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[linux-port] Support full IID comparison on GCC (#3062)
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The fallback layer for GCC currently uses pointer comparison to match
IIDs as uuid tagging for types is not supported.
Thus, when an external program dlopens libdxcompiler and calls
with a proper REFIID these will not match internal pointers and result
in E_NOINTERFACE.

Note that the reverted patches before this commit alleviated the
situation somewhat by replacing the pointer with a hash of the interface
name. While this again grants a stable value to be used when called from
external binaries these (usually FFI wrappers) now need to understand
whether the library has been compiled with full IID support (as a binary
compiled with Clang has no such limitations), and then pass the hash
anywhere they'd otherwise pass an IID.

WIP: Not all IIDs are added yet, which requires the extra "empty-GUID"
check in IsEqualIID.
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@MarijnS95
MarijnS95 authored Nov 20, 2020
1 parent 11e04d8 commit af14220
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Showing 9 changed files with 169 additions and 253 deletions.
113 changes: 67 additions & 46 deletions include/dxc/Support/WinAdapter.h
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Original file line number Diff line number Diff line change
Expand Up @@ -50,15 +50,9 @@
#define _countof(a) (sizeof(a) / sizeof(*(a)))

// If it is GCC, there is no UUID support and we must emulate it.
#ifdef __APPLE__
#define __EMULATE_UUID 1
#else // __APPLE__
#ifdef __GNUC__
#ifndef __clang__
#define __EMULATE_UUID 1
#endif // __GNUC__
#endif // __clang__
#endif // __APPLE__

#ifdef __EMULATE_UUID
#define __declspec(x)
Expand Down Expand Up @@ -452,15 +446,14 @@ typedef GUID CLSID;
typedef const GUID &REFGUID;
typedef const GUID &REFCLSID;

#ifdef __EMULATE_UUID
typedef const void *REFIID;
#define IsEqualIID(a, b) a == b
#define IsEqualCLSID(a, b) !memcmp(&a, &b, sizeof(GUID))
#else // __EMULATE_UUID
typedef GUID IID;
typedef IID *LPIID;
typedef const IID &REFIID;
inline bool IsEqualGUID(REFGUID rguid1, REFGUID rguid2) {
// Optimization:
if (&rguid1 == &rguid2)
return true;

return !memcmp(&rguid1, &rguid2, sizeof(GUID));
}

Expand All @@ -479,7 +472,6 @@ inline bool IsEqualIID(REFIID riid1, REFIID riid2) {
inline bool IsEqualCLSID(REFCLSID rclsid1, REFCLSID rclsid2) {
return IsEqualGUID(rclsid1, rclsid2);
}
#endif // __EMULATE_UUID

//===--------------------- Struct Types -----------------------------------===//

Expand Down Expand Up @@ -559,27 +551,63 @@ enum tagSTATFLAG {

#ifdef __EMULATE_UUID

size_t UuidStrHash(const char* k);

// The following macros are defined to facilitate the lack of 'uuid' on Linux.
#define DECLARE_CROSS_PLATFORM_UUIDOF(T) \
public: \
static REFIID uuidof() { return reinterpret_cast<REFIID>(T##_ID); } \
\
private: \
__attribute__((visibility("default"))) static const size_t T##_ID;

#define DEFINE_CROSS_PLATFORM_UUIDOF(T) \
__attribute__((visibility("default"))) const size_t T::T##_ID = \
UuidStrHash(#T);
#define __uuidof(T) T::uuidof()

constexpr uint8_t nybble_from_hex(char c) {
return ((c >= '0' && c <= '9')
? (c - '0')
: ((c >= 'a' && c <= 'f')
? (c - 'a' + 10)
: ((c >= 'A' && c <= 'F') ? (c - 'A' + 10)
: /* Should be an error */ -1)));
}

constexpr uint8_t byte_from_hex(char c1, char c2) {
return nybble_from_hex(c1) << 4 | nybble_from_hex(c2);
}

constexpr uint8_t byte_from_hexstr(const char str[2]) {
return nybble_from_hex(str[0]) << 4 | nybble_from_hex(str[1]);
}

constexpr GUID guid_from_string(const char str[37]) {
return GUID{static_cast<uint32_t>(byte_from_hexstr(str)) << 24 |
static_cast<uint32_t>(byte_from_hexstr(str + 2)) << 16 |
static_cast<uint32_t>(byte_from_hexstr(str + 4)) << 8 |
byte_from_hexstr(str + 6),
static_cast<uint16_t>(
static_cast<uint16_t>(byte_from_hexstr(str + 9)) << 8 |
byte_from_hexstr(str + 11)),
static_cast<uint16_t>(
static_cast<uint16_t>(byte_from_hexstr(str + 14)) << 8 |
byte_from_hexstr(str + 16)),
{byte_from_hexstr(str + 19), byte_from_hexstr(str + 21),
byte_from_hexstr(str + 24), byte_from_hexstr(str + 26),
byte_from_hexstr(str + 28), byte_from_hexstr(str + 30),
byte_from_hexstr(str + 32), byte_from_hexstr(str + 34)}};
}

template <typename interface> inline GUID __emulated_uuidof();

