WIDL compiler incompatibilities with Windows SDK
I attempted to compile the IDL files distributed in https://github.com/microsoft/win32metadata/tree/master/generation/WinSDK/RecompiledIdlHeaders using the latest (7.0.1-rc.1) version of the Wine IDL compiler, called WIDL. Unlike Microsoft's MIDL compiler which ships with Visual Studio, WIDL is open source.
More importantly, WIDL contains patches to generated header files that make e.g. COM calling conventions compatible with mingw-w64 and clang when targetting GNU ABI.
WIDL's import statement is case sensitive, Microsoft's MIDL compiler is not: it treats all imports as case-insensitive filepath matches.
import "OAIDL.IDL", import "oaidl.idl", etc. should match a file named OAIdl.Idl
Additionally, the Windows SDK and win32metadata IDL files do NOT use any form of standardized casing in imports. The same file will often be referred to three different ways (OAIdl.Idl, oaidl.idl, and OAIDL.IDL for example.)
The Windows SDK IDL files often place quotes in string literals, for example to emit comments in the generated header files:
cpp_quote("// URL Moniker Interfaces.")
WIDL fails to parse these correctly and reports a missing terminating ) instead.
I did not debug these, but found WIDL segfaults on the following files from the Windows SDK:
propidl.idl
propidlbase.idl
relogger.idl
bitscfg.idl
bits1_5.idl
bits2_0.idl
bits2_5.idl
bits3_0.idl
bits4_0.idl
bits5_0.idl
bits10_1.idl
bits10_2.idl
bits10_3.idl
Affects ~15 files.
compiling ./wmsinternaladminnetsource.idl
./wmsinternaladminnetsource.idl:188:18: error: Unexpected end of file during preprocessing
compiling ./audioenginebaseapo.idl
./audioenginebaseapo.idl:1435:18: error: Unexpected end of file during preprocessing
compiling ./audioclientactivationparams.idl
./audioclientactivationparams.idl:55:18: error: Unexpected end of file during preprocessing
compiling ./wmsbuffer.idl
./wmsbuffer.idl:143:18: error: Unexpected end of file during preprocessing
compiling ./wmsdkidl.idl
./wmsbuffer.idl:143:18: error: Unexpected end of file during preprocessing
compiling ./wmdxva.idl
./wmdxva.idl:73:18: error: Unexpected end of file during preprocessing
Affects ~7 files.
compiling ./wsdbase.idl
widl: tools/wrc/ppl.l:1342: add_text_to_macro: Assertion `mep->ppp->expanding == 0' failed.
Aborted
compiling ./mimeole.idl
widl: tools/wrc/ppl.l:1342: add_text_to_macro: Assertion `mep->ppp->expanding == 0' failed.
Aborted
compiling ./wincrypt.idl
widl: tools/wrc/ppl.l:1342: add_text_to_macro: Assertion `mep->ppp->expanding == 0' failed.
Aborted
This affects ~40 files.
For example, objidlbase.idl from the Windows SDK expects to be able to
typedef [unique] IMultiQI* LPMULTIQI;
interface IMultiQI : IUnknown
...
...
Microsoft's MIDL allows this, while WIDL views it as illegal (IMultiQI is not defined)
This affects ~215 files.
The Windows SDK declares annotations in the form of e.g.:
typedef struct D3D12_SHADER_BYTECODE
{
[annotation("_Field_size_bytes_full_(BytecodeLength)")] const void* pShaderBytecode;
SIZE_T BytecodeLength;
} D3D12_SHADER_BYTECODE;
WIDL does not allow annotation() at all, it seems.
WIDL fails to parse the multi-line help strings found in the Windows SDK IDL files, e.g.:
interface IUri : IUnknown
{
[helpstring("Uri_PROPERTYs represent properties that an URI may contain. "
"The Uri_PROPERTIYs in the range Uri_PROPERTY_STRING_START to "
"Uri_PROPERTY_STRING_LAST are string properties and the rest are DWORD "
"properties.")]
typedef enum
...
Single-line helpstring invocations are allowed by WIDL, however.
Affects ~85 files.
It's unclear why, but the MIDL compiler is able to resolve the IUnknown interface which is defined in unknwnbase.idl of the Windows SDK without importing it. For example, dbsrst.idl has no IDL imports and yet depends on it. I can only assume MIDL treats IUnknown as a builtin.
WIDL is unable to resolve this:
Affects ~15 files.
MIDL utilizes 64-bit integer constants, whih WIDL appears to not support:
compiling ./xamlom.idl
../shared/sdkddkver.h:284:32: error: integer constant 0xFFFF0000 is too large
compiling ./vds.idl
../shared/sdkddkver.h:284:32: error: integer constant 0xFFFF0000 is too large
Affects ~4 files.
