dotnet · radekdoulik · Mar 4, 2025 · Jan 21, 2025 · Jan 24, 2025 · Jan 27, 2025
diff --git a/eng/Subsets.props b/eng/Subsets.props
@@ -207,6 +207,7 @@
     <!-- Mono -->
     <SubsetName Include="Mono" Description="The Mono runtime and CoreLib. Equivalent to: $(DefaultMonoSubsets)" />
     <SubsetName Include="Mono.Runtime" Description="The Mono .NET runtime." />
+    <SubsetName Include="Mono.EmSDK" Description="The emsdk provisioning." />
     <SubsetName Include="Mono.AotCross" Description="The cross-compiler runtime for Mono AOT." />
     <SubsetName Include="Mono.CoreLib" Description="The managed System.Private.CoreLib library for Mono." />
     <SubsetName Include="Mono.Manifests" Description="The NuGet packages with manifests defining the mobile and Blazor workloads." />
@@ -264,6 +265,11 @@
     </ProjectToBuild>
   </ItemDefinitionGroup>
 
+  <!-- emscripten provisioning, needs to be placed before runtime projects -->
+  <ItemGroup Condition="$(_subset.Contains('+mono.emsdk+'))">
+    <ProjectToBuild Include="$(MonoProjectRoot)mono.proj" AdditionalProperties="%(AdditionalProperties);ProvisionEmscriptenOnly=true" Category="mono" />
+  </ItemGroup>
+
   <!-- CoreClr sets -->
   <ItemGroup Condition="$(_subset.Contains('+clr.corelib+'))">
     <ProjectToBuild Include="$(CoreClrProjectRoot)System.Private.CoreLib\System.Private.CoreLib.csproj" Category="clr" />
@@ -325,7 +331,7 @@
     The cross tools are used as part of the build process with the downloaded build tools, so we need to build them for the host architecture and build them as unsanitized binaries.
     -->
   <PropertyGroup>
-    <_BuildAnyCrossArch Condition="'$(CrossBuild)' == 'true' or '$(BuildArchitecture)' != '$(TargetArchitecture)' or '$(HostOS)' != '$(TargetOS)' or '$(EnableNativeSanitizers)' != ''">true</_BuildAnyCrossArch>
+    <_BuildAnyCrossArch Condition="('$(CrossBuild)' == 'true' or '$(BuildArchitecture)' != '$(TargetArchitecture)' or '$(HostOS)' != '$(TargetOS)' or '$(EnableNativeSanitizers)' != '') and '$(TargetArchitecture)' != 'wasm'">true</_BuildAnyCrossArch>
     <_BuildCrossComponents Condition="$(_subset.Contains('+clr.crossarchtools+'))">true</_BuildCrossComponents>
     <_BuildCrossComponents Condition="'$(ClrRuntimeBuildSubsets)' != '' and ('$(PrimaryRuntimeFlavor)' == 'CoreCLR' or '$(TargetsMobile)' == 'true')">true</_BuildCrossComponents>
     <_CrossBitwidthBuild Condition="'$(BuildArchitecture)' == 'x64' and ('$(TargetArchitecture)' == 'x86' or '$(TargetArchitecture)' == 'arm')">true</_CrossBitwidthBuild>

diff --git a/eng/pipelines/runtime.yml b/eng/pipelines/runtime.yml
@@ -117,6 +117,21 @@ extends:
                 eq(stageDependencies.EvaluatePaths.evaluate_paths.outputs['SetPathVars_non_mono_and_wasm.containsChange'], true),
                 eq(variables['isRollingBuild'], true))
 
