Nerixyz 91b90652bb
Reland "[CodeView] Generate S_DEFRANGE_REGISTER_REL_INDIR" (#189401)
Initially added in #187709. It was reverted in #188833, because
[llvm-clang-x86_64-sie-win](https://lab.llvm.org/buildbot/#/builders/46/builds/32873)
was failing in
`cross-project-tests/debuginfo-tests/dexter-tests/nrvo.cpp`.

The test passed for me locally. After checking on another machine, I
found that `S_DEFRANGE_REGISTER_REL_INDIR` is only supported by
dbgeng/WinDbg from Windows 10.0 Build 19041 (released 2020) onwards.
SDKs before this will fail to read the value. That buildbot is on
Windows 10.0 Build 17763.

I'm not sure if we should make the generation of that record
conditional. Debuggers that can't read the record will skip it. They'll
still see that there's some local variable, but won't be able to display
the value.

As far as I know, users of older Windows 10 builds should be able to
install a newer Windows SDK and use the WinDbg from that version. But I
haven't tested that.
2026-04-02 12:15:11 +02:00
..

                                                                   -*- rst -*-
This is a collection of tests to check debugging information generated by 
compiler. This test suite can be checked out inside clang/test folder. This 
will enable 'make test' for clang to pick up these tests.

Some tests (in the 'llgdb-tests' directory) are written with debugger
commands and checks for the intended debugger output in the source file,
using DEBUGGER: and CHECK: as prefixes respectively.

For example::

  define i32 @f1(i32 %i) nounwind ssp {
  ; DEBUGGER: break f1
  ; DEBUGGER: r
  ; DEBUGGER: p i 
  ; CHECK: $1 = 42 
  entry:
  }

is a testcase where the debugger is asked to break at function 'f1' and 
print value of argument 'i'. The expected value of 'i' is 42 in this case.

Other tests are written for use with the 'Dexter' tool (in the 'dexter-tests'
and 'dexter' directories respectively). These use a domain specific language
in comments to describe the intended debugger experience in a more abstract
way than debugger commands. This allows for testing integration across
multiple debuggers from one input language.

For example::

  void __attribute__((noinline, optnone)) bar(int *test) {}
  int main() {
    int test;
    test = 23;
    bar(&test); // DexLabel('before_bar')
    return test; // DexLabel('after_bar')
  }

  // DexExpectWatchValue('test', '23', on_line='before_bar')
  // DexExpectWatchValue('test', '23', on_line='after_bar')

Labels two lines with the names 'before_bar' and 'after_bar', and records that
the 'test' variable is expected to have the value 23 on both of them.