C++: respond to further PR review comments

rdmarsh2 · rdmarsh2 · commit f4ce7b9648a8 · 2018-11-26T16:16:46.000-08:00
diff --git a/cpp/ql/src/semmle/code/cpp/ir/implementation/MemoryAccessKind.qll b/cpp/ql/src/semmle/code/cpp/ir/implementation/MemoryAccessKind.qll
@@ -81,7 +81,7 @@ class PhiMemoryAccess extends MemoryAccessKind, TPhiMemoryAccess {
 }
 
 /**
- * The operand is a ChiOld operand, which accesses the same memory as its
+ * The operand is a ChiTotal operand, which accesses the same memory as its
  * definition.
  */
 class ChiTotalMemoryAccess extends MemoryAccessKind, TChiOldMemoryAccess {
@@ -91,14 +91,15 @@ class ChiTotalMemoryAccess extends MemoryAccessKind, TChiOldMemoryAccess {
 }
 
 /**
- * The operand is a ChiUpdate operand, which accesses the same memory as its
+ * The operand is a ChiPartial operand, which accesses the same memory as its
  * definition.
  */
 class ChiPartialMemoryAccess extends MemoryAccessKind, TChiUpdateMemoryAccess {
   override string toString() {
     result = "chi(partial)"
   }
 }
+
 /**
  * The operand accesses memory not modeled in SSA. Used only on the result of
  * `UnmodeledDefinition` and on the operands of `UnmodeledUse`.
diff --git a/cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/Instruction.qll b/cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/Instruction.qll
@@ -1322,6 +1322,9 @@ class UnmodeledDefinitionInstruction extends Instruction {
   }
 }
 
+/**
+ * An instruction that initializes all escaped memory.
+ */
 class AliasedDefinitionInstruction extends Instruction {
   AliasedDefinitionInstruction() {
     opcode instanceof Opcode::AliasedDefinition
@@ -1352,6 +1355,10 @@ class PhiInstruction extends Instruction {
   }
 }
 
+/**
+ * An instruction representing the write to a piece of memory resulting from a write to a subset
+ * of that memory.
+ */
 class ChiInstruction extends Instruction {
   ChiInstruction() {
     opcode instanceof Opcode::Chi
diff --git a/cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/Operand.qll b/cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/Operand.qll
@@ -382,7 +382,6 @@ class PhiOperand extends Operand, TPhiOperand {
   }
 }
 
-
 /**
  * An operand that reads a value from memory.
  */
@@ -391,3 +390,38 @@ class MemoryOperand extends Operand {
     exists(getMemoryAccess())
   }
 }
+
+/**
+ * The total operand of a Chi node, representing the previous value of the memory.
+ */
+class ChiTotalOperand extends Operand {
+  ChiTotalOperand() {
+    this = TNonPhiOperand(_, chiTotalOperand(), _)
+  }
+
+  override string toString() {
+    result = "ChiTotal"
+  }
+
+  override final MemoryAccessKind getMemoryAccess() {
+    result instanceof ChiTotalMemoryAccess
+  }
+}
+
+
+/**
+ * The partial operand of a Chi node, representing the value being written to part of the memory.
+ */
+class ChiPartialOperand extends Operand {
+  ChiPartialOperand() {
+    this = TNonPhiOperand(_, chiPartialOperand(), _)
+  }
+
+  override string toString() {
+    result = "ChiPartial"
+  }
+
+  override final MemoryAccessKind getMemoryAccess() {
+    result instanceof ChiPartialMemoryAccess
+  }
+}
diff --git a/cpp/ql/src/semmle/code/cpp/ir/implementation/raw/Instruction.qll b/cpp/ql/src/semmle/code/cpp/ir/implementation/raw/Instruction.qll
@@ -1322,6 +1322,9 @@ class UnmodeledDefinitionInstruction extends Instruction {
   }
 }
 
+/**
+ * An instruction that initializes all escaped memory.
+ */
 class AliasedDefinitionInstruction extends Instruction {
   AliasedDefinitionInstruction() {
     opcode instanceof Opcode::AliasedDefinition
@@ -1352,6 +1355,10 @@ class PhiInstruction extends Instruction {
   }
 }
 
+/**
+ * An instruction representing the write to a piece of memory resulting from a write to a subset
+ * of that memory.
+ */
 class ChiInstruction extends Instruction {
   ChiInstruction() {
     opcode instanceof Opcode::Chi
diff --git a/cpp/ql/src/semmle/code/cpp/ir/implementation/raw/Operand.qll b/cpp/ql/src/semmle/code/cpp/ir/implementation/raw/Operand.qll
@@ -382,7 +382,6 @@ class PhiOperand extends Operand, TPhiOperand {
   }
 }
 