+      - template: /eng/pipelines/common/platform-matrix.yml
+        parameters:
+          jobTemplate: /eng/pipelines/common/global-build-job.yml
+          buildConfig: ${{ variables.debugOnPrReleaseOnRolling }}
+          platforms:
+          - browser_wasm
+          jobParameters:
+            nameSuffix: AllSubsets_CoreCLR
+            buildArgs: -s mono.emsdk+clr.paltests -rc Release -c Release -lc $(_BuildConfig)
+            timeoutInMinutes: 120
+            condition: >-
+              or(
+                eq(stageDependencies.EvaluatePaths.evaluate_paths.outputs['SetPathVars_non_mono_and_wasm.containsChange'], true),
+                eq(variables['isRollingBuild'], true))
+
       #
       # Build CoreCLR and Libraries with Libraries tests
       # For running libraries tests and installer tests

diff --git a/src/coreclr/CMakeLists.txt b/src/coreclr/CMakeLists.txt
@@ -29,7 +29,7 @@ if(CORECLR_SET_RPATH)
     set(MACOSX_RPATH ON)
 endif(CORECLR_SET_RPATH)
 
-if(CLR_CMAKE_HOST_MACCATALYST OR CLR_CMAKE_HOST_IOS OR CLR_CMAKE_HOST_TVOS)
+if(CLR_CMAKE_HOST_MACCATALYST OR CLR_CMAKE_HOST_IOS OR CLR_CMAKE_HOST_TVOS OR CLR_CMAKE_HOST_BROWSER)
   set(FEATURE_STANDALONE_GC 0)
 endif()
 
@@ -148,8 +148,9 @@ endif()
 include_directories("pal/prebuilt/inc")
 include_directories(${CLR_ARTIFACTS_OBJ_DIR})
 
-add_subdirectory(tools/aot/jitinterface)
-
+if (NOT CLR_CMAKE_TARGET_BROWSER)
+  add_subdirectory(tools/aot/jitinterface)
+endif (NOT CLR_CMAKE_TARGET_BROWSER)
 
 if(NOT CLR_CROSS_COMPONENTS_BUILD)
   # NativeAOT only buildable for a subset of CoreCLR-supported configurations
@@ -262,7 +263,7 @@ if(CLR_CMAKE_HOST_UNIX)
   add_subdirectory(nativeresources)
 endif(CLR_CMAKE_HOST_UNIX)
 
-if(NOT CLR_CMAKE_HOST_TVOS)
+if(NOT CLR_CMAKE_HOST_TVOS AND NOT CLR_CMAKE_HOST_BROWSER)
   add_subdirectory(utilcode)
   add_subdirectory(inc)
 
@@ -280,7 +281,7 @@ if(NOT CLR_CMAKE_HOST_TVOS)
   add_subdirectory(dlls)
   add_subdirectory(unwinder)
   add_subdirectory(interop)
-endif()
+endif(NOT CLR_CMAKE_HOST_TVOS AND NOT CLR_CMAKE_HOST_BROWSER)
 
 if(NOT CLR_CMAKE_HOST_MACCATALYST AND NOT CLR_CMAKE_HOST_IOS AND NOT CLR_CMAKE_HOST_TVOS)
   add_subdirectory(tools)

diff --git a/src/coreclr/clrfeatures.cmake b/src/coreclr/clrfeatures.cmake
@@ -3,8 +3,10 @@ if(CLR_CMAKE_TARGET_TIZEN_LINUX)
 endif()
 
 if(NOT DEFINED FEATURE_EVENT_TRACE)
-  # To actually disable FEATURE_EVENT_TRACE, also change clr.featuredefines.props
-  set(FEATURE_EVENT_TRACE 1)
+  if (NOT CLR_CMAKE_TARGET_BROWSER)
+    # To actually disable FEATURE_EVENT_TRACE, also change clr.featuredefines.props
+    set(FEATURE_EVENT_TRACE 1)
+  endif()
 endif(NOT DEFINED FEATURE_EVENT_TRACE)
 
 if(NOT DEFINED FEATURE_PERFTRACING AND FEATURE_EVENT_TRACE)

diff --git a/src/coreclr/inc/volatile.h b/src/coreclr/inc/volatile.h
@@ -68,7 +68,7 @@
 #error The Volatile type is currently only defined for Visual C++ and GNU C++
 #endif
 
