fix: Drop the anonymous namespace from the benchmark URI

The namespace was extracted from __PRETTY_FUNCTION__ and rejected only when
spelled '(anonymous namespace)', as clang does, so with GCC, which spells it
'{anonymous}', it ended up in the URI: file.cpp::{anonymous}::bench[…]. Strip the
segment instead of bailing out, for both spellings, so the rest of the namespace
path is kept and no error is reported for a construct that is merely unnameable.

Author: chfast

core/src/uri.cpp

@@ -1,10 +1,22 @@
-#include <iostream>
 #include <string>
 
 #include "codspeed.h"
 
 namespace codspeed {
 
+// The anonymous namespace is not a part of any identifier the benchmark can be referred to by,
+// and its spelling differs between the compilers, so it is dropped from the namespace path.
+// Example: {anonymous}::outer:: (GCC) or (anonymous namespace)::outer:: (clang)
+// Returns: outer::
+std::string strip_anonymous_namespace(std::string ns) {
+  for (const std::string anon : {"{anonymous}::", "(anonymous namespace)::"}) {
+    for (auto pos = ns.find(anon); pos != std::string::npos; pos = ns.find(anon)) {
+      ns.erase(pos, anon.size());
+    }
+  }
+  return ns;
+}
+
 // Example: auto outer::test12::(anonymous class)::operator()() const
 // Returns: outer::test12::
 std::string extract_namespace_clang(const std::string &pretty_func) {
@@ -36,16 +48,10 @@ std::string extract_namespace_gcc(const std::string &pretty_func) {
 // Returns: An empty string if the namespace could not be extracted,
 //         otherwise the namespace with a trailing "::"
 std::string extract_lambda_namespace(const std::string &pretty_func) {
-  if (pretty_func.find("(anonymous namespace)") != std::string::npos) {
-    std::cerr << "[ERROR] Anonymous namespace not supported in " << pretty_func
-              << std::endl;
-    return {};
-  }
-
 #ifdef __clang__
-  return extract_namespace_clang(pretty_func);
+  return strip_anonymous_namespace(extract_namespace_clang(pretty_func));
 #elif __GNUC__
-  return extract_namespace_gcc(pretty_func);
+  return strip_anonymous_namespace(extract_namespace_gcc(pretty_func));
 #elif _MSC_VER
   // MSVC doesn't support __PRETTY_FUNCTION__ in the same way
   // Return empty string as fallback for Windows