Merge pull request #884 from github/michaelrfairhurst/address-compiler-compatibility-issue-misra-c-2023

First pass at addressing cross-compiler compatibility in MISRA 2023.

Author: MichaelRFairhurst

c/common/src/codingstandards/c/TgMath.qll

@@ -1,21 +1,38 @@
 import cpp
 
-private string getATgMathMacroName(boolean allowComplex) {
+private string getATgMathMacroName(boolean allowComplex, int numberOfParameters) {
   allowComplex = true and
+  numberOfParameters = 1 and
   result =
     [
       "acos", "acosh", "asin", "asinh", "atan", "atanh", "carg", "cimag", "conj", "cos", "cosh",
-      "cproj", "creal", "exp", "fabs", "log", "pow", "sin", "sinh", "sqrt", "tan", "tanh"
+      "cproj", "creal", "exp", "fabs", "log", "sin", "sinh", "sqrt", "tan", "tanh"
+    ]
+  or
+  allowComplex = true and
+  numberOfParameters = 2 and
+  result = "pow"
+  or
+  allowComplex = false and
+  numberOfParameters = 1 and
+  result =
+    [
+      "cbrt", "ceil", "erf", "erfc", "exp2", "expm1", "floor", "ilogb", "lgamma", "llrint",
+      "llround", "log10", "log1p", "log2", "logb", "lrint", "lround", "nearbyint", "rint", "round",
+      "tgamma", "trunc",
     ]
   or
   allowComplex = false and
+  numberOfParameters = 2 and
   result =
     [
-      "atan2", "cbrt", "ceil", "copysign", "erf", "erfc", "exp2", "expm1", "fdim", "floor", "fma",
-      "fmax", "fmin", "fmod", "frexp", "hypot", "ilogb", "ldexp", "lgamma", "llrint", "llround",
-      "log10", "log1p", "log2", "logb", "lrint", "lround", "nearbyint", "nextafter", "nexttoward",
-      "remainder", "remquo", "rint", "round", "scalbn", "scalbln", "tgamma", "trunc",
+      "atan2", "copysign", "fdim", "fmax", "fmin", "fmod", "frexp", "hypot", "ldexp", "nextafter",
+      "nexttoward", "remainder", "scalbn", "scalbln"
     ]
+  or
+  allowComplex = false and
+  numberOfParameters = 3 and
+  result = ["fma", "remquo"]
 }
 
 private predicate hasOutputArgument(string macroName, int index) {
@@ -27,19 +44,41 @@ private predicate hasOutputArgument(string macroName, int index) {
 class TgMathInvocation extends MacroInvocation {
   Call call;
   boolean allowComplex;
+  int numberOfParameters;
 
   TgMathInvocation() {
-    this.getMacro().getName() = getATgMathMacroName(allowComplex) and
+    this.getMacro().getName() = getATgMathMacroName(allowComplex, numberOfParameters) and
     call = getBestCallInExpansion(this)
   }
 
+  /** Account for extra parameters added by gcc */
+  private int getParameterOffset() {
+    // Gcc calls look something like: `__builtin_tgmath(cosf, cosd, cosl, arg)`, in this example
+    // there is a parameter offset of 3, so `getOperandArgument(0)` is equivalent to
+    // `call.getArgument(3)`.
+    result = call.getNumberOfArguments() - numberOfParameters
+  }
+
   Expr getOperandArgument(int i) {
-    result = call.getArgument(i) and
-    not hasOutputArgument(call.getTarget().getName(), i)
+    i >= 0 and
+    result = call.getArgument(i + getParameterOffset()) and
+    //i in [0..numberOfParameters - 1] and
+    not hasOutputArgument(getMacro().getName(), i)
+  }
+
+  /** Get all explicit conversions, except those added by clang in the macro body */
+  Expr getExplicitlyConvertedOperandArgument(int i) {
+    exists(Expr explicitConv |
+      explicitConv = getOperandArgument(i).getExplicitlyConverted() and
+      // clang explicitly casts most arguments, but not some integer arguments such as in `scalbn`.
+      if call.getTarget().getName().matches("__tg_%") and explicitConv instanceof Conversion
+      then result = explicitConv.(Conversion).getExpr()
+      else result = explicitConv
+    )
   }
 
   int getNumberOfOperandArguments() {
-    result = call.getNumberOfArguments() - count(int i | hasOutputArgument(getMacroName(), i))
+    result = numberOfParameters - count(int i | hasOutputArgument(getMacroName(), i))
   }
 
   Expr getAnOperandArgument() { result = getOperandArgument(_) }

c/common/test/rules/functionnoreturnattributecondition/test.c

@@ -77,7 +77,7 @@ _Noreturn void test_noreturn_f10(int i) { // COMPLIANT
   case 4:
     thrd_exit(0);
     break;
-  default:
+  default:;
     jmp_buf jb;
     longjmp(jb, 0);
   }