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, 51 insertions, 18 deletions

diff --git a/examples/cpu-com-example/main.cpp b/examples/cpu-com-example/main.cpp
index 2e9eeed79..dedbf69f5 100644
--- a/examples/cpu-com-example/main.cpp
+++ b/examples/cpu-com-example/main.cpp
@@ -7,7 +7,6 @@
 #include <slang-com-ptr.h>
 #include <slang-com-helper.h>
 
-
 // This includes a useful small function for setting up the prelude (described more further below).
 #include "../../source/core/slang-test-tool-util.h"
 
@@ -21,8 +20,9 @@ using namespace Slang;
 class IDoThings : public ISlangUnknown
 {
 public:
-    virtual int SLANG_MCALL doThing(int a, int b) = 0;
-    virtual int SLANG_MCALL calcHash(const char* in) = 0;
+    virtual SLANG_NO_THROW int SLANG_MCALL doThing(int a, int b) = 0;
+    virtual SLANG_NO_THROW int SLANG_MCALL calcHash(const char* in) = 0;
+    virtual SLANG_NO_THROW void SLANG_MCALL printMessage(const char* in) = 0;
 };
 
 static int _calcHash(const char* in)
@@ -36,7 +36,7 @@ static int _calcHash(const char* in)
     return hash;
 }
 
-class DoThings :public IDoThings
+class DoThings : public IDoThings
 {
 public:
     // We don't need queryInterface for this impl, or ref counting
@@ -45,17 +45,21 @@ public:
     virtual SLANG_NO_THROW uint32_t SLANG_MCALL release() SLANG_OVERRIDE  { return 1; }
 
     // IDoThings
-    virtual int SLANG_MCALL doThing(int a, int b) SLANG_OVERRIDE { return a + b + 1; }
-    virtual int SLANG_MCALL calcHash(const char* in) SLANG_OVERRIDE { return (int)_calcHash(in); }
+    virtual SLANG_NO_THROW int SLANG_MCALL doThing(int a, int b) SLANG_OVERRIDE { return a + b + 1; }
+    virtual SLANG_NO_THROW int SLANG_MCALL calcHash(const char* in) SLANG_OVERRIDE { return (int)_calcHash(in); }
+    virtual SLANG_NO_THROW void SLANG_MCALL printMessage(const char* in) SLANG_OVERRIDE { printf("%s\n", in); }
 };
 
 static SlangResult _innerMain(int argc, char** argv)
 {
+    // NOTE! This example only works if `slang-llvm` or a C++ compiler that Slang supports is available.
+
     // Create the session
     ComPtr<slang::IGlobalSession> slangSession;
     slangSession.attach(spCreateSession(NULL));
 
     // Set up the prelude
+    // NOTE: This isn't strictly necessary, as preludes are embedded in the binary.
     TestToolUtil::setSessionDefaultPreludeFromExePath(argv[0], slangSession);
 
     // Create a compile request
@@ -93,6 +97,19 @@ static SlangResult _innerMain(int argc, char** argv)
     ComPtr<ISlangSharedLibrary> sharedLibrary;
     SLANG_RETURN_ON_FAIL(request->getTargetHostCallable(0, sharedLibrary.writeRef()));
 
+    DoThings doThings;
+
+    {
+        auto doThingsPtr = (IDoThings**)sharedLibrary->findSymbolAddressByName("globalDoThings");
+        if (!doThingsPtr)
+        {
+            return SLANG_FAIL;
+        }
+        // Set the global interface
+        *doThingsPtr = &doThings;
+    }
+
+    // Test a free function
     {
         typedef const char* (*Func)(const char*);
         Func func = (Func)sharedLibrary->findFuncByName("getString");
@@ -107,25 +124,34 @@ static SlangResult _innerMain(int argc, char** argv)
 
         SLANG_ASSERT(text == returnedText);
     }
-    {
-        typedef int (*Func)(const char* text, IDoThings* doThings);
 
+    // Test hash
+    {
+        typedef int (*Func)(const char* text);
         Func func = (Func)sharedLibrary->findFuncByName("calcHash");
-
         if (!func)
         {
             return SLANG_FAIL;
         }
 
-        DoThings doThings;
-
         String text("Hello");
-
-        const int hash = func(text.getBuffer(), &doThings);
-        
+        const int hash = func(text.getBuffer());
         SLANG_ASSERT(hash == _calcHash(text.getBuffer()));
     }
-    
+
+    // Test printing
+    {
+        typedef void (*Func)(const char* text);
+
+        Func func = (Func)sharedLibrary->findFuncByName("printMessage");
+
+        if (!func)
+        {
+            return SLANG_FAIL;
+        }
+        func("Hello World!");
+    }
+
     return SLANG_OK;
 }
 
diff --git a/examples/cpu-com-example/shader.slang b/examples/cpu-com-example/shader.slang
index b0fe259be..44b1f5b81 100644
--- a/examples/cpu-com-example/shader.slang
+++ b/examples/cpu-com-example/shader.slang
@@ -1,6 +1,8 @@
 // shader.slang
 
-// Example of using 'NativeString'
+// Example using 'NativeString' and COM interface
+
+public __global __extern_cpp IDoThings globalDoThings;
 
 public __extern_cpp NativeString getString(NativeString in)
 {
@@ -12,10 +14,15 @@ interface IDoThings
 {
     int doThing(int a, int b);
     int calcHash(NativeString in);
+    void printMessage(NativeString nativeString);
 }
 
-public __extern_cpp int calcHash(NativeString text, IDoThings doThings)
+public __extern_cpp int calcHash(NativeString text)
 {
-    return doThings.calcHash(text);
+    return globalDoThings.calcHash(text);
 }
 
+public __extern_cpp void printMessage(NativeString text)
+{
+    return globalDoThings.printMessage(text);
+}