How does it work?

MagNumDB is a database that contains about 360,000 items. These items are constants, names, values all extracted from more than 9,000 header files (.h, .hxx, .hpp, .idl, etc.) provided by standard Windows and Visual Studio SDKs and WDKs.

Some values have been extracted from the very special uuid.lib file that contains the value of thousands of guids and property keys, not present anywhere else in header files. This can explain some duplicates (because names in uuid.lib are not always exactly the same as names in .h parsed files...).

It also contains around 36,0000 undocumented guids that we found ... meeeeep ...


To build this database, we have tried many existing parsers, things like CLANG or other fine tools, but they just don't suit our needs. They can't handle thousands of files that don't compile together, they can't handle some specific (or just very old) Microsoft constructs or annotations, they don't remember the stack of #define directives that led to a definition, they only give you a final AST, not a partial one, etc.

So, in the end, we have written a C/C++ parser named C2P5 (for C/CPP/PreProcessor/Parser), tailored specifically for computing constants. C2P5 is capable of preprocessing, parsing and partially evaluating all header files as if they were included in a one big virtual project (that of course, does not compile) on a 32G RAM machine. It currently supports the following preprocessor and C/C++ constructs:

  • #define preprocessor that define constants
  • #define preprocessor that define expression to compute constants
  • C and C++ constants, strings and enum definitions, and some level of pointerness
  • Special GUID constructs like DECLSPEC_UUID, DEFINE_GUIDSTRUCT, MIDL_INTERFACE, you name it
  • PROPERTYKEY constructs
  • Some IDL constructs
  • Etc.

The parser remembers dynamic preprocessor definitions (#if, #ifdef, etc.) that are conditions for constants definitions and expression computation. All parsed items are saved in the database, as well as the associated conditions. There may be more than one item corresponding to a given name, if there are differences in their associated conditions stack.

C2P5 supports the following types of constants, regardless of the way they are defined in source files:

  • integer, signed or unsigned, from 8-bit to 128-bit
  • floating point number, single (32-bit) or double (64-bit)
  • globally unique identifier, or guid, uuid, CLSID, IID, etc.
  • string, in narrow, wide, or utf-8/16/32 formats
  • character, in narrow, wide, or utf-8/16/32 formats
  • pointer, a constant cast as a pointer
  • property key, or PROPERTYKEY, or PKEY, a combination of a guid (fmtid) and a 32-bit integer (id).

 Powered by

C2P5 and this MagNumDB web site are written in C# and use a Lucene database as a full-text search engine. C2P5 uses a custom ANTLR4cs C grammar for expression parsing, not for preprocessor parsing.


 Frequently Asked Questions

  • Q: Can I run custom queries?
    A: Yes. You can use Lucene's query syntax. Note the Database is case insensitive. Check out the list of columns with their corresponding database column names:

    • Index: the item's index.
    • Name: the item's name, or title. For enum values, it's prefixed with the enum's name.
      Corresponding database field: title.
    • Type: the item's type, expressed in a specific, universal system.
      Corresponding database's field: valuetype, but use the value of the Storage type column for queries on items type.
    • Value: the item's value. For string values, it's displayed as is w/o quotes nor escaping.
      Corresponding database field: value. There is also a typedvalue field that can contain database's Int32, Int64, Float, Double or String typed values.
    • Hex Value: the item's hexadecimal value, only valid for integer types.
      There is no corresponding database field.
    • Signed Value: the item's signed value, only valid for integer and double types. Useful when you found a unsigned number and want to get the corresponding signed value (uint -> int for example).
      There is no corresponding database field.
    • Source lines(s): the source lines from which the item was extracted. Comments and characters such as TAB, CR are preserved.
      Corresponding database field: source.
    • File path: the file path from which the item was extracted, terminated by the line index.
      Corresponding database field: filepath. There are also directory and filename fields. filename is useful to query for values in a given file.
    • Score: Database's score value. Items are returned sorted by score.
    • Guid formats: a utility columns that proposes all possible guid formats. Only valid for guid types.
      There is no corresponding database field
    • Char type: the character encoding (narrow, wide, etc.). Only valid for char and string values.
      Corresponding database field: chartype.
    • Storage type: the exact storage type in the database. Only used for specific queries.
      Corresponding database field: valuetype.
    • Conditions: the list of preprocessor conditions for a given item. If a condition is surrounded with a REVERSE function, it means the reverse condition of what's surrounded was the condition.
      Corresponding database field: conditions. There may be multiple conditions fields for one item.

