Copyright	(c) 2026 Tushar Adhatrao
License	MIT
Stability	internal
Safe Haskell	None
Language	GHC2021

WasmEdge.Internal.FFI.Basic

Contents

Version
Logging
String (via shims)
Bytes (via shims)
Result (via shims)
Raw callback type

Description

Direct 'foreign import' declarations for all WasmEdge basic C API functions, via the cbits/wasmedge_hs_shims.c shim layer. All struct-by-value returns have been converted to out-pointer style.

Do not import this module in user code.

Synopsis

c_VersionGet :: IO CString
c_VersionGetMajor :: IO Word32
c_VersionGetMinor :: IO Word32
c_VersionGetPatch :: IO Word32
c_LogSetErrorLevel :: IO ()
c_LogSetDebugLevel :: IO ()
c_LogOff :: IO ()
c_LogSetLevel :: Word32 -> IO ()
c_LogSetCallback :: FunPtr RawLogCallbackT -> IO ()
c_StringCreateByCString :: Ptr CString_ -> CString -> IO ()
c_StringCreateByBuffer :: Ptr CString_ -> CString -> Word32 -> IO ()
c_StringWrap :: Ptr CString_ -> CString -> Word32 -> IO ()
c_StringIsEqual :: Ptr CString_ -> Ptr CString_ -> IO CBool
c_StringCopy :: Ptr CString_ -> CString -> Word32 -> IO Word32
c_StringDelete :: Ptr CString_ -> IO ()
c_StringGetLength :: Ptr CString_ -> IO Word32
c_StringGetBuf :: Ptr CString_ -> IO CString
c_BytesCreate :: Ptr CBytes_ -> Ptr Word8 -> Word32 -> IO ()
c_BytesWrap :: Ptr CBytes_ -> Ptr Word8 -> Word32 -> IO ()
c_BytesDelete :: Ptr CBytes_ -> IO ()
c_BytesGetLength :: Ptr CBytes_ -> IO Word32
c_BytesGetBuf :: Ptr CBytes_ -> IO (Ptr Word8)
c_Result_Success :: Ptr CResult_ -> IO ()
c_Result_Terminate :: Ptr CResult_ -> IO ()
c_Result_Fail :: Ptr CResult_ -> IO ()
c_ResultOK :: Ptr CResult_ -> IO CBool
c_ResultGen :: Ptr CResult_ -> Word32 -> Word32 -> IO ()
c_ResultGetCode :: Ptr CResult_ -> IO Word32
c_ResultGetCategory :: Ptr CResult_ -> IO Word32
c_ResultGetMessage :: Ptr CResult_ -> IO CString
type RawLogCallbackT = Ptr () -> IO ()
mkLogCallback :: RawLogCallbackT -> IO (FunPtr RawLogCallbackT)

Version

c_VersionGet :: IO CString #

Get the version string of the WasmEdge C API (e.g., "0.18.0"). The returned pointer points to a static string — do NOT free it.

c_VersionGetMajor :: IO Word32 #

Get the major version number.

c_VersionGetMinor :: IO Word32 #

Get the minor version number.

c_VersionGetPatch :: IO Word32 #

Get the patch version number.

Logging

c_LogSetErrorLevel :: IO () #

Set the logging system to filter to error level only.

c_LogSetDebugLevel :: IO () #

Set the logging system to filter to debug level (verbose).

c_LogOff :: IO () #

Turn off all logging output.

c_LogSetLevel :: Word32 -> IO () #

Set the log level to a specific Word32 value (maps to WasmEdge_LogLevel enum). Use the LogLevel type and logLevelToC for safe access.

c_LogSetCallback :: FunPtr RawLogCallbackT -> IO () #

Set a custom log callback (safe: callback may call back into Haskell).

String (via shims)

c_StringCreateByCString :: Ptr CString_ -> CString -> IO () #

Create a WasmEdge_String from a NULL-terminated C string. Caller owns the result; call c_StringDelete to free.

c_StringCreateByBuffer :: Ptr CString_ -> CString -> Word32 -> IO () #

Create a WasmEdge_String from a buffer with explicit length. Caller owns the result; call c_StringDelete to free.

c_StringWrap :: Ptr CString_ -> CString -> Word32 -> IO () #

Wrap a buffer as a WasmEdge_String (no copy; DO NOT call c_StringDelete).

c_StringIsEqual :: Ptr CString_ -> Ptr CString_ -> IO CBool #

Compare two WasmEdge_String objects for equality.

c_StringCopy :: Ptr CString_ -> CString -> Word32 -> IO Word32 #

Copy the content of a WasmEdge_String into a buffer.

c_StringDelete :: Ptr CString_ -> IO () #

Delete (free) a WasmEdge_String created by 'c_StringCreateBy*'.

c_StringGetLength :: Ptr CString_ -> IO Word32 #

Get the length of a WasmEdge_String.

c_StringGetBuf :: Ptr CString_ -> IO CString #

Get the const char* buffer of a WasmEdge_String.

Bytes (via shims)

c_BytesCreate :: Ptr CBytes_ -> Ptr Word8 -> Word32 -> IO () #

Create a WasmEdge_Bytes from a buffer (copies the data). Caller owns the result; call c_BytesDelete to free.

c_BytesWrap :: Ptr CBytes_ -> Ptr Word8 -> Word32 -> IO () #

Wrap a buffer as WasmEdge_Bytes (no copy; DO NOT call c_BytesDelete).

c_BytesDelete :: Ptr CBytes_ -> IO () #

Delete a WasmEdge_Bytes created by c_BytesCreate.

c_BytesGetLength :: Ptr CBytes_ -> IO Word32 #

Get the length of a WasmEdge_Bytes.

c_BytesGetBuf :: Ptr CBytes_ -> IO (Ptr Word8) #

Get the const uint8_t* buffer of a WasmEdge_Bytes.

Result (via shims)

c_Result_Success :: Ptr CResult_ -> IO () #

Fill a CResult_ with the Success code (0x00).

c_Result_Terminate :: Ptr CResult_ -> IO () #

Fill a CResult_ with the Terminate code (0x01).

c_Result_Fail :: Ptr CResult_ -> IO () #

Fill a CResult_ with the Fail code (0x02).

c_ResultOK :: Ptr CResult_ -> IO CBool #

Check whether a CResult_ represents success (Success or Terminate).

c_ResultGen :: Ptr CResult_ -> Word32 -> Word32 -> IO () #

Generate a result with a specific error category and code. Category is a Word32 mapping to WasmEdge_ErrCategory.

c_ResultGetCode :: Ptr CResult_ -> IO Word32 #

Get the 24-bit error code from a CResult_.

c_ResultGetCategory :: Ptr CResult_ -> IO Word32 #

Get the error category as a Word32.

c_ResultGetMessage :: Ptr CResult_ -> IO CString #

Get the error message as a static C string (do NOT free).

Raw callback type

type RawLogCallbackT = Ptr () -> IO () #

The raw C type of a log callback: void callback(const WasmEdge_LogMessage *msg)

We represent the message pointer as 'Ptr ()' since hsc2hs will resolve the exact struct layout separately. Users should use the public setLogCallback API instead of this raw import.

mkLogCallback :: RawLogCallbackT -> IO (FunPtr RawLogCallbackT) #