{"id":18605,"date":"2018-03-14T12:53:39","date_gmt":"2018-03-14T19:53:39","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/vcblog\/?p=18605"},"modified":"2019-02-18T17:48:01","modified_gmt":"2019-02-18T17:48:01","slug":"build-time-improvement-recommendation-turn-off-map-use-pdbs","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/cppblog\/build-time-improvement-recommendation-turn-off-map-use-pdbs\/","title":{"rendered":"Build Time Improvement Recommendation: Turn off \/MAP, use PDBs"},"content":{"rendered":"

\u70b9\u8fd9\u91cc\u770b\u4e2d\u6587\u7248<\/a><\/p>\n

Map file is a plaintext file that contains information about where certain names and symbols exist in\u00a0a binary produced by the linker.\u00a0It also\u00a0contain detailed information on all sections in your binary (code, data, etc.) and\u00a0which OBJ\/LIB\u00a0each symbol is\u00a0defined in. The Windows debuggers (like windbg.exe) can use map files to help locate where a program crashed based on a crash address. Map files are an old technology: with modern releases of the MSVC toolset<\/span>,<\/span> PDB (Program Database) files do everything map files do and more. <\/span><\/p>\n

Producing a map file takes a long time. If you see the <\/span>linker switch \/MAP<\/span><\/a> in your build but you don\u2019t have a need for map files, you should remove the switch to speed up your build. We\u2019ve done work recently to speed up the production of a map file but generating map files will be a slow process.<\/span><\/span><\/p>\n

\"\"<\/a><\/p>\n

If you are one of the few who needs map files (for example, to quickly check whether interested set of functions or data are laid out in expected or correct order in binary)<\/span>,<\/span> rest assured that we\u2019re not removing them. However<\/span>,<\/span> here are a few points as to why you should turn off \/MAP and simply use PDBs:<\/span><\/p>\n