-
 /**
  * An operand that reads a value from memory.
  */
@@ -391,3 +390,38 @@ class MemoryOperand extends Operand {
     exists(getMemoryAccess())
   }
 }
+
+/**
+ * The total operand of a Chi node, representing the previous value of the memory.
+ */
+class ChiTotalOperand extends Operand {
+  ChiTotalOperand() {
+    this = TNonPhiOperand(_, chiTotalOperand(), _)
+  }
+
+  override string toString() {
+    result = "ChiTotal"
+  }
+
+  override final MemoryAccessKind getMemoryAccess() {
+    result instanceof ChiTotalMemoryAccess
+  }
+}
+
+
+/**
+ * The partial operand of a Chi node, representing the value being written to part of the memory.
+ */
+class ChiPartialOperand extends Operand {
+  ChiPartialOperand() {
+    this = TNonPhiOperand(_, chiPartialOperand(), _)
+  }
+
+  override string toString() {
+    result = "ChiPartial"
+  }
+
+  override final MemoryAccessKind getMemoryAccess() {
+    result instanceof ChiPartialMemoryAccess
+  }
+}
diff --git a/cpp/ql/src/semmle/code/cpp/ir/implementation/unaliased_ssa/Instruction.qll b/cpp/ql/src/semmle/code/cpp/ir/implementation/unaliased_ssa/Instruction.qll
@@ -1322,6 +1322,9 @@ class UnmodeledDefinitionInstruction extends Instruction {
   }
 }
 
+/**
+ * An instruction that initializes all escaped memory.
+ */
 class AliasedDefinitionInstruction extends Instruction {
   AliasedDefinitionInstruction() {
     opcode instanceof Opcode::AliasedDefinition
@@ -1352,6 +1355,10 @@ class PhiInstruction extends Instruction {
   }
 }
 
+/**
+ * An instruction representing the write to a piece of memory resulting from a write to a subset
+ * of that memory.
+ */
 class ChiInstruction extends Instruction {
   ChiInstruction() {
     opcode instanceof Opcode::Chi
diff --git a/cpp/ql/src/semmle/code/cpp/ir/implementation/unaliased_ssa/Operand.qll b/cpp/ql/src/semmle/code/cpp/ir/implementation/unaliased_ssa/Operand.qll
@@ -382,7 +382,6 @@ class PhiOperand extends Operand, TPhiOperand {
   }
 }
 
-
 /**
  * An operand that reads a value from memory.
  */
@@ -391,3 +390,38 @@ class MemoryOperand extends Operand {
     exists(getMemoryAccess())
   }
 }
+
+/**
+ * The total operand of a Chi node, representing the previous value of the memory.
+ */
+class ChiTotalOperand extends Operand {
+  ChiTotalOperand() {
+    this = TNonPhiOperand(_, chiTotalOperand(), _)
+  }
+
+  override string toString() {
+    result = "ChiTotal"
+  }
+
+  override final MemoryAccessKind getMemoryAccess() {
+    result instanceof ChiTotalMemoryAccess
+  }
+}
+
+
+/**
+ * The partial operand of a Chi node, representing the value being written to part of the memory.
+ */
+class ChiPartialOperand extends Operand {
+  ChiPartialOperand() {
+    this = TNonPhiOperand(_, chiPartialOperand(), _)
+  }
+
+  override string toString() {
+    result = "ChiPartial"
+  }
+
+  override final MemoryAccessKind getMemoryAccess() {
+    result instanceof ChiPartialMemoryAccess
+  }
+}
diff --git a/cpp/ql/src/semmle/code/cpp/ir/implementation/unaliased_ssa/internal/SimpleSSA.qll b/cpp/ql/src/semmle/code/cpp/ir/implementation/unaliased_ssa/internal/SimpleSSA.qll
@@ -9,7 +9,6 @@ private newtype TVirtualVariable =
     not variableAddressEscapes(var)
   }
 
-
 private VirtualVariable getVirtualVariable(IRVariable var) {
   result.getIRVariable() = var
 }
diff --git a/cpp/ql/src/semmle/code/cpp/ir/internal/OperandTag.qll b/cpp/ql/src/semmle/code/cpp/ir/internal/OperandTag.qll
@@ -325,6 +325,10 @@ class ChiTotalOperandTag extends OperandTag, TChiTotalOperand {
   }
 }
 
