From 45e6bd321e749219290618bf735fabc68a1579fc Mon Sep 17 00:00:00 2001
From: eidheim <eidheim@gmail.com>
Date: Thu, 3 Aug 2017 12:04:10 +0200
Subject: [PATCH] Added remove_include_guard to Utility

---
 src/Utility.cc | 90 +++++++++++++++++++++++++++++++++++++++++++++++++-
 src/Utility.h  |  4 ++-
 2 files changed, 92 insertions(+), 2 deletions(-)

diff --git a/src/Utility.cc b/src/Utility.cc
index cede9a2..854e02e 100644
--- a/src/Utility.cc
+++ b/src/Utility.cc
@@ -1,4 +1,5 @@
 #include "Utility.h"
+#include <regex>
 
 std::string clangmm::to_string(CXString cx_string) {
   std::string string;
@@ -7,4 +8,91 @@ std::string clangmm::to_string(CXString cx_string) {
     clang_disposeString(cx_string);
   }
   return string;
-}
\ No newline at end of file
+}
+
+void clangmm::remove_include_guard(std::string &buffer) {
+  static std::regex ifndef_regex1("^[ \t]*#[ \t]*ifndef[ \t]+([A-Za-z0-9_]+).*$");
+  static std::regex ifndef_regex2("^[ \t]*#[ \t]*if[ \t]+![ \t]*defined[ \t]*\\([ \t]*([A-Za-z0-9_]+).*$");
+  static std::regex define_regex("^[ \t]*#[ \t]*define[ \t]+([A-Za-z0-9_]+).*$");
+  static std::regex endif_regex("^[ \t]*#[ \t]*endif.*$");
+  std::vector<std::pair<size_t, size_t>> ranges;
+  bool found_ifndef=false, found_define=false;
+  bool line_comment=false, multiline_comment=false;
+  size_t start_of_line=0;
+  std::string line;
+  std::string preprocessor_identifier;
+  for(size_t c=0;c<buffer.size();++c) {
+    if(!line_comment && !multiline_comment && buffer[c]=='/' && c+1<buffer.size() && (buffer[c+1]=='/' || buffer[c+1]=='*')) {
+      if(buffer[c+1]=='/')
+        line_comment=true;
+      else
+        multiline_comment=true;
+      ++c;
+    }
+    else if(multiline_comment && buffer[c]=='*' && c+1<buffer.size() && buffer[c+1]=='/') {
+      multiline_comment=false;
+      ++c;
+    }
+    else if(buffer[c]=='\n') {
+      bool empty_line=true;
+      for(auto &chr: line) {
+        if(chr!=' ' && chr!='\t') {
+          empty_line=false;
+          break;
+        }
+      }
+      
+      std::smatch sm;
+      if(empty_line) {}
+      else if(!found_ifndef && (std::regex_match(line, sm, ifndef_regex1) || std::regex_match(line, sm, ifndef_regex2))) {
+        found_ifndef=true;
+        ranges.emplace_back(start_of_line, c);
+        preprocessor_identifier=sm[1].str();
+      }
+      else if(found_ifndef && std::regex_match(line, sm, define_regex)) {
+        found_define=true;
+        ranges.emplace_back(start_of_line, c);
+        if(preprocessor_identifier!=sm[1].str())
+          return;
+        break;
+      }
+      else
+        return;
+      
+      line_comment=false;
+      line.clear();
+      if(c+1<buffer.size())
+        start_of_line=c+1;
+      else
+        return;
+    }
+    else if(!line_comment && !multiline_comment && buffer[c]!='\r')
+      line+=buffer[c];
+  }
+  if(found_ifndef && found_define) {
+    size_t last_char_pos=std::string::npos;
+    for(size_t c=buffer.size()-1;c!=std::string::npos;--c) {
+      if(last_char_pos==std::string::npos) {
+        if(buffer[c]!=' ' && buffer[c]!='\t' && buffer[c]!='\r' && buffer[c]!='\n')
+          last_char_pos=c;
+      }
+      else {
+        if(buffer[c]=='\n' && c+1<buffer.size()) {
+          auto line=buffer.substr(c+1, last_char_pos-c);
+          std::smatch sm;
+          if(std::regex_match(line, sm, endif_regex)) {
+            ranges.emplace_back(c+1, last_char_pos+1);
+            for(auto &range: ranges) {
+              for(size_t c=range.first;c<range.second;++c) {
+                if(buffer[c]!='\r')
+                  buffer[c]=' ';
+              }
+            }
+            return;
+          }
+          return;
+        }
+      }
+    }
+  }
+}
diff --git a/src/Utility.h b/src/Utility.h
index 45cf2ea..dbc28a1 100644
--- a/src/Utility.h
+++ b/src/Utility.h
@@ -5,6 +5,8 @@
 
 namespace clangmm {
   std::string to_string(CXString cx_string);
+  
+  void remove_include_guard(std::string &buffer);
 }
 
-#endif  // UTILITY_H_
\ No newline at end of file
+#endif  // UTILITY_H_