    Some important points to note:

    • If you search for a negative number (like error codes expressed using signed integers), you can surround the search with double quotes, for example searching for "-2147009290" is equivalent to searching for 0x80073CF6, 80073CF6 (or even 3CF6 in this specific case). If you don't surround negative numbers with double quotes, the system will search for signed and unsigned corresponding values.
    • The full-text search uses items' name, value, hex value, guid formats, source lines, etc. so refine your search if you get back too many items.
    • You can search for guid binary values using just a part of their full definition. For example, if you search for '79eac9c5', it will get you 3 guid entries
    • Leading wild card search (*whatever) is allowed, but it may slow down the search significantly.

    Here are some example or custom queries:

    title:wm_user returns the WM_USER Windows message item, not all items that reference the WM_USER token.

    title:wm_u* returns all items (Windows messages probably) whose name starts with WM_U*.

    value:1024 AND title:wm_* returns all items (Windows messages probably) whose name starts with WM_U* and value is 1024. Note AND must be UPPERCASE for database to understand it as an AND operator.

    value:"00000002-0000-0000-C000-000000000046" returns the IMalloc IID guid value.

  • Q: I always get back 400 items at most. Why?
    A: The MagNumDb site currently limits the number of returned items to this value by design. This should be enough for most real search scenarios (like enums with a big list of values).

  • Q: Some values are empty. Why?
    A: The expression evaluator cannot always compute the final value, because it sometimes require contextual information (custom defines, compiler architecture, etc.) that the parser doesn't have at parsing time. You can enable the Source line(s) column to check what's the corresponding source and try to work it out by yourself. The origin file path and line number is also included.

  • Q: Can I get all values for a given enum?
    A: Sure. For example, __VSHPROPID is the name of an enum, and a query like this: parent:__VSHPROPID will get all the enum's values (66 entries).

  • Q: I sometimes get back items whose name starts with "__magnumdb__enum_". Why?
    A: C allows unnamed enums. The MagNumDb parser just gives them a name, using the defining file name and a counter.

  • Q: I sometimes get back the same item/name twice or more with different values. For example:  TARGET_IS_NT60_OR_LATER. Why?
    A: This can be the case with defines. Their value may be different if they were surrounded by # directives (#if, #else, etc.) in the original source code. You can enable the Condition(s) column to check what are the corresponding conditions for a given item.
    Note: if a condition is surrounded with a funny REVERSE function token, it means the reverse condition of what's surrounded.

  • Q: I can't connect from an IP address but from another one, it works. Why?
    A: The server is constantly monitored for excessive usage. It's possible your IP address has been banned because massive sets of queries where observed. If you think this is an error, send us an email.

 Database Metrics

  • Last update date: Thursday October 7, 2021
  • Items count: 362743
  • Parsed files count: 9541
  • Windows SDK version: 10.0.22000.0
  • NetFx SDK version: 4.8
  • MSVC Tools version: 14.29.30133

 Rest API

There is a JSON version API (you will have to figure out the schema, it's pretty obvious) that you can call here (the search query is the 'q' parameter):

Note this API also has a 400 items maximum limit and the server is monitored for excessive usage (the key can be removed without notice). If you want to get a key, send us an email.



We welcome feedback.
Seen anything missing? A bug? A wrong value? Do you have any suggestion for improvements? Do you have an idea for a cool new feature?

Please contact us here

 About MagNumDB

MagNumDB  2017-2022 Simon Mourier V1.4.0. All rights reserved.

Profile for Simon Mourier at Stack Overflow, Q&A for professional and enthusiast programmers

All product names, logos, and brands are property of their respective owners. All company, product and service names used in this website are for identification purposes only.

All values, names, source code fragments displayed here have been extracted from files that are property of their respective owners.


