From: Pierre-Marie de Rodat <derodat@adacore.com>
To: gcc-patches@gcc.gnu.org
Cc: Eric Botcazou <ebotcazou@adacore.com>
Subject: [Ada] Adjust description of Pure_Function pragma
Date: Mon, 4 Jul 2022 07:49:58 +0000 [thread overview]
Message-ID: <20220704074958.GA98864@adacore.com> (raw)
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The current wording can be read as implying that the result of a call
to a pure function does not depend on the context, which is incorrect.
The pragma only guarantees the absence of side effects of such a call.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* doc/gnat_rm/implementation_defined_pragmas.rst (Pure_Function):
Fix ambiguous wording about context dependence.
* gnat_rm.texi: Regenerate.
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[-- Type: text/x-diff, Size: 1957 bytes --]
diff --git a/gcc/ada/doc/gnat_rm/implementation_defined_pragmas.rst b/gcc/ada/doc/gnat_rm/implementation_defined_pragmas.rst
--- a/gcc/ada/doc/gnat_rm/implementation_defined_pragmas.rst
+++ b/gcc/ada/doc/gnat_rm/implementation_defined_pragmas.rst
@@ -5504,9 +5504,9 @@ overloaded declaration exists, in which case the pragma applies
to all entities). It specifies that the function ``Entity`` is
to be considered pure for the purposes of code generation. This means
that the compiler can assume that there are no side effects, and
-in particular that two calls with identical arguments produce the
-same result. It also means that the function can be used in an
-address clause.
+in particular that two identical calls produce the same result in
+the same context. It also means that the function can be used in
+an address clause.
Note that, quite deliberately, there are no static checks to try
to ensure that this promise is met, so ``Pure_Function`` can be used
diff --git a/gcc/ada/gnat_rm.texi b/gcc/ada/gnat_rm.texi
--- a/gcc/ada/gnat_rm.texi
+++ b/gcc/ada/gnat_rm.texi
@@ -21,7 +21,7 @@
@copying
@quotation
-GNAT Reference Manual , May 24, 2022
+GNAT Reference Manual , Jun 24, 2022
AdaCore
@@ -7088,9 +7088,9 @@ overloaded declaration exists, in which case the pragma applies
to all entities). It specifies that the function @code{Entity} is
to be considered pure for the purposes of code generation. This means
that the compiler can assume that there are no side effects, and
-in particular that two calls with identical arguments produce the
-same result. It also means that the function can be used in an
-address clause.
+in particular that two identical calls produce the same result in
+the same context. It also means that the function can be used in
+an address clause.
Note that, quite deliberately, there are no static checks to try
to ensure that this promise is met, so @code{Pure_Function} can be used
reply other threads:[~2022-07-04 7:50 UTC|newest]
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