Merge pull request #4604 from criemen/ir-block-sort-order

C++, C# IR: Stabilize sort order for basic blocks.

Author: Robert Marsh

cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/IRBlock.qll

@@ -26,15 +26,6 @@ class IRBlockBase extends TIRBlock {
   /** Gets the source location of the first non-`Phi` instruction in this block. */
   final Language::Location getLocation() { result = getFirstInstruction().getLocation() }
 
-  /**
-   * INTERNAL: Do not use.
-   *
-   * Gets a string that uniquely identifies this block within its enclosing function.
-   *
-   * This predicate is used by debugging and printing code only.
-   */
-  final string getUniqueId() { result = getFirstInstruction(this).getUniqueId() }
-
   /**
    * INTERNAL: Do not use.
    *
@@ -47,14 +38,15 @@ class IRBlockBase extends TIRBlock {
       config.shouldEvaluateDebugStringsForFunction(this.getEnclosingFunction())
     ) and
     this =
-      rank[result + 1](IRBlock funcBlock, int sortOverride |
+      rank[result + 1](IRBlock funcBlock, int sortOverride, int sortKey1, int sortKey2 |
         funcBlock.getEnclosingFunction() = getEnclosingFunction() and
+        funcBlock.getFirstInstruction().hasSortKeys(sortKey1, sortKey2) and
         // Ensure that the block containing `EnterFunction` always comes first.
         if funcBlock.getFirstInstruction() instanceof EnterFunctionInstruction
         then sortOverride = 0
         else sortOverride = 1
       |
-        funcBlock order by sortOverride, funcBlock.getUniqueId()
+        funcBlock order by sortOverride, sortKey1, sortKey2
       )
   }
 

cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/Instruction.qll

@@ -171,6 +171,16 @@ class Instruction extends Construction::TStageInstruction {
    */
   final string getUniqueId() { result = Construction::getInstructionUniqueId(this) }
 
+  /**
+   * INTERNAL: Do not use.
+   *
+   * Gets two sort keys for this instruction - used to order instructions for printing
+   * in test outputs.
+   */
+  final predicate hasSortKeys(int key1, int key2) {
+    Construction::instructionHasSortKeys(this, key1, key2)
+  }
+
   /**
    * Gets the basic block that contains this instruction.
    */

cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/internal/SSAConstruction.qll

@@ -856,7 +856,8 @@ private module CachedForDebugging {
     exists(Alias::MemoryLocation location, OldBlock phiBlock, string specificity |
       instr = getPhi(phiBlock, location) and
       result =
-        "Phi Block(" + phiBlock.getUniqueId() + ")[" + specificity + "]: " + location.getUniqueId() and
+        "Phi Block(" + phiBlock.getFirstInstruction().getUniqueId() + ")[" + specificity + "]: " +
+          location.getUniqueId() and
       if location instanceof Alias::VirtualVariable
       then
         // Sort Phi nodes for virtual variables before Phi nodes for member locations.
@@ -873,6 +874,24 @@ private module CachedForDebugging {
     result.getAST() = var.getAST() and
     result.getTag() = var.getTag()
   }
+
+  cached
+  predicate instructionHasSortKeys(Instruction instr, int key1, int key2) {
+    exists(OldInstruction oldInstr |
+      oldInstr = getOldInstruction(instr) and
+      oldInstr.hasSortKeys(key1, key2)
+    )
+    or
+    instr instanceof TUnreachedInstruction and
+    key1 = maxValue() and
+    key2 = maxValue()
+  }
+
+  /**
+   * Returns the value of the maximum representable integer.
+   */
+  cached
+  int maxValue() { result = 2147483647 }
 }
 
 module SSAConsistency {

cpp/ql/src/semmle/code/cpp/ir/implementation/raw/IRBlock.qll

@@ -26,15 +26,6 @@ class IRBlockBase extends TIRBlock {
   /** Gets the source location of the first non-`Phi` instruction in this block. */
   final Language::Location getLocation() { result = getFirstInstruction().getLocation() }
 
-  /**
-   * INTERNAL: Do not use.
-   *
-   * Gets a string that uniquely identifies this block within its enclosing function.
-   *
-   * This predicate is used by debugging and printing code only.
-   */
-  final string getUniqueId() { result = getFirstInstruction(this).getUniqueId() }
-
   /**
    * INTERNAL: Do not use.
    *
@@ -47,14 +38,15 @@ class IRBlockBase extends TIRBlock {
       config.shouldEvaluateDebugStringsForFunction(this.getEnclosingFunction())
     ) and
     this =
-      rank[result + 1](IRBlock funcBlock, int sortOverride |
+      rank[result + 1](IRBlock funcBlock, int sortOverride, int sortKey1, int sortKey2 |
         funcBlock.getEnclosingFunction() = getEnclosingFunction() and
+        funcBlock.getFirstInstruction().hasSortKeys(sortKey1, sortKey2) and
         // Ensure that the block containing `EnterFunction` always comes first.
         if funcBlock.getFirstInstruction() instanceof EnterFunctionInstruction
         then sortOverride = 0
         else sortOverride = 1
       |
-        funcBlock order by sortOverride, funcBlock.getUniqueId()
+        funcBlock order by sortOverride, sortKey1, sortKey2
       )
   }
 

cpp/ql/src/semmle/code/cpp/ir/implementation/raw/Instruction.qll

@@ -171,6 +171,16 @@ class Instruction extends Construction::TStageInstruction {
    */
   final string getUniqueId() { result = Construction::getInstructionUniqueId(this) }
 
