric/conversion/cast.hpp> // NOLINT(build/include_order) extern "C" { @@ -29,6 +28,10 @@ extern "C" { namespace { +using Int = uw_Basis_int; +using Substring = uw_Regex__FFI_substring_t; +using SubstringList = uw_Regex__FFI_substring_list_t; + // Asserts a condition without crashing or releasing information about where the // error occurred. This function is essential for web programming, where an // attacker should not be able to bring down the app by causing an assertion @@ -45,11 +48,6 @@ void Assert(uw_context* const context, const bool condition, Assert(context, condition, FATAL, message); } -void DeleteMatchResults(void* match_result, - [[gnu::unused]] const int _will_retry) { - delete reinterpret_cast<std::cmatch*>(match_result); -} - // Bounds-checked numeric type conversion template <typename Target, typename Source> Target Number(uw_context* const context, Source arg) { @@ -79,101 +77,56 @@ std::regex Compile(uw_context* const context, const char needle_string[]) { return needle; } +// Treats 'list' as a 'std::vector<Substring>*' and 'delete's it. +void DeleteGroupList(void* list, [[gnu::unused]] const int will_retry) { + delete reinterpret_cast<std::vector<Substring>*>(list); +} + } // namespace -uw_Basis_bool uw_Regex__FFI_succeeded([[gnu::unused]] uw_context* const context, - const uw_Regex__FFI_match match) { - if (reinterpret_cast<std::cmatch*>(match.result)->empty()) { - return uw_Basis_False; - } else { - return uw_Basis_True; - } +Int uw_Regex__FFI_substring_start(uw_context* const context, + const Substring substring) { + return Number<Int>(context, substring.start); } -uw_Basis_int uw_Regex__FFI_n_subexpression_matches( - uw_context* const context, const uw_Regex__FFI_match match) { - const std::cmatch::size_type n_matches = - reinterpret_cast<std::cmatch*>(match.result)->size(); - if (n_matches == 0) { - // Nothing got matched. - return 0; - } else { - // At least one match occurred. Compute the number of parenthesized - // subexpressions that got matched, and return it. - return Number<uw_Basis_int>(context, n_matches) - 1; - } +Int uw_Regex__FFI_substring_length(uw_context* const context, + const Substring substring) { + return Number<Int>(context, substring.length); } -uw_Basis_string uw_Regex__FFI_subexpression_match( - uw_context* const context, const uw_Regex__FFI_match match, - const uw_Basis_int match_index_signed) { - const std::cmatch* const match_result = - reinterpret_cast<std::cmatch*>(match.result); - const std::size_t match_index = - Number<std::size_t>(context, match_index_signed); - Assert(context, match_index < match_result->size(), - "regex: match does not exist"); - const auto matched_substring = (*match_result)[match_index + 1]; - // Save the matched substring. - const std::size_t result_length = - Number<std::size_t>(context, matched_substring.length()); - uw_Basis_string result = - reinterpret_cast<uw_Basis_string>(uw_malloc(context, result_length + 1)); - Assert(context, std::snprintf(result, result_length + 1, "%s", - matched_substring.str().c_str()) >= 0, - "regex: snprintf failed during match"); - return result; +Int uw_Regex__FFI_substring_list_length(uw_context* const context, + const SubstringList list) { + return Number<Int>( + context, reinterpret_cast<const std::vector<Substring>*>(list)->size()); } -uw_Regex__FFI_match uw_Regex__FFI_do_match(uw_context* const context, - const uw_Basis_string needle_string, - const uw_Basis_string haystack) { - std::regex needle = Compile(context, needle_string); - uw_Regex__FFI_match result; - // Make a duplicate of the string to match against, so if it goes out of - // scope in the calling Ur code, we still have it. - const auto haystack_length = std::strlen(haystack); - result.haystack = - reinterpret_cast<char*>(uw_malloc(context, haystack_length + 1)); - Assert(context, std::snprintf(result.haystack, haystack_length + 1, "%s", - haystack) >= 0, - "regex: snprintf failed during match"); - // Allocate to store the match information. - auto* match_results = new std::cmatch; - Assert(context, uw_register_transactional(context, match_results, nullptr, - nullptr, DeleteMatchResults) == 0, - "regex: could not register DeleteMatchResults finalizer"); - result.result = match_results; - // Execute the regex on the saved haystack, not the original one. - std::regex_search(result.haystack, *match_results, needle); - return result; +Substring uw_Regex__FFI_substring_list_get(uw_context* const context, + const SubstringList list, + const Int index_int) { + const auto index = Number<std::size_t>(context, index_int); + try { + return reinterpret_cast<const std::vector<Substring>*>(list)->at(index); + } catch (const std::out_of_range& e) { + uw_error(context, FATAL, "regex: index out of range", e.what()); + } } -uw_Basis_string uw_Regex__FFI_replace(uw_context* const context, - const uw_Basis_string needle_string, - const uw_Basis_string replacement, - const uw_Basis_string haystack) { - std::regex needle = Compile(context, needle_string); - // Perform the replacement. - std::string result; - try { - result = std::regex_replace(haystack, needle, replacement); - } catch (const std::regex_error& e) { - switch (e.code()) { - case std::regex_constants::error_space: - case std::regex_constants::error_stack: - // We ran out of memory. - uw_error(context, BOUNDED_RETRY, "regex: replacement failed: %s", - e.what()); - default: - uw_error(context, FATAL, "regex: replacement failed: %s", e.what()); - } +SubstringList uw_Regex__FFI_do_match(uw_context* const context, + const uw_Basis_string needle, + const uw_Basis_string haystack) { + // Perform the match. + std::cmatch match_results; + std::regex_search(haystack, match_results, Compile(context, needle)); + Assert(context, match_results.ready(), "regex: search failed"); + // Marshal the results into the form Ur expects. + auto* const result = new std::vector<Substring>; + Assert(context, uw_register_transactional(context, result, nullptr, nullptr, + DeleteGroupList) == 0, + "regex: could not register DeleteGroupList finalizer"); + for (std::size_t i = 0; i < match_results.size(); i++) { + result->emplace_back( + Substring{Number<long>(context, match_results.position(i)), + Number<long>(context, match_results.length(i))}); } - // Save the result string. - char* const result_string = - reinterpret_cast<char*>(uw_malloc(context, result.length() + 1)); - Assert(context, std::snprintf(result_string, result.length() + 1, "%s", - result.c_str()) >= 0, - "regex: snprintf failed during replace"); - return result_string; + return result; } |