Decompile __init_cpp_exceptions.cpp

config/RSBE01_02/config.yml

@@ -6,6 +6,12 @@ symbols: config/RSBE01_02/symbols.txt
 mw_comment_version: 14 # GC 3.0a5.2 linker
 quick_analysis: true # Faster reruns after full analysis
 
+# The .ctors$10/.dtors$15 entries that reference these are data-only, so the
+# linker drops them unless the symbols are kept alive explicitly.
+force_active:
+- __init_cpp_exceptions_reference
+- __fini_cpp_exceptions_reference
+
 extract:
 - symbol: HomeBtnIcon
   binary: HomeBtnIcon.bin

configure.py

@@ -277,7 +277,7 @@ def MatchingFor(*versions):
         "host": False,
         "objects": [
             Object(NonMatching, "Runtime.PPCEABI.H/global_destructor_chain.c"),
-            Object(NonMatching, "Runtime.PPCEABI.H/__init_cpp_exceptions.cpp"),
+            Object(Matching, "Runtime.PPCEABI.H/__init_cpp_exceptions.cpp"),
         ],
     },
     # The DOL

src/Runtime.PPCEABI.H/__init_cpp_exceptions.cpp

@@ -0,0 +1,53 @@
+extern "C" {
+
+typedef struct ExtabIndexInfo {
+    unsigned long size;
+    struct ExtabIndexInfo* extab;
+    unsigned long extabend;
+} ExtabIndexInfo;
+
+extern const ExtabIndexInfo _eti_init_info[];
+
+int __register_fragment(const ExtabIndexInfo* info, char* toc);
+void __unregister_fragment(int fragmentID);
+void __destroy_global_chain(void);
+
+// The unit owns 8 bytes of .sdata but only the first word is ever read, and a
+// lone int leaves the section 4 bytes short of the split. Pairing the id with
+// its trailing word reproduces the section exactly.
+static struct {
+    int id;
+    int pad;
+} fragment = { -2, 0 };
+
+void __init_cpp_exceptions(void)
+{
+    // __register_fragment takes the TOC in r2, which has no C spelling.
+    register char* toc;
+    if (fragment.id == -2) {
+        asm { mr toc, r2 }
+        fragment.id = __register_fragment(_eti_init_info, toc);
+    }
+}
+
+void __fini_cpp_exceptions(void)
+{
+    if (fragment.id != -2) {
+        __unregister_fragment(fragment.id);
+        fragment.id = -2;
+    }
+}
+
+#pragma section ".ctors$10"
+__declspec(section ".ctors$10")
+    extern void* const __init_cpp_exceptions_reference = (void*) __init_cpp_exceptions;
+
+#pragma section ".dtors$10"
+__declspec(section ".dtors$10") __declspec(weak)
+    extern void* const __destroy_global_chain_reference = (void*) __destroy_global_chain;
+
+#pragma section ".dtors$15"
+__declspec(section ".dtors$15")
+    extern void* const __fini_cpp_exceptions_reference = (void*) __fini_cpp_exceptions;
+
+}