DownstreamCompileOptions using POD types (#2381)

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

* Make DownstreamCompileOptions use POD types.

* CharSliceAllocator -> SliceAllocator
Added SliceConverter
CharSliceCaster -> SliceCaster

* First attempt at zero terminating around blobs.

* Fix clang warning.

* Add SlangTerminatedChars
Make Blob implementations support it.
Make most blobs 'terminated'.

* Fix bug setting up sourceFiles for CommandLineDownstreamCompiler.

* Traffic in TerminatedCharSlice for sourceFiles.
Use ArtifactDesc to generate temporary file names for source.

* Fix typo in testing for shared library/C++.

1 files changed, 103 insertions, 0 deletions

diff --git a/source/compiler-core/slang-slice-allocator.h b/source/compiler-core/slang-slice-allocator.h
new file mode 100644
index 000000000..41ed3943a
--- /dev/null
+++ b/source/compiler-core/slang-slice-allocator.h
@@ -0,0 +1,103 @@
+// slang-slice-allocator.h
+#ifndef SLANG_SLICE_ALLOCATOR_H
+#define SLANG_SLICE_ALLOCATOR_H
+
+// Has definition of CharSlice 
+#include "slang-artifact.h"
+
+#include "../core/slang-memory-arena.h"
+
+namespace Slang
+{
+
+/* 
+The reason to wrap in a struct rather than have as free functions is doing so will lead to compile time 
+errors with incorrect usage around temporaries.
+*/
+struct SliceCaster
+{
+        /// The slice will only be in scope whilst the string is
+    static TerminatedCharSlice asTerminatedCharSlice(const String& in) { auto unowned = in.getUnownedSlice(); return TerminatedCharSlice(unowned.begin(), unowned.getLength()); }
+
+    static CharSlice asCharSlice(const String& in) { auto unowned = in.getUnownedSlice(); return CharSlice(unowned.begin(), unowned.getLength()); }
+
+    template <typename T>
+    static Slice<T*> asSlice(const List<ComPtr<T>>& list) { return makeSlice((T*const*)list.getBuffer(), list.getCount()); }
+
+        /// Get a list as a slice
+    template <typename T>
+    static Slice<T> asSlice(const List<T>& list) { return Slice<T>(list.getBuffer(), list.getCount()); }
+
+private:
+        /// We don't want to make a temporary list into a slice..
+    template <typename T>
+    static Slice<T> asSlice(const List<T>&& list) = delete; 
+        // We don't want temporaries to be 'asSliced' so disable
+    static TerminatedCharSlice asTerminatedCharSlice(const String&& in) = delete;
+    static CharSlice asCharSlice(const String&& in) = delete;
+};
+
+struct SliceAllocator;
+
+struct SliceConverter
+{
+        /// Convert into a list of strings
+    static List<String> toList(const Slice<TerminatedCharSlice>& in);
+
+        /// NOTE! the slice is only guarenteed to stay in scope whilst the blob does
+    static TerminatedCharSlice toTerminatedCharSlice(SliceAllocator& allocator, ISlangBlob* blob);
+
+    template <typename T>
+    static List<ComPtr<T>> toComPtrList(const Slice<T*>& in)
+    {
+        ISlangUnknown* check = (T*)nullptr;
+        SLANG_UNUSED(check);
+        List<ComPtr<T>> list;
+        list.setCount(in.count);
+        for (Index i = 0; i < in.count; ++i) list[i] = ComPtr<T>(in[i]);
+        return list;
+    }
+};
+
+SLANG_FORCE_INLINE UnownedStringSlice asStringSlice(const CharSlice& slice)
+{
+    return UnownedStringSlice(slice.begin(), slice.end());
+}
+
+SLANG_FORCE_INLINE CharSlice asCharSlice(const UnownedStringSlice& slice)
+{
+    return CharSlice(slice.begin(), slice.getLength());
+}
+
+SLANG_FORCE_INLINE String asString(const CharSlice& slice)
+{
+    return String(slice.begin(), slice.end()); 
+}
+
+struct SliceAllocator
+{
+    TerminatedCharSlice allocate(const Slice<char>& slice);
+    TerminatedCharSlice allocate(const UnownedStringSlice& slice);
+    TerminatedCharSlice allocate(const String& in) { return allocate(in.getUnownedSlice()); }
+    TerminatedCharSlice allocate(const char* in);
+    TerminatedCharSlice allocate(const char* start, const char* end) { return allocate(UnownedStringSlice(start, end)); }
+
+    Slice<TerminatedCharSlice> allocate(const List<String>& in);
+
+        /// Get the backing arena
+    MemoryArena& getArena() { return m_arena; }
+
+    void deallocateAll() { m_arena.deallocateAll(); }
+
+    SliceAllocator():
+        m_arena(1024)
+    {
+    }
+protected:
+    
+    MemoryArena m_arena;
+};
+
+} // namespace Slang
+
+#endif