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0002501Frama-CPlug-in > wppublic2020-03-10 11:442020-06-12 08:59
Reporterjens 
Assigned ToAllanBlanchard 
PrioritynormalSeveritymajorReproducibilityalways
StatusclosedResolutionfixed 
PlatformOSLinux, macOSOS Version
Product VersionFrama-C 20-Calcium 
Target VersionFixed in VersionFrama-C 21-Scandium 
Summary0002501: error in generated proof obligation
DescriptionThe attached file 'issue.c' contains a simplified (but still not very small) example of an issue I have within ACSL by Example.

There is lemma R_2 for the logic function R.
The definition of R uses the logic function F contained in the axiomatic block A.
When trying to verify R_2 with the command line below I obtain the message
                  [Why3 Error] anomaly: Failure("Can't find 'L_F' in why3 namespace")

frama-c -wp -wp-prover alt-ergo -wp-prover native:coq issue.c
[kernel] Parsing issue.c (with preprocessing)
[wp] Warning: native support for coq is deprecated, use tip instead
[wp] 2 goals scheduled
[wp] [Failed] Goal typed_lemma_R_2
  Alt-Ergo 2.3.1: Failed
                  [Why3 Error] anomaly: Failure("Can't find 'L_F' in why3 namespace")
       Coq: Unknown
[wp] [Cache] found:1
[wp] Proved goals: 1 / 2
  Qed: 0
  Coq: 0 (unknown: 1)
  Alt-Ergo 2.3.1: 1 (10ms) (23) (cached: 1) (failed: 1)


When looking at the generated verification condition with Coq I found the following:
The generated hypothesis 'FixL_R' uses of course the function 'L_F'.
However, the necessary import clause 'Require Import A_A.' comes only AFTER the definition of 'FixL_R'.

Additional InformationThere is a work-around by calling the helper function 'Fix' in the definition of R (see the comment in the code).

The problem also "disappears' if lemma 'R_1' is removed (but I don't have this option).

While looking at this problem, I noticed that in general coq definitions and import clauses are interspersed in the verification conditions...
TagsNo tags attached.
Attached Filesc issue.c (857) 2020-03-10 11:44
https://bts.frama-c.com/file_download.php?file_id=1347&type=bug

Notes
(0006971)
jens   
2020-05-09 16:45   
With 20.0+dev (Calcium), installed early May 2020 from https://git.frama-c.com/pub/frama-c, the error is still present.
(0006972)
AllanBlanchard   
2020-05-12 17:12   
(Last edited: 2020-05-12 17:27)
The problem has been fixed. The fix will be available in the next release (and in the upcoming bĂȘta) but not immediately in the public development version.


Issue History
2020-03-10 11:44jensNew Issue
2020-03-10 11:44jensStatusnew => assigned
2020-03-10 11:44jensAssigned To => correnson
2020-03-10 11:44jensFile Added: issue.c
2020-03-16 12:32corrensonAssigned Tocorrenson => AllanBlanchard
2020-05-09 16:46jensNote Added: 0006971
2020-05-12 17:12AllanBlanchardNote Added: 0006972
2020-05-12 17:12AllanBlanchardStatusassigned => resolved
2020-05-12 17:12AllanBlanchardFixed in Version => Frama-C 21-Scandium
2020-05-12 17:12AllanBlanchardResolutionopen => fixed
2020-05-12 17:27AllanBlanchardNote Edited: 0006972bug_revision_view_page.php?bugnote_id=6972#r458
2020-06-12 08:59signolesStatusresolved => closed