Currently, the tests that check stepping through atomic sequences use a
hardcoded step distance, which is unreliable because this distance
depends on LLVM's codegeneration. The relocations that clang emits can
change the distance of the step.
Additionally, it was a poor idea to compute and check the step distance
because that is not what we should actually be verifying. In the tests
we already know where execution should stop after the step - for
example, at a branch instruction - therefore, it is better to check the
opcode of the instruction rather than the step distance. The step
distance itself is not important and can sometimes be misleading.
This patch rewrites the tests, so now they checks the opcode of the
instruction after the step instead of the step distance.
lldb-server had limited support for single-stepping through the lr/sc
atomic sequence. This patch enhances that support for all possible
atomic sequences.
The previous version contained an incorrect regex pattern in the test,
causing the riscv-specific test to run on other platforms. This reland
fixes the regex (see lldb/test/API/riscv/step/TestSoftwareStep.py)
lldb-server had limited support for single-stepping through the lr/sc
atomic sequence. This patch enhances that support for all possible
atomic sequences.
