arch,base,sim: Move Process loader hooks into the Process class.

This code was originally in the ObjectFile class, but not all object
files will become Processes. All Processes will ultimately come from
ObjectFiles though, so it makes more sense to put that class there.

Change-Id: Ie73e4cdecbb51ce53d24cf68911a6cfc0685d771
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21468
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

src/arch/alpha/linux/process.cc

@@ -48,7 +48,7 @@ using namespace AlphaISA;
 namespace
 {
 
-class AlphaLinuxObjectFileLoader : public ObjectFile::Loader
+class AlphaLinuxObjectFileLoader : public Process::Loader
 {
   public:
     Process *

src/arch/arm/freebsd/process.cc

@@ -56,7 +56,7 @@ using namespace ArmISA;
 namespace
 {
 
-class ArmFreebsdObjectFileLoader : public ObjectFile::Loader
+class ArmFreebsdObjectFileLoader : public Process::Loader
 {
   public:
     Process *

src/arch/arm/linux/process.cc

@@ -65,7 +65,7 @@ using namespace ArmISA;
 namespace
 {
 
-class ArmLinuxObjectFileLoader : public ObjectFile::Loader
+class ArmLinuxObjectFileLoader : public Process::Loader
 {
   public:
     Process *

src/arch/mips/linux/process.cc

@@ -51,7 +51,7 @@ using namespace MipsISA;
 namespace
 {
 
-class MipsLinuxObjectFileLoader : public ObjectFile::Loader
+class MipsLinuxObjectFileLoader : public Process::Loader
 {
   public:
     Process *

src/arch/power/linux/process.cc

@@ -51,7 +51,7 @@ using namespace PowerISA;
 namespace
 {
 
-class PowerLinuxObjectFileLoader : public ObjectFile::Loader
+class PowerLinuxObjectFileLoader : public Process::Loader
 {
   public:
     Process *

src/arch/riscv/linux/process.cc

@@ -55,7 +55,7 @@ using namespace RiscvISA;
 namespace
 {
 
-class RiscvLinuxObjectFileLoader : public ObjectFile::Loader
+class RiscvLinuxObjectFileLoader : public Process::Loader
 {
   public:
     Process *

src/arch/sparc/linux/process.cc

@@ -48,7 +48,7 @@ using namespace SparcISA;
 namespace
 {
 
-class SparcLinuxObjectFileLoader : public ObjectFile::Loader
+class SparcLinuxObjectFileLoader : public Process::Loader
 {
   public:
     Process *

src/arch/sparc/solaris/process.cc

@@ -46,7 +46,7 @@ using namespace SparcISA;
 namespace
 {
 
-class SparcSolarisObjectFileLoader : public ObjectFile::Loader
+class SparcSolarisObjectFileLoader : public Process::Loader
 {
   public:
     Process *

src/arch/x86/linux/process.cc

@@ -58,7 +58,7 @@ using namespace X86ISA;
 namespace
 {
 
-class X86LinuxObjectFileLoader : public ObjectFile::Loader
+class X86LinuxObjectFileLoader : public Process::Loader
 {
   public:
     Process *

src/base/loader/object_file.cc

@@ -42,37 +42,6 @@ using namespace std;
 
 ObjectFile::ObjectFile(ImageFileDataPtr ifd) : ImageFile(ifd) {}
 
-namespace
-{
-
-typedef std::vector<ObjectFile::Loader *> LoaderList;
-
-LoaderList &
-object_file_loaders()
-{
-    static LoaderList loaders;
-    return loaders;
-}
-
-} // anonymous namespace
-
-ObjectFile::Loader::Loader()
-{
-    object_file_loaders().emplace_back(this);
-}
-
-Process *
-ObjectFile::tryLoaders(ProcessParams *params, ObjectFile *obj_file)
-{
-    for (auto &loader: object_file_loaders()) {
-        Process *p = loader->load(params, obj_file);
-        if (p)
-            return p;
-    }
-
-    return nullptr;
-}
-
 namespace {
 
 typedef std::vector<ObjectFileFormat *> ObjectFileFormatList;

src/base/loader/object_file.hh

@@ -40,8 +40,6 @@
 #include "base/logging.hh"
 #include "base/types.hh"
 
