Allowed SVFG optimisation to be configurable & fixed reading/writing existing results

Johanmyst · Johanmyst · commit def7c043fe32 · 2025-05-02T10:10:24.000Z
The current `SVFGBuilder` optimises the SVFG based on the command-line argument. However, when using SVF as a library, this is inconvenient. This commit changes the builder to use an additional flag to control optimisation behaviour.

Moreover, this commit fixes the reading/writing issues for optimised SVFGs. Currently, the writing happens post-optimisation, which causes the reading step to fail due to missing/unexpected nodes. This commit also ensures the *unoptimised SVFG* is written to a file *prior to optimising it*, and reads an unoptimised SVFG from a file and then optimises it. This fixes these crashing issues.
diff --git a/svf/include/Graphs/SVFGOPT.h b/svf/include/Graphs/SVFGOPT.h
@@ -81,9 +81,18 @@ class SVFGOPT : public SVFG
         keepContextSelfCycle = true;
     }
 
+    /// Optimised SVFG's aren't written in their optimised form; read full SVFG and optimise it
+    void readAndOptSVFG(const std::string &filename);
+
+    /// Optimised SVFG's shouldn't be written in their optimised form; writes the full SVFG to file before optimising
+    void buildAndWriteSVFG(const std::string &filename);
+
 protected:
     void buildSVFG() override;
 
+    /// Separate optimisation function to avoid duplicate code
+    void optimiseSVFG();
+
     /// Connect SVFG nodes between caller and callee for indirect call sites
     //@{
     inline void connectAParamAndFParam(const PAGNode* cs_arg, const PAGNode* fun_arg, const CallICFGNode*, CallSiteID csId, SVFGEdgeSetTy& edges) override
diff --git a/svf/include/MSSA/SVFGBuilder.h b/svf/include/MSSA/SVFGBuilder.h
@@ -49,7 +49,10 @@ class SVFGBuilder
     typedef SVFG::SVFGEdgeSetTy SVFGEdgeSet;
 
     /// Constructor
-    explicit SVFGBuilder(bool _SVFGWithIndCall = false): svfg(nullptr), SVFGWithIndCall(_SVFGWithIndCall) {}
+    explicit SVFGBuilder(bool _SVFGWithIndCall = false, bool _OptimiseSVFG = false) :
+        svfg(nullptr), SVFGWithIndCall(_SVFGWithIndCall), OptimiseSVFG(_OptimiseSVFG)
+    {
+    }
 
     /// Destructor
     virtual ~SVFGBuilder() = default;
@@ -91,6 +94,8 @@ class SVFGBuilder
     std::unique_ptr<SVFG> svfg;
     /// SVFG with precomputed indirect call edges
     bool SVFGWithIndCall;
+    /// Build optimised version of SVFG
+    bool OptimiseSVFG;
 };
 
 } // End namespace SVF
diff --git a/svf/lib/Graphs/SVFGOPT.cpp b/svf/lib/Graphs/SVFGOPT.cpp
@@ -43,11 +43,29 @@ static std::string KeepAllSelfCycle = "all";
 static std::string KeepContextSelfCycle = "context";
 static std::string KeepNoneSelfCycle = "none";
 
+/// Optimised SVFGs aren't written to file; reads the full SVFG and optimises it
+void SVFGOPT::readAndOptSVFG(const std::string &filename)
+{
+    SVFG::readFile(filename);
+    optimiseSVFG();
+}
+
+/// Shouldn't write optimised SVFG to file; writes the built SVFG to file before optimisation
+void SVFGOPT::buildAndWriteSVFG(const std::string &filename)
+{
+    SVFG::buildSVFG();
+    SVFG::writeToFile(filename);
+    optimiseSVFG();
+}
 
 void SVFGOPT::buildSVFG()
 {
     SVFG::buildSVFG();
+    optimiseSVFG();
+}
 
+/// Separate function to optimise the SVFG to avoid duplicate code
+void SVFGOPT::optimiseSVFG() {
     if(Options::DumpVFG())
         dump("SVFG_before_opt");
 
@@ -62,6 +80,7 @@ void SVFGOPT::buildSVFG()
     stat->sfvgOptEnd();
 
 }
+
 /*!
  *
  */
diff --git a/svf/lib/MSSA/SVFGBuilder.cpp b/svf/lib/MSSA/SVFGBuilder.cpp
@@ -41,15 +41,18 @@ using namespace SVFUtil;
 
 SVFG* SVFGBuilder::buildPTROnlySVFG(BVDataPTAImpl* pta)
 {
-    if(Options::OPTSVFG())
+    if(Options::OPTSVFG() || this->OptimiseSVFG)
         return build(pta, VFG::PTRONLYSVFG_OPT);
     else
         return build(pta, VFG::PTRONLYSVFG);
 }
 
 SVFG* SVFGBuilder::buildFullSVFG(BVDataPTAImpl* pta)
 {
-    return build(pta, VFG::FULLSVFG);
+    if(Options::OPTSVFG() || this->OptimiseSVFG)
+        return build(pta, VFG::FULLSVFG_OPT);
+    else
+        return build(pta, VFG::FULLSVFG);
 }
 
 

Original file line number	Diff line number	Diff line change
`@@ -41,15 +41,18 @@ using namespace SVFUtil;`
`41`	`41`
`42`	`42`	`SVFG* SVFGBuilder::buildPTROnlySVFG(BVDataPTAImpl* pta)`
`43`	`43`	`{`
`44`		`- if(Options::OPTSVFG())`
	`44`	`+ if(Options::OPTSVFG() \|\| this->OptimiseSVFG)`
`45`	`45`	`return build(pta, VFG::PTRONLYSVFG_OPT);`
`46`	`46`	`else`
`47`	`47`	`return build(pta, VFG::PTRONLYSVFG);`
`48`	`48`	`}`
`49`	`49`
`50`	`50`	`SVFG* SVFGBuilder::buildFullSVFG(BVDataPTAImpl* pta)`
`51`	`51`	`{`
`52`		`- return build(pta, VFG::FULLSVFG);`
	`52`	`+ if(Options::OPTSVFG() \|\| this->OptimiseSVFG)`
	`53`	`+ return build(pta, VFG::FULLSVFG_OPT);`
	`54`	`+ else`
	`55`	`+ return build(pta, VFG::FULLSVFG);`
`53`	`56`	`}`
`54`	`57`
`55`	`58`