<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=http://email.email.llvm.org/c/eJzlVk1v4zYQ_TXyZSBBH3Y2PviQrJMiQNFdLBDkGFDkSGJMkwI_rHV-fYeSAseuuyhQ9FRAYSQOOW-G8-bRtRHHzQsm5ReLwIO1qL06QscOUrfANEjnAsLQIdllA0cTwAYNyU0uhncaISlvty93Px5B6saA6b3cy3e0SbkGo8EEC7VRPv0wCKilZvYI0kPDpHIZ_AhaR7STT9roO4TeYho3f2zhZt8r9OjABc7RuSYodcySfJvkd9P4yZdFJlA1kA5y9omSvNpz18ZCb5w_w2nlgTAY6LCvab1pAK011iXVjEL-5mf8nJHIDA9xYXz5_eEeDkzR2XljQDHb4v9k8cXhOEOlJn65eM5O1oo2dMzTIB0MzH0iGZXnWt2T8ivUwcMTCAMtehCyaTAyFYIiVjGPc4FAYI9aRALMFDqgdTLysBlpSD6CwzPGJKv77xd4qy2RuvO-HytePtIzDEMmrOlr8zMjGtKMo793L9jPyuZMlF7Ikmb6o--MrpLqUaik2hbUBieYC579cxyVv7lWH45VO-jSHk44WXR3BWwcn4BT4Ty13HiolywPjs7p7yit1GE_rc5OaJCaz58jOKShFwSSCqxDmzrkns7bQWrRWIE2rZXhO0pwyxnvSGjuT6Ym6Gk1WbvGGetHs-uV9GdGQpa8iSnSi1ZSY8qU-liJ3RWXKdU57YxPHYkOpD1i3xmF0du49S3s-9Szep5qW0t6Qn1_Aujjq5CWMko57Ul7a_YmOv_wIY7apM4zT-lGuFaH-Ml3kDaW7TGKXkzN-KtnPI3fSCHJ8xvBfBJgchcV6JK-DYUAfjCwN9p3tKI1sTuYFlNTXa5X1LiOGnTqNpx793o05RJIfuGMWaMlijI1_Dnl7uBZ77QZNEzqv315_fb9tVivfpHqE7wFR52PLpLylNCcNni6WXbxQhFVuRaNyOMl8pfc_sucvpqghCa1osio-LB9egCLo9jwGPJxzvO3P55fexZr7NG-0opfZP2C8TrFySvvmG7JE9OEHHVKnu5IKjprkfD4yIFTYSnNSSE71pO-OWjo1gou7n2ug_YByjzLl6NIauPjfHFLE9lCbCqxrtZswQIlaje7vRGLYNXmXHVaUt5Qz4ITW3_-l87EpM8xgKhFq2pVFItug3WNvKmLVbFCntdlgdjc8kLw9W3FRFEuFKtRuQ0JX1KWGocpB3on3Vv8-wjkpsxLevIiL5br6iZb3hS4rG-44MsvTDR1ssxxT78wsugnM7Zd2M0ka6F1ZFTSeXcyMmr_ViOOAVOEXnqFm7EuFIMI9HuDuMRsAyR3bKIkt8x14_z7YgxvM8b2JyqGDg8>53511</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            bolt produces dwarf data that crashes dwz
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          kmod
      </td>
    </tr>
</table>

<pre>
    We're currently having an issue where if you run `dwz` (DWARF info optimizer) on our bolt-optimized binary it fails. Running `dwz` on the pre-bolt binary completes successfully.

Running `readelf -wi` on either the pre-bolt or post-bolt binary gives a number of errors:
```
readelf: Error: LEB value too large
readelf: Error: LEB value too large
readelf: Error: LEB value too large
readelf: Error: LEB value too large
readelf: Error: LEB value too large
readelf: Error: LEB value too large
```
so it's possible that this was an issue with the pre-bolt binary, but I do get different ultimate errors depending on the version of bolt I use.