-class Process;
-class ProcessParams;
 class SymbolTable;
 
 class ObjectFile : public ImageFile
@@ -131,38 +129,6 @@ class ObjectFile : public ImageFile
 
   public:
     Addr entryPoint() const { return entry; }
-
-    /**
-     * Each instance of a Loader subclass will have a chance to try to load
-     * an object file when tryLoaders is called. If they can't because they
-     * aren't compatible with it (wrong arch, wrong OS, etc), then they
-     * silently fail by returning nullptr so other loaders can try.
-     */
-    class Loader
-    {
-      public:
-        Loader();
-
-        /* Loader instances are singletons. */
-        Loader(const Loader &) = delete;
-        void operator=(const Loader &) = delete;
-
-        virtual ~Loader() {}
-
-        /**
-         * Each subclass needs to implement this method. If the loader is
-         * compatible with the passed in object file, it should return the
-         * created Process object corresponding to it. If not, it should fail
-         * silently and return nullptr. If there's a non-compatibliity related
-         * error like file IO errors, etc., those should fail non-silently
-         * with a panic or fail as normal.
-         */
-        virtual Process *load(ProcessParams *params, ObjectFile *obj_file) = 0;
-    };
-
-    // Try all the Loader instance's "load" methods one by one until one is
-    // successful. If none are, complain and fail.
-    static Process *tryLoaders(ProcessParams *params, ObjectFile *obj_file);
 };
 
 class ObjectFileFormat

src/sim/process.cc

@@ -75,6 +75,37 @@
 using namespace std;
 using namespace TheISA;
 
+namespace
+{
+
+typedef std::vector<Process::Loader *> LoaderList;
+
+LoaderList &
+process_loaders()
+{
+    static LoaderList loaders;
+    return loaders;
+}
+
+} // anonymous namespace
+
+Process::Loader::Loader()
+{
+    process_loaders().emplace_back(this);
+}
+
+Process *
+Process::tryLoaders(ProcessParams *params, ObjectFile *obj_file)
+{
+    for (auto &loader: process_loaders()) {
+        Process *p = loader->load(params, obj_file);
+        if (p)
+            return p;
+    }
+
+    return nullptr;
+}
+
 static std::string
 normalize(std::string& directory)
 {
@@ -554,7 +585,7 @@ ProcessParams::create()
     ObjectFile *obj_file = createObjectFile(executable);
     fatal_if(!obj_file, "Cannot load object file %s.", executable);
 
-    Process *process = ObjectFile::tryLoaders(this, obj_file);
+    Process *process = Process::tryLoaders(this, obj_file);
     fatal_if(!process, "Unknown error creating process object.");
 
     return process;

src/sim/process.hh

@@ -183,6 +183,38 @@ class Process : public SimObject
 
     SETranslatingPortProxy initVirtMem; // memory proxy for initial image load
 
+    /**
+     * Each instance of a Loader subclass will have a chance to try to load
+     * an object file when tryLoaders is called. If they can't because they
+     * aren't compatible with it (wrong arch, wrong OS, etc), then they
+     * silently fail by returning nullptr so other loaders can try.
+     */
+    class Loader
+    {
+      public:
+        Loader();
+
+        /* Loader instances are singletons. */
+        Loader(const Loader &) = delete;
+        void operator=(const Loader &) = delete;
+
+        virtual ~Loader() {}
+
+        /**
+         * Each subclass needs to implement this method. If the loader is
+         * compatible with the passed in object file, it should return the
+         * created Process object corresponding to it. If not, it should fail
+         * silently and return nullptr. If there's a non-compatibliity related
+         * error like file IO errors, etc., those should fail non-silently
+         * with a panic or fail as normal.
+         */
+        virtual Process *load(ProcessParams *params, ObjectFile *obj_file) = 0;
+    };
+
+    // Try all the Loader instance's "load" methods one by one until one is
+    // successful. If none are, complain and fail.
+    static Process *tryLoaders(ProcessParams *params, ObjectFile *obj_file);
+
     ObjectFile *objFile;
     MemoryImage image;
     MemoryImage interpImage;