Fix name mangling and source file finding logic for precompiled module validation. (#3784)

* Fix name mangling.

* Fix source validation.

* Caching and search path fixes.

1 files changed, 24 insertions, 9 deletions

diff --git a/source/slang/slang.cpp b/source/slang/slang.cpp
index 978dff7c4..241ec7f43 100644
--- a/source/slang/slang.cpp
+++ b/source/slang/slang.cpp
@@ -486,6 +486,7 @@ SlangResult Session::_readBuiltinModule(ISlangFileSystem* fileSystem, Scope* sco
     {
         RefPtr<Module> module(new Module(linkage, srcModule.astBuilder));
         module->setName(moduleName);
+        module->setDigest(srcModule.digest);
 
         ModuleDecl* moduleDecl = as<ModuleDecl>(srcModule.astRootNode);
         // Set the module back reference on the decl
@@ -3699,7 +3700,7 @@ bool Linkage::isBinaryModuleUpToDate(String fromPath, RiffContainer* container)
             // If we cannot find the source file from `fromPath`,
             // try again from the module's source file path.
             if (moduleHeader.dependentFiles.getCount() != 0)
-                sourceFile = loadSourceFile(moduleHeader.dependentFiles.getFirst(), file);
+                sourceFile = loadSourceFile(Path::getParentDirectory(moduleHeader.dependentFiles.getFirst()), file);
         }
         if (!sourceFile)
             return false;
@@ -3922,7 +3923,27 @@ ISlangUnknown* Module::getInterface(const Guid& guid)
 
 void Module::buildHash(DigestBuilder<SHA1>& builder)
 {
-    SLANG_UNUSED(builder);
+    builder.append(computeDigest());
+}
+
+SHA1::Digest Module::computeDigest()
+{
+    if (m_digest == SHA1::Digest())
+    {
+        DigestBuilder<SHA1> digestBuilder;
+        auto version = String(getBuildTagString());
+        digestBuilder.append(version);
+        getOptionSet().buildHash(digestBuilder);
+
+        auto fileDependencies = getFileDependencies();
+
+        for (auto file : fileDependencies)
+        {
+            digestBuilder.append(file->getDigest());
+        }
+        m_digest = digestBuilder.finalize();
+    }
+    return m_digest;
 }
 
 void Module::addModuleDependency(Module* module)
@@ -4245,12 +4266,6 @@ SLANG_NO_THROW void SLANG_MCALL ComponentType::getEntryPointHash(
     // will already be reflected in the resulting hash.
     getLinkage()->buildHash(builder, targetIndex);
 
-    // Enumerate all file dependencies and add them to the hash.
-    for (SourceFile* sourceFile : getFileDependencies())
-    {
-        builder.append(sourceFile->getDigest());
-    }
-
     buildHash(builder);
 
     // Add the name and name override for the specified entry point to the hash.
@@ -5239,7 +5254,7 @@ void Linkage::prepareDeserializedModule(SerialContainerData::Module& moduleEntry
         }
     }
     module->setPathInfo(filePathInfo);
-
+    module->setDigest(moduleEntry.digest);
     module->_collectShaderParams();
     module->_discoverEntryPoints(sink);