refactor(driver): move PATH-mode lli runner into PathRunner

PathRunner.cc holds the lli lookup, LLVM 23 version check and lli
execution, and is built only with CPSC_RUN_MODE=PATH like
EmbeddedRunner.cc is for EMBEDDED.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 83 insertions, 0 deletions

diff --git a/tools/driver/PathRunner.cc b/tools/driver/PathRunner.cc
new file mode 100644
index 0000000..01d8478
--- /dev/null
+++ b/tools/driver/PathRunner.cc
@@ -0,0 +1,83 @@
+#include "PathRunner.h"
+#include "cps/Diagnostics.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/FileUtilities.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Program.h"
+#include "llvm/Support/Regex.h"
+#include "llvm/Support/raw_ostream.h"
+
+namespace {
+
+bool checkLliVersion(llvm::StringRef LliPath) {
+    llvm::SmallString<256> VersionPath;
+    if (auto EC = llvm::sys::fs::createTemporaryFile("cpsc-lli-version", "txt", VersionPath)) {
+        llvm::errs() << cps::diagnosticPrefix(cps::Severity::Fatal) << "cannot check lli version: " << EC.message() << "\n";
+        return false;
+    }
+    llvm::FileRemover TemporaryVersion(VersionPath);
+    std::string ExecutionError;
+    int Result = llvm::sys::ExecuteAndWait(LliPath, {LliPath, "--version"},
+        std::nullopt, {llvm::StringRef(""), llvm::StringRef(VersionPath), llvm::StringRef("")},
+        5, 0, &ExecutionError);
+    if (Result != 0) {
+        llvm::errs() << cps::diagnosticPrefix(cps::Severity::Fatal) << "cannot check lli version at '" << LliPath
+                     << "' (status " << Result << ")";
+        if (!ExecutionError.empty()) llvm::errs() << ": " << ExecutionError;
+        llvm::errs() << "\n";
+        return false;
+    }
+    auto Version = llvm::MemoryBuffer::getFile(VersionPath);
+    if (!Version) {
+        llvm::errs() << cps::diagnosticPrefix(cps::Severity::Fatal) << "cannot read lli version: "
+                     << Version.getError().message() << "\n";
+        return false;
+    }
+    llvm::SmallVector<llvm::StringRef, 2> Matches;
+    if (!llvm::Regex("LLVM version ([0-9]+)\\.").match((*Version)->getBuffer(), &Matches)) {
+        llvm::errs() << cps::diagnosticPrefix(cps::Severity::Fatal) << "cannot identify LLVM version of lli at '"
+                     << LliPath << "'; LLVM 23 is required\n";
+        return false;
+    }
+    if (Matches[1] != "23") {
+        llvm::errs() << cps::diagnosticPrefix(cps::Severity::Fatal) << "-r requires lli from LLVM 23; found LLVM "
+                     << Matches[1] << " at '" << LliPath << "'\n";
+        return false;
+    }
+    return true;
+}
+
+} // namespace
+
+bool findLli(std::string &LliPath) {
+    auto Lli = llvm::sys::findProgramByName("lli");
+    if (!Lli) {
+        llvm::errs() << cps::diagnosticPrefix(cps::Severity::Fatal) << "-r requires lli from LLVM 23 in PATH: " << Lli.getError().message() << "\n";
+        return false;
+    }
+    LliPath = *Lli;
+    return checkLliVersion(LliPath);
+}
+
+int runLli(const std::string &LliPath, const std::string &IRPath,
+           const std::vector<std::string> &Objects) {
+    llvm::SmallString<256> RunPath(IRPath);
+    if (auto PathError = llvm::sys::fs::make_absolute(RunPath)) {
+        llvm::errs() << cps::diagnosticPrefix(cps::Severity::Error) << "cannot resolve IR path: " << PathError.message() << "\n";
+        return 1;
+    }
+    std::string ExecutionError;
+    std::vector<std::string> LliArgs = {LliPath};
+    for (const auto &Object : Objects) LliArgs.push_back("-extra-object=" + Object);
+    LliArgs.push_back(std::string(RunPath));
+    std::vector<llvm::StringRef> LliArgv(LliArgs.begin(), LliArgs.end());
+    int Result = llvm::sys::ExecuteAndWait(LliPath, LliArgv,
+                                         std::nullopt, {}, 0, 0, &ExecutionError);
+    if (Result < 0) {
+        llvm::errs() << cps::diagnosticPrefix(cps::Severity::Error) << "lli execution failed (status " << Result << "): "
+                     << ExecutionError << "\n";
+        return 1;
+    }
+    return Result;
+}