[PATCH] [gdb/testsuite] Fix pi approximation

[PATCH] [gdb/testsuite] Fix pi approximation

[Tom de Vries]

In gdb.dap/ada-non-ascii/prog.adb, I came across the following:
...
   π : Integer := 3;            --  The Indiana Approximation.
...

This article [1] explains the background behind the comment: the Indiana pi
bill.

Given that the common interpretation seems to be that the bill implies that
π == 3.2 [2]:
...
The bill ... has been claimed to imply a number of different values for π,
although the closest it comes to explicitly asserting one is the wording "the
ratio of the diameter and circumference is as five-fourths to four", which
would make π = 16⁄5 = 3.2, ... .
...
change the type to float, and set it to 3.2.

Luckily, in this particular case, changing the approximation of π has no
effect, so the test-case still passes :) .

Tested on x86_64-linux.

[1] https://en.wikipedia.org/wiki/Indiana_pi_bill
[2] https://en.wikipedia.org/wiki/Approximations_of_pi#Indiana_bill
---
 gdb/testsuite/gdb.dap/ada-non-ascii/prog.adb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gdb/testsuite/gdb.dap/ada-non-ascii/prog.adb b/gdb/testsuite/gdb.dap/ada-non-ascii/prog.adb
index 7853be5eff8..b2885b3759e 100644
--- a/gdb/testsuite/gdb.dap/ada-non-ascii/prog.adb
+++ b/gdb/testsuite/gdb.dap/ada-non-ascii/prog.adb
@@ -16,7 +16,7 @@
 with Pack; use Pack;
 
 procedure Prog is
-   π : Integer := 3;            --  The Indiana Approximation.
+   π : Float := 3.2;            --  The Indiana Approximation.
    φ : constant := 7;           --  Not even close.
 begin
    Do_Nothing (π'Address);      --  BREAK

base-commit: 449035c35f2169e0c690d83f28306275ab7f7463
-- 
2.51.0

Re: [PATCH] [gdb/testsuite] Fix pi approximation

[Kevin Buettner]

On Mon, 26 Jan 2026 13:41:12 +0100
Tom de Vries <tdevries@suse.de> wrote:

> From: Tom de Vries <tdevries@suse.de>
> To: gdb-patches@sourceware.org
> Subject: [PATCH] [gdb/testsuite] Fix pi approximation
> Date: Mon, 26 Jan 2026 13:41:12 +0100
> 
> In gdb.dap/ada-non-ascii/prog.adb, I came across the following:
> ...
>    __ : Integer := 3;            --  The Indiana Approximation.
> ...
> 
> This article [1] explains the background behind the comment: the Indiana
> pi bill.
> 
> Given that the common interpretation seems to be that the bill implies
> that __ == 3.2 [2]:
> ...
> The bill ... has been claimed to imply a number of different values for
> __, although the closest it comes to explicitly asserting one is the
> wording "the ratio of the diameter and circumference is as five-fourths
> to four", which would make __ = 16___5 = 3.2, ... .
> ...
> change the type to float, and set it to 3.2.
> 
> Luckily, in this particular case, changing the approximation of __ has no
> effect, so the test-case still passes :) .
> 
> Tested on x86_64-linux.
> 
> [1] https://en.wikipedia.org/wiki/Indiana_pi_bill
> [2] https://en.wikipedia.org/wiki/Approximations_of_pi#Indiana_bill

I had, of course, heard of this, but I did not realize that the
approximation was 3.2 instead of 3.  But since we strive for
historical accuracy in all of our testing ;) ...

Approved-by: Kevin Buettner <kevinb@redhat.com>