-#if defined(__GNUC__) && !defined(HOST_X86) && !defined(HOST_AMD64) && !defined(HOST_ARM) && !defined(HOST_ARM64) && !defined(HOST_LOONGARCH64) && !defined(HOST_RISCV64) && !defined(HOST_S390X) && !defined(HOST_POWERPC64)
+#if defined(__GNUC__) && !defined(HOST_X86) && !defined(HOST_AMD64) && !defined(HOST_ARM) && !defined(HOST_ARM64) && !defined(HOST_LOONGARCH64) && !defined(HOST_RISCV64) && !defined(HOST_S390X) && !defined(HOST_POWERPC64) && !defined(HOST_WASM)
 #error The Volatile type is currently only defined for GCC when targeting x86, AMD64, ARM, ARM64, LOONGARCH64, RISCV64, PPC64LE, or S390X CPUs
 #endif
 

@@ -28,7 +28,13 @@ else()
     add_custom_target(interpreter_exports DEPENDS ${EXPORTS_FILE})
 endif()
 
-add_library_clr(clrinterpreter SHARED ${INTERPRETER_SOURCES})
+if(CLR_CMAKE_TARGET_BROWSER)
+  set(LIBRARY_TYPE STATIC)
+else()
+  set(LIBRARY_TYPE SHARED)
+endif()
+
+add_library_clr(clrinterpreter ${LIBRARY_TYPE} ${INTERPRETER_SOURCES})
 
 add_dependencies(clrinterpreter interpreter_exports)
 

diff --git a/src/coreclr/jit/CMakeLists.txt b/src/coreclr/jit/CMakeLists.txt
@@ -495,6 +495,9 @@ elseif(CLR_CMAKE_TARGET_ARCH_LOONGARCH64)
 elseif(CLR_CMAKE_TARGET_ARCH_RISCV64)
   set(JIT_ARCH_SOURCES ${JIT_RISCV64_SOURCES})
   set(JIT_ARCH_HEADERS ${JIT_RISCV64_HEADERS})
+elseif(CLR_CMAKE_TARGET_ARCH_WASM)
+  set(JIT_ARCH_SOURCES ${JIT_WASM32_SOURCES})
+  set(JIT_ARCH_HEADERS ${JIT_WASM32_HEADERS})
 else()
   clr_unknown_arch()
 endif()

diff --git a/src/coreclr/pal/CMakeLists.txt b/src/coreclr/pal/CMakeLists.txt
@@ -6,7 +6,12 @@ include_directories(${COREPAL_SOURCE_DIR}/inc)
 include_directories(${COREPAL_SOURCE_DIR}/src)
 include_directories(${COREPAL_SOURCE_DIR}/../inc)
 
-add_compile_options(-fexceptions)
+if (NOT CLR_CMAKE_TARGET_BROWSER)
+    add_compile_options(-fexceptions)
+else()
+    add_compile_options(-fwasm-exceptions)
+    add_link_options(-fwasm-exceptions -sEXIT_RUNTIME=1)
+endif()
 
 add_subdirectory(src)
 add_subdirectory(tests)
diff --git a/src/coreclr/pal/inc/pal.h b/src/coreclr/pal/inc/pal.h
@@ -2469,6 +2469,26 @@ typedef struct _KNONVOLATILE_CONTEXT_POINTERS {
     //
 
 } KNONVOLATILE_CONTEXT_POINTERS, *PKNONVOLATILE_CONTEXT_POINTERS;
+#elif defined(HOST_WASM)
+#define CONTEXT_CONTROL 0
+#define CONTEXT_INTEGER 0
+#define CONTEXT_FLOATING_POINT 0
+#define CONTEXT_FULL 0
+
+#define CONTEXT_XSTATE 0
+
+#define CONTEXT_EXCEPTION_ACTIVE 0x8000000L
+#define CONTEXT_SERVICE_ACTIVE 0x10000000L
+#define CONTEXT_EXCEPTION_REQUEST 0x40000000L
+#define CONTEXT_EXCEPTION_REPORTING 0x80000000L
+
+typedef struct _CONTEXT {
+    ULONG ContextFlags;
+} CONTEXT, *PCONTEXT, *LPCONTEXT;
+
+typedef struct _KNONVOLATILE_CONTEXT_POINTERS {
+    DWORD none;
+} KNONVOLATILE_CONTEXT_POINTERS, *PKNONVOLATILE_CONTEXT_POINTERS;
 
