FLP34-C: Support all forms of fabs/log2

Author: lcartey

c/cert/src/rules/FLP34-C/UncheckedFloatingPointConversion.ql

@@ -75,18 +75,18 @@ where
     withinIntegralRange(underlyingTypeAfter, [upperBound(c.getExpr()), lowerBound(c.getExpr())])
     or
     // Heuristic - is there are guard the abs value of the float can fit in the precision of an int?
-    exists(GuardCondition gc, FunctionCall log2f, FunctionCall fabsf, Expr precision |
+    exists(GuardCondition gc, FunctionCall log2, FunctionCall fabs, Expr precision |
       // gc.controls(c, false) and
-      log2f.getTarget().hasGlobalOrStdName("log2f") and
-      fabsf.getTarget().hasGlobalOrStdName("fabsf") and
-      log2f.getArgument(0) = fabsf and
+      log2.getTarget().hasGlobalOrStdName("log2" + ["", "l", "f"]) and
+      fabs.getTarget().hasGlobalOrStdName("fabs" + ["", "l", "f"]) and
+      log2.getArgument(0) = fabs and
       // Precision is either a macro expansion or function call
       (
         precision.(FunctionCall).getTarget() instanceof PopCount
         or
         precision = any(PrecisionMacro pm).getAnInvocation().getExpr()
       ) and
-      gc.ensuresLt(precision, log2f, 0, c.getExpr().getBasicBlock(), false)
+      gc.ensuresLt(precision, log2, 0, c.getExpr().getBasicBlock(), false)
     )
   )
 select c, "Conversion of float to integer without appropriate guards avoiding undefined behavior."

c/cert/test/rules/FLP34-C/test.c

@@ -28,10 +28,28 @@ size_t popcount(uintmax_t num) {
 #define PRECISION(umax_value) popcount(umax_value)
 
 void test_precision_check(float f) {
+  if (isnan(f) || PRECISION(INT_MAX) < log2(fabs(f)) ||
+      (f != 0.0F && fabs(f) < FLT_MIN)) {
+    /* Handle error */
+  } else {
+    int i = f; // COMPLIANT
+  }
+}
+
+void test_precision_check_double(double f) {
   if (isnan(f) || PRECISION(INT_MAX) < log2f(fabsf(f)) ||
       (f != 0.0F && fabsf(f) < FLT_MIN)) {
     /* Handle error */
   } else {
     int i = f; // COMPLIANT
   }
+}
+
+void test_precision_check_long_double(long double f) {
+  if (isnan(f) || PRECISION(INT_MAX) < log2l(fabsl(f)) ||
+      (f != 0.0F && fabsl(f) < FLT_MIN)) {
+    /* Handle error */
+  } else {
+    int i = f; // COMPLIANT
+  }
 }