diff --git a/backends/ext_pdf_doc/templates/ext_pdf.adoc.erb b/backends/ext_pdf_doc/templates/ext_pdf.adoc.erb
index 4abd27c6c9..bcc0b93859 100644
--- a/backends/ext_pdf_doc/templates/ext_pdf.adoc.erb
+++ b/backends/ext_pdf_doc/templates/ext_pdf.adoc.erb
@@ -31,7 +31,7 @@
     raise "TODO: #{ext_version["state"]} description"
   end
 %>
-:company: <%= ext.company["name"] %>
+:company: <%= ext.company.nil? ? "unknown" : ext.company["name"] %>
 :url-riscv: https://riscv.org
 :doctype: book
 :preface-title: Licensing and Acknowledgements
@@ -119,9 +119,9 @@ endif::[]
 
 [preface]
 == Copyright and license information
-This document is released under the <%= ext.doc_license["url"] %>[<%= ext.doc_license["name"] %>].
+This document is released under the <%= ext.doc_license.nil? ? "unknown" : ext.doc_license["url"] %>[<%= ext.doc_license.nil? ? "unknown" : ext.doc_license["name"] %>].
 
-Copyright <%= ext_version["ratification_date"].split("-")[0] %> by <%= ext.company["name"] %>.
+Copyright <%= ext_version["ratification_date"].split("-")[0] %> by <%= ext.company.nil? ? "unknown" : ext.company["name"] %>.
 
 [preface]
 == Acknowledgements
@@ -129,10 +129,12 @@ Copyright <%= ext_version["ratification_date"].split("-")[0] %> by <%= ext.compa
 <%- ext.versions.each do |version| -%>
 Contributors to version <%= version["version"] %> of the specification (in alphabetical order) include: +
 
+<%- unless version["contributors"].nil? -%>
 <%- version["contributors"].sort { |a, b| a["name"].split(" ").last <=> b["name"].split(" ").last }.each do |c| -%>
  * <%= c["name"] %> <<%= c["email"] %>> (<%= c["company"] %>)
 <%- end -%>
 <%- end -%>
+<%- end -%>
 
 We express our gratitude to everyone that contributed to, reviewed or
 improved this specification through their comments and questions.
@@ -252,7 +254,7 @@ This CSR format changes dynamically.
 <%- csr.fields.each do |field| -%>
 | xref:<%=csr.name%>-<%=field.name%>-def[`<%= field.name %>`]
 | <%= field.location_pretty(arch_def) %>
-| <%= field.type_pretty(arch_def) %>
+| <%= field.type_pretty(arch_def.symtab) %>
 | <%= field.reset_value_pretty(arch_def) %>
 
 <%- end -%>
@@ -278,7 +280,7 @@ Description::
 <%= field.description %>
 
 Type::
-<%= field.type_pretty(arch_def) %>
+<%= field.type_pretty(arch_def.symtab) %>
 
 Reset value::
 <%= field.reset_value_pretty(arch_def) %>
@@ -315,7 +317,7 @@ This CSR may return a value that is different from what is stored in hardware.
 
 [source,idl,subs="specialchars,macros"]
 ----
-<%= csr.sw_read_ast(arch_def.idl_compiler).gen_adoc %>
+<%= csr.sw_read_ast(arch_def.symtab).gen_adoc %>
 ----
 <%- end -%>
 
@@ -415,22 +417,18 @@ RV64::
 <%- end -%>
 
 Operation::
+<%- unless i.data["operation()"].nil? -%>
 [source,idl,subs="specialchars,macros"]
 ----
-<%= i.operation_ast(arch_def.idl_compiler).gen_adoc %>
+<%= i.operation_ast(arch_def.symtab).gen_adoc %>
 ----
+<%- end -%>
 
 Included in::
-[%header,cols="4,2"]
-|===
-|Extension
-|Minimum version
 
-<%- i.defined_by.each do |ext_req| -%>
-|<%= ext_req.name %>
-|<%= ext_req.version_requirement %>
-<%- end -%>
-|===
+<%= i.defined_by.to_asciidoc %>
+
+
 <<<
 <%- end -%>
 <%- end -%>
@@ -438,7 +436,7 @@ Included in::
 <<<
 == IDL Functions
 
-<%- ext.reachable_functions_unevaluated.sort { |a,b| a.name <=> b.name }.each do |f| -%>
+<%- ext.reachable_functions(arch_def.symtab).sort { |a,b| a.name <=> b.name }.each do |f| -%>
 [#<%= f.name %>-func-def]
 === <%= f.name %><%- if f.builtin? -%> (builtin)<%- end -%>
 
diff --git a/lib/arch_obj_models/extension.rb b/lib/arch_obj_models/extension.rb
index 994594a28e..a03c5d3f01 100644
--- a/lib/arch_obj_models/extension.rb
+++ b/lib/arch_obj_models/extension.rb
@@ -256,11 +256,11 @@ def reachable_functions_unevaluated
 
     funcs = []
     instructions.each do |inst|
-      funcs += inst.operation_ast(arch_def.idl_compiler).reachable_functions_unevaluated(arch_def)
+      funcs += inst.operation_ast(arch_def.symtab).reachable_functions(arch_def.symtab)
     end
 
     csrs.each do |csr|
-      funcs += csr.reachable_functions_unevaluated(arch_def)
+      funcs += csr.reachable_functions(arch_def)
     end
 
     @reachable_functions_unevaluated = funcs.uniq(&:name)