Add support for building clang on WASI.

Author: veluca93

clang/lib/Driver/Driver.cpp

@@ -1561,7 +1561,7 @@ bool Driver::getCrashDiagnosticFile(StringRef ReproCrashFilename,
     CrashDiagDir = "/";
   path::append(CrashDiagDir, "Library/Logs/DiagnosticReports");
   int PID =
-#if LLVM_ON_UNIX
+#if LLVM_ON_UNIX && !defined(__wasi__)
       getpid();
 #else
       0;

llvm/include/llvm/ADT/bit.h

@@ -24,12 +24,12 @@
 #endif
 
 #if defined(_MSC_VER) && !defined(_DEBUG)
-#include <cstdlib>  // for _byteswap_{ushort,ulong,uint64}
+#include <cstdlib> // for _byteswap_{ushort,ulong,uint64}
 #endif
 
 #if defined(__linux__) || defined(__GNU__) || defined(__HAIKU__) ||            \
     defined(__Fuchsia__) || defined(__EMSCRIPTEN__) || defined(__NetBSD__) ||  \
-    defined(__OpenBSD__) || defined(__DragonFly__)
+    defined(__OpenBSD__) || defined(__DragonFly__) || defined(__wasi__)
 #include <endian.h>
 #elif defined(_AIX)
 #include <sys/machine.h>

llvm/include/llvm/Support/Memory.h

@@ -41,7 +41,9 @@ namespace sys {
   private:
     void *Address;    ///< Address of first byte of memory area
     size_t AllocatedSize; ///< Size, in bytes of the memory area
+#ifndef __wasi__
     unsigned Flags = 0;
+#endif
     friend class Memory;
   };
 

llvm/lib/Support/CrashRecoveryContext.cpp

@@ -7,14 +7,17 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/CrashRecoveryContext.h"
+
 #include "llvm/Config/llvm-config.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/ExitCodes.h"
 #include "llvm/Support/Signals.h"
 #include "llvm/Support/thread.h"
 #include <cassert>
 #include <mutex>
+#ifndef __wasi__
 #include <setjmp.h>
+#endif
 
 using namespace llvm;
 
@@ -31,7 +34,9 @@ struct CrashRecoveryContextImpl {
   const CrashRecoveryContextImpl *Next;
 
   CrashRecoveryContext *CRC;
+#ifndef __wasi__
   ::jmp_buf JumpBuffer;
+#endif
   volatile unsigned Failed : 1;
   unsigned SwitchedThread : 1;
   unsigned ValidJumpBuffer : 1;
@@ -72,9 +77,11 @@ struct CrashRecoveryContextImpl {
 
     CRC->RetCode = RetCode;
 
+#ifndef __wasi__
     // Jump back to the RunSafely we were called under.
     if (ValidJumpBuffer)
       longjmp(JumpBuffer, 1);
+#endif
 
     // Otherwise let the caller decide of the outcome of the crash. Currently
     // this occurs when using SEH on Windows with MSVC or clang-cl.
@@ -118,7 +125,7 @@ CrashRecoveryContext::~CrashRecoveryContext() {
   }
   IsRecoveringFromCrash = PC;
 
-  CrashRecoveryContextImpl *CRCI = (CrashRecoveryContextImpl *) Impl;
+  CrashRecoveryContextImpl *CRCI = (CrashRecoveryContextImpl *)Impl;
   delete CRCI;
 }
 
@@ -154,8 +161,8 @@ void CrashRecoveryContext::Disable() {
   uninstallExceptionOrSignalHandlers();
 }
 
-void CrashRecoveryContext::registerCleanup(CrashRecoveryContextCleanup *cleanup)
-{
+void CrashRecoveryContext::registerCleanup(
+    CrashRecoveryContextCleanup *cleanup) {
   if (!cleanup)
     return;
   if (head)
@@ -164,16 +171,15 @@ void CrashRecoveryContext::registerCleanup(CrashRecoveryContextCleanup *cleanup)
   head = cleanup;
 }
 
-void
-CrashRecoveryContext::unregisterCleanup(CrashRecoveryContextCleanup *cleanup) {
+void CrashRecoveryContext::unregisterCleanup(
+    CrashRecoveryContextCleanup *cleanup) {
   if (!cleanup)
     return;
   if (cleanup == head) {
     head = cleanup->next;
     if (head)
       head->prev = nullptr;
-  }
-  else {
+  } else {
     cleanup->prev->next = cleanup->next;
     if (cleanup->next)
       cleanup->next->prev = cleanup->prev;
@@ -263,16 +269,14 @@ bool CrashRecoveryContext::RunSafely(function_ref<void()> Fn) {
 
 #include "llvm/Support/Windows/WindowsSupport.h"
 
