Move C interface from slang.h to slang-deprecated.h (#5301)

* Squash redundant move warnings

* Move C interface from slang.h to slang-deprecated.h

spGetBuildTagString remains, because it's useful to have before the
global session exists.

This C API is used quite pervasively in the C++ helpers (for example
slang::UserAttribute. It's not trivial to move these to
slang-deprecated.h as they're entangled with some enums which are
themselves used elsewhere in the compiler.

The fact that these helpers use the C API can be viewed as an
implementation detail for now, and this usage moved to slang-deprecated
in due course.

Closes https://github.com/shader-slang/slang/issues/4758

* Squash warnings for our usage of our deprecated API

---------

Co-authored-by: Yong He <yonghe@outlook.com>

7 files changed, 9 insertions, 5 deletions

diff --git a/source/slang/slang-api.cpp b/source/slang/slang-api.cpp
index 412cec0d4..ccecc74e1 100644
--- a/source/slang/slang-api.cpp
+++ b/source/slang/slang-api.cpp
@@ -225,7 +225,9 @@ SLANG_API SlangCompileRequest* spCreateCompileRequest(
 {
     slang::ICompileRequest* request = nullptr;
     // Will return with suitable ref count
+    SLANG_ALLOW_DEPRECATED_BEGIN
     session->createCompileRequest(&request);
+    SLANG_ALLOW_DEPRECATED_END
     return request;
 }
 
diff --git a/source/slang/slang-ast-val.cpp b/source/slang/slang-ast-val.cpp
index 68a55e567..f30041175 100644
--- a/source/slang/slang-ast-val.cpp
+++ b/source/slang/slang-ast-val.cpp
@@ -120,7 +120,7 @@ String Val::toString()
 {
     StringBuilder builder;
     toText(builder);
-    return std::move(builder);
+    return builder;
 }
 
 HashCode Val::getHashCode()
diff --git a/source/slang/slang-compiler.cpp b/source/slang/slang-compiler.cpp
index 5bbc92e97..af4468383 100644
--- a/source/slang/slang-compiler.cpp
+++ b/source/slang/slang-compiler.cpp
@@ -940,7 +940,7 @@ namespace Slang
                 {
                     builder << ";" << _getDisplayPath(sink, sourceFiles[i]);
                 }
-                return std::move(builder);
+                return builder;
             }
         }
     }
diff --git a/source/slang/slang-ir.cpp b/source/slang/slang-ir.cpp
index f190b3a11..d0dcfd4fb 100644
--- a/source/slang/slang-ir.cpp
+++ b/source/slang/slang-ir.cpp
@@ -7684,7 +7684,7 @@ namespace Slang
     {
         StringBuilder sb;
         printSlangIRAssembly(sb, module, options, sourceManager);
-        return std::move(sb);
+        return sb;
     }
 
     void dumpIR(IRModule* module, const IRDumpOptions& options, SourceManager* sourceManager, ISlangWriter* writer)
diff --git a/source/slang/slang-mangle.cpp b/source/slang/slang-mangle.cpp
index 5a0d41f09..93b29ccbe 100644
--- a/source/slang/slang-mangle.cpp
+++ b/source/slang/slang-mangle.cpp
@@ -823,7 +823,7 @@ namespace Slang
         builder << "_Sh";
         builder.append(uint64_t(hash), 16);
 
-        return std::move(builder);
+        return builder;
     }
 
 }
diff --git a/source/slang/slang-options.cpp b/source/slang/slang-options.cpp
index 48c593889..43f98872d 100644
--- a/source/slang/slang-options.cpp
+++ b/source/slang/slang-options.cpp
@@ -1148,7 +1148,9 @@ SlangResult OptionsParser::_compileReproDirectory(SlangSession* session, EndToEn
     {
         // Create a fresh request
         ComPtr<slang::ICompileRequest> request;
+        SLANG_ALLOW_DEPRECATED_BEGIN
         SLANG_RETURN_ON_FAIL(session->createCompileRequest(request.writeRef()));
+        SLANG_ALLOW_DEPRECATED_END
 
         auto requestImpl = asInternal(request);
 
diff --git a/source/slang/slang-preprocessor.cpp b/source/slang/slang-preprocessor.cpp
index c4a2bd95e..600e28bc5 100644
--- a/source/slang/slang-preprocessor.cpp
+++ b/source/slang/slang-preprocessor.cpp
@@ -3487,7 +3487,7 @@ static String _readDirectiveMessage(PreprocessorDirectiveContext* context)
         result.append(token.getContent());
     }
 
-    return std::move(result);
+    return result;
 }
 
 // Handle a `#warning` directive