 #else
 #error Unknown architecture for defining CONTEXT.
@@ -2600,6 +2620,8 @@ PALIMPORT BOOL PALAPI PAL_GetUnwindInfoSize(SIZE_T baseAddress, ULONG64 ehFrameH
 #define PAL_CS_NATIVE_DATA_SIZE 96
 #elif defined(__HAIKU__) && defined(__x86_64__)
 #define PAL_CS_NATIVE_DATA_SIZE 56
+#elif defined(HOST_WASM)
+#define PAL_CS_NATIVE_DATA_SIZE 76
 #else
 #error  PAL_CS_NATIVE_DATA_SIZE is not defined for this architecture
 #endif

diff --git a/src/coreclr/pal/inc/rt/palrt.h b/src/coreclr/pal/inc/rt/palrt.h
@@ -1003,6 +1003,14 @@ typedef struct _DISPATCHER_CONTEXT {
     DWORD Reserved;
 } DISPATCHER_CONTEXT, *PDISPATCHER_CONTEXT;
 
+#elif defined(HOST_WASM)
+
+typedef struct _DISPATCHER_CONTEXT {
+    // WASM does not build the VM or JIT at this point,
+    // so we only provide a dummy definition.
+    DWORD Reserved;
+} DISPATCHER_CONTEXT, *PDISPATCHER_CONTEXT;
+
 #else
 
 #error Unknown architecture for defining DISPATCHER_CONTEXT.

diff --git a/src/coreclr/pal/src/CMakeLists.txt b/src/coreclr/pal/src/CMakeLists.txt
@@ -10,7 +10,7 @@ elseif (CLR_CMAKE_TARGET_FREEBSD)
   include_directories(SYSTEM $ENV{ROOTFS_DIR}/usr/local/include)
 endif()
 
-if(NOT CLR_CMAKE_USE_SYSTEM_LIBUNWIND)
+if(NOT CLR_CMAKE_USE_SYSTEM_LIBUNWIND AND NOT CLR_CMAKE_TARGET_ARCH_WASM)
   include_directories(${CLR_SRC_NATIVE_DIR}/external/libunwind/include)
   include_directories(${CLR_SRC_NATIVE_DIR}/external/libunwind/include/tdep)
   include_directories(${CLR_ARTIFACTS_OBJ_DIR}/external/libunwind/include)
@@ -21,7 +21,7 @@ elseif(NOT CLR_CMAKE_TARGET_APPLE)
   find_unwind_libs(UNWIND_LIBS)
 else()
   add_subdirectory(${CLR_SRC_NATIVE_DIR}/external/libunwind_extras ${CLR_ARTIFACTS_OBJ_DIR}/external/libunwind)
-endif(NOT CLR_CMAKE_USE_SYSTEM_LIBUNWIND)
+endif(NOT CLR_CMAKE_USE_SYSTEM_LIBUNWIND AND NOT CLR_CMAKE_TARGET_ARCH_WASM)
 
 include(configure.cmake)
 
@@ -59,6 +59,8 @@ elseif(CLR_CMAKE_HOST_ARCH_S390X)
   set(PAL_ARCH_SOURCES_DIR s390x)
 elseif(CLR_CMAKE_HOST_ARCH_POWERPC64)
   set(PAL_ARCH_SOURCES_DIR ppc64le)
+elseif(CLR_CMAKE_HOST_ARCH_WASM)
+  set(PAL_ARCH_SOURCES_DIR wasm)
 endif()
 
 if(CLR_CMAKE_USE_SYSTEM_LIBUNWIND)
@@ -113,18 +115,26 @@ endif(CLR_CMAKE_TARGET_HAIKU)
 # turn off capability to remove unused functions (which was enabled in debug build with sanitizers)
 set(CMAKE_SHARED_LINKER_FLAGS_DEBUG "${CMAKE_SHARED_LINKER_FLAGS_DEBUG} -Wl,--no-gc-sections")
 
