make level_enum from_str() case insensitive #3525

include/spdlog/cfg/helpers-inl.h

@@ -19,13 +19,6 @@ namespace spdlog {
 namespace cfg {
 namespace helpers {
 
-// inplace convert to lowercase
-inline std::string &to_lower_(std::string &str) {
-    std::transform(str.begin(), str.end(), str.begin(), [](char ch) {
-        return static_cast<char>((ch >= 'A' && ch <= 'Z') ? ch + ('a' - 'A') : ch);
-    });
-    return str;
-}
 
 // inplace trim spaces
 inline std::string &trim_(std::string &str) {
@@ -82,10 +75,9 @@ SPDLOG_INLINE void load_levels(const std::string &levels_spec) {
 
     for (auto &name_level : key_vals) {
         const auto &logger_name = name_level.first;
-        const auto &level_name = to_lower_(name_level.second);
-        const auto level = level::from_str(level_name);
+        const auto level = level::from_str(name_level.second);
         // ignore unrecognized level names
-        if (level == level::off && level_name != "off") {
+        if (level == level::off && !strings_equal_ci(name_level.second, to_string_view(level::off))) {
             continue;
         }
         if (logger_name.empty())  // no logger name indicates global level

include/spdlog/cfg/helpers.h

@@ -19,6 +19,7 @@ namespace helpers {
 // turn off all logging except for logger1 and logger2: "off,logger1=debug,logger2=info"
 //
 SPDLOG_API void load_levels(const std::string &levels_spec);
+
 }  // namespace helpers
 
 }  // namespace cfg

include/spdlog/common-inl.h

@@ -29,15 +29,18 @@ SPDLOG_INLINE const char *to_short_c_str(spdlog::level::level_enum l) SPDLOG_NOE
 }
 
 SPDLOG_INLINE spdlog::level::level_enum from_str(const std::string &name) SPDLOG_NOEXCEPT {
-    auto it = std::find(std::begin(level_string_views), std::end(level_string_views), name);
+    auto it = std::find_if(std::begin(level_string_views), std::end(level_string_views),
+                           [name](string_view_t sv) { return strings_equal_ci(name, sv); } );
+
     if (it != std::end(level_string_views))
         return static_cast<level::level_enum>(std::distance(std::begin(level_string_views), it));
 
     // check also for "warn" and "err" before giving up..
-    if (name == "warn") {
+    if (strings_equal_ci(name, "warn") && strings_equal_ci(to_string_view(level::warn), "warning")) {
         return level::warn;
     }
-    if (name == "err") {
+    else if (strings_equal_ci(name, "err") && strings_equal_ci(to_string_view(level::err), "error")) {
+    // if (name == "err") {
         return level::err;
     }
     return level::off;
@@ -65,4 +68,24 @@ SPDLOG_INLINE void throw_spdlog_ex(const std::string &msg, int last_errno) {
 
 SPDLOG_INLINE void throw_spdlog_ex(std::string msg) { SPDLOG_THROW(spdlog_ex(std::move(msg))); }
 
+#if __cplusplus >= 201703L
+constexpr
+#endif
+SPDLOG_API char to_lower(char ch) {
+    return static_cast<char>((ch >= 'A' && ch <= 'Z') ? ch + ('a' - 'A') : ch);
+}
+
+
+SPDLOG_INLINE bool strings_equal_ci(string_view_t s1, string_view_t s2) {
+    if (s1.size() != s2.size()) {
+        return false;
+    }
+    for(size_t idx = 0; idx < s1.size(); idx++) {
+        if (to_lower(s1[idx]) != to_lower(s2[idx])) {
+            return false;
+        }
+    }
+    return true;
+}
+
 }  // namespace spdlog

include/spdlog/common.h

@@ -278,6 +278,9 @@ enum level_enum : int {
 
 SPDLOG_API const string_view_t &to_string_view(spdlog::level::level_enum l) SPDLOG_NOEXCEPT;
 SPDLOG_API const char *to_short_c_str(spdlog::level::level_enum l) SPDLOG_NOEXCEPT;
+
+// Checks whether name is the same as one of the log level names and returns the respective enum.
+// The comparison is case-insensitive.
 SPDLOG_API spdlog::level::level_enum from_str(const std::string &name) SPDLOG_NOEXCEPT;
 
 }  // namespace level
@@ -296,6 +299,11 @@ enum class pattern_time_type {
     utc     // log utc
 };
 
+//
+// Returns true if two strings are equal, case-insensitive
+//
+SPDLOG_API bool strings_equal_ci(string_view_t s1, string_view_t s2);
+
 //
 // Log exception
 //

tests/test_misc.cpp

@@ -65,11 +65,13 @@ TEST_CASE("to_short_c_str", "[convert_to_short_c_str]") {
 
 TEST_CASE("to_level_enum", "[convert_to_level_enum]") {
     REQUIRE(spdlog::level::from_str("trace") == spdlog::level::trace);
+    REQUIRE(spdlog::level::from_str("TrAcE") == spdlog::level::trace);
     REQUIRE(spdlog::level::from_str("debug") == spdlog::level::debug);
     REQUIRE(spdlog::level::from_str("info") == spdlog::level::info);
     REQUIRE(spdlog::level::from_str("warning") == spdlog::level::warn);
     REQUIRE(spdlog::level::from_str("warn") == spdlog::level::warn);
     REQUIRE(spdlog::level::from_str("error") == spdlog::level::err);
+    REQUIRE(spdlog::level::from_str("err") == spdlog::level::err);
     REQUIRE(spdlog::level::from_str("critical") == spdlog::level::critical);
     REQUIRE(spdlog::level::from_str("off") == spdlog::level::off);
     REQUIRE(spdlog::level::from_str("null") == spdlog::level::off);