MIDL allows helpstring attributes on enum members, WIDL does not:
compiling ./imapi2.idl
./imapi2.idl:73: error: inapplicable attribute helpstring for enum member
Affects ~57 files.
The win32metadata project merely copies the IDL files from the Windows SDK and makes those open source. However, those IDL files also depend on type libraries (shipped with windows?)
WIDL cannot locate them:
compiling ./sapi.idl
error: cannot find stdole32.tlb
compiling ./msclus.idl
error: cannot find stdole2.tlb
There were a handful of other uncategorized issues we did not investigate.
compiling ./wdstptmgmt.idl
./wdstptmgmt.idl:86: error: 'PWDSTRANSPORT_FEATURE_FLAGS': [v1_enum] attribute applied to non-enum type
compiling ./smtpevent.idl
./smtpevent.idl:719: error: 'PMTI_NEXT_HOP_TYPE': [v1_enum] attribute applied to non-enum type
compiling ./netlistmgr.idl
./netlistmgr.idl:565: error: syntax error, unexpected ';', expecting '{'
./documenttarget.idl:141: error: syntax error, unexpected ';', expecting '{'
compiling ./msctf.idl
./msctf.idl:529: error: redefinition of struct TF_PERSISTENT_PROPERTY_HEADER_ACP
compiling ./icontentprefetchertasktrigger.idl
./icontentprefetchertasktrigger.idl:18: error: inapplicable attribute annotation for function IsRegisteredForContentPrefetch
compiling ./windows.data.pdf.interop.idl
compiling ./wincodec.idl
./wincodec.idl:1381: error: parameter 'ppbData' of function 'GetDataPointer' cannot derive from void *
compiling ./certexit.idl
./certmod.idl:32: error: instantiation of data is illegal
compiling ./directmanipulation.idl
./directmanipulation.idl:276:1: warning: Newline in string constant encountered (started line 275)
./directmanipulation.idl:288:1: warning: Newline in string constant encountered (started line 287)
./directmanipulation.idl:300:1: warning: Newline in string constant encountered (started line 299)
./directmanipulation.idl:314:1: warning: Newline in string constant encountered (started line 313)
./directmanipulation.idl:326:1: warning: Newline in string constant encountered (started line 325)
./directmanipulation.idl:340:1: warning: Newline in string constant encountered (started line 339)
./directmanipulation.idl:272: error: syntax error, unexpected aSTRING, expecting ')'
./msdatsrc.idl:36: error: syntax error, unexpected $undefined, expecting ')'
compiling ./sapiaut.idl
./sapiaut.idl:179: error: expression is not constant
compiling ./wbemtran.idl
./wbemtran.idl:47: error: inapplicable attribute size_is for typedef
compiling ./sapiddk.idl
./sapiddk.idl:486: error: syntax error, unexpected ';'
compiling ./certpol.idl
./certmod.idl:32: error: instantiation of data is illegal
compiling ./objidl.idl
error: write_conf_or_var_desc: couldn't find variable cRequest in Finish_Pull
compiling ./tspubplugincom.idl
./tspubplugincom.idl:46: error: syntax error, unexpected tLONG, expecting ')'
compiling ./objidlbase.idl
error: write_conf_or_var_desc: couldn't find variable cRequest in Finish_Pull
compiling ./ctfutb.idl
./ctfutb.idl:218: error: interface ITfLangBarMgr already defined at ./ctfutb.idl:181
compiling ./wbemads.idl
./wbemdisp.idl:2121: error: inapplicable attribute nonextensible for dispinterface ISWbemSinkEvents
compiling ./icontact.idl
./icontact.idl:979: warning: duplicate attribute ref, unique or ptr
./icontact.idl:1062: warning: duplicate attribute ref, unique or ptr
compiling ./vmr9.idl
./vmr9.idl:92: warning: duplicate attribute local
./vmr9.idl:164: warning: duplicate attribute local
./vmr9.idl:196: warning: duplicate attribute local
./vmr9.idl:221: warning: duplicate attribute local
./vmr9.idl:278: warning: duplicate attribute local
./vmr9.idl:474: warning: duplicate attribute local
./vmr9.idl:627: warning: duplicate attribute local
./vmr9.idl:664: warning: duplicate attribute local
./vmr9.idl:1065: warning: duplicate attribute local
compiling ./naptypes.idl
./naptypes.idl:102: error: 'string': [range] attribute applied to non-integer type
compiling ./wuapi.idl
./wuapi.idl:313: error: syntax error, unexpected aSTRING, expecting ')'
compiling ./windows.graphics.imaging.interop.idl
compiling ./documenttarget.idl
./documenttarget.idl:35:1: warning: Newline in string constant encountered (started line 34)
compiling ./certmod.idl
./certmod.idl:32: error: instantiation of data is illegal