Add `IGlobalSession::getSessionDescDigest`. (#3669)

* Add `IGlobalSession::getSessionDescDigest`.

* Fix.

1 files changed, 3 insertions, 1 deletions

diff --git a/source/slang/slang-compiler.h b/source/slang/slang-compiler.h
index 4876026a0..0dd0012ad 100755
--- a/source/slang/slang-compiler.h
+++ b/source/slang/slang-compiler.h
@@ -1835,7 +1835,7 @@ namespace Slang
         // Updates the supplied builder with linkage-related information, which includes preprocessor
         // defines, the compiler version, and other compiler options. This is then merged with the hash
         // produced for the program to produce a key that can be used with the shader cache.
-        void buildHash(DigestBuilder<SHA1>& builder, SlangInt targetIndex);
+        void buildHash(DigestBuilder<SHA1>& builder, SlangInt targetIndex = -1);
 
         void addTarget(
             slang::TargetDesc const& desc);
@@ -3003,6 +3003,8 @@ namespace Slang
         SLANG_NO_THROW SlangResult SLANG_MCALL parseCommandLineArguments(
             int argc, const char* const* argv, slang::SessionDesc* outSessionDesc, ISlangUnknown** outAllocation) override;
 
+        SLANG_NO_THROW SlangResult SLANG_MCALL getSessionDescDigest(slang::SessionDesc* sessionDesc, ISlangBlob** outBlob) override;
+
             /// Get the downstream compiler for a transition
         IDownstreamCompiler* getDownstreamCompiler(CodeGenTarget source, CodeGenTarget target);