Remove some wrong unused warnings, do not issue warnings if there are errors.

This patch fixes to omissions when variables were not set as referenced
and removes the warnings if errors have previously been issued.

gcc/fortran/ChangeLog:

	PR fortran/30438
	PR fortran/125801
	* io.cc (gfc_resolve_dt): Set internal unit as used on read.o
	* resolve.cc (resolve_transfer): Move setting value as used
	before possible early return.
	(gfc_resolve): Only call warn_unused_vs_set if there are no
	pending errors.

gcc/testsuite/ChangeLog:

	PR fortran/30438
	PR fortran/125801
	* gfortran.dg/warn_unused_but_set_error_1.f90: New test.
	* gfortran.dg/warn_unused_intent_out_2.f90: New test.

diff --git a/gcc/fortran/io.cc b/gcc/fortran/io.cc
index 4720ea9a1f2e367a7a720845c06270877445be9a..db0d1fdce798fea2ef0360c3db165eace34bb124 100644 (file)
--- a/gcc/fortran/io.cc
+++ b/gcc/fortran/io.cc
@@ -3412,6 +3412,8 @@ gfc_resolve_dt (gfc_code *dt_code, gfc_dt *dt, locus *loc)
 
          gfc_expr_set_at (e, &e->where, VALUE_VARDEF);
        }
+      else
+       gfc_value_used_expr (e, VALUE_USED);
     }
 
   if (e->rank && e->ts.type != BT_CHARACTER)

diff --git a/gcc/fortran/resolve.cc b/gcc/fortran/resolve.cc
index d479b6a80e51dbdbcee91969d29c45297ba42058..9f1626c2949e968ba23b9381b8dbdc174e47cc85 100644 (file)
--- a/gcc/fortran/resolve.cc
+++ b/gcc/fortran/resolve.cc
@@ -11769,6 +11769,10 @@ resolve_transfer (gfc_code *code)
       return;
     }
 
+  if (dt && (dt->dt_io_kind->value.iokind == M_WRITE
+            || dt->dt_io_kind->value.iokind == M_PRINT))
+    gfc_value_used_expr (exp, VALUE_USED);
+
   if (exp == NULL || (exp->expr_type != EXPR_VARIABLE
                      && exp->expr_type != EXPR_FUNCTION
                      && exp->expr_type != EXPR_ARRAY
@@ -11901,10 +11905,6 @@ resolve_transfer (gfc_code *code)
       return;
     }
 
-  if (dt && (dt->dt_io_kind->value.iokind == M_WRITE
-            || dt->dt_io_kind->value.iokind == M_PRINT))
-    gfc_value_used_expr (exp, VALUE_USED);
-
 }
 
 
@@ -21000,7 +21000,12 @@ gfc_resolve (gfc_namespace *ns)
 
   if (warn_unused_but_set_variable || warn_unused_intent_out
       || warn_unused_read || warn_undefined_vars)
-    warn_unused_vs_set (ns);
+    {
+      int error_count;
+      gfc_get_errors (NULL, &error_count);
+      if (error_count == 0)
+       warn_unused_vs_set (ns);
+    }
 
   if (ns->omp_assumes)
     gfc_resolve_omp_assumptions (ns->omp_assumes);

diff --git a/gcc/testsuite/gfortran.dg/warn_unused_but_set_error_1.f90 b/gcc/testsuite/gfortran.dg/warn_unused_but_set_error_1.f90
new file mode 100644 (file)
index 0000000..f9b1520
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/warn_unused_but_set_error_1.f90
@@ -0,0 +1,8 @@
+! { dg-do compile }
+! { dg-options "-Wundefined-vars -Wunused-but-set-variable" }
+! Make sure that no warning are emitted after an error.
+program main
+  real :: a, b
+  b = sum(a) ! { dg-error "must be an array" }
+end program main
+  

diff --git a/gcc/testsuite/gfortran.dg/warn_unused_intent_out_2.f90 b/gcc/testsuite/gfortran.dg/warn_unused_intent_out_2.f90
new file mode 100644 (file)
index 0000000..7d0657c
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/warn_unused_intent_out_2.f90
@@ -0,0 +1,21 @@
+! { dg-do compile }
+! { dg-options "-Wunused-intent-out" }
+! PR fortran/125801 - no warnings should be emitted here.
+
+subroutine unused_1
+  character(len=20) c_val
+  integer val
+
+  CALL getarg(1,c_val)
+  READ(c_val,*) val
+  print*,val
+end subroutine unused_1
+
+subroutine unused_2
+
+  INTEGER t1,t2
+  CALL SYSTEM_CLOCK(t1)
+  CALL sleep(1)
+  CALL SYSTEM_CLOCK(t2)
+  print*,"Ende: ",(t2-t1)/1000.0
+end subroutine unused_2