Understanding Traces

yk can print the traces it has created to stderr to help with debugging. However, these traces are often lengthy, and not always easy to understand. This section briefly explains how to get yk to print its traces, and how to make them a bit easier to understand.

Producing a trace

YKD_LOG_IR

YKD_LOG_IR=[<path>:]<irstage_1>[,...,<irstage_n>] logs IR from different stages to path. The special value - (i.e. a single dash) can be used for <path> to indicate stderr.

The following ir_stages are supported:

• aot: the entire AOT IR for the interpreter.
• debugstrs: if compiled into the interpreter, “debug strings” specific to that interpreter (e.g. showing the opcodes executed).
• hir: high-level JIT IR.
• jit-asm: the assembler code of the compiled JIT IR trace.