Enable emscripten builds to compile slang.dll to WebAssembly. (#5131)

* Compile fixes for Wasm

The issues are all are due to 'long' types being 32 bits on WASM.

- class members redeclared errors
- << with StringBuilder and unsigned long is ambiguous

This helps to address issue #5115.

* Use the host executable suffix for generators

Since the generators are run at build-time, we should not use CMAKE_EXECUTABLE_SUFFIX,
which is the suffix for the target platform.
Instead, define CMAKE_HOST_EXECUTABLE_SUFFIX as appropriate, and use that suffix instead.

This helps to address issue #5115.

* Add support for Wasm as a platform

This helps to address issue #5115.

* Add emscripten build

This closes #5115.

5 files changed, 13 insertions, 11 deletions

diff --git a/source/core/slang-io.cpp b/source/core/slang-io.cpp
index dd390fc28..928026267 100644
--- a/source/core/slang-io.cpp
+++ b/source/core/slang-io.cpp
@@ -20,7 +20,8 @@
 #   include <shellapi.h>
 #endif
 
-#if defined(__linux__) || defined(__CYGWIN__) || SLANG_APPLE_FAMILY
+#if defined(__linux__) || defined(__CYGWIN__) || SLANG_APPLE_FAMILY || SLANG_WASM
+#   include <fcntl.h>
 #   include <unistd.h>
 // For Path::find
 #   include <fnmatch.h>
@@ -1012,6 +1013,7 @@ namespace Slang
         }
         return SLANG_FAIL;
 #else
+        SLANG_UNUSED(outPath);
         return SLANG_E_NOT_IMPLEMENTED;
 #endif
     }
diff --git a/source/slang/slang-ast-dump.cpp b/source/slang/slang-ast-dump.cpp
index a1ab7a5c8..b3a554e6d 100644
--- a/source/slang/slang-ast-dump.cpp
+++ b/source/slang/slang-ast-dump.cpp
@@ -304,9 +304,9 @@ struct ASTDumpContext
 
     void dump(uint32_t v)
     {
-        m_writer->emit(UInt(v));
+        m_writer->emit((uint64_t)v);
     }
-    void dump(UInt v)
+    void dump(uint64_t v)
     {
         m_writer->emit(v);
     }
diff --git a/source/slang/slang-parameter-binding.cpp b/source/slang/slang-parameter-binding.cpp
index 115ccc55e..ea22cbcba 100644
--- a/source/slang/slang-parameter-binding.cpp
+++ b/source/slang/slang-parameter-binding.cpp
@@ -3748,7 +3748,7 @@ static void _appendRange(Index start, LayoutSize size, StringBuilder& ioBuf)
         ioBuf << "[ " << start << " ... ";
         if (size.isFinite())
         {
-            ioBuf << start + size.getFiniteValue() << ")";
+            ioBuf << start + (Index)size.getFiniteValue() << ")";
         }
         else
         {
diff --git a/source/slang/slang-workspace-version.cpp b/source/slang/slang-workspace-version.cpp
index d85724328..f3ae6271a 100644
--- a/source/slang/slang-workspace-version.cpp
+++ b/source/slang/slang-workspace-version.cpp
@@ -457,7 +457,7 @@ ArrayView<Index> DocumentVersion::getUTF8Boundaries(Index line)
 }
 
 void DocumentVersion::oneBasedUTF8LocToZeroBasedUTF16Loc(
-    Index inLine, Index inCol, Index& outLine, Index& outCol)
+    Index inLine, Index inCol, int64_t& outLine, int64_t& outCol)
 {
     if (inLine <= 0)
     {
@@ -472,12 +472,12 @@ void DocumentVersion::oneBasedUTF8LocToZeroBasedUTF16Loc(
 }
 
 void DocumentVersion::oneBasedUTF8LocToZeroBasedUTF16Loc(
-    Index inLine, Index inCol, int& outLine, int& outCol)
+    Index inLine, Index inCol, int32_t& outLine, int32_t& outCol)
 {
-    Index ioutLine, ioutCol;
+    int64_t ioutLine, ioutCol;
     oneBasedUTF8LocToZeroBasedUTF16Loc(inLine, inCol, ioutLine, ioutCol);
-    outLine = (int)ioutLine;
-    outCol = (int)ioutCol;
+    outLine = (int32_t)ioutLine;
+    outCol = (int32_t)ioutCol;
 }
 
 void DocumentVersion::zeroBasedUTF16LocToOneBasedUTF8Loc(
diff --git a/source/slang/slang-workspace-version.h b/source/slang/slang-workspace-version.h
index d6cbfe6c5..46d11b493 100644
--- a/source/slang/slang-workspace-version.h
+++ b/source/slang/slang-workspace-version.h
@@ -38,9 +38,9 @@ namespace Slang
         ArrayView<Index> getUTF8Boundaries(Index line);
 
         void oneBasedUTF8LocToZeroBasedUTF16Loc(
-            Index inLine, Index inCol, Index& outLine, Index& outCol);
+            Index inLine, Index inCol, int64_t& outLine, int64_t& outCol);
         void oneBasedUTF8LocToZeroBasedUTF16Loc(
-            Index inLine, Index inCol, int& outLine, int& outCol);
+            Index inLine, Index inCol, int32_t& outLine, int32_t& outCol);
         void zeroBasedUTF16LocToOneBasedUTF8Loc(
             Index inLine, Index inCol, Index& outLine, Index& outCol);