[cfe-dev] [analyzer] Summary IPA thoughts +code

[Artem Dergachev via cfe-dev]

Dear All,

We've published a snapshot of one of our development branches, which 
contains the Summary IPA prototype preview. As we mentioned, there are a 
lot of problems with it, including,

   - it's branched from clang-3.4,
   - it includes quite a bit of unrelated changes, including our 
inter-unit draft, in a single blob;

so even though it's in no way ready for any sort of review, i guess it 
could help a bit as a temporary reference in discussing issues.

We deeply apologize for the mess; of course the code will be changed 
significantly if/once we decide to put it on actual review for accepting 
into the base clang repo, but at least we got it at least somehow 
working and got a chance to make properly :)


The github branch with a single blob for everything is at:

   https://github.com/haoNoQ/clang/tree/summary-ipa-draft



=== Places to look at, with necessary pre-cautions :) ===


   * ExprEngine::inlineCall()
https://github.com/haoNoQ/clang/blob/summary-ipa-draft/lib/StaticAnalyzer/Core/ExprEngineCallAndReturn.cpp#L468


Most of the calling bureaucracy is coded there, such as storing 
summaries, creating auxiliary ExprEngine's for constructing 
ExplodedGraphs for summaries, etc.

-----

   * include/clang/StaticAnalyzer/Core/PathSensitive/FunctionCallSummary.h
https://github.com/haoNoQ/clang/blob/summary-ipa-draft/include/clang/StaticAnalyzer/Core/PathSensitive/FunctionCallSummary.h

   * lib/StaticAnalyzer/Core/FunctionCallSummary.cpp
https://github.com/haoNoQ/clang/blob/summary-ipa-draft/lib/StaticAnalyzer/Core/FunctionCallSummary.cpp

     These files include the alpha-renaming stuff (the "Summarizer" 
object and its "compose***()" methods), and the procedure of applying 
the summary ("CallFunction()"). The latter includes summary-apply 
procedures for store bindings (TODO - move to ***StoreManager.cpp, fix 
the necessary abstractions, fix HandleBinding() accordingly), return 
values, and calling checkers. TODO - the procedure for alpha-renaming 
CXXTempObjectRegion will be fixed, do not look there yet :)

-----

   * RangeConstraintManager::applyCallBranchSummary(),
https://github.com/haoNoQ/clang/blob/summary-ipa-draft/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp#L1337

   *                         handleSummaryRange()
https://github.com/haoNoQ/clang/blob/summary-ipa-draft/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp#L1295

     The procedure of applying the summary for range constraints, which 
includes finding pre-conditions for the summary and handling unreachable 
branches.

-----

   * lib/StaticAnalyzer/Checkers/IntegerOverflowChecker.cpp
https://github.com/haoNoQ/clang/blob/summary-ipa-draft/lib/StaticAnalyzer/Checkers/IntegerOverflowChecker.cpp

   * lib/StaticAnalyzer/Checkers/ConstModifiedChecker.cpp
https://github.com/haoNoQ/clang/blob/summary-ipa-draft/lib/StaticAnalyzer/Checkers/ConstModifiedChecker.cpp

     The two checkers, with necessary modifications for running under 
summary IPA, which were used for gathering experimental data. The 
IntegerOverflow checker was also discussed in 
http://reviews.llvm.org/D4066 , authored by Julia Trofimovich, another 
colleague of ours, and the ConstModified checker was created by Alexey, 
also corresponding to one of the items in the list of potential checkers.

-----

   * test/Analysis/summary-ipa*
https://github.com/haoNoQ/clang/blob/summary-ipa-draft/test/Analysis/summary-ipa.cpp
https://github.com/haoNoQ/clang/blob/summary-ipa-draft/test/Analysis/summary-ipa.c
https://github.com/haoNoQ/clang/blob/summary-ipa-draft/test/Analysis/summary-ipa-temporaries.cpp
https://github.com/haoNoQ/clang/blob/summary-ipa-draft/test/Analysis/summary-ipa-symranges.cpp
https://github.com/haoNoQ/clang/blob/summary-ipa-draft/test/Analysis/summary-ipa-xfail.cpp

     Some fancy tests which we pass. They don't cover everything (TODO - 
we'd have to cover most of the paths during the refactoring, of course), 
but these tests already have some fancy examples we had to dig through.