versioner: remove parsing of platforms.

Leave the machinery to use a symbol database around so that we can
switch over to parsing libc.map.txt in the future.

Test: tools/versioner/run_tests.py
Change-Id: Ifa8899b698764e4aeb6aa8bb2cdb2d44a67b863f
diff --git a/tools/versioner/src/versioner.cpp b/tools/versioner/src/versioner.cpp
index a082f07..efb39bd 100644
--- a/tools/versioner/src/versioner.cpp
+++ b/tools/versioner/src/versioner.cpp
@@ -33,6 +33,7 @@
 #include <iostream>
 #include <map>
 #include <memory>
+#include <optional>
 #include <set>
 #include <sstream>
 #include <string>
@@ -614,9 +615,6 @@
     std::string versioner_dir = to_string(top) + "/bionic/tools/versioner";
     location.header_path = versioner_dir + "/current";
     location.dependency_dir = versioner_dir + "/dependencies";
-    if (platform_dir.empty()) {
-      platform_dir = versioner_dir + "/platforms";
-    }
   } else {
     if (!android::base::Realpath(argv[optind], &location.header_path)) {
       err(1, "failed to get realpath for path '%s'", argv[optind]);
@@ -653,16 +651,10 @@
   }
 
   std::set<CompilationType> compilation_types;
-  NdkSymbolDatabase symbol_database;
+  std::optional<NdkSymbolDatabase> symbol_database;
 
   compilation_types = generateCompilationTypes(selected_architectures, selected_levels);
 
-  // Do this before compiling so that we can early exit if the platforms don't match what we
-  // expect.
-  if (!platform_dir.empty()) {
-    symbol_database = parsePlatforms(compilation_types, platform_dir);
-  }
-
   auto start = std::chrono::high_resolution_clock::now();
   std::unique_ptr<HeaderDatabase> declaration_database =
       compileHeaders(compilation_types, location);
@@ -682,8 +674,8 @@
       failed = true;
     }
 
-    if (!platform_dir.empty()) {
-      if (!checkVersions(compilation_types, declaration_database.get(), symbol_database)) {
+    if (symbol_database) {
+      if (!checkVersions(compilation_types, declaration_database.get(), *symbol_database)) {
         printf("versioner: version check failed\n");
         failed = true;
       }