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  1. Sep 10, 2019
  2. May 09, 2018
    • Shiva Chen's avatar
      [DebugInfo] Add DILabel metadata and intrinsic llvm.dbg.label. · 2c864551
      Shiva Chen authored
      In order to set breakpoints on labels and list source code around
      labels, we need collect debug information for labels, i.e., label
      name, the function label belong, line number in the file, and the
      address label located. In order to keep these information in LLVM
      IR and to allow backend to generate debug information correctly.
      We create a new kind of metadata for labels, DILabel. The format
      of DILabel is
      
      !DILabel(scope: !1, name: "foo", file: !2, line: 3)
      
      We hope to keep debug information as much as possible even the
      code is optimized. So, we create a new kind of intrinsic for label
      metadata to avoid the metadata is eliminated with basic block.
      The intrinsic will keep existing if we keep it from optimized out.
      The format of the intrinsic is
      
      llvm.dbg.label(metadata !1)
      
      It has only one argument, that is the DILabel metadata. The
      intrinsic will follow the label immediately. Backend could get the
      label metadata through the intrinsic's parameter.
      
      We also create DIBuilder API for labels to be used by Frontend.
      Frontend could use createLabel() to allocate DILabel objects, and use
      insertLabel() to insert llvm.dbg.label intrinsic in LLVM IR.
      
      Differential Revision: https://reviews.llvm.org/D45024
      
      Patch by Hsiangkai Wang.
      
      llvm-svn: 331841
      2c864551
  3. Nov 17, 2017
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