[llvm] [clang] [SystemZ][z/OS] This change adds support for the PPA2 section in zOS (PR #68926)

[Ulrich Weigand via cfe-commits]

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@@ -976,6 +976,46 @@ void CodeGenModule::Release() {
       Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity();
   getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth);
 
+  if (getTriple().isOSzOS()) {
+    getModule().addModuleFlag(llvm::Module::Warning,
+                              "zos_product_major_version",
+                              uint32_t(CLANG_VERSION_MAJOR));
+    getModule().addModuleFlag(llvm::Module::Warning,
+                              "zos_product_minor_version",
+                              uint32_t(CLANG_VERSION_MINOR));
+    getModule().addModuleFlag(llvm::Module::Warning, "zos_product_patchlevel",
+                              uint32_t(CLANG_VERSION_PATCHLEVEL));
+    std::string ProductId;
+#ifdef CLANG_VENDOR
+    ProductId = #CLANG_VENDOR;
+#else
+    ProductId = "clang";
+#endif
+    // Remove - from Product Id, which makes it consistent with legacy.
+    std::size_t DashFound = ProductId.find("-");
+    if (DashFound != std::string::npos)
+      ProductId.erase(ProductId.begin() + DashFound);
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uweigand wrote:

Now that this code is moved here, it could only make a difference when compiling clang with a `CLANG_VENDOR` containing a dash.  If that is a problem for your use case, then why not simply build with the desired `CLANG_VENDOR` to begin with?  It's a bit unclear to me which general problem this code solves at this place now.

https://github.com/llvm/llvm-project/pull/68926