https://invent.kde.org/utilities/konsole/-/merge_requests/621
https://invent.kde.org/utilities/konsole/-/commit/b8c90a830ceaf293e61f6cd5217bb3e584f997b8 (backport)


From b8c90a830ceaf293e61f6cd5217bb3e584f997b8 Mon Sep 17 00:00:00 2001
From: Heiko Becker <heiko.becker@kde.org>
Date: Tue, 22 Mar 2022 22:08:10 +0100
Subject: [PATCH] Detect the presence of malloc_trim to fix the build with musl

malloc_trim is indeed a GNU extension, but an extension of glibc.
Relying on __GNUC__ unfortunately doesn't help with that. Check for
the actual presence of malloc_trim with cmake's check_function_exists
instead.
This fixes the build with musl libc, which doesn't come with
malloc_trim.

Co-authored-by: Ahmad Samir <a.samirh78@gmail.com>
(cherry picked from commit f6310c2b791275f3727f2240ca7fab9f58db943d)
---
 CMakeLists.txt             |  2 +-
 src/Screen.cpp             | 17 +++++++----------
 src/config-konsole.h.cmake |  4 ++--
 3 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f2c9d43ac..b306597ba 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -94,7 +94,7 @@ set(HAVE_X11 ${X11_FOUND})
 # Check for function GETPWUID
 check_symbol_exists(getpwuid "pwd.h" HAVE_GETPWUID)
 
-check_include_files(malloc.h      HAVE_MALLOC_H)
+check_function_exists(malloc_trim HAVE_MALLOC_TRIM)
 
 # See above includes for defaults
 add_definitions(
diff --git a/src/Screen.cpp b/src/Screen.cpp
index e57314cd5..dff9b54a4 100644
--- a/src/Screen.cpp
+++ b/src/Screen.cpp
@@ -28,13 +28,11 @@
 #include "history/HistoryType.h"
 #include "profile/Profile.h"
 
-#ifdef HAVE_MALLOC_H
-    // For malloc_trim, which is a GNU extension
-    #ifdef __GNUC__
-    extern "C" {
-            #include <malloc.h>
-    }
-    #endif
+#ifdef HAVE_MALLOC_TRIM
+// For malloc_trim, which is a GNU extension
+extern "C" {
+#include <malloc.h>
+}
 #endif
 
 using namespace Konsole;
@@ -1799,14 +1797,13 @@ void Screen::setScroll(const HistoryType &t, bool copyPreviousScroll)
         t.scroll(_history);
     }
 
-#ifdef HAVE_MALLOC_H
+#ifdef HAVE_MALLOC_TRIM
+
 #ifdef Q_OS_LINUX
-#ifdef __GNUC__
     // We might have been using gigabytes of memory, so make sure it is actually released
     malloc_trim(0);
 #endif
 #endif
-#endif
 }
 
 bool Screen::hasScroll() const
diff --git a/src/config-konsole.h.cmake b/src/config-konsole.h.cmake
index b74992b0a..4b1d9b515 100644
--- a/src/config-konsole.h.cmake
+++ b/src/config-konsole.h.cmake
@@ -15,5 +15,5 @@
 
 #cmakedefine HAVE_GETPWUID ${HAVE_GETPWUID}
 
-/* Define to 1 if you have the <malloc.h> header file. */
-#cmakedefine HAVE_MALLOC_H 1
+/* Defined if system has the malloc_trim function, which is a GNU extension */
+#cmakedefine HAVE_MALLOC_TRIM
-- 
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