-set(ARCH_SOURCES
-  arch/${PAL_ARCH_SOURCES_DIR}/context2.S
-  arch/${PAL_ARCH_SOURCES_DIR}/debugbreak.S
-  arch/${PAL_ARCH_SOURCES_DIR}/exceptionhelper.S
-)
+if (NOT CLR_CMAKE_TARGET_ARCH_WASM)
+  set(ARCH_SOURCES
+    arch/${PAL_ARCH_SOURCES_DIR}/context2.S
+    arch/${PAL_ARCH_SOURCES_DIR}/debugbreak.S
+    arch/${PAL_ARCH_SOURCES_DIR}/exceptionhelper.S
+  )
+endif()
+
+if (CLR_CMAKE_TARGET_ARCH_WASM)
+  set(PLATFORM_SOURCES
+  arch/${PAL_ARCH_SOURCES_DIR}/stubs.cpp
+  )
+endif()
 
-if(NOT CLR_CMAKE_TARGET_APPLE)
+if(NOT CLR_CMAKE_TARGET_APPLE AND NOT CLR_CMAKE_TARGET_ARCH_WASM)
   list(APPEND PLATFORM_SOURCES
     arch/${PAL_ARCH_SOURCES_DIR}/callsignalhandlerwrapper.S
     arch/${PAL_ARCH_SOURCES_DIR}/signalhandlerhelper.cpp
   )
-endif(NOT CLR_CMAKE_TARGET_APPLE)
+endif(NOT CLR_CMAKE_TARGET_APPLE AND NOT CLR_CMAKE_TARGET_ARCH_WASM)
 
 if(CLR_CMAKE_HOST_ARCH_ARM)
   if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
@@ -210,9 +220,9 @@ set_source_files_properties(
     INCLUDE_DIRECTORIES ${CMAKE_CURRENT_SOURCE_DIR}/../inc/rt
 )
 
-if(NOT CLR_CMAKE_USE_SYSTEM_LIBUNWIND)
+if(NOT CLR_CMAKE_USE_SYSTEM_LIBUNWIND AND NOT CLR_CMAKE_TARGET_ARCH_WASM)
   set(LIBUNWIND_OBJECTS $<TARGET_OBJECTS:libunwind>)
-endif(NOT CLR_CMAKE_USE_SYSTEM_LIBUNWIND)
+endif(NOT CLR_CMAKE_USE_SYSTEM_LIBUNWIND AND NOT CLR_CMAKE_TARGET_ARCH_WASM)
 
