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Re: [PATCH, Fortran] Optionally suppress no-automatic overwrites recursive warning - for review
On 20/09/2019 07:46, Bernhard Reutner-Fischer wrote:
On Thu, 19 Sep 2019 17:46:29 +0200
Tobias Burnus <tobias@codesourcery.com> wrote:
Hi Mark,
On 9/19/19 3:40 PM, Mark Eggleston wrote:
The following warning is produced when -fno-automatic and -frecursive
are used at the same time:
f951: Warning: Flag '-fno-automatic' overwrites '-frecursive'
This patch allows the warning to be switched off using a new option,
-Woverwrite-recursive, initialised to on.
I don't have a test case for this as I don't know how to test for a
warning that isn't related to a line of code.
Try:
! { dg-warning "Flag .-fno-automatic. overwrites .-frecursive." "" {
target *-*-* } 0 }
The syntax is { dg-warning "message", "label" {target ...} linenumber },
where linenumber = 0 means it can be on any line.
Thanks that was the bit I was missing. Test cases now added.
If the output doesn't match (but I think it does with "Warning:"),
general messages can be caught with "dg-message".
Also:
@@ -411,7 +411,7 @@ gfc_post_options (const char **pfilename)
&& flag_max_stack_var_size != 0)
gfc_warning_now (0, "Flag %<-fno-automatic%> overwrites %<-fmax-stack-var-size=%d%>",
flag_max_stack_var_size);
- else if (!flag_automatic && flag_recursive)
+ else if (!flag_automatic && flag_recursive && warn_overwrite_recursive)
gfc_warning_now (0, "Flag %<-fno-automatic%> overwrites %<-frecursive%>");
else if (!flag_automatic && flag_openmp)
gfc_warning_now (0, "Flag %<-fno-automatic%> overwrites %<-frecursive%> implied by "
Doesn't look right to me. Do you want
gfc_warning_now (OPT_Woverwrite_recursive, "Flag ...
instead?
Done.
thanks,
Additionally I realised that I hadn't updated the manual.
Updated patch is attached.
Updated change log:
gcc/fortran
Mark Eggleston <mark.eggleston@codethink.com>
* invoke.texi: Add -Wno-overwrite-recursive to list of options. Add
description of -Wno-overwrite-recursive. Fix typo in description
of -Winteger-division.
* lang.opt: Add option -Woverwrite-recursive initialised as on.
* option.c (gfc_post_options): Output warning only if it is enabled.
gcc/testsuite
Mark Eggleston <mark.eggleston@codethink.com>
* gfortran.dg/no_overwrite_recursive_1.f90: New test.
* gfortran.dg/no_overwrite_recursive_2.f90: New test.
OK to commit?
Mark
--
https://www.codethink.co.uk/privacy.html
>From e3c40212a648d9fbf8ea33525a943cc85e0652b0 Mon Sep 17 00:00:00 2001
From: Mark Eggleston <markeggleston@codethink.com>
Date: Tue, 16 Apr 2019 09:09:12 +0100
Subject: [PATCH] Suppress warning with -Wno-overwrite-recursive
The message "Warning: Flag '-fno-automatic' overwrites '-frecursive'" is
output by default when -fno-automatic and -frecursive are used together.
It warns that recursion may be broken, however if all the relavent variables
in the recursive procedure have automatic attributes the warning is
unnecessary so -Wno-overwrite-recursive can be used to suppress it. This
will allow compilation when warnings are regarded as errors.
Suppress warning with -Wno-overwrite-recursive
---
gcc/fortran/invoke.texi | 20 +++++++++++++++-----
gcc/fortran/lang.opt | 4 ++++
gcc/fortran/options.c | 5 +++--
.../gfortran.dg/no_overwrite_recursive_1.f90 | 11 +++++++++++
.../gfortran.dg/no_overwrite_recursive_2.f90 | 10 ++++++++++
5 files changed, 43 insertions(+), 7 deletions(-)
create mode 100644 gcc/testsuite/gfortran.dg/no_overwrite_recursive_1.f90
create mode 100644 gcc/testsuite/gfortran.dg/no_overwrite_recursive_2.f90
diff --git a/gcc/fortran/invoke.texi b/gcc/fortran/invoke.texi
index 40eeadd00db..b60749b3755 100644
--- a/gcc/fortran/invoke.texi
+++ b/gcc/fortran/invoke.texi
@@ -149,10 +149,11 @@ and warnings}.