+ChiTotalOperandTag chiTotalOperand() {
+  result = TChiTotalOperand()
+}
+
 class ChiPartialOperandTag extends OperandTag, TChiPartialOperand {
   override final string toString() {
     result = "ChiPartial"
@@ -334,3 +338,7 @@ class ChiPartialOperandTag extends OperandTag, TChiPartialOperand {
     result = 15
   }
 }
+
+ChiPartialOperandTag chiPartialOperand() {
+  result = TChiPartialOperand()
+}

Original file line number	Diff line number	Diff line change
`@@ -81,7 +81,7 @@ class PhiMemoryAccess extends MemoryAccessKind, TPhiMemoryAccess {`
`81`	`81`	`}`
`82`	`82`
`83`	`83`	`/**`
`84`		`- * The operand is a ChiOld operand, which accesses the same memory as its`
	`84`	`+ * The operand is a ChiTotal operand, which accesses the same memory as its`
`85`	`85`	`* definition.`
`86`	`86`	`*/`
`87`	`87`	`class ChiTotalMemoryAccess extends MemoryAccessKind, TChiOldMemoryAccess {`
`@@ -91,14 +91,15 @@ class ChiTotalMemoryAccess extends MemoryAccessKind, TChiOldMemoryAccess {`
`91`	`91`	`}`
`92`	`92`
`93`	`93`	`/**`
`94`		`- * The operand is a ChiUpdate operand, which accesses the same memory as its`
	`94`	`+ * The operand is a ChiPartial operand, which accesses the same memory as its`
`95`	`95`	`* definition.`
`96`	`96`	`*/`
`97`	`97`	`class ChiPartialMemoryAccess extends MemoryAccessKind, TChiUpdateMemoryAccess {`
`98`	`98`	`override string toString() {`
`99`	`99`	`result = "chi(partial)"`
`100`	`100`	`}`
`101`	`101`	`}`
	`102`	`+`
`102`	`103`	`/**`
`103`	`104`	`* The operand accesses memory not modeled in SSA. Used only on the result of`
`104`	`105`	* `UnmodeledDefinition` and on the operands of `UnmodeledUse`.
Original file line number	Diff line number	Diff line change
`@@ -1322,6 +1322,9 @@ class UnmodeledDefinitionInstruction extends Instruction {`
`1322`	`1322`	`}`
`1323`	`1323`	`}`
`1324`	`1324`
	`1325`	`+/**`
	`1326`	`+ * An instruction that initializes all escaped memory.`
	`1327`	`+ */`
`1325`	`1328`	`class AliasedDefinitionInstruction extends Instruction {`
`1326`	`1329`	`AliasedDefinitionInstruction() {`
`1327`	`1330`	`opcode instanceof Opcode::AliasedDefinition`
`@@ -1352,6 +1355,10 @@ class PhiInstruction extends Instruction {`
`1352`	`1355`	`}`
`1353`	`1356`	`}`
`1354`	`1357`
	`1358`	`+/**`
	`1359`	`+ * An instruction representing the write to a piece of memory resulting from a write to a subset`
	`1360`	`+ * of that memory.`
	`1361`	`+ */`
`1355`	`1362`	`class ChiInstruction extends Instruction {`
`1356`	`1363`	`ChiInstruction() {`
`1357`	`1364`	`opcode instanceof Opcode::Chi`
Original file line number	Diff line number	Diff line change
`@@ -9,7 +9,6 @@ private newtype TVirtualVariable =`
`9`	`9`	`not variableAddressEscapes(var)`
`10`	`10`	`}`
`11`	`11`
`12`		`-`
`13`	`12`	`private VirtualVariable getVirtualVariable(IRVariable var) {`
`14`	`13`	`result.getIRVariable() = var`
`15`	`14`	`}`
Original file line number	Diff line number	Diff line change
`@@ -325,6 +325,10 @@ class ChiTotalOperandTag extends OperandTag, TChiTotalOperand {`
`325`	`325`	`}`
`326`	`326`	`}`
`327`	`327`
	`328`	`+ChiTotalOperandTag chiTotalOperand() {`
	`329`	`+ result = TChiTotalOperand()`
	`330`	`+}`
	`331`	`+`
`328`	`332`	`class ChiPartialOperandTag extends OperandTag, TChiPartialOperand {`
`329`	`333`	`override final string toString() {`
`330`	`334`	`result = "ChiPartial"`
`@@ -334,3 +338,7 @@ class ChiPartialOperandTag extends OperandTag, TChiPartialOperand {`
`334`	`338`	`result = 15`
`335`	`339`	`}`
`336`	`340`	`}`
	`341`	`+`
	`342`	`+ChiPartialOperandTag chiPartialOperand() {`
	`343`	`+ result = TChiPartialOperand()`
	`344`	`+}`