C++: Improve join order in IR reachability

dave-bartolomeo · dave-bartolomeo · commit b2e596fcc278 · 2018-12-10T21:22:55.000-08:00
diff --git a/cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/internal/reachability/ReachableBlock.qll b/cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/internal/reachability/ReachableBlock.qll
@@ -22,7 +22,9 @@ IRBlock getAFeasiblePredecessor(IRBlock successor) {
 }
 
 predicate isBlockReachable(IRBlock block) {
-  getAFeasiblePredecessor*(block) = block.getFunctionIR().getEntryBlock()
+  exists(FunctionIR f |
+    getAFeasiblePredecessor*(block) = f.getEntryBlock()
+  )
 }
 
 predicate isInstructionReachable(Instruction instr) {
@@ -43,7 +45,9 @@ class ReachableInstruction extends Instruction {
 
 module Graph {
   predicate isEntryBlock(ReachableBlock block) {
-    block = block.getFunctionIR().getEntryBlock()
+    exists(FunctionIR f |
+      block = f.getEntryBlock()
+    )
   }
 
   predicate blockSuccessor(ReachableBlock pred, ReachableBlock succ) {
diff --git a/cpp/ql/src/semmle/code/cpp/ir/implementation/raw/internal/reachability/ReachableBlock.qll b/cpp/ql/src/semmle/code/cpp/ir/implementation/raw/internal/reachability/ReachableBlock.qll
@@ -22,7 +22,9 @@ IRBlock getAFeasiblePredecessor(IRBlock successor) {
 }
 
 predicate isBlockReachable(IRBlock block) {
-  getAFeasiblePredecessor*(block) = block.getFunctionIR().getEntryBlock()
+  exists(FunctionIR f |
+    getAFeasiblePredecessor*(block) = f.getEntryBlock()
+  )
 }
 
 predicate isInstructionReachable(Instruction instr) {
@@ -43,7 +45,9 @@ class ReachableInstruction extends Instruction {
 
 module Graph {
   predicate isEntryBlock(ReachableBlock block) {
-    block = block.getFunctionIR().getEntryBlock()
+    exists(FunctionIR f |
+      block = f.getEntryBlock()
+    )
   }
 
   predicate blockSuccessor(ReachableBlock pred, ReachableBlock succ) {
diff --git a/cpp/ql/src/semmle/code/cpp/ir/implementation/unaliased_ssa/internal/reachability/ReachableBlock.qll b/cpp/ql/src/semmle/code/cpp/ir/implementation/unaliased_ssa/internal/reachability/ReachableBlock.qll
@@ -22,7 +22,9 @@ IRBlock getAFeasiblePredecessor(IRBlock successor) {
 }
 
 predicate isBlockReachable(IRBlock block) {
-  getAFeasiblePredecessor*(block) = block.getFunctionIR().getEntryBlock()
+  exists(FunctionIR f |
+    getAFeasiblePredecessor*(block) = f.getEntryBlock()
+  )
 }
 
 predicate isInstructionReachable(Instruction instr) {
@@ -43,7 +45,9 @@ class ReachableInstruction extends Instruction {
 
 module Graph {
   predicate isEntryBlock(ReachableBlock block) {
-    block = block.getFunctionIR().getEntryBlock()
+    exists(FunctionIR f |
+      block = f.getEntryBlock()
+    )
   }
 
   predicate blockSuccessor(ReachableBlock pred, ReachableBlock succ) {

Original file line number	Diff line number	Diff line change
`@@ -22,7 +22,9 @@ IRBlock getAFeasiblePredecessor(IRBlock successor) {`
`22`	`22`	`}`
`23`	`23`
`24`	`24`	`predicate isBlockReachable(IRBlock block) {`
`25`		`- getAFeasiblePredecessor*(block) = block.getFunctionIR().getEntryBlock()`
	`25`	`+ exists(FunctionIR f \|`
	`26`	`+ getAFeasiblePredecessor*(block) = f.getEntryBlock()`
	`27`	`+ )`
`26`	`28`	`}`
`27`	`29`
`28`	`30`	`predicate isInstructionReachable(Instruction instr) {`
`@@ -43,7 +45,9 @@ class ReachableInstruction extends Instruction {`
`43`	`45`
`44`	`46`	`module Graph {`
`45`	`47`	`predicate isEntryBlock(ReachableBlock block) {`
`46`		`- block = block.getFunctionIR().getEntryBlock()`
	`48`	`+ exists(FunctionIR f \|`
	`49`	`+ block = f.getEntryBlock()`
	`50`	`+ )`
`47`	`51`	`}`
`48`	`52`
`49`	`53`	`predicate blockSuccessor(ReachableBlock pred, ReachableBlock succ) {`