-Wc-binding-type -Wcharacter-truncation -Wconversion @gol
-Wdo-subscript -Wfunction-elimination -Wimplicit-interface @gol
-Wimplicit-procedure -Wintrinsic-shadow -Wuse-without-only @gol
--Wintrinsics-std -Wline-truncation -Wno-align-commons -Wno-tabs @gol
--Wreal-q-constant -Wsurprising -Wunderflow -Wunused-parameter @gol
--Wrealloc-lhs -Wrealloc-lhs-all -Wfrontend-loop-interchange @gol
--Wtarget-lifetime -fmax-errors=@var{n} -fsyntax-only -pedantic @gol
+-Wintrinsics-std -Wline-truncation -Wno-align-commons @gol
+-Wno-overwrite-recursive -Wno-tabs -Wreal-q-constant -Wsurprising @gol
+-Wunderflow -Wunused-parameter -Wrealloc-lhs -Wrealloc-lhs-all @gol
+-Wfrontend-loop-interchange -Wtarget-lifetime -fmax-errors=@var{n} @gol
+-fsyntax-only -pedantic @gol
-pedantic-errors @gol
}
@@ -997,7 +998,7 @@ nor has been declared as @code{EXTERNAL}.
@opindex @code{Winteger-division}
@cindex warnings, integer division
@cindex warnings, division of integers
-Warn if a constant integer division truncates it result.
+Warn if a constant integer division truncates its result.
As an example, 3/5 evaluates to 0.
@item -Wintrinsics-std
@@ -1010,6 +1011,15 @@ it as @code{EXTERNAL} procedure because of this. @option{-fall-intrinsics} can
be used to never trigger this behavior and always link to the intrinsic
regardless of the selected standard.
+@item -Wno-overwrite-recursive
+@opindex @code{Woverwrite-recursive}
+@cindex warnings, overwrite recursive
+Do not warn when @option{-fno-automatic} is used with @option{-frecursive}. Recursion
+will be broken if the relevant local variables do not have the attribute
+@code{AUTOMATIC} explicitly declared. This option can be used to suppress the warning
+when it is known that recursion is not broken. Useful for build environment that use
+@option{-Werror}.
+
@item -Wreal-q-constant
@opindex @code{Wreal-q-constant}
@cindex warnings, @code{q} exponent-letter
diff --git a/gcc/fortran/lang.opt b/gcc/fortran/lang.opt
index 767725c5801..015da85a4a4 100644
--- a/gcc/fortran/lang.opt
+++ b/gcc/fortran/lang.opt
@@ -293,6 +293,10 @@ Wopenmp-simd
Fortran
; Documented in C
+Woverwrite-recursive
+Fortran Warning Var(warn_overwrite_recursive) Init(1)
+Warn that -fno-automatic may break recursion.
+
Wpedantic
Fortran
; Documented in common.opt
diff --git a/gcc/fortran/options.c b/gcc/fortran/options.c
index a0f95fa8832..8c38a493dc8 100644
--- a/gcc/fortran/options.c
+++ b/gcc/fortran/options.c
@@ -418,8 +418,9 @@ gfc_post_options (const char **pfilename)
&& flag_max_stack_var_size != 0)
gfc_warning_now (0, "Flag %<-fno-automatic%> overwrites %<-fmax-stack-var-size=%d%>",
flag_max_stack_var_size);
- else if (!flag_automatic && flag_recursive)
- gfc_warning_now (0, "Flag %<-fno-automatic%> overwrites %<-frecursive%>");
+ else if (!flag_automatic && flag_recursive && warn_overwrite_recursive)
+ gfc_warning_now (OPT_Woverwrite_recursive, "Flag %<-fno-automatic%> "
+ "overwrites %<-frecursive%>");
else if (!flag_automatic && flag_openmp)
gfc_warning_now (0, "Flag %<-fno-automatic%> overwrites %<-frecursive%> implied by "
"%<-fopenmp%>");
diff --git a/gcc/testsuite/gfortran.dg/no_overwrite_recursive_1.f90 b/gcc/testsuite/gfortran.dg/no_overwrite_recursive_1.f90
new file mode 100644
index 00000000000..f12c4b8a4c7
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/no_overwrite_recursive_1.f90
@@ -0,0 +1,11 @@
+! { dg-do compile }
+! { dg-options "-fno-automatic -frecursive" }
+!
+! Test case contributed by Mark Eggleston <mark.eggleston@codethink.com>
+!
+
+program test
+ ! do nothing
+end program
+
+! { dg-warning "Flag '-fno-automatic' overwrites '-frecursive'" "warning" { target *-*-* } 0 }
diff --git a/gcc/testsuite/gfortran.dg/no_overwrite_recursive_2.f90 b/gcc/testsuite/gfortran.dg/no_overwrite_recursive_2.f90
new file mode 100644
index 00000000000..09445375481
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/no_overwrite_recursive_2.f90
@@ -0,0 +1,10 @@
+! { dg-do compile }
+! { dg-options "-fno-automatic -frecursive -Wno-overwrite-recursive" }
+!
+! Test case contributed by Mark Eggleston <mark.eggleston@codethink.com>
+!
+
+program test
+ ! do nothing
+end program
+
--
2.11.0