-static LONG CALLBACK ExceptionHandler(PEXCEPTION_POINTERS ExceptionInfo)
-{
+static LONG CALLBACK ExceptionHandler(PEXCEPTION_POINTERS ExceptionInfo) {
   // DBG_PRINTEXCEPTION_WIDE_C is not properly defined on all supported
   // compilers and platforms, so we define it manually.
   constexpr ULONG DbgPrintExceptionWideC = 0x4001000AL;
-  switch (ExceptionInfo->ExceptionRecord->ExceptionCode)
-  {
+  switch (ExceptionInfo->ExceptionRecord->ExceptionCode) {
   case DBG_PRINTEXCEPTION_C:
   case DbgPrintExceptionWideC:
-  case 0x406D1388:  // set debugger thread name
+  case 0x406D1388: // set debugger thread name
     return EXCEPTION_CONTINUE_EXECUTION;
   }
 
@@ -307,7 +311,7 @@ static LONG CALLBACK ExceptionHandler(PEXCEPTION_POINTERS ExceptionInfo)
 // CrashRecoveryContext at all.  So we make use of a thread-local
 // exception table.  The handles contained in here will either be
 // non-NULL, valid VEH handles, or NULL.
-static LLVM_THREAD_LOCAL const void* sCurrentExceptionHandle;
+static LLVM_THREAD_LOCAL const void *sCurrentExceptionHandle;
 
 static void installExceptionOrSignalHandlers() {
   // We can set up vectored exception handling now.  We will install our
@@ -342,10 +346,11 @@ static void uninstallExceptionOrSignalHandlers() {
 // reliable fashion -- if we get a signal outside of a crash recovery context we
 // simply disable crash recovery and raise the signal again.
 
+#ifndef __wasi__
 #include <signal.h>
 
-static const int Signals[] =
-    { SIGABRT, SIGBUS, SIGFPE, SIGILL, SIGSEGV, SIGTRAP };
+static const int Signals[] = {SIGABRT, SIGBUS,  SIGFPE,
+                              SIGILL,  SIGSEGV, SIGTRAP};
 static const unsigned NumSignals = std::size(Signals);
 static struct sigaction PrevActions[NumSignals];
 
@@ -389,8 +394,10 @@ static void CrashRecoverySignalHandler(int Signal) {
   if (CRCI)
     const_cast<CrashRecoveryContextImpl *>(CRCI)->HandleCrash(RetCode, Signal);
 }
+#endif
 
 static void installExceptionOrSignalHandlers() {
+#ifndef __wasi__
   // Setup the signal handler.
   struct sigaction Handler;
   Handler.sa_handler = CrashRecoverySignalHandler;
@@ -400,12 +407,15 @@ static void installExceptionOrSignalHandlers() {
   for (unsigned i = 0; i != NumSignals; ++i) {
     sigaction(Signals[i], &Handler, &PrevActions[i]);
   }
+#endif
 }
 
 static void uninstallExceptionOrSignalHandlers() {
+#ifndef __wasi__
   // Restore the previous signal handlers.
   for (unsigned i = 0; i != NumSignals; ++i)
     sigaction(Signals[i], &PrevActions[i], nullptr);
+#endif
 }
 
 #endif // !_WIN32
@@ -418,9 +428,11 @@ bool CrashRecoveryContext::RunSafely(function_ref<void()> Fn) {
     Impl = CRCI;
 
     CRCI->ValidJumpBuffer = true;
+#ifndef __wasi__
     if (setjmp(CRCI->JumpBuffer) != 0) {
       return false;
     }
+#endif
   }
 
   Fn();
@@ -469,7 +481,7 @@ bool CrashRecoveryContext::throwIfCrash(int RetCode) {
     return false;
 #if defined(_WIN32)
   ::RaiseException(RetCode, 0, 0, NULL);
-#else
+#elif !defined(__wasi__)
   llvm::sys::unregisterHandlers();
   raise(RetCode - 128);
 #endif
@@ -502,7 +514,7 @@ struct RunSafelyOnThreadInfo {
 
 static void RunSafelyOnThread_Dispatch(void *UserData) {
   RunSafelyOnThreadInfo *Info =
-    reinterpret_cast<RunSafelyOnThreadInfo*>(UserData);
+      reinterpret_cast<RunSafelyOnThreadInfo *>(UserData);
 
   if (Info->UseBackgroundPriority)
     setThreadBackgroundPriority();
@@ -512,7 +524,7 @@ static void RunSafelyOnThread_Dispatch(void *UserData) {
 bool CrashRecoveryContext::RunSafelyOnThread(function_ref<void()> Fn,
                                              unsigned RequestedStackSize) {
   bool UseBackgroundPriority = hasThreadBackgroundPriority();
-  RunSafelyOnThreadInfo Info = { Fn, this, UseBackgroundPriority, false };
+  RunSafelyOnThreadInfo Info = {Fn, this, UseBackgroundPriority, false};
   llvm::thread Thread(RequestedStackSize == 0
                           ? std::nullopt
                           : std::optional<unsigned>(RequestedStackSize),

llvm/lib/Support/LockFileManager.cpp

@@ -34,7 +34,9 @@
 #include <unistd.h>
 #endif
 
-#if defined(__APPLE__) && defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && (__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ > 1050)
+#if defined(__APPLE__) &&                                                      \
+    defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) &&                  \
+    (__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ > 1050)
 #define USE_OSX_GETHOSTUUID 1
 #else
 #define USE_OSX_GETHOSTUUID 0
@@ -94,7 +96,7 @@ static std::error_code getHostID(SmallVectorImpl<char> &HostID) {
   StringRef UUIDRef(UUIDStr);
   HostID.append(UUIDRef.begin(), UUIDRef.end());
 
-#elif LLVM_ON_UNIX
+#elif LLVM_ON_UNIX && !defined(__wasi__)
   char HostName[256];
   HostName[255] = 0;
   HostName[0] = 0;
@@ -116,9 +118,11 @@ bool LockFileManager::processStillExecuting(StringRef HostID, int PID) {
   if (getHostID(StoredHostID))
     return true; // Conservatively assume it's executing on error.
 
