From afe50b1cf384dc6394568cb69baebd623b07812d Mon Sep 17 00:00:00 2001
From: Thiago Macieira <thiago.macieira@intel.com>
Date: Wed, 22 May 2024 19:51:05 -0300
Subject: [PATCH] CMake: remove test for alloca for the global config

We don't test for this anywhere in qtbase except for the qmake check
(and qmake doesn't use alloca() anywhere). There are a couple of uses of
alloca() itself in qtbase, but they are all in platform-specific code
(android and qnx platform plugins) or third-party content (sqlite and
imgui).

The uses of this alloca() test in qtdeclarative have been removed too
(it still uses alloca() but has local tests).

Change-Id: If3345151ddf84c43a4f1fffd17d1f1519f5d3e39
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>
---
 configure.cmake                           | 61 -----------------------
 src/corelib/global/qconfig-bootstrapped.h |  7 ---
 src/tools/configure.cmake                 |  3 +-
 3 files changed, 1 insertion(+), 70 deletions(-)

diff --git a/configure.cmake b/configure.cmake
index f42d921d7ba..d752b564ee1 100644
--- a/configure.cmake
+++ b/configure.cmake
@@ -416,55 +416,6 @@ int main(void)
 }
 ")
 
-# alloca_stdlib_h
-qt_config_compile_test(alloca_stdlib_h
-    LABEL "alloca() in stdlib.h"
-    CODE
-"#include <stdlib.h>
-
-int main(void)
-{
-    /* BEGIN TEST: */
-alloca(1);
-    /* END TEST: */
-    return 0;
-}
-")
-
-# alloca_h
-qt_config_compile_test(alloca_h
-    LABEL "alloca() in alloca.h"
-    CODE
-"#include <alloca.h>
-#ifdef __QNXNTO__
-// extra include needed in QNX7 to define NULL for the alloca() macro
-#  include <stddef.h>
-#endif
-
-int main(void)
-{
-    /* BEGIN TEST: */
-alloca(1);
-    /* END TEST: */
-    return 0;
-}
-")
-
-# alloca_malloc_h
-qt_config_compile_test(alloca_malloc_h
-    LABEL "alloca() in malloc.h"
-    CODE
-"#include <malloc.h>
-
-int main(void)
-{
-    /* BEGIN TEST: */
-alloca(1);
-    /* END TEST: */
-    return 0;
-}
-")
-
 # stack_protector
 if(NOT WASM AND NOT VXWORKS)
     # emcc doesn't support this, but the detection accidentally succeeds
@@ -1005,18 +956,6 @@ qt_feature("posix_fallocate" PRIVATE
     LABEL "POSIX fallocate()"
     CONDITION TEST_posix_fallocate
 )
-qt_feature("alloca_h" PRIVATE
-    LABEL "alloca.h"
-    CONDITION TEST_alloca_h
-)
-qt_feature("alloca_malloc_h" PRIVATE
-    LABEL "alloca() in malloc.h"
-    CONDITION NOT QT_FEATURE_alloca_h AND TEST_alloca_malloc_h
-)
-qt_feature("alloca" PRIVATE
-    LABEL "alloca()"
-    CONDITION QT_FEATURE_alloca_h OR QT_FEATURE_alloca_malloc_h OR TEST_alloca_stdlib_h
-)
 qt_feature("force-system-libs" PRIVATE
     LABEL "Force the usage of system libraries"
     AUTODETECT OFF
diff --git a/src/corelib/global/qconfig-bootstrapped.h b/src/corelib/global/qconfig-bootstrapped.h
index c2fe4661f6c..39793fdaf51 100644
--- a/src/corelib/global/qconfig-bootstrapped.h
+++ b/src/corelib/global/qconfig-bootstrapped.h
@@ -33,13 +33,6 @@
 #define QT_NO_DEPRECATED
 
 // Keep feature-test macros in alphabetic order by feature name:
-#define QT_FEATURE_alloca 1
-#define QT_FEATURE_alloca_h -1
-#ifdef _WIN32
-# define QT_FEATURE_alloca_malloc_h 1
-#else
-# define QT_FEATURE_alloca_malloc_h -1
-#endif
 #define QT_FEATURE_cborstreamreader -1
 #define QT_FEATURE_cborstreamwriter 1
 #define QT_CRYPTOGRAPHICHASH_ONLY_SHA1
diff --git a/src/tools/configure.cmake b/src/tools/configure.cmake
index f813b727ba3..618dc09f3b5 100644
--- a/src/tools/configure.cmake
+++ b/src/tools/configure.cmake
@@ -23,8 +23,7 @@ qt_feature("windeployqt" PRIVATE
 
 qt_feature("qmake" PRIVATE
     PURPOSE "The qmake tool helps simplify the build process for development projects across different platforms."
-    CONDITION QT_FEATURE_settings AND QT_FEATURE_alloca AND
-        (QT_FEATURE_alloca_malloc_h OR NOT WIN32) AND QT_FEATURE_cborstreamwriter AND
+    CONDITION QT_FEATURE_settings AND QT_FEATURE_cborstreamwriter AND
         QT_FEATURE_datestring AND QT_FEATURE_regularexpression AND QT_FEATURE_temporaryfile)
 
 qt_configure_add_summary_section(NAME "Core tools")