 add_library(coreclrpal
   STATIC

diff --git a/src/coreclr/pal/src/arch/wasm/stubs.cpp b/src/coreclr/pal/src/arch/wasm/stubs.cpp
@@ -0,0 +1,73 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+#include "pal/dbgmsg.h"
+#include "pal/signal.hpp"
+
+SET_DEFAULT_DEBUG_CHANNEL(EXCEPT); // some headers have code with asserts, so do this first
+
+/* debugbreak */
+
+extern "C" void
+DBG_DebugBreak()
+{
+    asm volatile ("unreachable");
+}
+
+/* context */
+
+extern "C" void
+RtlCaptureContext(OUT PCONTEXT ContextRecord)
+{
+    _ASSERT("RtlCaptureContext not implemented on wasm");
+}
+
+extern "C" void
+CONTEXT_CaptureContext(LPCONTEXT lpContext)
+{
+    _ASSERT("CONTEXT_CaptureContext not implemented on wasm");
+}
+
+extern "C" void ThrowExceptionFromContextInternal(CONTEXT* context, PAL_SEHException* ex)
+{
+    _ASSERT("ThrowExceptionFromContextInternal not implemented on wasm");
+}
+
+/* unwind */
+
+void ExecuteHandlerOnCustomStack(int code, siginfo_t *siginfo, void *context, size_t sp, SignalHandlerWorkerReturnPoint* returnPoint)
+{
+    _ASSERT("ExecuteHandlerOnCustomStack not implemented on wasm");
+}
+
+extern "C" int unw_getcontext(int)
+{
+    _ASSERT("unw_getcontext not implemented on wasm");
+    return 0;
+}
+
+extern "C" int unw_init_local(int, int)
+{
+    _ASSERT("unw_init_local not implemented on wasm");
+    return 0;
+}
+
+extern "C" int unw_step(int)
+{
+    _ASSERT("unw_step not implemented on wasm");
+    return 0;
+}
+
+extern "C" int unw_is_signal_frame(int)
+{
+    _ASSERT("unw_is_signal_frame not implemented on wasm");
+    return 0;
+}
+
+/* threading */
+
+extern "C" int pthread_setschedparam(pthread_t, int, const struct sched_param *)
+{
+    _ASSERT("pthread_setschedparam not implemented on wasm");
+    return 0;
+}
diff --git a/src/coreclr/pal/src/configure.cmake b/src/coreclr/pal/src/configure.cmake
@@ -937,6 +937,9 @@ elseif(CLR_CMAKE_TARGET_HAIKU)
   # Haiku does not have ptrace.
   set(DEADLOCK_WHEN_THREAD_IS_SUSPENDED_WHILE_BLOCKED_ON_MUTEX 0)
   set(HAVE_SCHED_OTHER_ASSIGNABLE 1)
+elseif(CLR_CMAKE_TARGET_BROWSER)
+  set(DEADLOCK_WHEN_THREAD_IS_SUSPENDED_WHILE_BLOCKED_ON_MUTEX 0)
+  set(HAVE_SCHED_OTHER_ASSIGNABLE 0)
 else() # Anything else is Linux
   # LTTNG is not available on Android, so don't error out
   if(NOT HAVE_LTTNG_TRACEPOINT_H AND NOT CLR_CMAKE_TARGET_ANDROID AND FEATURE_EVENT_TRACE)

diff --git a/src/coreclr/pal/src/debug/debug.cpp b/src/coreclr/pal/src/debug/debug.cpp
@@ -111,6 +111,9 @@ This is a no-op for x86 architectures where the instruction and data
 caches are coherent in hardware. For non-X86 architectures, this call
 usually maps to a kernel API to flush the D-caches on all processors.
 
+It is also no-op on wasm. We don't have a way to flush the instruction
+cache and it is also not needed.
+
 --*/
 BOOL
 PALAPI
@@ -422,7 +425,12 @@ DebugBreak(
 BOOL
 IsInDebugBreak(void *addr)
 {
+#if defined (__wasm__)
+    _ASSERT("IsInDebugBreak not implemented on wasm");
+    return false;
+#else
     return (addr >= (void *)DBG_DebugBreak) && (addr <= (void *)DBG_DebugBreak_End);
+#endif
 }
 
 /*++

diff --git a/src/coreclr/pal/src/exception/seh-unwind.cpp b/src/coreclr/pal/src/exception/seh-unwind.cpp
@@ -497,6 +497,8 @@ void UnwindContextToWinContext(unw_cursor_t *cursor, CONTEXT *winContext)
     unw_get_reg(cursor, UNW_PPC64_R28, (unw_word_t *) &winContext->R28);
     unw_get_reg(cursor, UNW_PPC64_R29, (unw_word_t *) &winContext->R29);
     unw_get_reg(cursor, UNW_PPC64_R30, (unw_word_t *) &winContext->R30);
+#elif defined(HOST_WASM)
+    ASSERT("UnwindContextToWinContext not implemented for WASM");
 #else
 #error unsupported architecture
 #endif
@@ -631,6 +633,8 @@ void GetContextPointers(unw_cursor_t *cursor, unw_context_t *unwContext, KNONVOL
     GetContextPointer(cursor, unwContext, UNW_PPC64_R29, (SIZE_T **)&contextPointers->R29);
     GetContextPointer(cursor, unwContext, UNW_PPC64_R30, (SIZE_T **)&contextPointers->R30);
     GetContextPointer(cursor, unwContext, UNW_PPC64_R31, (SIZE_T **)&contextPointers->R31);
+#elif defined(HOST_WASM)
+    ASSERT("GetContextPointers not implemented for WASM");
 #else
 #error unsupported architecture
 #endif