[Pre-bolt binary](https://www.dropbox.com/s/ztdax3r0ad2tdi2/python3?dl=1)
[Post-bolt binary](https://www.dropbox.com/s/l0jsgnvy3gwn2rv/python3.bolt?dl=1)

I created the post-bolt binary using:
```
llvm-bolt ./python3 -o ./python3.bolt -update-debug-sections -reorder-blocks=cache+ -reorder-functions=hfsort+ -split-functions=3 -icf=1 -inline-all -split-eh -reorder-functions-use-hot-size -peepholes=all -jump-tables=aggressive -inline-ap -indirect-call-promotion=all -dyno-stats -use-gnu-stack -frame-opt=hot
```

Our project currently uses a version of bolt from two months ago, and that version of bolt leads to this error:
```
$ dwz python3.bolt
dwz: python3.bolt: Unknown DWARF DW_OP_195
```

I just tested bolt from current trunk (d329dfd0) and that version leads to this error:
```
$ dwz python3.bolt
dwz: python3.bolt: Couldn't find DIE referenced by DW_OP_GNU_parameter_ref
```

We haven't changed anything in our bolt usage recently, and this issue happens for us in Ubuntu 20.04 but not in 18.04.
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzlVk1v2zgQ_TXyZSBBlmQnPviQ1MkiwGJbFAhyDChxKDGhSYEfVp1fv0NJgWM3W-ylpwIKLXGG8zicN4-pDT9unzAprixCE6xF7dUROnaQugWmQToXEIYOyS4FHE0AGzQk65wPbzRCUlzvnm6-34PUwoDpvdzLN7RJsQGjwQQLtVE-fTdwqKVm9gjSg2BSuQy-B60j2ikmLfQdQm8xjYvflzRm3yv06MCFpkHnRFDqmCX5LslvpvFDLIuMoxKQDnKOiZKi2vPQxkJvnD_DaeWBMBjosK_J3whAa411STmjULz5GT9nJDLDXXSML3_f3cKBKTo7bwwoZlv8Q5wvDscZKjXxy8VzdrJWtKBjngbpYGDuA8moPJ_VPSm-QB08PAA30KIHLoXAyFQIiljFPM4FAo49ah4JMFPogNbJyEMx0pBiBIdnjElWt98u8FY7InXnfT9WvLinZxiGjFvT1-ZHRjSkGUd_b56zH6XNGS88lwXN9EffGV0m5T1XSblbUhucYC549v9xVP7iWn04lu2gC3s44WQx3Cdg4_gADRXOU8uNh3rJ8uDonP6L0kod9pN3dkKD1Hz8HMEhDT0nkJRjHdrUYePpvB2kFo3laNNameaVEtw1rOlIaG5PJhH05E3WTjhj_Wh2vZL-zEjIshExRXrRSmpMmVLvnth9EjKlOqed8akj0YG0R-w7ozBGG5e-hH2felbPU21rSU-o708AfXzl0lJGaUNr0t6avYnB32Pwozap88xTuhGu1SF-Nq-QCsv2GEUvpmb8p2c8jV9JISnyC8F8EGAKFxXokr6CtgB-MLA32nfk0ZrYHUzzqaku_RU1rqMGnboN5979fDdFBSS_cMas0RJFmRr-nHI38KhftRk0TOq_e3r--u15uVn9ItUHeAmOOh9dJOUpoTlt8HSzvMYLhZfFhguex0vkp9x-Z05fTFBck1rRzqj4sHu4A4uj2DRxy8c5z7_-eXzuWayxR_tMHr_I-gnjdYpT1KZjuqVITBNy1Cl5uiOp6KxFwmtGDpwKS2lOCtmxnvTNgaBbK7i49rEO2gco8iyvRpHUxsf55TVNZAu-Lfmm3LCFl17hdkQhsvFAtyedDLMCqHnZdMCNZa4b598WwartuTK1pM6hnkUpysP8k87kpc9xk1GvVuVquVx021oIvq6RFWy9qVh1veblWhSr8mqNFRmqhWI1KrclcUyKQuMw5UnvpI0LuS3ygp58mS-rTbnOqvUSq3rd8Ka6YlzUSZXjnv6HyOI-MmPbhd1OwhVaR0YlnXcnI6MGbzXiCEfxWaDi2-3r3vDFiLsd9_0vI3L37Q">