#define CROSS_PLATFORM_UUIDOF(interface, spec) \
struct interface; \
template <> inline GUID __emulated_uuidof<interface>() { \
static const IID _IID = guid_from_string(spec); \
return _IID; \
}

#define __uuidof(T) __emulated_uuidof<typename std::decay<T>::type>()

#define IID_PPV_ARGS(ppType) \
(**(ppType)).uuidof(), reinterpret_cast<void **>(ppType)
__uuidof(decltype(**(ppType))), reinterpret_cast<void **>(ppType)

#else // __EMULATE_UUID

#define DECLARE_CROSS_PLATFORM_UUIDOF(T)
#define DEFINE_CROSS_PLATFORM_UUIDOF(T)
#ifndef CROSS_PLATFORM_UUIDOF
// Warning: This macro exists in dxcapi.h as well
#define CROSS_PLATFORM_UUIDOF(interface, spec) \
struct __declspec(uuid(spec)) interface;
#endif

template <typename T> inline void **IID_PPV_ARGS_Helper(T **pp) {
return reinterpret_cast<void **>(pp);
Expand All @@ -590,8 +618,9 @@ template <typename T> inline void **IID_PPV_ARGS_Helper(T **pp) {

//===--------------------- COM Interfaces ---------------------------------===//

struct __declspec(uuid("00000000-0000-0000-C000-000000000046")) IUnknown {
IUnknown() : m_count(0){};
CROSS_PLATFORM_UUIDOF(IUnknown, "00000000-0000-0000-C000-000000000046")
struct IUnknown {
IUnknown() : m_count(0) {};
virtual HRESULT QueryInterface(REFIID riid, void **ppvObject) = 0;
virtual ULONG AddRef();
virtual ULONG Release();
Expand All @@ -602,33 +631,27 @@ struct __declspec(uuid("00000000-0000-0000-C000-000000000046")) IUnknown {

private:
std::atomic<unsigned long> m_count;

DECLARE_CROSS_PLATFORM_UUIDOF(IUnknown)
};

struct __declspec(uuid("ECC8691B-C1DB-4DC0-855E-65F6C551AF49")) INoMarshal
: public IUnknown {
DECLARE_CROSS_PLATFORM_UUIDOF(INoMarshal)
};
CROSS_PLATFORM_UUIDOF(INoMarshal, "ECC8691B-C1DB-4DC0-855E-65F6C551AF49")
struct INoMarshal : public IUnknown {};

struct __declspec(uuid("00000002-0000-0000-C000-000000000046")) IMalloc
: public IUnknown {
CROSS_PLATFORM_UUIDOF(IMalloc, "00000002-0000-0000-C000-000000000046")
struct IMalloc : public IUnknown {
virtual void *Alloc(size_t size);
virtual void *Realloc(void *ptr, size_t size);
virtual void Free(void *ptr);
virtual HRESULT QueryInterface(REFIID riid, void **ppvObject);
};

struct __declspec(uuid("0C733A30-2A1C-11CE-ADE5-00AA0044773D"))
ISequentialStream : public IUnknown {
CROSS_PLATFORM_UUIDOF(ISequentialStream, "0C733A30-2A1C-11CE-ADE5-00AA0044773D")
struct ISequentialStream : public IUnknown {
virtual HRESULT Read(void *pv, ULONG cb, ULONG *pcbRead) = 0;
virtual HRESULT Write(const void *pv, ULONG cb, ULONG *pcbWritten) = 0;

DECLARE_CROSS_PLATFORM_UUIDOF(ISequentialStream)
};

struct __declspec(uuid("0000000c-0000-0000-C000-000000000046")) IStream
: public ISequentialStream {
CROSS_PLATFORM_UUIDOF(IStream, "0000000c-0000-0000-C000-000000000046")
struct IStream : public ISequentialStream {
virtual HRESULT Seek(LARGE_INTEGER dlibMove, DWORD dwOrigin,
ULARGE_INTEGER *plibNewPosition) = 0;
virtual HRESULT SetSize(ULARGE_INTEGER libNewSize) = 0;
Expand All @@ -649,8 +672,6 @@ struct __declspec(uuid("0000000c-0000-0000-C000-000000000046")) IStream
virtual HRESULT Stat(STATSTG *pstatstg, DWORD grfStatFlag) = 0;

virtual HRESULT Clone(IStream **ppstm) = 0;

DECLARE_CROSS_PLATFORM_UUIDOF(IStream)
};

//===--------------------- COM Pointer Types ------------------------------===//
Expand Down
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