From ab7eca92926fdc1da880120c116a1832fce56a29 Mon Sep 17 00:00:00 2001
From: Richard Biener <rguenther@suse.de>
Date: Tue, 19 May 2020 08:36:13 +0200
Subject: [PATCH] lto/95190 - amend -flto docs for diagnostic option handling
This documents new GCC 10 behavior on diagnostic options and -flto.
2020-05-22 Richard Biener <rguenther@suse.de>
PR lto/95190
* doc/invoke.texi (flto): Document behavior of diagnostic
options.
---
gcc/ChangeLog | 6 ++++++
gcc/doc/invoke.texi | 8 ++++++++
2 files changed, 14 insertions(+)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 390a344e459a..0c3045a6005f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2020-05-22 Richard Biener <rguenther@suse.de>
+
+ PR lto/95190
+ * doc/invoke.texi (flto): Document behavior of diagnostic
+ options.
+
2020-05-22 Richard Biener <rguenther@suse.de>
* tree-vectorizer.h (vect_is_simple_use): New overload.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 7217e27151d6..8b9935dfe652 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -11205,6 +11205,14 @@ conflicting translation units. Specifically
precedence; and for example @option{-ffp-contract=off} takes precedence
over @option{-ffp-contract=fast}. You can override them at link time.
+Diagnostic options such as @option{-Wstringop-overflow} are passed
+through to the link stage and their setting matches that of the
+compile-step at function granularity. Note that this matters only
+for diagnostics emitted during optimization. Note that code
+transforms such as inlining can lead to warnings being enabled
+or disabled for regions if code not consistent with the setting
+at compile time.
+
When you need to pass options to the assembler via @option{-Wa} or
@option{-Xassembler} make sure to either compile such translation
units with @option{-fno-lto} or consistently use the same assembler
--
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