Index Score Name Type Value Hex value Signed value Guid formats Char type Storage type Source line(s) File path Condition(s)
Index Score Name Type Value Hex value Signed value Guid formats Char type Storage type Source line(s) File path Condition(s)
1 10.21793 SRB_COMMAND::SRB_READ_DATA Int32 0 0x00000000 0 System.Int32
SRB_READ_DATA,              // read data from hardware
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(578,0)
2 10.21793 SRB_COMMAND::SRB_WRITE_DATA Int32 1 0x00000001 1 System.Int32
SRB_WRITE_DATA,             // write data to the hardware
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(579,0)
3 10.21793 SRB_COMMAND::SRB_GET_STREAM_STATE Int32 2 0x00000002 2 System.Int32
SRB_GET_STREAM_STATE,       // get the state of the stream
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(580,0)
4 10.21793 SRB_COMMAND::SRB_SET_STREAM_STATE Int32 3 0x00000003 3 System.Int32
SRB_SET_STREAM_STATE,       // set the state of the stream
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(581,0)
5 10.21793 SRB_COMMAND::SRB_SET_STREAM_PROPERTY Int32 4 0x00000004 4 System.Int32
SRB_SET_STREAM_PROPERTY,    // set a property of the stream
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(582,0)
6 10.21793 SRB_COMMAND::SRB_GET_STREAM_PROPERTY Int32 5 0x00000005 5 System.Int32
SRB_GET_STREAM_PROPERTY,    // get a property value for the stream
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(583,0)
7 10.21793 SRB_COMMAND::SRB_OPEN_MASTER_CLOCK Int32 6 0x00000006 6 System.Int32
SRB_OPEN_MASTER_CLOCK,      // indicates that the master clock is on this
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(584,0)
8 10.21793 SRB_COMMAND::SRB_INDICATE_MASTER_CLOCK Int32 7 0x00000007 7 System.Int32
SRB_INDICATE_MASTER_CLOCK,  // supplies the handle to the master clock
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(586,0)
9 10.21793 SRB_COMMAND::SRB_UNKNOWN_STREAM_COMMAND Int32 8 0x00000008 8 System.Int32
SRB_UNKNOWN_STREAM_COMMAND, // IRP function is unknown to class driver
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(587,0)
10 10.21793 SRB_COMMAND::SRB_SET_STREAM_RATE Int32 9 0x00000009 9 System.Int32
SRB_SET_STREAM_RATE,        // set the rate at which the stream should run
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(588,0)
11 10.21793 SRB_COMMAND::SRB_PROPOSE_DATA_FORMAT Int32 10 0x0000000A 10 System.Int32
SRB_PROPOSE_DATA_FORMAT,    // propose a new format, DOES NOT CHANGE IT!
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(589,0)
12 10.21793 SRB_COMMAND::SRB_CLOSE_MASTER_CLOCK Int32 11 0x0000000B 11 System.Int32
SRB_CLOSE_MASTER_CLOCK,     // indicates that the master clock is closed
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(590,0)
13 10.21793 SRB_COMMAND::SRB_PROPOSE_STREAM_RATE Int32 12 0x0000000C 12 System.Int32
SRB_PROPOSE_STREAM_RATE,    // propose a new rate, DOES NOT CHANGE IT!
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(591,0)
14 10.21793 SRB_COMMAND::SRB_SET_DATA_FORMAT Int32 13 0x0000000D 13 System.Int32
SRB_SET_DATA_FORMAT,        // sets a new data format
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(592,0)
15 10.21793 SRB_COMMAND::SRB_GET_DATA_FORMAT Int32 14 0x0000000E 14 System.Int32
SRB_GET_DATA_FORMAT,        // returns the current data format
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(593,0)
16 10.21793 SRB_COMMAND::SRB_BEGIN_FLUSH Int32 15 0x0000000F 15 System.Int32
SRB_BEGIN_FLUSH,            // beginning flush state
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(594,0)
17 10.21793 SRB_COMMAND::SRB_END_FLUSH Int32 16 0x00000010 16 System.Int32
SRB_END_FLUSH,              // ending flush state
