Re: [PATCH 3/3] Fortran: Fix mpz and mpfr memory leaks

[Harald Anlauf via Gcc-patches]

Hi Bernhard,

there is neither context nor a related PR with a testcase showing
that this patch fixes issues seen there.

On 4/2/23 17:05, Bernhard Reutner-Fischer via Gcc-patches wrote:

From: Bernhard Reutner-Fischer <al...@gcc.gnu.org>

Cc: fort...@gcc.gnu.org

gcc/fortran/ChangeLog:

        * array.cc (gfc_ref_dimen_size): Free mpz memory before ICEing.
        * expr.cc (find_array_section): Fix mpz memory leak.
        * simplify.cc (gfc_simplify_reshape): Fix mpz memory leaks in
        error paths.
        (gfc_simplify_set_exponent): Fix mpfr memory leak.
---
  gcc/fortran/array.cc    | 3 +++
  gcc/fortran/expr.cc     | 8 ++++----
  gcc/fortran/simplify.cc | 7 ++++++-
  3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/gcc/fortran/array.cc b/gcc/fortran/array.cc
index be5eb8b6a0f..8b1e816a859 100644
--- a/gcc/fortran/array.cc
+++ b/gcc/fortran/array.cc
@@ -2541,6 +2541,9 @@ gfc_ref_dimen_size (gfc_array_ref *ar, int dimen, mpz_t 
*result, mpz_t *end)
        return t;

      default:
+      mpz_clear (lower);
+      mpz_clear (stride);
+      mpz_clear (upper);
        gfc_internal_error ("gfc_ref_dimen_size(): Bad dimen_type");
      }

What is the point of clearing variables before issuing a gfc_internal_error?

diff --git a/gcc/fortran/expr.cc b/gcc/fortran/expr.cc
index 7fb33f81788..b4736804eda 100644
--- a/gcc/fortran/expr.cc
+++ b/gcc/fortran/expr.cc
@@ -1539,6 +1539,7 @@ find_array_section (gfc_expr *expr, gfc_ref *ref)
    mpz_init_set_ui (delta_mpz, one);
    mpz_init_set_ui (nelts, one);
    mpz_init (tmp_mpz);
+  mpz_init (ptr);

    /* Do the initialization now, so that we can cleanup without
       keeping track of where we were.  */
@@ -1682,7 +1683,6 @@ find_array_section (gfc_expr *expr, gfc_ref *ref)
        mpz_mul (delta_mpz, delta_mpz, tmp_mpz);
      }

-  mpz_init (ptr);
    cons = gfc_constructor_first (base);

    /* Now clock through the array reference, calculating the index in
@@ -1735,7 +1735,8 @@ find_array_section (gfc_expr *expr, gfc_ref *ref)
                     "at %L requires an increase of the allowed %d "
                     "upper limit.  See %<-fmax-array-constructor%> "
                     "option", &expr->where, flag_max_array_constructor);
-         return false;
+         t = false;
+         goto cleanup;
        }

        cons = gfc_constructor_lookup (base, limit);
@@ -1750,8 +1751,6 @@ find_array_section (gfc_expr *expr, gfc_ref *ref)
                                   gfc_copy_expr (cons->expr), NULL);
      }

-  mpz_clear (ptr);
-
  cleanup:

    mpz_clear (delta_mpz);
@@ -1765,6 +1764,7 @@ cleanup:
        mpz_clear (ctr[d]);
        mpz_clear (stride[d]);
      }
+  mpz_clear (ptr);
    gfc_constructor_free (base);
    return t;
  }
diff --git a/gcc/fortran/simplify.cc b/gcc/fortran/simplify.cc
index ecf0e3558df..d1f06335e79 100644
--- a/gcc/fortran/simplify.cc
+++ b/gcc/fortran/simplify.cc
@@ -6866,6 +6866,7 @@ gfc_simplify_reshape (gfc_expr *source, gfc_expr 
*shape_exp,
          gfc_error ("The SHAPE array for the RESHAPE intrinsic at %L has a "
                     "negative value %d for dimension %d",
                     &shape_exp->where, shape[rank], rank+1);
+         mpz_clear (index);
          return &gfc_bad_expr;
        }

@@ -6889,6 +6890,7 @@ gfc_simplify_reshape (gfc_expr *source, gfc_expr 
*shape_exp,
        {
          gfc_error ("Shapes of ORDER at %L and SHAPE at %L are different",
                     &order_exp->where, &shape_exp->where);
+         mpz_clear (index);
          return &gfc_bad_expr;
        }

@@ -6902,6 +6904,7 @@ gfc_simplify_reshape (gfc_expr *source, gfc_expr 
*shape_exp,
        {
          gfc_error ("Sizes of ORDER at %L and SHAPE at %L are different",
                     &order_exp->where, &shape_exp->where);
+         mpz_clear (index);
          return &gfc_bad_expr;
        }

@@ -6918,6 +6921,7 @@ gfc_simplify_reshape (gfc_expr *source, gfc_expr 
*shape_exp,
                         "in the range [1, ..., %d] for the RESHAPE intrinsic "
                         "near %L", order[i], &order_exp->where, rank,
                         &shape_exp->where);
+             mpz_clear (index);
              return &gfc_bad_expr;
            }

@@ -6926,6 +6930,7 @@ gfc_simplify_reshape (gfc_expr *source, gfc_expr 
*shape_exp,
            {
              gfc_error ("ORDER at %L is not a permutation of the size of "
                         "SHAPE at %L", &order_exp->where, &shape_exp->where);
+             mpz_clear (index);
              return &gfc_bad_expr;
            }
          x[order[i]] = 1;
@@ -7408,7 +7413,7 @@ gfc_simplify_set_exponent (gfc_expr *x, gfc_expr *i)
    exp2 = (unsigned long) mpz_get_d (i->value.integer);
    mpfr_mul_2exp (result->value.real, frac, exp2, GFC_RND_MODE);

-  mpfr_clears (absv, log2, pow2, frac, NULL);
+  mpfr_clears (exp, absv, log2, pow2, frac, NULL);

    return range_check (result, "SET_EXPONENT");
  }