[Lldb-commits] [PATCH] D79491: [lldb] Revive TestBasicEntryValuesX86_64

[Pavel Labath via Phabricator via lldb-commits]

labath marked 2 inline comments as done.
labath added a comment.

I should note that I did look into making an assembly file out of this, but that turned out to be more complicated than I expected and then David convinced me that it should be possible to write this in a way that prevents the optimizer from being too smart. Nevertheless, I am still interested in making assembly-based tests for this (and similar features) because it enables testing scenarios that we could not get (reliably or at all) a compiler to produce.



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Comment at: lldb/test/API/functionalities/param_entry_vals/basic_entry_values_x86_64/main.cpp:21-22
+  ++global;
   //% self.filecheck("image lookup -va $pc", "main.cpp", "-check-prefix=FUNC1-DESC")
   // FUNC1-DESC: name = "sink", type = "int &", location = DW_OP_entry_value(DW_OP_reg5 RDI)
 }
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If we remove this check, the test will be completely architecture- and abi-independent. I don't think this check is particularly useful (we use llvm to print the dwarf expression, and there are better ways to test the image lookup command). Maybe we could just keep it to ensure that we really are evaluating entry values, but change the check the just search for the DW_OP_entry_value keyword (and then run the test on all architectures)?


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Comment at: lldb/test/API/functionalities/param_entry_vals/basic_entry_values_x86_64/main.cpp:61-62
-
-  //% self.filecheck("expr x", "main.cpp", "-check-prefix=FUNC2-EXPR-FAIL", expect_cmd_failure=True)
-  // FUNC2-EXPR-FAIL: couldn't get the value of variable x: variable not available
-
----------------
I'm not sure why this was previously expected to fail -- I don't see a reason why the compiler couldn't emit an entry value for `x` now, or before this patch. And in the new setup, the expression actually succeeds.


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https://reviews.llvm.org/D79491