[llvm] [DTLTO] [LLVM] Initial DTLTO cache implementation (PR #156433)

[Teresa Johnson via llvm-commits]

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@@ -2488,20 +2530,26 @@ class OutOfProcessThinBackend : public CGThinBackend {
         removeFile(JsonFile);
     });
 
-    SmallVector<StringRef, 3> Args = {DistributorPath};
-    llvm::append_range(Args, DistributorArgs);
-    Args.push_back(JsonFile);
-    std::string ErrMsg;
-    if (sys::ExecuteAndWait(Args[0], Args,
-                            /*Env=*/std::nullopt, /*Redirects=*/{},
-                            /*SecondsToWait=*/0, /*MemoryLimit=*/0, &ErrMsg)) {
-      return make_error<StringError>(
-          BCError + "distributor execution failed" +
-              (!ErrMsg.empty() ? ": " + ErrMsg + Twine(".") : Twine(".")),
-          inconvertibleErrorCode());
+    if (CachedJobs.load() < Jobs.size()) {
+      SmallVector<StringRef, 3> Args = {DistributorPath};
+      llvm::append_range(Args, DistributorArgs);
+      Args.push_back(JsonFile);
+      std::string ErrMsg;
+      if (sys::ExecuteAndWait(Args[0], Args,
+                              /*Env=*/std::nullopt, /*Redirects=*/{},
+                              /*SecondsToWait=*/0, /*MemoryLimit=*/0,
+                              &ErrMsg)) {
+        return make_error<StringError>(
+            BCError + "distributor execution failed" +
+                (!ErrMsg.empty() ? ": " + ErrMsg + Twine(".") : Twine(".")),
+            inconvertibleErrorCode());
+      }
     }
 
     for (auto &Job : Jobs) {
+      if (Cache.isValid() && !Job.CacheKey.empty())
----------------
teresajohnson wrote:

Can Cache.isValid be false if CacheKey is not empty?

https://github.com/llvm/llvm-project/pull/156433