From: Bruno Haible <bruno@clisp.org>
Date: Tue, 5 May 2026 15:15:39 +0000 (+0200)
Subject: HACKING: Explain how to use the undefined-behaviour sanitizer.
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=d760a401052e9573f50d9b258e1f94958a5f7389;p=thirdparty%2Fgettext.git

HACKING: Explain how to use the undefined-behaviour sanitizer.

* HACKING (Customizing the Undefined Behaviour Sanitizer): New section.
---

diff --git a/HACKING b/HACKING
index f33e5431b..33a145357 100644
--- a/HACKING
+++ b/HACKING
@@ -513,6 +513,28 @@ For C source code:
   Only static variables are better kept declared upfront in a function or block.
 
 
+Customizing the Undefined Behaviour Sanitizer (UBSAN)
+=====================================================
+
+Using gcc with UBSAN is as usual:
+
+  CC="gcc -fsanitize=undefined,signed-integer-overflow,shift,integer-divide-by-zero -fno-sanitize-recover=undefined"
+  CXX="g++ -fsanitize=undefined,signed-integer-overflow,shift,integer-divide-by-zero -fno-sanitize-recover=undefined"
+  CFLAGS="-O1 -fno-omit-frame-pointer -ggdb"
+  CXXFLAGS="-O1 -fno-omit-frame-pointer -ggdb"
+  export CC CXX CFLAGS CXXFLAGS
+
+Using clang with UBSAN needs a customization, to avoid errors such as
+  "runtime error: call to function get_control_data through pointer to incorrect function type"
+coming from libtextstyle, namely
+
+  CC="clang -fsanitize=undefined,signed-integer-overflow,shift,integer-divide-by-zero -fno-sanitize=function -fno-sanitize-recover=undefined"
+  CXX="clang++ -fsanitize=undefined,signed-integer-overflow,shift,integer-divide-by-zero -fno-sanitize=function -fno-sanitize-recover=undefined"
+  CFLAGS="-O1 -fno-omit-frame-pointer -ggdb"
+  CXXFLAGS="-O1 -fno-omit-frame-pointer -ggdb"
+  export CC CXX CFLAGS CXXFLAGS
+
+
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