Actual global support (#2262)

* #include an absolute path didn't work - because paths were taken to always be relative.

* Use TerminatedUnownedStringSlice for literals in output C++.

* Remove Escape/Unescape functions used in slang-token-reader.cpp
Add target type of 'host-cpp' etc to map to the target types.

* Fix some corner cases around string encoding.

* Added unit test for string escaping.
Fixed some assorted escaping bugs.

* Updated test output.

* Added decode test.

* Stop using hex output, to get around 'greedy' aspect. Use octal instead.

* Added HostHostCallable
Small changes to use ArtifactDesc/Info instead of large switches.

* Fix C++ emit to handle arbitrary function export.

* Add options handling for callable without an output being specified.

* Can compile with COM interface. Added example using com interface.

* Use the IR Ptr type instead of hack in C++ emit for interfaces.

* Fix issue with outputting the COM call when ptr is used.

* Fix crash issue on compilation failure.

* Add support for __global.

* Added `ActualGlobalRate`
Added special handling around globals and COM interfaces.
Tested out in cpu-com-example.

* Fix typo in NodeBase.

* Support for accessing globals by name working.

* Check that actual global initialization is working.

* Refactor the com replacement such that it doesn't need a cache or do anything special with GlobalVar.

* Remove context.
Only create replacement if needed.

* Split out COM host-callable into a unit-test.

* host-callable com testing on C++and llvm.

* Comment around the COM ptr replacement.

* Disable com test on vs 32 bit.
Fix C++ prelude

* Disable 32 bit targets testing com host-callable.

* Use JSON parsing to locate VS version.

* Need platform detection in C++prelude.

* Fix com host callable test for LLVM.

* Work around for not being able to include "targetConditionals.h"

2 files changed, 110 insertions, 0 deletions

diff --git a/prelude/slang-cpp-prelude.h b/prelude/slang-cpp-prelude.h
index db83222a6..ff6bb8f6f 100644
--- a/prelude/slang-cpp-prelude.h
+++ b/prelude/slang-cpp-prelude.h
@@ -99,7 +99,109 @@ Any compilers not detected by the above logic are now now explicitly zeroed out.
 #    endif
 #endif /* SLANG_COMPILER */
 
+/*
+The following section attempts to detect the target platform being compiled for.
+
+If an application defines `SLANG_PLATFORM` before including this header,
+they take responsibility for setting any compiler-dependent macros
+used later in the file.
+
+Most applications should not need to touch this section.
+*/
+#ifndef SLANG_PLATFORM
+#    define SLANG_PLATFORM
+/**
+Operating system defines, see http://sourceforge.net/p/predef/wiki/OperatingSystems/
+*/
+#    if defined(WINAPI_FAMILY) && WINAPI_FAMILY == WINAPI_PARTITION_APP
+#        define SLANG_WINRT 1 /* Windows Runtime, either on Windows RT or Windows 8 */
+#    elif defined(XBOXONE)
+#        define SLANG_XBOXONE 1
+#    elif defined(_WIN64) /* note: XBOXONE implies _WIN64 */
+#        define SLANG_WIN64 1
+#    elif defined(_M_PPC)
+#        define SLANG_X360 1
+#    elif defined(_WIN32) /* note: _M_PPC implies _WIN32 */
+#        define SLANG_WIN32 1
+#    elif defined(__ANDROID__)
+#        define SLANG_ANDROID 1
+#    elif defined(__linux__) || defined(__CYGWIN__) /* note: __ANDROID__ implies __linux__ */
+#        define SLANG_LINUX 1
+#    elif defined(__APPLE__) && !defined(SLANG_LLVM)
+#        include "TargetConditionals.h"
+#        if TARGET_OS_MAC
+#            define SLANG_OSX 1
+#        else
+#            define SLANG_IOS 1
+#        endif
+#    elif defined(__APPLE__)
+// On `slang-llvm` we can't inclue "TargetConditionals.h" in general, so for now assume its OSX.
+#       define SLANG_OSX 1
+#    elif defined(__CELLOS_LV2__)
+#        define SLANG_PS3 1
+#    elif defined(__ORBIS__)
+#        define SLANG_PS4 1
+#    elif defined(__SNC__) && defined(__arm__)
+#        define SLANG_PSP2 1
+#    elif defined(__ghs__)
+#        define SLANG_WIIU 1
+#    else
+#        error "unknown target platform"
+#    endif
+
+
+/*
+Any platforms not detected by the above logic are now now explicitly zeroed out.
+*/
+#    ifndef SLANG_WINRT
+#        define SLANG_WINRT 0
+#    endif
+#    ifndef SLANG_XBOXONE
+#        define SLANG_XBOXONE 0
+#    endif
+#    ifndef SLANG_WIN64
+#        define SLANG_WIN64 0
+#    endif
+#    ifndef SLANG_X360
+#        define SLANG_X360 0
+#    endif
+#    ifndef SLANG_WIN32
+#        define SLANG_WIN32 0
+#    endif
+#    ifndef SLANG_ANDROID
+#        define SLANG_ANDROID 0
+#    endif
+#    ifndef SLANG_LINUX
+#        define SLANG_LINUX 0
+#    endif
+#    ifndef SLANG_IOS
+#        define SLANG_IOS 0
+#    endif
+#    ifndef SLANG_OSX
+#        define SLANG_OSX 0
+#    endif
+#    ifndef SLANG_PS3
+#        define SLANG_PS3 0
+#    endif
+#    ifndef SLANG_PS4
+#        define SLANG_PS4 0
+#    endif
+#    ifndef SLANG_PSP2
+#        define SLANG_PSP2 0
+#    endif
+#    ifndef SLANG_WIIU
+#        define SLANG_WIIU 0
+#    endif
+#endif /* SLANG_PLATFORM */
+
+
+/* Shorthands for "families" of compilers/platforms */
 #define SLANG_GCC_FAMILY (SLANG_CLANG || SLANG_SNC || SLANG_GHS || SLANG_GCC)
+#define SLANG_WINDOWS_FAMILY (SLANG_WINRT || SLANG_WIN32 || SLANG_WIN64)
+#define SLANG_MICROSOFT_FAMILY (SLANG_XBOXONE || SLANG_X360 || SLANG_WINDOWS_FAMILY)
+#define SLANG_LINUX_FAMILY (SLANG_LINUX || SLANG_ANDROID)
+#define SLANG_APPLE_FAMILY (SLANG_IOS || SLANG_OSX)                  /* equivalent to #if __APPLE__ */
+#define SLANG_UNIX_FAMILY (SLANG_LINUX_FAMILY || SLANG_APPLE_FAMILY) /* shortcut for unix/posix platforms */
 
 // GCC Specific
 #if SLANG_GCC_FAMILY
@@ -147,6 +249,9 @@ convention for interface methods.
 #   define SLANG_MCALL SLANG_STDCALL
 #endif
 
+
+
+
 struct SlangUUID
 {
     uint32_t data1;
diff --git a/prelude/slang-llvm.h b/prelude/slang-llvm.h
index 22966ead0..08d6a74dd 100644
--- a/prelude/slang-llvm.h
+++ b/prelude/slang-llvm.h
@@ -1,6 +1,11 @@
 #ifndef SLANG_LLVM_H
 #define SLANG_LLVM_H
 
+// TODO(JS): 
+// Disable exception declspecs, as not supported on LLVM without some extra options.
+// We could enable with `-fms-extensions`
+#define SLANG_DISABLE_EXCEPTIONS 1
+
 #ifndef SLANG_PRELUDE_ASSERT
 #   ifdef DEBUG
 extern "C" void assertFailure(const char* msg);