| Message ID | f1212af8-c5a4-ae0e-247e-df273784a991@netcologne.de |
|---|---|
| State | New |
| Headers | show |
> 2017-01-22 Thomas Koenig <tkoenig@netcologne.de> > > * arith.c (arith_power): If simplifying integer power expression > to zero, warn if -Winteger-division is given. > > 2017-01-22 Thomas Koenig <tkoenig@netcologne.de> > > * gfortran.dg/integer_exponentiation_7.f90: New test. The idea seems reasonable, but I am not sure about the wording (“truncated” in particular). “Integer exponentiation truncated to constant 0”? Why not “Negative integer exponent has result value zero”? Other than that, OK to commit. FX
Index: arith.c =================================================================== --- arith.c (Revision 244747) +++ arith.c (Arbeitskopie) @@ -874,6 +874,11 @@ arith_power (gfc_expr *op1, gfc_expr *op2, gfc_exp { /* if op2 < 0, op1**op2 == 0 because abs(op1) > 1. */ mpz_set_si (result->value.integer, 0); + if (warn_integer_division) + gfc_warning_now (OPT_Winteger_division, "Integer " + "exponentiation truncated to constant " + "%qs at %L", "0", &result->where); + } else if (gfc_extract_int (op2, &power)) {
Hello world, a reacent thread on c.l.f showed another common error - expecting 10**(-3) to expect something different from zero. The attached patch warns about this result if -Winteger-division is active. Why -Winteger-division? Two reasons: First, 10**(-3) ist just a shorthand for integer division. Second, I did not want to add yet another warning flag. Regression-tested. OK for trunk? Thomas 2017-01-22 Thomas Koenig <tkoenig@netcologne.de> * arith.c (arith_power): If simplifying integer power expression to zero, warn if -Winteger-division is given. 2017-01-22 Thomas Koenig <tkoenig@netcologne.de> * gfortran.dg/integer_exponentiation_7.f90: New test.