WIP: Support for other source target language (#971)

* WIP: Setting up C/Cpp source compilation targets.

* WIP: Emitting C/CPP.

* WIP: Split out SourceSink, and use it for source output on emit.

* SourceSink -> SourceStream

* * Made SourceStream use m_ prefixing of members.
* Make all methods use lower camel
* Removed methods from SourceStream interface that are not used externally (use _ prefixing)
* Improvements to documentation

* EmitContext is now effectively empty, so just use SharedEmitContext as EmitContext.

* SharedEmitContext -> EmitContext

* Methods to LowerCamel in emit.cpp

* Split out EmitContext and ExtensionUsageTracker into separate files.

* Split out EmitVisitor into slang-c-like-source-emitter files.

* EmitVisitor -> CLikeSourceEmitter

* Tidy up around CLikeSourceEmitter - simplify header.

* Small tidy up - removing repeated comments that are in header.

* Remove EmitContext paramter threading.

* Small tidy up.
Use prefixed macros for slang-c-like-source-emitter.h

* Small tidy up in slang-c-like-source-emitter.cpp

* First pass at splitting out UnmangleContext.

* MangledNameParser -> MangledLexer.

* WIP making EmitOp (EOp) enum available outside of cpp

* Generating EmitOpInfo from macro.

* Split out emit precedence handling.
Don't use kOp_ style anymore, just use an array indexed by EmitOp.

* Disable C simple test for now.

* Keep g++/clang happy with token pasting.

* Fix win32 narrowing warning.

1 files changed, 44 insertions, 0 deletions

diff --git a/source/slang/slang-extension-usage-tracker.cpp b/source/slang/slang-extension-usage-tracker.cpp
new file mode 100644
index 000000000..f679e15db
--- /dev/null
+++ b/source/slang/slang-extension-usage-tracker.cpp
@@ -0,0 +1,44 @@
+// slang-extension-usage-tracker.cpp
+#include "slang-extension-usage-tracker.h"
+
+namespace Slang {
+
+void ExtensionUsageTracker::requireGLSLExtension(const String& name)
+{
+    if (m_glslExtensionsRequired.Contains(name))
+        return;
+
+    StringBuilder& sb = m_glslExtensionRequireLines;
+
+    sb.append("#extension ");
+    sb.append(name);
+    sb.append(" : require\n");
+
+    m_glslExtensionsRequired.Add(name);
+}
+
+void ExtensionUsageTracker::requireGLSLVersion(ProfileVersion version)
+{
+    // Check if this profile is newer
+    if ((UInt)version > (UInt)m_glslProfileVersion)
+    {
+        m_glslProfileVersion = version;
+    }
+}
+
+void ExtensionUsageTracker::requireGLSLHalfExtension()
+{
+    if (!m_hasGLSLHalfExtension)
+    {
+        // https://github.com/KhronosGroup/GLSL/blob/master/extensions/ext/GL_EXT_shader_16bit_storage.txt
+        requireGLSLExtension("GL_EXT_shader_16bit_storage");
+
+        // https://github.com/KhronosGroup/GLSL/blob/master/extensions/ext/GL_EXT_shader_explicit_arithmetic_types.txt
+        requireGLSLExtension("GL_EXT_shader_explicit_arithmetic_types");
+
+        m_hasGLSLHalfExtension = true;
+    }
+}
+
+
+} // namespace Slang