Merge branch next and update CodeQL to v2.23.9

c/cert/src/rules/EXP30-C/DependenceOnOrderOfFunctionArgumentsForSideEffects.ql

@@ -19,7 +19,7 @@
 import cpp
 import codingstandards.c.cert
 import codingstandards.cpp.SideEffect
-import semmle.code.cpp.dataflow.TaintTracking
+import semmle.code.cpp.dataflow.new.TaintTracking
 import semmle.code.cpp.valuenumbering.GlobalValueNumbering
 
 /** Holds if the function's return value is derived from the `AliasParamter` p. */

c/cert/test/rules/ARR30-C/DoNotFormOutOfBoundsPointersOrArraySubscripts.expected

@@ -5,7 +5,13 @@
 | test.c:45:17:45:30 | ... + ... | Buffer may access up to offset 101*1 which is greater than the fixed size 100 of the $@. | test.c:45:17:45:22 | buffer | buffer |
 | test.c:55:5:55:13 | ... - ... | Buffer access may be to a negative index in the buffer. | test.c:55:5:55:9 | ptr16 | buffer |
 | test.c:57:5:57:14 | ... + ... | Buffer accesses offset 22 which is greater than the fixed size 20 of the $@. | test.c:57:5:57:9 | ptr16 | buffer |
+| test.c:58:5:58:14 | ... - ... | Buffer access may be to a negative index in the buffer. | test.c:55:5:55:9 | ptr16 | buffer |
+| test.c:58:5:58:14 | ... - ... | Buffer access may be to a negative index in the buffer. | test.c:56:5:56:9 | ptr16 | buffer |
+| test.c:58:5:58:14 | ... - ... | Buffer access may be to a negative index in the buffer. | test.c:57:5:57:9 | ptr16 | buffer |
 | test.c:58:5:58:14 | ... - ... | Buffer access may be to a negative index in the buffer. | test.c:58:5:58:9 | ptr16 | buffer |
 | test.c:63:3:63:9 | access to array | Buffer access may be to a negative index in the buffer. | test.c:63:3:63:5 | arr | buffer |
 | test.c:65:3:65:9 | access to array | Buffer accesses offset 44 which is greater than the fixed size 40 of the $@. | test.c:65:3:65:5 | arr | buffer |
+| test.c:66:3:66:10 | access to array | Buffer access may be to a negative index in the buffer. | test.c:63:3:63:5 | arr | buffer |
+| test.c:66:3:66:10 | access to array | Buffer access may be to a negative index in the buffer. | test.c:64:3:64:5 | arr | buffer |
+| test.c:66:3:66:10 | access to array | Buffer access may be to a negative index in the buffer. | test.c:65:3:65:5 | arr | buffer |
 | test.c:66:3:66:10 | access to array | Buffer access may be to a negative index in the buffer. | test.c:66:3:66:5 | arr | buffer |

c/cert/test/rules/EXP30-C/DependenceOnOrderOfFunctionArgumentsForSideEffects.expected

@@ -1,25 +1 @@
-WARNING: module 'DataFlow' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:28,31-39)
-WARNING: module 'DataFlow' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:28,59-67)
-WARNING: module 'DataFlow' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:31,33-41)
-WARNING: module 'DataFlow' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:31,57-65)
-WARNING: module 'DataFlow' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:35,33-41)
-WARNING: module 'DataFlow' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:35,59-67)
-WARNING: module 'DataFlow' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:44,5-13)
-WARNING: module 'DataFlow' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:44,25-33)
-WARNING: module 'DataFlow' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:44,53-61)
-WARNING: module 'DataFlow' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:47,31-39)
-WARNING: module 'DataFlow' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:47,57-65)
-WARNING: module 'DataFlow' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:56,31-39)
-WARNING: module 'DataFlow' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:56,55-63)
-WARNING: module 'DataFlow' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:63,31-39)
-WARNING: module 'DataFlow' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:63,57-65)
-WARNING: module 'DataFlow' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:75,31-39)
-WARNING: module 'DataFlow' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:75,55-63)
-WARNING: module 'TaintTracking' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:28,5-18)
-WARNING: module 'TaintTracking' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:31,7-20)
-WARNING: module 'TaintTracking' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:35,7-20)
-WARNING: module 'TaintTracking' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:47,5-18)
-WARNING: module 'TaintTracking' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:56,5-18)
-WARNING: module 'TaintTracking' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:63,5-18)
-WARNING: module 'TaintTracking' has been deprecated and may be removed in future (DependenceOnOrderOfFunctionArgumentsForSideEffects.ql:75,5-18)
 | test.c:20:3:20:4 | call to f1 | Depending on the order of evaluation for the arguments $@ and $@ for side effects on shared state is unspecified and can result in unexpected behavior. | test.c:20:6:20:7 | call to f2 | call to f2 | test.c:20:12:20:13 | call to f3 | call to f3 |

