View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0001423 | Issue 8 drafts | Shell and Utilities | public | 2020-11-18 21:28 | 2021-03-11 16:39 |
| Reporter | joerg | Assigned To | |||
| Priority | normal | Severity | Objection | Type | Clarification Requested |
| Status | Closed | Resolution | Withdrawn | ||
| Product Version | Draft 1.1 | ||||
| Name | Jörg Schilling | ||||
| Organization | |||||
| User Reference | |||||
| Section | make | ||||
| Page Number | 2888 | ||||
| Line Number | 97001-97006 | ||||
| Final Accepted Text | |||||
| Summary | 0001423: The make commandline argument macro::=value has unspecified bahavior | ||||
| Description | It is common accepted behavior that make macro=value overwrites definitions from makefiles. This can be implemented in two ways - evaluate the command line argument before reading makefiles and mark the related macro readonly - evaluate the command line argument after reading makefiles Both methods result in the same result (even though the assumption that command line arguments overwrite makefiles should be specified in the standard). Note that the current text allows a make implementation to evaluate command line macro assignments before reading makefiles witout making them readonly and if this would be done, the assignments in the makefiles would overwrite the commandline arguments. With the command make macro::=value the two possible implementations mentioned above give different results. My gut feeling is that people would expect "make 'macro::=$(macro2)'" expands $(macro2) as defined in the makefiles instead of expanding it as empty macro value, but this needs to be specified in the standard. | ||||
| Desired Action | After line 97005 after the text "in the order they appear" insert the text: as if the command line macro definitions were evaluated after reading the makefiles | ||||
| Tags | No tags attached. | ||||
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The claim that the behaviour is unspecified is incorrect, and the suggested change would contradict existing text that specifies the behaviour here (not because it would require different behaviour, but because the existing text handles this a different way). See draft 1.1 page 2896 lines 97343-97361 noting in particular line 97344 "before the makefile(s) are read" and lines 97360-97361 "Macros defined in the makefile(s) shall not override macro definitions from source 1 or source 2." Can we process this bug as withdrawn? |
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The problem with that text is that it makes macro::=value on the command line a useless feature since at that time, there are no macro definitions that could be expanded. So it would be a wise idea to remove macro::= value from the beginning of line 97002. This definitely needs to be discussed. |
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There can be macro definitions from earlier command line macro assignments. E.g.:echo 'all: ; echo $(BAR)' | make -f - FOO=1 BAR::='$(FOO)' FOO=2is required to output 1 whereas with BAR='$(FOO)' it would output 2. |
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Just because you are correct with this note, people would intuitively expect make BAR::='$(FOO)' to expand previous definitions from FOO in the makefiles. I know this is harder to implement, but shouldn't we avoid to standardize unexpected results? |
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There is no such thing as "previous definitions from FOO in the makefiles". The standard clearly states that macro definitions are taken from the command line before the makefile(s) are read, as I pointed out in my first note. Of course the usual "as if" rule applies here. |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2020-11-18 21:28 | joerg | New Issue | |
| 2020-11-18 21:28 | joerg | Name | => Jörg Schilling |
| 2020-11-18 21:28 | joerg | Section | => make |
| 2020-11-18 21:28 | joerg | Page Number | => 2888 |
| 2020-11-18 21:28 | joerg | Line Number | => 97001-97006 |
| 2020-11-19 09:38 | geoffclare | Note Added: 0005115 | |
| 2020-11-19 11:29 | joerg | Note Added: 0005116 | |
| 2020-11-19 11:29 | joerg | Note Edited: 0005116 | |
| 2020-11-19 12:19 | geoffclare | Note Added: 0005117 | |
| 2020-11-19 13:39 | joerg | Note Added: 0005118 | |
| 2020-11-19 13:40 | joerg | Note Edited: 0005118 | |
| 2020-11-19 14:40 | geoffclare | Note Added: 0005119 | |
| 2020-11-20 11:58 | joerg | Note Edited: 0005118 | |
| 2021-03-11 16:39 | geoffclare | Status | New => Closed |
| 2021-03-11 16:39 | geoffclare | Resolution | Open => Withdrawn |
