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3507. P0881R7 ("stacktrace") does not define "actual file name", "actual line number"

Section: [stacktrace.entry.query] Status: Open Submitter: Thomas Köppe Opened: 2020-12-02 Last modified: 2023-01-11

Priority: 2

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The specification of [stacktrace.entry.query] uses the terms "presumed or actual name of the source file" and "actual line number". It makes reference to 15.11 [cpp.predefined], which introduces the term "presumed". It does not clearly define the term, but it describes how the presumed values can be modified with preprocessor directives. However, there is no definition whatsoever of "actual".

The term should either be defined, or we should strike the "actual" parts of the stacktrace wording. We should consult implementers about this.

I don't have a proposed resolution, but if we want to keep "actual", then perhaps we should define both "presumed" and "actual" in 15.11 [cpp.predefined].

[2021-01-15; Telecon prioritization]

Set priority to 2 following reflector and telecon discussions.

[2023-01-11; LWG telecon]

We want to know the original intended meaning of "actual line number" here. Presumably debuginfo stored in binaries uses a real line number in the source, not one that might have been set by a #line directive. The "presumed or actual" wording was added in R2 of the paper, possibly as a result of LWG review.

Proposed resolution: