Introduce recursive dumping/diffing of types.

1) Types are now quantifed into one of the following:
	a) RecordType - structures/ unions/ classes.
	b) EnumType - enumerated types.
	c) QualifiedType - types with qualifiers intact.
	d) PointerType - pointer to a type.
	e) LvalueReferenceType
	f) RvalueReferenceType
	g) ArrayType

2) ABI diffing now diffs based on types directly / indirectly reachable
by function signatures / global variable types by default. Also added an option
to header-abi-diff:

-check-all-apis : Include changes to all APIs exported via exported
headers whether directly / indirectly used by function signatures /
global variable types or not.

3) Introduced an internal representation of abi information. This
enables us to switch formats of abi-dumps / abi-diffs more easily
without changing the AST parsing code. For example: In the future, if we
wanted to add options to view the abi-dumps in html / xml we could just
add classes which extended IRDumper and implement dumping methods.

4) The linked ABI dump of a shared library also includes a list of the
exported functions and objects collected from the .dynsym table. This makes it
possible to avoid false reports of ABI breakages when functions/ global
variables are moved to assembly files.

Test: abi-dumping and linking: make -j64 from ToT
      abi_diffing: change parameter types directly, indirectly.
      Ran tests/test.py with soong running the built tool, all tests passed.

Bug: 62060883

Bug: 63865902

Change-Id: Id9ef757165a1669049fde20bda4147d5074cc191

vndk/tools/header-checker/header-abi-diff/src/header_abi_diff.cpp

@@ -14,6 +14,8 @@
 
 #include "abi_diff.h"
 
+#include <fstream>
+
 #include <llvm/Support/CommandLine.h>
 #include <llvm/Support/FileSystem.h>
 #include <llvm/Support/raw_ostream.h>
@@ -49,6 +51,12 @@ static llvm::cl::opt<bool> advice_only(
     "advice-only", llvm::cl::desc("Advisory mode only"), llvm::cl::Optional,
     llvm::cl::cat(header_checker_category));
 
+static llvm::cl::opt<bool> check_all_apis(
+    "check-all-apis",
+    llvm::cl::desc("All apis, whether referenced or not, by exported symbols in"
+                   " the dynsym table of a shared library are checked"),
+    llvm::cl::Optional, llvm::cl::cat(header_checker_category));
+
 static llvm::cl::opt<bool> suppress_local_warnings(
     "suppress_local_warnings", llvm::cl::desc("suppress local warnings"),
     llvm::cl::Optional, llvm::cl::cat(header_checker_category));
@@ -58,6 +66,13 @@ static llvm::cl::opt<bool> allow_extensions(
     llvm::cl::desc("Do not return a non zero status on extensions"),
     llvm::cl::Optional, llvm::cl::cat(header_checker_category));
 
+static llvm::cl::opt<bool> allow_unreferenced_changes(
+    "allow-unreferenced-changes",
+    llvm::cl::desc("Do not return a non zero status on changes to data"
+                   " structures which are not directly referenced by exported"
+                   " APIs."),
+    llvm::cl::Optional, llvm::cl::cat(header_checker_category));
+
 static std::set<std::string> LoadIgnoredSymbols(std::string &symbol_list_path) {
   std::ifstream symbol_ifstream(symbol_list_path);
   std::set<std::string> ignored_symbols;
@@ -80,38 +95,50 @@ int main(int argc, const char **argv) {
     ignored_symbols = LoadIgnoredSymbols(ignore_symbol_list);
   }
   HeaderAbiDiff judge(lib_name, arch, old_dump, new_dump, compatibility_report,
-                      ignored_symbols);
+                      ignored_symbols, check_all_apis);
 
-  CompatibilityStatus status  = judge.GenerateCompatibilityReport();
+  abi_util::CompatibilityStatusIR status = judge.GenerateCompatibilityReport();
 
   std::string status_str = "";
-  switch (status) {
-    case CompatibilityStatus::INCOMPATIBLE:
-      status_str = "broken";
-      break;
-    case CompatibilityStatus::EXTENSION:
-      status_str = "extended";
-      break;
-    default:
-      break;
-  }
+  std::string unreferenced_change_str = "";
+  std::string error_or_warning_str = "\033[36;1mwarning: \033[0m";
 
+  if (status == abi_util::CompatibilityStatusIR::Incompatible) {
+    error_or_warning_str = "\033[31;1merror: \033[0m";
+    status_str = " INCOMPATIBLE CHANGES";
+  } else if (status & abi_util::CompatibilityStatusIR::Extension) {
+    status_str = "EXTENDING CHANGES";
+  }
+  if (status & abi_util::CompatibilityStatusIR::UnreferencedChanges) {
+    unreferenced_change_str = ", changes in exported headers, which are";
+    unreferenced_change_str += " not directly referenced by exported symbols.";
+    unreferenced_change_str += " This MIGHT be an ABI breaking change due to";
+    unreferenced_change_str += " internal typecasts.";
+
+  }
   if (!suppress_local_warnings && status) {
     llvm::errs() << "******************************************************\n"
-                 << "VNDK Abi "
+                 << error_or_warning_str
+                 << "VNDK library: "
+                 << lib_name
+                 << "'s ABI has "
                  << status_str
-                 << ":"
+                 << unreferenced_change_str
                  << " Please check compatiblity report at : "
                  << compatibility_report << "\n"
-                 << "*****************************************************\n";
+                 << "******************************************************\n";
+  }
+
+  if ((allow_extensions &&
+      (status & abi_util::CompatibilityStatusIR::Extension)) ||
+      (allow_unreferenced_changes &&
+      (status & abi_util::CompatibilityStatusIR::UnreferencedChanges))) {
+    return abi_util::CompatibilityStatusIR::Compatible;
   }
 
   if (advice_only) {
-    return CompatibilityStatus::COMPATIBLE;
+    return abi_util::CompatibilityStatusIR::Compatible;
   }
 
-  if (allow_extensions && status == CompatibilityStatus::EXTENSION) {
-    return CompatibilityStatus::COMPATIBLE;
-  }
   return status;
 }