[WIP] Add exception handling support.

Author: whitequark

.gitmodules

@@ -1,6 +1,6 @@
 [submodule "src/llvm-project"]
 	path = src/llvm-project
-	url = https://github.com/llvm/llvm-project
+	url = https://github.com/whitequark/llvm-project
 [submodule "src/wasi-libc"]
 	path = src/wasi-libc
 	url = https://github.com/CraneStation/wasi-libc

Makefile

@@ -131,7 +131,7 @@ build/compiler-rt.BUILT: build/llvm.BUILT build/wasi-libc.BUILT
 		-DCOMPILER_RT_ENABLE_IOS=OFF \
 		-DCOMPILER_RT_DEFAULT_TARGET_ONLY=On \
 		-DWASI_SDK_PREFIX=$(BUILD_PREFIX) \
-		-DCMAKE_C_FLAGS="$(DEBUG_PREFIX_MAP)" \
+		-DCMAKE_C_FLAGS="$(DEBUG_PREFIX_MAP) -fwasm-exceptions" \
 		-DLLVM_CONFIG_PATH=$(ROOT_DIR)/build/llvm/bin/llvm-config \
 		-DCOMPILER_RT_OS_DIR=wasi \
 		-DCMAKE_INSTALL_PREFIX=$(PREFIX)/lib/clang/$(CLANG_VERSION)/ \
@@ -162,13 +162,13 @@ LIBCXX_CMAKE_FLAGS = \
     -DCMAKE_BUILD_TYPE=RelWithDebugInfo \
     -DLIBCXX_ENABLE_SHARED:BOOL=OFF \
     -DLIBCXX_ENABLE_EXPERIMENTAL_LIBRARY:BOOL=OFF \
-    -DLIBCXX_ENABLE_EXCEPTIONS:BOOL=OFF \
+    -DLIBCXX_ENABLE_EXCEPTIONS:BOOL=ON \
     -DLIBCXX_ENABLE_FILESYSTEM:BOOL=OFF \
     -DLIBCXX_CXX_ABI=libcxxabi \
     -DLIBCXX_CXX_ABI_INCLUDE_PATHS=$(LLVM_PROJ_DIR)/libcxxabi/include \
     -DLIBCXX_HAS_MUSL_LIBC:BOOL=ON \
     -DLIBCXX_ABI_VERSION=2 \
-    -DLIBCXXABI_ENABLE_EXCEPTIONS:BOOL=OFF \
+    -DLIBCXXABI_ENABLE_EXCEPTIONS:BOOL=ON \
     -DLIBCXXABI_ENABLE_SHARED:BOOL=OFF \
     -DLIBCXXABI_SILENT_TERMINATE:BOOL=ON \
     -DLIBCXXABI_ENABLE_THREADS:BOOL=OFF \
@@ -177,6 +177,10 @@ LIBCXX_CMAKE_FLAGS = \
     -DLIBCXXABI_BUILD_EXTERNAL_THREAD_LIBRARY:BOOL=OFF \
     -DLIBCXXABI_HAS_WIN32_THREAD_API:BOOL=OFF \
     -DLIBCXXABI_ENABLE_PIC:BOOL=OFF \
+    -DLIBUNWIND_ENABLE_ASSERTIONS:BOOL=OFF \
+    -DLIBUNWIND_ENABLE_SHARED:BOOL=OFF \
+    -DLIBUNWIND_ENABLE_THREADS:BOOL=OFF \
+    -DLIBUNWIND_USE_COMPILER_RT:BOOL=ON \
     -DWASI_SDK_PREFIX=$(BUILD_PREFIX) \
     -DUNIX:BOOL=ON \
     --debug-trycompile
@@ -186,11 +190,12 @@ build/libcxx.BUILT: build/llvm.BUILT build/compiler-rt.BUILT build/wasi-libc.BUI
 	mkdir -p build/libcxx
 	cd build/libcxx && cmake -G Ninja $(LIBCXX_CMAKE_FLAGS) \
 		-DCMAKE_SYSROOT=$(BUILD_PREFIX)/share/wasi-sysroot \
-		-DCMAKE_C_FLAGS="$(DEBUG_PREFIX_MAP)" \
-		-DCMAKE_CXX_FLAGS="$(DEBUG_PREFIX_MAP)" \
+		-DCMAKE_C_FLAGS="$(DEBUG_PREFIX_MAP) -fwasm-exceptions" \
+		-DCMAKE_CXX_FLAGS="$(DEBUG_PREFIX_MAP) -fwasm-exceptions" \
 		-DLIBCXX_LIBDIR_SUFFIX=$(ESCAPE_SLASH)/wasm32-wasi \
 		-DLIBCXXABI_LIBDIR_SUFFIX=$(ESCAPE_SLASH)/wasm32-wasi \
-		-DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi" \
+		-DLIBUNWIND_LIBDIR_SUFFIX=$(ESCAPE_SLASH)/wasm32-wasi \
+		-DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi;libunwind" \
 		$(LLVM_PROJ_DIR)/runtimes
 	ninja $(NINJA_FLAGS) -C build/libcxx
 	# Do the install.