From e2ec6458551d7b3acceb69f50c062ffe99159b2c Mon Sep 17 00:00:00 2001
From: Ryan Houdek <Sonicadvance1@gmail.com>
Date: Wed, 10 Mar 2021 11:08:30 -0800
Subject: [PATCH] Extends error message about not being able to find guest
 interpreter

Passes the result back up to the frontend as well which allows us to early exit correctly.
Also ensures that we return ENOEXEC on these error cases so if someone is waiting on a return value, they don't just get zero
Fixes #757
---
 External/FEXCore/Source/Utils/ELFLoader.cpp        | 8 +++++---
 External/FEXCore/include/FEXCore/Utils/ELFLoader.h | 2 ++
 Source/Tests/ELFLoader.cpp                         | 8 +++++++-
 Source/Tests/HarnessHelpers.h                      | 2 ++
 4 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/External/FEXCore/Source/Utils/ELFLoader.cpp b/External/FEXCore/Source/Utils/ELFLoader.cpp
index 4249725c1..64dd5327f 100644
--- a/External/FEXCore/Source/Utils/ELFLoader.cpp
+++ b/External/FEXCore/Source/Utils/ELFLoader.cpp
@@ -67,8 +67,10 @@ bool ELFContainer::IsSupportedELF(std::string const &Filename) {
 }
 
 ELFContainer::ELFContainer(std::string const &Filename, std::string const &RootFS, bool CustomInterpreter) {
+  Loaded = true;
   if (!LoadELF(Filename)) {
     LogMan::Msg::E("Couldn't Load ELF file");
+    Loaded = false;
     return;
   }
 
@@ -87,7 +89,9 @@ ELFContainer::ELFContainer(std::string const &Filename, std::string const &RootF
       // Found the interpreter in the rootfs
     }
     else if (!LoadELF(RawString)) {
-      LogMan::Msg::E("Couldn't load dynamic ELF file's interpreter");
+      LogMan::Msg::E("Failed to find guest ELF's interpter '%s'", RawString);
+      LogMan::Msg::E("Did you forget to set an x86 rootfs? Currently '%s'", RootFS.c_str());
+      Loaded = false;
       return;
     }
   }
@@ -129,8 +133,6 @@ bool ELFContainer::LoadELF(std::string const &Filename) {
   if (!ELFFile.is_open())
     return false;
 
-  LogMan::Throw::A(ELFFile.is_open(), "Failed to open file");
-
   ELFFile.seekg(0, ELFFile.end);
   FileSize = ELFFile.tellg();
   ELFFile.seekg(0, ELFFile.beg);
diff --git a/External/FEXCore/include/FEXCore/Utils/ELFLoader.h b/External/FEXCore/include/FEXCore/Utils/ELFLoader.h
index 258554961..cdb5ee05f 100644
--- a/External/FEXCore/include/FEXCore/Utils/ELFLoader.h
+++ b/External/FEXCore/include/FEXCore/Utils/ELFLoader.h
@@ -70,6 +70,7 @@ public:
 
   bool WasDynamic() const { return DynamicProgram; }
   bool HasDynamicLinker() const { return !DynamicLinker.empty(); }
+  bool WasLoaded() const { return Loaded; }
   std::string &InterpreterLocation() { return DynamicLinker; }
 
   std::vector<char const*> const *GetNecessaryLibs() const { return &NecessaryLibs; }
@@ -155,6 +156,7 @@ private:
   bool DynamicProgram{false};
   std::string DynamicLinker;
   ProgramHeader TLSHeader{};
+  bool Loaded {false};
 };
 
 } // namespace ELFLoader
diff --git a/Source/Tests/ELFLoader.cpp b/Source/Tests/ELFLoader.cpp
index 79696cc11..2a55c9fe5 100644
--- a/Source/Tests/ELFLoader.cpp
+++ b/Source/Tests/ELFLoader.cpp
@@ -220,10 +220,16 @@ int main(int argc, char **argv, char **const envp) {
     // Early exit if the program passed in doesn't exist
     // Will prevent a crash later
     LogMan::Msg::E("%s: command not found", Program.c_str());
-    return 0;
+    return -ENOEXEC;
   }
 
   FEX::HarnessHelper::ELFCodeLoader Loader{Program, LDPath(), Args, ParsedArgs, envp, &Environment};
+
+  if (!Loader.ELFWasLoaded()) {
+    // Loader couldn't load this program for some reason
+    return -ENOEXEC;
+  }
+
   FEXCore::Config::Set(FEXCore::Config::CONFIG_APP_FILENAME, std::filesystem::canonical(Program));
   FEXCore::Config::Set(FEXCore::Config::CONFIG_IS64BIT_MODE, Loader.Is64BitMode() ? "1" : "0");
 
diff --git a/Source/Tests/HarnessHelpers.h b/Source/Tests/HarnessHelpers.h
index 70acc286d..f876e315b 100644
--- a/Source/Tests/HarnessHelpers.h
+++ b/Source/Tests/HarnessHelpers.h
@@ -747,6 +747,8 @@ public:
     return Info;
   }
 
+  bool ELFWasLoaded() const { return File.WasLoaded(); }
+
 private:
   ::ELFLoader::ELFContainer File;
   ::ELFLoader::ELFSymbolDatabase DB;