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(595,0)
18 10.21793 SRB_COMMAND::SRB_GET_STREAM_INFO Int32 256 0x00000100 256 System.Int32
SRB_GET_STREAM_INFO = 0x100,// get the stream information structure
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(601,0)
19 10.21793 SRB_COMMAND::SRB_OPEN_STREAM Int32 257 0x00000101 257 System.Int32
SRB_OPEN_STREAM,            // open the specified stream
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(602,0)
20 10.21793 SRB_COMMAND::SRB_CLOSE_STREAM Int32 258 0x00000102 258 System.Int32
SRB_CLOSE_STREAM,           // close the specified stream
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(603,0)
21 10.21793 SRB_COMMAND::SRB_OPEN_DEVICE_INSTANCE Int32 259 0x00000103 259 System.Int32
SRB_OPEN_DEVICE_INSTANCE,   // open an instance of the device
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(604,0)
22 10.21793 SRB_COMMAND::SRB_CLOSE_DEVICE_INSTANCE Int32 260 0x00000104 260 System.Int32
SRB_CLOSE_DEVICE_INSTANCE,  // close an instance of the device
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(605,0)
23 10.21793 SRB_COMMAND::SRB_GET_DEVICE_PROPERTY Int32 261 0x00000105 261 System.Int32
SRB_GET_DEVICE_PROPERTY,    // get a property of the device
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(606,0)
24 10.21793 SRB_COMMAND::SRB_SET_DEVICE_PROPERTY Int32 262 0x00000106 262 System.Int32
SRB_SET_DEVICE_PROPERTY,    // set a property for the device
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(607,0)
25 10.21793 SRB_COMMAND::SRB_INITIALIZE_DEVICE Int32 263 0x00000107 263 System.Int32
SRB_INITIALIZE_DEVICE,      // initialize the device
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(608,0)
26 10.21793 SRB_COMMAND::SRB_CHANGE_POWER_STATE Int32 264 0x00000108 264 System.Int32
SRB_CHANGE_POWER_STATE,     // change power state
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(609,0)
27 10.21793 SRB_COMMAND::SRB_UNINITIALIZE_DEVICE Int32 265 0x00000109 265 System.Int32
SRB_UNINITIALIZE_DEVICE,    // uninitialize the device
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(610,0)
28 10.21793 SRB_COMMAND::SRB_UNKNOWN_DEVICE_COMMAND Int32 266 0x0000010A 266 System.Int32
SRB_UNKNOWN_DEVICE_COMMAND, // IRP function is unknown to class driver
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(611,0)
29 10.21793 SRB_COMMAND::SRB_PAGING_OUT_DRIVER Int32 267 0x0000010B 267 System.Int32
SRB_PAGING_OUT_DRIVER,      // indicates that the driver is to be paged out
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(612,0)
30 10.21793 SRB_COMMAND::SRB_GET_DATA_INTERSECTION Int32 268 0x0000010C 268 System.Int32
SRB_GET_DATA_INTERSECTION,  // returns stream data intersection
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(615,0)
31 10.21793 SRB_COMMAND::SRB_INITIALIZATION_COMPLETE Int32 269 0x0000010D 269 System.Int32
SRB_INITIALIZATION_COMPLETE,// indicates init sequence has completed
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(616,0)
32 10.21793 SRB_COMMAND::SRB_SURPRISE_REMOVAL Int32 270 0x0000010E 270 System.Int32
SRB_SURPRISE_REMOVAL        // indicates surprise removal of HW has occurred
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(617,0)
33 10.21793 SRB_COMMAND::SRB_DEVICE_METHOD Int32 271 0x0000010F 271 System.Int32
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(621,0)
34 10.21793 SRB_COMMAND::SRB_STREAM_METHOD Int32 272 0x00000110 272 System.Int32
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(622,0)
35 10.21793 SRB_COMMAND::SRB_NOTIFY_IDLE_STATE Int32 273 0x00000111 273 System.Int32
, SRB_NOTIFY_IDLE_STATE       // called on first open and last close
%ProgramFiles(x86)%\Windows Kits\10\Include\10.0.22000.0\km\strmini.h(626,0)