TypeGraph: Create dummy containers

These represent types which don't store any interesting data for us to
measure, but which are required by a real container so can not be
replaced with our own generated class types.

std::allocator often has bad DWARF, so it must be replaced after the
DWARF is fixed up in Flattener. The others could be replaced earlier in
the transformation process if desired, but I've left them all together
for simplicity for now.

This fixes the folly::fbstring tests.

.circleci/config.yml

@@ -20,7 +20,7 @@ workflows:
             - build-gcc
           oid_test_args: "-ftype-graph"
           tests_regex: "OidIntegration\\..*"
-          exclude_regex: ".*inheritance_polymorphic.*|.*fbstring.*"
+          exclude_regex: ".*inheritance_polymorphic.*"
       - coverage:
           requires:
             - test-gcc
@@ -41,6 +41,7 @@ workflows:
             - build-clang
           oid_test_args: "-ftype-graph"
           tests_regex: "OidIntegration\\..*"
+          # Tests disabled due to bad DWARF generated by the old clang compiler in CI
           exclude_regex: ".*inheritance_polymorphic.*|.*fbstring.*|.*std_string_*|.*multi_arg_tb_.*|.*ignored_a"
 
 executors:

dev.oid.toml

@@ -46,5 +46,4 @@ containers = [
     "PWD/types/std_variant.toml",
     "PWD/types/thrift_isset_type.toml",
     "PWD/types/weak_ptr_type.toml",
-    "PWD/types/std_char_traits.toml",
 ]

oi/ContainerInfo.cpp

@@ -273,5 +273,6 @@ ContainerInfo::ContainerInfo(std::string typeName_,
     : typeName(std::move(typeName_)),
       matcher(getMatcher(typeName)),
       ctype(ctype_),
-      header(std::move(header_)) {
+      header(std::move(header_)),
+      codegen(Codegen{"// DummyDecl %1%\n", "// DummyFunc %1%\n"}) {
 }

oi/type_graph/CMakeLists.txt

@@ -15,6 +15,7 @@ add_library(type_graph
 )
 add_dependencies(type_graph libdrgn)
 target_link_libraries(type_graph
+  container_info
   symbol_service
 
   "-L${DRGN_PATH}/.libs"

oi/type_graph/TypeIdentifier.cpp

@@ -20,6 +20,15 @@
 
 namespace type_graph {
 
+// TODO:
+// - read these from a TOML file
+// - don't require specifying ctype and header
+const std::array<ContainerInfo, 3> TypeIdentifier::dummyContainers_ = {
+    ContainerInfo{"std::allocator", DUMMY_TYPE, "memory"},
+    ContainerInfo{"std::char_traits", DUMMY_TYPE, "string"},
+    ContainerInfo{"folly::fbstring_core", DUMMY_TYPE, "folly/FBString.h"},
+};
+
 Pass TypeIdentifier::createPass() {
   auto fn = [](TypeGraph& typeGraph) {
     TypeIdentifier typeId{typeGraph};
@@ -67,6 +76,24 @@ void TypeIdentifier::visit(Container& c) {
       continue;
     }
 
+    if (Class* paramClass = dynamic_cast<Class*>(param.type)) {
+      bool replaced = false;
+      for (const auto& info : dummyContainers_) {
+        if (std::regex_search(paramClass->fqName(), info.matcher)) {
+          // Create dummy containers
+          auto* dummy =
+              typeGraph_.make_type<Container>(info, param.type->size());
+          dummy->templateParams = paramClass->templateParams;
+          c.templateParams[i] = dummy;
+          replaced = true;
+        }
+      }
+
+      if (replaced) {
+        continue;
+      }
+    }
+
     if (std::find(stubParams.begin(), stubParams.end(), i) !=
         stubParams.end()) {
       size_t size = param.type->size();

oi/type_graph/TypeIdentifier.h

@@ -15,11 +15,13 @@
  */
 #pragma once
 
+#include <array>
 #include <unordered_set>
 
 #include "PassManager.h"
 #include "Types.h"
 #include "Visitor.h"
+#include "oi/ContainerInfo.h"
 
 namespace type_graph {
 
@@ -46,6 +48,8 @@ class TypeIdentifier : public RecursiveVisitor {
  private:
   std::unordered_set<Type*> visited_;
   TypeGraph& typeGraph_;
+
+  static const std::array<ContainerInfo, 3> dummyContainers_;
 };
 
 }  // namespace type_graph

test/ci.oid.toml

@@ -42,7 +42,6 @@ containers = [
     "../types/std_variant.toml",
     "../types/thrift_isset_type.toml",
     "../types/weak_ptr_type.toml",
-    "../types/std_char_traits.toml",
 ]
 
 [headers]

types/std_char_traits.toml

@@ -1,17 +0,0 @@
-[info]
-type_name = "std::char_traits"
-ctype = "DUMMY_TYPE"
-header = "string"
-
-# Old:
-typeName = "std::char_traits<"
-ns = ["namespace std"]
-numTemplateParams = 1
-
-[codegen]
-decl = """
-// DummyDecl %1%
-"""
-func = """
-// DummyFunc %1%
-"""