Internals: In .tree files show filename as letter

src/V3Error.cpp

@@ -34,6 +34,9 @@
 //======================================================================
 // Statics
 
+map<string,int> FileLine::s_namemap;
+deque<string> FileLine::s_names;
+// s_defaultFileLine must be after s_name* initializer and in same .cpp file
 FileLine FileLine::s_defaultFileLine = FileLine(EmptySecret());
 
 int V3Error::s_errCount = 0;
@@ -70,8 +73,9 @@ V3ErrorCode::V3ErrorCode(const char* msgp) {
 // FileLine class functions
 
 FileLine::FileLine(FileLine::EmptySecret) {
+    // Sort of a singleton
     m_lineno=0;
-    m_filename="COMMAND_LINE";
+    m_filenameno=nameToNumber("AstRoot");
 
     m_warnOn=0;
     for (int codei=V3ErrorCode::EC_MIN; codei<V3ErrorCode::_ENUM_MAX; codei++) {
@@ -80,6 +84,31 @@ FileLine::FileLine(FileLine::EmptySecret) {
     }
 }
 
+int FileLine::nameToNumber(const string& filename) {
+    // Convert filenames to a filenameno
+    // This lets us assign a nice small identifier for debug messages, but more
+    // importantly lets us use a 4 byte int instead of 8 byte pointer in every FileLine.
+    map<string,int>::const_iterator iter = s_namemap.find(filename);
+    if (VL_LIKELY(iter != s_namemap.end())) return iter->second;
+    int num = s_names.size();
+    s_names.push_back(filename);
+    s_namemap.insert(make_pair(filename,num));
+    return num;
+}
+
+const string FileLine::filenameLetters() const {
+    const int size = 1 + (64 / 4);  // Each letter retires more than 4 bits of a > 64 bit number
+    char out[size];
+    char* op = out+size-1;
+    *--op = '\0';  // We build backwards
+    int num = m_filenameno;
+    do {
+	*--op = 'a'+num%26;
+	num /= 26;
+    } while (num);
+    return op;
+}
+
 string FileLine::lineDirectiveStrg(int enterExit) const {
     char numbuf[20]; sprintf(numbuf, "%d", lineno());
     char levelbuf[20]; sprintf(levelbuf, "%d", enterExit);
@@ -262,6 +291,8 @@ void FileLine::deleteAllRemaining() {
 	// Eventually the list will be empty and terminate the loop.
     }
     fileLineLeakChecks.clear();
+    s_names.clear();
+    s_namemap.clear();
 #endif
 }