More reflection API features. (#4740)

* More reflection API features.

+ Lookup methods and members (by string) on types
+ Fix issue with looking up non-static members through the scope operator '::'
+ `GenericReflection`: Cast a decl to generic to access unspecialized generic parameter names and constraints
+ `GenericReflection`: Use `getGenericContainer()` from function, variable or type to access the 'nearest' generic parent along with specialization info
+ `GenericReflection::getConcreteType` and `GenericReflection::getConcreteIntVal`: to get the concrete type of a param in the context of the reflection object
+ `GenericReflection::getOuterGenericContainer` to go up one level and get the outer generic declarations (if there are more than one enclosing generic scopes)
+ `DeclReflection::getParent`: go to parent declaration.
+ Change `VariableReflection` to be a `DeclRef` rather than a decl (allows us to return properly substituted types for methods, members, and more)

* Fix Falcor issue

1 files changed, 86 insertions, 1 deletions

diff --git a/source/slang/slang.cpp b/source/slang/slang.cpp
index cf8c19033..9ba02ee50 100644
--- a/source/slang/slang.cpp
+++ b/source/slang/slang.cpp
@@ -26,6 +26,8 @@
 #include "slang-parser.h"
 #include "slang-preprocessor.h"
 #include "slang-type-layout.h"
+#include "slang-lookup.h"
+
 #
 #include "slang-options.h"
 
@@ -2279,7 +2281,10 @@ DeclRef<Decl> ComponentType::findDeclFromString(
         linkage,
         nullptr,
         sink);
-    SemanticsVisitor visitor(&sharedSemanticsContext);
+    SemanticsContext context(&sharedSemanticsContext);
+    context = context.allowStaticReferenceToNonStaticMember();
+
+    SemanticsVisitor visitor(context);
 
     auto checkedExpr = visitor.CheckExpr(expr);
     if (auto declRefExpr = as<DeclRefExpr>(checkedExpr))
@@ -2291,6 +2296,86 @@ DeclRef<Decl> ComponentType::findDeclFromString(
     return result;
 }
 
+DeclRef<Decl> ComponentType::findDeclFromStringInType(
+    Type* type,
+    String const& name,
+    LookupMask mask,
+    DiagnosticSink* sink)
+{
+    DeclRef<Decl> result;
+
+    // Only look up in the type if it is a DeclRefType
+    if (!as<DeclRefType>(type))
+        return DeclRef<Decl>();
+
+    // TODO(JS): For now just used the linkages ASTBuilder to keep on scope
+    //
+    // The parseTermString uses the linkage ASTBuilder for it's parsing.
+    //
+    // It might be possible to just create a temporary ASTBuilder - the worry though is
+    // that the parsing sets a member variable in AST node to one of these scopes, and then
+    // it become a dangling pointer. So for now we go with the linkages.
+    auto astBuilder = getLinkage()->getASTBuilder();
+
+    // Otherwise, we need to start looking in
+    // the modules that were directly or
+    // indirectly referenced.
+    //
+    Scope* scope = _getOrCreateScopeForLegacyLookup(astBuilder);
+
+    auto linkage = getLinkage();
+
+    SLANG_AST_BUILDER_RAII(linkage->getASTBuilder());
+
+    Expr* expr = linkage->parseTermString(name, scope);
+
+    SharedSemanticsContext sharedSemanticsContext(
+        linkage,
+        nullptr,
+        sink);
+    SemanticsContext context(&sharedSemanticsContext);
+    context = context.allowStaticReferenceToNonStaticMember();
+
+    SemanticsVisitor visitor(context);
+
+    GenericAppExpr* genericOuterExpr = nullptr;
+    if (as<GenericAppExpr>(expr))
+    {
+        // Unwrap the generic application, and re-wrap it around the static-member expr
+        genericOuterExpr = as<GenericAppExpr>(expr);
+        expr = genericOuterExpr->functionExpr;
+    }
+
+    if (!as<VarExpr>(expr))
+        return result;
+
+    auto rs = astBuilder->create<StaticMemberExpr>();
+    auto typeExpr = astBuilder->create<SharedTypeExpr>();
+    auto typetype = astBuilder->getOrCreate<TypeType>(type);
+    typeExpr->type = typetype;
+    rs->baseExpression = typeExpr;
+    rs->name = as<VarExpr>(expr)->name;
+
+    expr = rs;
+
+    // If we have a generic-app expression, re-wrap the static-member expr
+    if (genericOuterExpr)
+    {
+        genericOuterExpr->functionExpr = expr;
+        expr = genericOuterExpr;
+    }
+    
+    auto checkedTerm = visitor.CheckTerm(expr);
+    auto resolvedTerm = visitor.maybeResolveOverloadedExpr(checkedTerm, mask, sink);
+
+    if (auto declRefExpr = as<DeclRefExpr>(resolvedTerm))
+    {
+        result = declRefExpr->declRef;
+    }
+
+    return result;
+}
+
 static void collectExportedConstantInContainer(
     Dictionary<String, IntVal*>& dict,
     ASTBuilder* builder,