Add opt-in native guest function replacement service

2026-10-28 02:56:36 -04:00 · 2026-09-14 15:58:24 -07:00
parent 4be26f162e
commit ae98d82f22
11 changed files with 260 additions and 2 deletions
@@ -0,0 +1,58 @@
+#include "code_generator.h"
+#include "control_flow.h"
+#include <cstdio>
+#include <cstdlib>
+
+static void check(bool condition, const char* message) {
+    if (!condition) {
+        std::fprintf(stderr, "FAIL: %s\n", message);
+        std::exit(1);
+    }
+}
+
+int main() {
+    constexpr uint32_t base = 0x80010000u;
+    PSXRecomp::PS1Executable exe{};
+    exe.header.load_address = exe.header.initial_pc = base;
+    const uint32_t words[] = {0x24020001u, 0x10400002u, 0, 0x24030002u, 0x03E00008u, 0};
+    for (uint32_t word : words)
+        for (unsigned byte = 0; byte < 4; ++byte)
+            exe.code_data.push_back(static_cast<uint8_t>(word >> (byte * 8)));
+    exe.header.file_size = static_cast<uint32_t>(exe.code_data.size());
+    PSXRecomp::Function function{};
+    function.start_addr = base;
+    function.size = exe.header.file_size;
+    function.end_addr = base + function.size;
+    function.name = "replacement_test";
+    PSXRecomp::ControlFlowAnalyzer analyzer(exe);
+    const auto flow = analyzer.analyze_function(function);
+    PSXRecomp::CodeGenConfig config{};
+    config.indent = "    ";
+    const auto generate = [&]() {
+        PSXRecomp::CodeGenerator generator(exe, config);
+        return generator.generate_function(function, flow).full_code;
+    };
+    const std::string hook = "if (psx_mod_try_function_replacement(cpu, 0x80010000u)) return;";
+    check(generate().find("psx_mod_try_function_replacement") == std::string::npos,
+          "default configuration emits no replacement call");
+    config.mod_function_entry_funcs.insert(base + 4);
+    check(generate().find("psx_mod_try_function_replacement") == std::string::npos,
+          "listing a different address does not hook this function");
+    config.mod_function_entry_funcs.insert(base);
+    const auto code = generate();
+    const auto at = code.find(hook);
+    check(at != std::string::npos && code.find(hook, at + 1) == std::string::npos,
+          "explicit function entry emits exactly one replacement call");
+    check(code.find("psx_mod_function_entry(cpu, 0x80010000u);") < at,
+          "existing preparation callback runs before replacement");
+    check(at < code.find("block_80010000:"), "fallback body remains after replacement");
+    const auto continuation = code.find("switch (_cont)");
+    check(continuation != std::string::npos && continuation < at,
+          "interior CPS resumes bypass fresh-entry replacement");
+    PSXRecomp::CodeGenerator generator(exe, config);
+    check(generator.build_shared_decls_header({}).find(
+              "extern int psx_mod_try_function_replacement(CPUState* cpu, uint32_t address);") !=
+              std::string::npos,
+          "generated shards declare runtime replacement ABI");
+    std::puts("PASS default-off, exact-entry, fallback and continuation-safe replacement codegen");
+}