c/common/src/codingstandards/c/OutOfBounds.qll

@@ -11,7 +11,6 @@ import codingstandards.cpp.Allocations
 import codingstandards.cpp.Overflow
 import codingstandards.cpp.PossiblyUnsafeStringOperation
 import codingstandards.cpp.SimpleRangeAnalysisCustomizations
-private import semmle.code.cpp.dataflow.DataFlow
 import semmle.code.cpp.valuenumbering.GlobalValueNumbering
 
 module OOB {
@@ -380,8 +379,13 @@ module OOB {
     StrncatLibraryFunction() { this.getName() = getNameOrInternalName(["strncat", "wcsncat"]) }
 
     override predicate getALengthParameterIndex(int i) {
-      // `strncat` and `wcsncat` exclude the size of a null terminator
-      i = 2
+      // The source need not contain a null terminator within the first `n` characters.
+      none()
+    }
+
+    override predicate getANullTerminatedParameterIndex(int i) {
+      // The destination must be null-terminated.
+      i = 0
     }
   }
 
@@ -645,42 +649,46 @@ module OOB {
   }
 
   /**
-   * A class for reasoning about the offset of a variable from the original value flowing to it
-   * as a result of arithmetic or pointer arithmetic expressions.
+   * Gets the offset of `expr` from `underlyingBase` due to arithmetic or pointer arithmetic.
+   *
+   * `underlyingBase` may be the arithmetic operand's base expression or `expr` itself, allowing
+   * callers to use whichever dataflow node is available.
    */
   bindingset[expr]
-  private int getArithmeticOffsetValue(Expr expr, Expr base) {
-    result = getMinStatedValue(expr.(PointerArithmeticExpr).getOperand()) and
-    base = expr.(PointerArithmeticExpr).getPointer()
-    or
-    // &(array[index]) expressions
-    result =
-      getMinStatedValue(expr.(AddressOfExpr).getOperand().(PointerArithmeticExpr).getOperand()) and
-    base = expr.(AddressOfExpr).getOperand().(PointerArithmeticExpr).getPointer()
-    or
-    result = getMinStatedValue(expr.(AddExpr).getRightOperand()) and
-    base = expr.(AddExpr).getLeftOperand()
-    or
-    result = -getMinStatedValue(expr.(SubExpr).getRightOperand()) and
-    base = expr.(SubExpr).getLeftOperand()
-    or
-    expr instanceof IncrementOperation and
-    result = 1 and
-    base = expr.(IncrementOperation).getOperand()
-    or
-    expr instanceof DecrementOperation and
-    result = -1 and
-    base = expr.(DecrementOperation).getOperand()
-    or
-    // fall-back if `expr` is not an arithmetic or pointer arithmetic expression
-    not expr instanceof PointerArithmeticExpr and
-    not expr.(AddressOfExpr).getOperand() instanceof PointerArithmeticExpr and
-    not expr instanceof AddExpr and
-    not expr instanceof SubExpr and
-    not expr instanceof IncrementOperation and
-    not expr instanceof DecrementOperation and
-    base = expr and
-    result = 0
+  private int getArithmeticOffsetValue(Expr expr, Expr underlyingBase) {
+    exists(Expr base | underlyingBase = [base, expr] |
+      result = getMinStatedValue(expr.(PointerArithmeticExpr).getOperand()) and
+      base = expr.(PointerArithmeticExpr).getPointer()
+      or
+      // &(array[index]) expressions
+      result =
+        getMinStatedValue(expr.(AddressOfExpr).getOperand().(PointerArithmeticExpr).getOperand()) and
+      base = expr.(AddressOfExpr).getOperand().(PointerArithmeticExpr).getPointer()
+      or
+      result = getMinStatedValue(expr.(AddExpr).getRightOperand()) and
+      base = expr.(AddExpr).getLeftOperand()
+      or
+      result = -getMinStatedValue(expr.(SubExpr).getRightOperand()) and
+      base = expr.(SubExpr).getLeftOperand()
+      or
+      expr instanceof IncrementOperation and
+      result = 1 and
+      base = expr.(IncrementOperation).getOperand()
+      or
+      expr instanceof DecrementOperation and
+      result = -1 and
+      base = expr.(DecrementOperation).getOperand()
+      or
+      // fall-back if `expr` is not an arithmetic or pointer arithmetic expression
+      not expr instanceof PointerArithmeticExpr and
+      not expr.(AddressOfExpr).getOperand() instanceof PointerArithmeticExpr and
+      not expr instanceof AddExpr and
+      not expr instanceof SubExpr and
+      not expr instanceof IncrementOperation and
+      not expr instanceof DecrementOperation and
+      base = expr and
+      result = 0
+    )
   }
 
   private int constOrZero(Expr e) {

c/common/test/rules/constlikereturnvalue/ConstLikeReturnValue.expected

@@ -1,5 +1,4 @@
 problems
-| test.c:11:7:11:12 | * ... | test.c:18:16:18:21 | call to getenv | test.c:11:7:11:12 | * ... | The object returned by the function getenv should not be modified. |
 | test.c:11:8:11:12 | c_str | test.c:18:16:18:21 | call to getenv | test.c:11:7:11:12 | * ... | The object returned by the function getenv should not be modified. |
 | test.c:67:5:67:9 | conv4 | test.c:64:11:64:20 | call to localeconv | test.c:67:5:67:9 | conv4 | The object returned by the function localeconv should not be modified. |
 | test.c:76:5:76:8 | conv | test.c:72:25:72:34 | call to localeconv | test.c:76:5:76:8 | conv | The object returned by the function localeconv should not be modified. |

