Build runtime and libraries for WebAssembly (#4876)

* Fix issues building the runtime, corelib and type loader for WebAssembly

* Fix test infrastructure to allow running with the wasm flavor

2 files changed, 42 insertions, 1 deletions

diff --git a/src/Native/Runtime/unix/PalRedhawkUnix.cpp b/src/Native/Runtime/unix/PalRedhawkUnix.cpp
index af11b38f0..0b91e07a5 100644
--- a/src/Native/Runtime/unix/PalRedhawkUnix.cpp
+++ b/src/Native/Runtime/unix/PalRedhawkUnix.cpp
@@ -800,6 +800,10 @@ bool QueryCacheSize()
             }
         }
     }
+
+#elif defined(_WASM_)
+    // Processor cache size not available on WebAssembly
+    success = false;
 #else
 #error Do not know how to get cache size on this platform
 #endif // __linux__
diff --git a/src/Native/Runtime/unix/UnixContext.cpp b/src/Native/Runtime/unix/UnixContext.cpp
index 0fdbc23ca..549271e30 100644
--- a/src/Native/Runtime/unix/UnixContext.cpp
+++ b/src/Native/Runtime/unix/UnixContext.cpp
@@ -19,6 +19,34 @@
 
 #include "UnixContext.h"
 
+// WebAssembly has a slightly different version of LibUnwind that doesn't define unw_get_save_loc
+#if defined(_WASM_)
+enum unw_save_loc_type_t
+{
+    UNW_SLT_NONE,       /* register is not saved ("not an l-value") */
+    UNW_SLT_MEMORY,     /* register has been saved in memory */
+    UNW_SLT_REG         /* register has been saved in (another) register */
+};
+typedef enum unw_save_loc_type_t unw_save_loc_type_t;
+
+struct unw_save_loc_t
+{
+    unw_save_loc_type_t type;
+    union
+    {
+        unw_word_t addr;        /* valid if type==UNW_SLT_MEMORY */
+        unw_regnum_t regnum;    /* valid if type==UNW_SLT_REG */
+    }
+    u;
+};
+typedef struct unw_save_loc_t unw_save_loc_t;
+
+int unw_get_save_loc(unw_cursor_t*, int, unw_save_loc_t*)
+{
+    return -1;
+}
+#endif // _WASM
+
 #ifdef __APPLE__
 
 #define MCREG_Rip(mc)       ((mc)->__ss.__rip)
@@ -255,6 +283,8 @@ bool GetUnwindProcInfo(PCODE ip, unw_proc_info_t *procInfo)
     unwContext.data[16] = ip;
 #elif _ARM_
     ((uint32_t*)(unwContext.data))[15] = ip;
+#elif _WASM_
+    ASSERT(false);
 #else
     #error "GetUnwindProcInfo is not supported on this arch yet."
 #endif
@@ -358,6 +388,9 @@ static void GetContextPointer(unw_cursor_t *cursor, unw_context_t *unwContext, i
 #define GET_CONTEXT_POINTERS                    \
     GET_CONTEXT_POINTER(UNW_X86_EBP, Rbp)       \
     GET_CONTEXT_POINTER(UNW_X86_EBX, Rbx)
+#elif defined (_WASM_)
+// No registers
+#define GET_CONTEXT_POINTERS
 #else
 #error unsupported architecture
 #endif
@@ -454,7 +487,11 @@ void UnwindCursorToRegDisplay(unw_cursor_t *cursor, unw_context_t *unwContext, R
 #define ASSIGN_TWO_ARGUMENT_REGS
     // MCREG_X0(nativeContext->uc_mcontext) = arg0Reg;       \
     // MCREG_X1(nativeContext->uc_mcontext) = arg1Reg;
-
+#elif defined(_WASM_)
+    // TODO: determine how unwinding will work on WebAssembly
+#define ASSIGN_CONTROL_REGS
+#define ASSIGN_INTEGER_REGS
+#define ASSIGN_TWO_ARGUMENT_REGS
 #else
 #error unsupported architecture
 #endif