[PATCH] Fortran: check types of operands of arithmetic binary operations [PR107217]

[PATCH] Fortran: check types of operands of arithmetic binary operations [PR107217]

[Harald Anlauf]

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Dear all,

we need to check that the operands of arithmetic binary operations
are consistent and of numeric type.

The PR reported an issue for multiplication ("*"), but we better
extend this to the other binary operations.

I chose the following solution:
- consistent types for +,-,*,/, keeping an internal error if any
  unhandled type shows up,
- numeric types for **

Regtested on x86_64-pc-linux-gnu.  OK for mainline?

Thanks,
Harald


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From a95f251504bcb8ba28b7db1d2b7990631c761e9c Mon Sep 17 00:00:00 2001
From: Harald Anlauf <anlauf@gmx.de>
Date: Tue, 11 Oct 2022 22:08:48 +0200
Subject: [PATCH] Fortran: check types of operands of arithmetic binary
 operations [PR107217]

gcc/fortran/ChangeLog:

	PR fortran/107217
	* arith.cc (gfc_arith_plus): Compare consistency of types of operands.
	(gfc_arith_minus): Likewise.
	(gfc_arith_times): Likewise.
	(gfc_arith_divide): Likewise.
	(arith_power): Check that both operands are of numeric type.

gcc/testsuite/ChangeLog:

	PR fortran/107217
	* gfortran.dg/pr107217.f90: New test.
---
 gcc/fortran/arith.cc                   | 15 +++++++++++++++
 gcc/testsuite/gfortran.dg/pr107217.f90 | 18 ++++++++++++++++++
 2 files changed, 33 insertions(+)
 create mode 100644 gcc/testsuite/gfortran.dg/pr107217.f90

diff --git a/gcc/fortran/arith.cc b/gcc/fortran/arith.cc
index 9e079e42995..14ba931e37f 100644
--- a/gcc/fortran/arith.cc
+++ b/gcc/fortran/arith.cc
@@ -624,6 +624,9 @@ gfc_arith_plus (gfc_expr *op1, gfc_expr *op2, gfc_expr **resultp)
   gfc_expr *result;
   arith rc;

+  if (op1->ts.type != op2->ts.type)
+    return ARITH_INVALID_TYPE;
+
   result = gfc_get_constant_expr (op1->ts.type, op1->ts.kind, &op1->where);

   switch (op1->ts.type)
@@ -658,6 +661,9 @@ gfc_arith_minus (gfc_expr *op1, gfc_expr *op2, gfc_expr **resultp)
   gfc_expr *result;
   arith rc;

+  if (op1->ts.type != op2->ts.type)
+    return ARITH_INVALID_TYPE;
+
   result = gfc_get_constant_expr (op1->ts.type, op1->ts.kind, &op1->where);

   switch (op1->ts.type)
@@ -692,6 +698,9 @@ gfc_arith_times (gfc_expr *op1, gfc_expr *op2, gfc_expr **resultp)
   gfc_expr *result;
   arith rc;

+  if (op1->ts.type != op2->ts.type)
+    return ARITH_INVALID_TYPE;
+
   result = gfc_get_constant_expr (op1->ts.type, op1->ts.kind, &op1->where);

   switch (op1->ts.type)
@@ -727,6 +736,9 @@ gfc_arith_divide (gfc_expr *op1, gfc_expr *op2, gfc_expr **resultp)
   gfc_expr *result;
   arith rc;

+  if (op1->ts.type != op2->ts.type)
+    return ARITH_INVALID_TYPE;
+
   rc = ARITH_OK;

   result = gfc_get_constant_expr (op1->ts.type, op1->ts.kind, &op1->where);
@@ -815,6 +827,9 @@ arith_power (gfc_expr *op1, gfc_expr *op2, gfc_expr **resultp)
   gfc_expr *result;
   arith rc;

+  if (!gfc_numeric_ts (&op1->ts) || !gfc_numeric_ts (&op2->ts))
+    return ARITH_INVALID_TYPE;
+
   rc = ARITH_OK;
   result = gfc_get_constant_expr (op1->ts.type, op1->ts.kind, &op1->where);

diff --git a/gcc/testsuite/gfortran.dg/pr107217.f90 b/gcc/testsuite/gfortran.dg/pr107217.f90
new file mode 100644
index 00000000000..9c8492e64f0
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr107217.f90
@@ -0,0 +1,18 @@
+! { dg-do compile }
+! PR fortran/107217 - ICE in gfc_arith_times
+! Contributed by G.Steinmetz
+
+program p
+  print *, [real :: (['1'])] * 2 ! { dg-error "Cannot convert" }
+  print *, 2 * [real :: (['1'])] ! { dg-error "Cannot convert" }
+  print *, [real :: (['1'])] + 2 ! { dg-error "Cannot convert" }
+  print *, [real :: (['1'])] - 2 ! { dg-error "Cannot convert" }
+  print *, [real :: (['1'])] / 2 ! { dg-error "Cannot convert" }
+  print *, 1 / [real :: (['1'])] ! { dg-error "Cannot convert" }
+  print *, [real :: (['1'])] ** 2 ! { dg-error "Cannot convert" }
+  print *, 2 ** [real :: (['1'])] ! { dg-error "Cannot convert" }
+  print *, 2.0 ** [real :: (.true.)] ! { dg-error "Cannot convert" }
+  print *, [real :: (.true.)] ** 2.0 ! { dg-error "Cannot convert" }
+  print *, [complex :: (['1'])] ** (1.0,2.0) ! { dg-error "Cannot convert" }
+  print *, (1.0,2.0) ** [complex :: (['1'])] ! { dg-error "Cannot convert" }
+end
--
2.35.3

Re: [PATCH] Fortran: check types of operands of arithmetic binary operations [PR107217]

[Mikael Morin]

Le 11/10/2022 à 22:23, Harald Anlauf via Fortran a écrit :
> Dear all,
> 
> we need to check that the operands of arithmetic binary operations
> are consistent and of numeric type.
> 
> The PR reported an issue for multiplication ("*"), but we better
> extend this to the other binary operations.
> 
> I chose the following solution:
> - consistent types for +,-,*,/, keeping an internal error if any
>    unhandled type shows up,

I thought it was insufficient for cases where types are consistent but 
invalid, for example:
    print *, [real :: ([.true.])] / [real :: ([.false.])]
but this case is properly caught, and a few other as well, so no problem.

> - numeric types for **
> 
> Regtested on x86_64-pc-linux-gnu.  OK for mainline?
> 
Yes, thanks.