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, 125 insertions, 0 deletions

diff --git a/source/slang/slang-mangled-lexer.h b/source/slang/slang-mangled-lexer.h
new file mode 100644
index 000000000..4890ae80f
--- /dev/null
+++ b/source/slang/slang-mangled-lexer.h
@@ -0,0 +1,125 @@
+// slang-mangled-lexer.h
+#ifndef SLANG_MANGLED_LEXER_H_INCLUDED
+#define SLANG_MANGLED_LEXER_H_INCLUDED
+
+#include "../core/basic.h"
+
+#include "compiler.h"
+
+namespace Slang
+{
+
+/* A lexer like utility class used for decoding mangled names.
+Expects names to be correctly constructed - any errors will cause asserts/failures */
+class MangledLexer
+{
+public:
+        /// Reads a count at current position 
+    UInt readCount();
+
+    void readGenericParam();
+
+    void readGenericParams();
+
+    SLANG_INLINE void readSimpleIntVal();
+
+    UnownedStringSlice readRawStringSegment();
+
+    void readNamedType();
+
+    void readType();
+
+    void readVal();
+
+    void readGenericArg() { readVal(); }
+
+    void readGenericArgs();
+
+    SLANG_INLINE void readExtensionSpec();
+
+    UnownedStringSlice readSimpleName();
+
+    UInt readParamCount();
+
+        /// Ctor
+    SLANG_FORCE_INLINE MangledLexer(String const& str);
+
+private:
+
+    // Call at the beginning of a mangled name,
+    // to strip off the main prefix
+    void _start() { _expect("_S"); }
+
+    static bool _isDigit(char c) { return (c >= '0') && (c <= '9'); }
+
+        /// Returns the character at the current position
+    char _peek() { return *m_cursor; }
+        // Returns the current character and moves to next character.
+    char _next() { return *m_cursor++; }
+
+    SLANG_INLINE void _expect(char c);
+
+    void _expect(char const* str)
+    {
+        while (char c = *str++)
+            _expect(c);
+    }
+
+    char const* m_cursor = nullptr;
+    char const* m_begin = nullptr;
+    char const* m_end = nullptr;
+};
+
+// -------------------------------------------------------------------------- -
+SLANG_FORCE_INLINE MangledLexer::MangledLexer(String const& str)
+    : m_cursor(str.begin())
+    , m_begin(str.begin())
+    , m_end(str.end())
+{
+    _start();
+}
+
+// ---------------------------------------------------------------------------
+SLANG_INLINE void MangledLexer::readSimpleIntVal()
+{
+    int c = _peek();
+    if (_isDigit((char)c))
+    {
+        _next();
+    }
+    else
+    {
+        readVal();
+    }
+}
+
+// ---------------------------------------------------------------------------
+SLANG_INLINE void MangledLexer::readNamedType()
+{
+    // TODO: handle types with more complicated names
+    readRawStringSegment();
+}
+
+// ---------------------------------------------------------------------------
+SLANG_INLINE void MangledLexer::readExtensionSpec()
+{
+    _expect("X");
+    readType();
+}
+
+// ---------------------------------------------------------------------------
+SLANG_INLINE void MangledLexer::_expect(char c)
+{
+    if (_peek() == c)
+    {
+        _next();
+    }
+    else
+    {
+        // ERROR!
+        SLANG_UNEXPECTED("mangled name error");
+    }
+}
+
+}
+#endif