c/misra/src/rules/RULE-14-3/ControllingExprInvariant.ql

@@ -40,7 +40,9 @@ where
         conditionAlwaysFalse(expr) and
         not (
           getEssentialTypeCategory(getEssentialType(expr)) instanceof EssentiallyBooleanType and
-          expr.getValue() = "0"
+          expr.getValue() = "0" and
+          // Only apply to expressions that do not reference variables.
+          not exists(VariableAccess va | va = expr.getAChild*())
         )
         or
         conditionAlwaysTrue(expr) and

c/misra/test/rules/RULE-14-3/ControllingExprInvariant.expected

@@ -3,6 +3,8 @@
 | test.c:16:9:16:13 | ... > ... | Controlling expression in if statement has an invariant value. |
 | test.c:20:20:20:24 | ... < ... | Controlling expression in loop statement has an invariant value. |
 | test.c:27:10:27:14 | ... < ... | Controlling expression in loop statement has an invariant value. |
-| test.c:37:3:37:6 | 1 | Controlling expression in conditional statement has an invariant value. |
-| test.c:38:3:38:3 | 1 | Controlling expression in conditional statement has an invariant value. |
-| test.c:45:10:45:26 | ... && ... | Controlling expression in loop statement has an invariant value. |
+| test.c:35:12:35:12 | 0 | Controlling expression in loop statement has an invariant value. |
+| test.c:39:3:39:6 | 1 | Controlling expression in conditional statement has an invariant value. |
+| test.c:40:3:40:3 | 1 | Controlling expression in conditional statement has an invariant value. |
+| test.c:47:10:47:26 | ... && ... | Controlling expression in loop statement has an invariant value. |
+| test.c:49:10:49:21 | ... && ... | Controlling expression in loop statement has an invariant value. |

c/misra/test/rules/RULE-14-3/test.c

@@ -31,6 +31,8 @@ void f3() {
 void f4() {
   do {
   } while (0u == 1u); // COMPLIANT - by exception 2
+  do {
+  } while (0); // NON_COMPLIANT - a bare literal `0` is not essentially Boolean
 }
 
 void f5(bool b1) {
@@ -44,4 +46,6 @@ void f6(int p1) {
   }
   while (1 == 0 && p1 > 12) { // NON_COMPLIANT
   }
+  while (0 && p1 > 12) { // NON_COMPLIANT
+  }
 }

c/misra/test/rules/RULE-21-18/test.c

@@ -103,4 +103,10 @@ void test(void) {
     strxfrm(buf + 1, buf2,
             sizeof(buf) - 1); // NON_COMPLIANT - not null-terminated
   }
-}
+}
+
+void test_strncat_bounded_source(void) {
+  char destination[2] = {0};
+  char source[1] = {'x'};
+  strncat(destination, source, 1); // COMPLIANT
+}

change_notes/2026-08-28-cpp-all-upgrade-result-changes.md

@@ -0,0 +1,9 @@
+- Upgraded CodeQL to v2.23.9, updating `codeql/cpp-all` and related dependencies. 
+- `RULE-1-2` - `LanguageExtensionsShouldNotBeUsed.ql`: fixed a false negative where `_Decimal32`,
+  `_Decimal64` and `_Decimal128` declarations were no longer reported as compiler extensions.
+- `ENV30-C`, `RULE-21-19`, `RULE-25-5-2`: fixed a duplicate alert reported for the same pointer
+  write.
+- `INT31-C` - `IntegerConversionCausesDataLoss.ql`: fixed a false positive on the standard-permitted
+  `(time_t)-1` conversion.
+- `RULE-14-3` - `ControllingExprInvariant.ql`: fixed a false negative where a loop's compound
+  controlling expression that always evaluates to false was incorrectly permitted.

cpp/cert/src/rules/EXP50-CPP/DoNotDependOnTheOrderOfEvaluationForSideEffectsInFunctionCallsAsFunctionArguments.ql

@@ -19,7 +19,6 @@
 import cpp
 import codingstandards.cpp.cert
 import codingstandards.cpp.SideEffect
-import semmle.code.cpp.dataflow.DataFlow
 import semmle.code.cpp.dataflow.TaintTracking
 import semmle.code.cpp.valuenumbering.GlobalValueNumbering
 

cpp/cert/src/rules/MEM52-CPP/DetectAndHandleMemoryAllocationErrors.ql

@@ -18,7 +18,7 @@
 import cpp
 import codingstandards.cpp.cert
 import semmle.code.cpp.controlflow.Guards
-import semmle.code.cpp.dataflow.DataFlow
+import semmle.code.cpp.dataflow.new.DataFlow
 import codingstandards.cpp.exceptions.ExceptionSpecifications
 
 /**