[clang] [clang-sycl-linker] Generate SymbolTable for each image (PR #161287)

[Joseph Huber via cfe-commits]

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@@ -486,6 +492,22 @@ Error runSYCLLink(ArrayRef<std::string> Files, const ArgList &Args) {
   SmallVector<std::string> SplitModules;
   SplitModules.emplace_back(*LinkedFile);
 
+  // Generate symbol table.
+  SmallVector<std::string> SymbolTable;
+  for (size_t I = 0, E = SplitModules.size(); I != E; ++I) {
+    Expected<std::unique_ptr<Module>> ModOrErr =
+        getBitcodeModule(SplitModules[I], C);
+    if (!ModOrErr)
+      return ModOrErr.takeError();
+
+    SmallVector<StringRef> Symbols;
+    for (Function &F : **ModOrErr) {
+      if (isKernel(F))
+        Symbols.push_back(F.getName());
+    }
+    SymbolTable.emplace_back(llvm::join(Symbols.begin(), Symbols.end(), "\n"));
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jhuber6 wrote:

Right, that's a data structure that's basically `Map<string, const char *>` so it doesn't know how to iterate over multiple of them. Now I'm wishing I put the size of the string in as part of the `StringEntry`. (You could put that as a string in a different string entry if you really wanted to). My main desire to just stick with normal strings is that you don't need to bother with the `join` stuff, but if it's that much of a pain I suppose it makes sense.

https://github.com/llvm/llvm-project/pull/161287