-  // Check whether the process is dead. If so, we're done.
+    // Check whether the process is dead. If so, we're done.
+#ifndef __wasi__ // no other processes anyway
   if (StoredHostID == HostID && getsid(PID) == -1 && errno == ESRCH)
     return false;
+#endif
 #endif
 
   return true;
@@ -136,9 +140,10 @@ namespace {
 class RemoveUniqueLockFileOnSignal {
   StringRef Filename;
   bool RemoveImmediately;
+
 public:
   RemoveUniqueLockFileOnSignal(StringRef Name)
-  : Filename(Name), RemoveImmediately(true) {
+      : Filename(Name), RemoveImmediately(true) {
     sys::RemoveFileOnSignal(Filename, nullptr);
   }
 
@@ -157,8 +162,7 @@ class RemoveUniqueLockFileOnSignal {
 
 } // end anonymous namespace
 
-LockFileManager::LockFileManager(StringRef FileName)
-{
+LockFileManager::LockFileManager(StringRef FileName) {
   this->FileName = FileName;
   if (std::error_code EC = sys::fs::make_absolute(this->FileName)) {
     std::string S("failed to obtain absolute path for ");
@@ -217,8 +221,7 @@ LockFileManager::LockFileManager(StringRef FileName)
 
   while (true) {
     // Create a link from the lock file name. If this succeeds, we're done.
-    std::error_code EC =
-        sys::fs::create_link(UniqueLockFileName, LockFileName);
+    std::error_code EC = sys::fs::create_link(UniqueLockFileName, LockFileName);
     if (!EC) {
       RemoveUniqueFile.lockAcquired();
       return;

llvm/lib/Support/Unix/Memory.inc

@@ -36,6 +36,7 @@ extern "C" void sys_icache_invalidate(const void *Addr, size_t len);
 extern "C" void __clear_cache(void *, void *);
 #endif
 
+#ifndef __wasi__
 static int getPosixProtectionFlags(unsigned Flags) {
   switch (Flags & llvm::sys::Memory::MF_RWE_MASK) {
   case llvm::sys::Memory::MF_READ:
@@ -66,6 +67,7 @@ static int getPosixProtectionFlags(unsigned Flags) {
   // Provide a default return value as required by some compilers.
   return PROT_NONE;
 }
+#endif
 
 namespace llvm {
 namespace sys {
@@ -77,6 +79,17 @@ MemoryBlock Memory::allocateMappedMemory(size_t NumBytes,
   if (NumBytes == 0)
     return MemoryBlock();
 
+#ifdef __wasi__
+  MemoryBlock Result;
+  Result.Address = malloc(NumBytes);
+  if (!Result.Address) {
+    EC = errnoAsErrorCode();
+    Result.AllocatedSize = 0;
+  } else {
+    Result.AllocatedSize = NumBytes;
+  }
+  return Result;
+#else
   // On platforms that have it, we can use MAP_ANON to get a memory-mapped
   // page without file backing, but we need a fallback of opening /dev/zero
   // for strictly POSIX platforms instead.
@@ -146,14 +159,19 @@ MemoryBlock Memory::allocateMappedMemory(size_t NumBytes,
   }
 
   return Result;
+#endif
 }
 
 std::error_code Memory::releaseMappedMemory(MemoryBlock &M) {
+#ifdef __wasi__
+  free(M.Address);
+#else
   if (M.Address == nullptr || M.AllocatedSize == 0)
     return std::error_code();
 
   if (0 != ::munmap(M.Address, M.AllocatedSize))
     return errnoAsErrorCode();
+#endif
 
   M.Address = nullptr;
   M.AllocatedSize = 0;
@@ -163,6 +181,7 @@ std::error_code Memory::releaseMappedMemory(MemoryBlock &M) {
 
 std::error_code Memory::protectMappedMemory(const MemoryBlock &M,
                                             unsigned Flags) {
+#ifndef __wasi__
   static const Align PageSize = Align(Process::getPageSizeEstimate());
   if (M.Address == nullptr || M.AllocatedSize == 0)
     return std::error_code();
@@ -200,6 +219,7 @@ std::error_code Memory::protectMappedMemory(const MemoryBlock &M,
 
   if (InvalidateCache)
     Memory::InvalidateInstructionCache(M.Address, M.AllocatedSize);
+#endif
 
   return std::error_code();
 }