[gcc r12-3513] Implement PR ada/101385

[gcc r12-3513] Implement PR ada/101385

[Eric Botcazou]

https://gcc.gnu.org/g:f3922acfdfff1e426bd1238cf09eeb84332464c9

commit r12-3513-gf3922acfdfff1e426bd1238cf09eeb84332464c9
Author: Eric Botcazou <ebotcazou@adacore.com>
Date:   Tue Sep 14 10:32:00 2021 +0200

    Implement PR ada/101385
    
    For consistency's sake with -Wall & -w, this makes -Werror imply -gnatwe.
    
    gcc/ada/
            PR ada/101385
            * doc/gnat_ugn/building_executable_programs_with_gnat.rst
            (-Wall): Minor fixes.
            (-w): Likewise.
            (-Werror): Document that it also sets -gnatwe by default.
            * gcc-interface/lang-specs.h (ada): Expand -gnatwe if -Werror is
            passed and move expansion of -gnatw switches to before -gnatez.

Diff:
---
 .../doc/gnat_ugn/building_executable_programs_with_gnat.rst   | 11 +++++++----
 gcc/ada/gcc-interface/lang-specs.h                            |  7 ++++---
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/gcc/ada/doc/gnat_ugn/building_executable_programs_with_gnat.rst b/gcc/ada/doc/gnat_ugn/building_executable_programs_with_gnat.rst
index 07c38df6fa0..5a69967615f 100644
--- a/gcc/ada/doc/gnat_ugn/building_executable_programs_with_gnat.rst
+++ b/gcc/ada/doc/gnat_ugn/building_executable_programs_with_gnat.rst
@@ -4157,16 +4157,16 @@ of the pragma in the :title:`GNAT_Reference_manual`).
   This switch enables most warnings from the GCC back end.
   The code generator detects a number of warning situations that are missed
   by the GNAT front end, and this switch can be used to activate them.
-  The use of this switch also sets the default front end warning mode to
-  :switch:`-gnatwa`, that is, most front end warnings activated as well.
+  The use of this switch also sets the default front-end warning mode to
+  :switch:`-gnatwa`, that is, most front-end warnings are activated as well.
 
 
 .. index:: -w (gcc)
 
 :switch:`-w`
   Conversely, this switch suppresses warnings from the GCC back end.
-  The use of this switch also sets the default front end warning mode to
-  :switch:`-gnatws`, that is, front end warnings suppressed as well.
+  The use of this switch also sets the default front-end warning mode to
+  :switch:`-gnatws`, that is, front-end warnings are suppressed as well.
 
 
 .. index:: -Werror (gcc)
@@ -4175,6 +4175,9 @@ of the pragma in the :title:`GNAT_Reference_manual`).
   This switch causes warnings from the GCC back end to be treated as
   errors.  The warning string still appears, but the warning messages are
   counted as errors, and prevent the generation of an object file.
+  The use of this switch also sets the default front-end warning mode to
+  :switch:`-gnatwe`, that is, front-end warning messages and style check
+  messages are treated as errors as well.
 
 
 A string of warning parameters can be used in the same parameter. For example::
diff --git a/gcc/ada/gcc-interface/lang-specs.h b/gcc/ada/gcc-interface/lang-specs.h
index f5a7496ad5d..d26cc8d0534 100644
--- a/gcc/ada/gcc-interface/lang-specs.h
+++ b/gcc/ada/gcc-interface/lang-specs.h
@@ -36,7 +36,7 @@
    "\
  %{pg:%{fomit-frame-pointer:%e-pg and -fomit-frame-pointer are incompatible}}\
  %{!S:%{!c:%e-c or -S required for Ada}}\
- gnat1 %{I*} %{k8:-gnatk8} %{Wall:-gnatwa} %{w:-gnatws} %{!Q:-quiet}\
+ gnat1 %{I*} %{k8:-gnatk8} %{!Q:-quiet}\
     %{nostdinc*} %{nostdlib*}\
     %{fcompare-debug-second:-gnatd_A} \
     %{O*} %{W*} %{w} %{p} %{pg:-p} " ADA_DUMPS_OPTIONS " \
@@ -44,8 +44,9 @@
 #if defined(TARGET_VXWORKS_RTP)
    "%{fRTS=rtp|fRTS=rtp-smp|fRTS=ravenscar-cert-rtp:-mrtp} "
 #endif
-   "%{gnatea:-gnatez} %{g*&m*&f*} "
-   "%1 %{!S:%{o*:%w%*-gnatO}} \
+   "%{Wall:-gnatwa} %{Werror:-gnatwe} %{w:-gnatws} \
+    %{gnatea:-gnatez} %{g*&m*&f*} \
+    %1 %{!S:%{o*:%w%*-gnatO}} \
     %i %{S:%W{o*}%{!o*:-o %w%b.s}} \
     %{gnatc*|gnats*: -o %j} %{-param*} \
     %{!gnatc*:%{!gnats*:%(invoke_as)}}", 0, 0, 0},