[compiler-rt] [clang] [libc] [libcxx] [lld] [clang-tools-extra] [llvm] [flang] [ELF] --save-temps --lto-emit-asm: derive ELF/asm file names from bitcode file names (PR #78835)

[Fangrui Song via cfe-commits]

================
@@ -352,32 +357,49 @@ std::vector<InputFile *> BitcodeCompiler::compile() {
     pruneCache(config->thinLTOCacheDir, config->thinLTOCachePolicy, files);
 
   if (!config->ltoObjPath.empty()) {
-    saveBuffer(buf[0], config->ltoObjPath);
+    saveBuffer(buf[0].second, config->ltoObjPath);
     for (unsigned i = 1; i != maxTasks; ++i)
-      saveBuffer(buf[i], config->ltoObjPath + Twine(i));
-  }
-
-  if (config->saveTempsArgs.contains("prelink")) {
-    if (!buf[0].empty())
-      saveBuffer(buf[0], config->outputFile + ".lto.o");
-    for (unsigned i = 1; i != maxTasks; ++i)
-      saveBuffer(buf[i], config->outputFile + Twine(i) + ".lto.o");
-  }
-
-  if (config->ltoEmitAsm) {
-    saveBuffer(buf[0], config->outputFile);
-    for (unsigned i = 1; i != maxTasks; ++i)
-      saveBuffer(buf[i], config->outputFile + Twine(i));
-    return {};
+      saveBuffer(buf[i].second, config->ltoObjPath + Twine(i));
   }
 
+  bool savePrelink = config->saveTempsArgs.contains("prelink");
   std::vector<InputFile *> ret;
-  for (unsigned i = 0; i != maxTasks; ++i)
-    if (!buf[i].empty())
-      ret.push_back(createObjFile(MemoryBufferRef(buf[i], "lto.tmp")));
+  const char *ext = config->ltoEmitAsm ? ".s" : ".o";
+  for (unsigned i = 0; i != maxTasks; ++i) {
+    StringRef bitcodeFilePath;
+    StringRef objBuf;
+    if (files[i]) {
----------------
MaskRay wrote:

Clarified the comment a bit

https://github.com/llvm/llvm-project/pull/78835