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0001190Frama-CKernelpublic2012-06-08 15:382012-06-09 16:04
Assigned Tovirgile 
PrioritynormalSeverityminorReproducibilityhave not tried
PlatformOSOS Version
Product VersionFrama-C Nitrogen-20111001 
Target VersionFixed in Version 
Summary0001190: __builtin_alloca
DescriptionIn a file with a local array which size in defined by a variable :
   float a[n];
I get :
   [kernel] warning: Variable-sized local variable a
which is ok. But then, when I use the value analysis, I get :
  [kernel] warning: No code for function __builtin_alloca,
                     default assigns generated
because the declaration has been translated in :
  __lengthofa = (unsigned int)n;
  a = (float *)__builtin_alloca(sizeof(*a) * __lengthofa);
which looks fine, but the question is :
shouldn't the assigns property be defined somewhere inside Frama-C for the builtin functions ?
As a workaround, what prototype and assigns should I write for this function.
TagsNo tags attached.
Attached Files

2012-06-09 16:04   
Within Value, __builtin_alloca should be stubbed by a malloc-like builtin. Some of the existing builtins in malloc.h could be used.

Issue History
2012-06-08 15:38AnneNew Issue
2012-06-08 17:31signolesStatusnew => assigned
2012-06-08 17:31signolesAssigned To => virgile
2012-06-09 16:04yakobowskiNote Added: 0003069