+  /**
+   * INTERNAL: Do not use.
+   *
+   * Gets two sort keys for this instruction - used to order instructions for printing
+   * in test outputs.
+   */
+  final predicate hasSortKeys(int key1, int key2) {
+    Construction::instructionHasSortKeys(this, key1, key2)
+  }
+
   /**
    * Gets the basic block that contains this instruction.
    */

cpp/ql/src/semmle/code/cpp/ir/implementation/raw/internal/IRConstruction.qll

@@ -380,10 +380,21 @@ private module CachedForDebugging {
   string getTempVariableUniqueId(IRTempVariable var) {
     exists(TranslatedElement element |
       var = element.getTempVariable(_) and
-      result = element.getId() + ":" + getTempVariableTagId(var.getTag())
+      result = element.getId().toString() + ":" + getTempVariableTagId(var.getTag())
     )
   }
 
+  cached
+  predicate instructionHasSortKeys(Instruction instruction, int key1, int key2) {
+    key1 = getInstructionTranslatedElement(instruction).getId() and
+    getInstructionTag(instruction) =
+      rank[key2](InstructionTag tag, string tagId |
+        tagId = getInstructionTagId(tag)
+      |
+        tag order by tagId
+      )
+  }
+
   cached
   string getInstructionUniqueId(Instruction instruction) {
     result =

cpp/ql/src/semmle/code/cpp/ir/implementation/raw/internal/TranslatedElement.qll

@@ -752,10 +752,10 @@ abstract class TranslatedElement extends TTranslatedElement {
   abstract TranslatedElement getChild(int id);
 
   /**
-   * Gets the an identifier string for the element. This string is unique within
+   * Gets the an identifier string for the element. This id is unique within
    * the scope of the element's function.
    */
-  final string getId() { result = getUniqueId().toString() }
+  final int getId() { result = getUniqueId() }
 
   private TranslatedElement getChildByRank(int rankIndex) {
     result =

cpp/ql/src/semmle/code/cpp/ir/implementation/unaliased_ssa/IRBlock.qll

@@ -26,15 +26,6 @@ class IRBlockBase extends TIRBlock {
   /** Gets the source location of the first non-`Phi` instruction in this block. */
   final Language::Location getLocation() { result = getFirstInstruction().getLocation() }
 
-  /**
-   * INTERNAL: Do not use.
-   *
-   * Gets a string that uniquely identifies this block within its enclosing function.
-   *
-   * This predicate is used by debugging and printing code only.
-   */
-  final string getUniqueId() { result = getFirstInstruction(this).getUniqueId() }
-
   /**
    * INTERNAL: Do not use.
    *
@@ -47,14 +38,15 @@ class IRBlockBase extends TIRBlock {
       config.shouldEvaluateDebugStringsForFunction(this.getEnclosingFunction())
     ) and
     this =
-      rank[result + 1](IRBlock funcBlock, int sortOverride |
+      rank[result + 1](IRBlock funcBlock, int sortOverride, int sortKey1, int sortKey2 |
         funcBlock.getEnclosingFunction() = getEnclosingFunction() and
+        funcBlock.getFirstInstruction().hasSortKeys(sortKey1, sortKey2) and
         // Ensure that the block containing `EnterFunction` always comes first.
         if funcBlock.getFirstInstruction() instanceof EnterFunctionInstruction
         then sortOverride = 0
         else sortOverride = 1
       |
-        funcBlock order by sortOverride, funcBlock.getUniqueId()
+        funcBlock order by sortOverride, sortKey1, sortKey2
       )
   }
 

cpp/ql/src/semmle/code/cpp/ir/implementation/unaliased_ssa/Instruction.qll

@@ -171,6 +171,16 @@ class Instruction extends Construction::TStageInstruction {
    */
   final string getUniqueId() { result = Construction::getInstructionUniqueId(this) }
 
+  /**
+   * INTERNAL: Do not use.
+   *
+   * Gets two sort keys for this instruction - used to order instructions for printing
+   * in test outputs.
+   */
+  final predicate hasSortKeys(int key1, int key2) {
+    Construction::instructionHasSortKeys(this, key1, key2)
+  }
+
   /**
    * Gets the basic block that contains this instruction.
    */

cpp/ql/src/semmle/code/cpp/ir/implementation/unaliased_ssa/internal/SSAConstruction.qll

@@ -856,7 +856,8 @@ private module CachedForDebugging {
     exists(Alias::MemoryLocation location, OldBlock phiBlock, string specificity |
       instr = getPhi(phiBlock, location) and
       result =
-        "Phi Block(" + phiBlock.getUniqueId() + ")[" + specificity + "]: " + location.getUniqueId() and
+        "Phi Block(" + phiBlock.getFirstInstruction().getUniqueId() + ")[" + specificity + "]: " +
+          location.getUniqueId() and
       if location instanceof Alias::VirtualVariable
       then
         // Sort Phi nodes for virtual variables before Phi nodes for member locations.
@@ -873,6 +874,24 @@ private module CachedForDebugging {
     result.getAST() = var.getAST() and
     result.getTag() = var.getTag()
   }
+
+  cached
+  predicate instructionHasSortKeys(Instruction instr, int key1, int key2) {
+    exists(OldInstruction oldInstr |
+      oldInstr = getOldInstruction(instr) and
+      oldInstr.hasSortKeys(key1, key2)
+    )
+    or
+    instr instanceof TUnreachedInstruction and
+    key1 = maxValue() and
+    key2 = maxValue()
+  }
+
+  /**
+   * Returns the value of the maximum representable integer.
+   */
+  cached
+  int maxValue() { result = 2147483647 }
 }
 
 module SSAConsistency {