From 1891e2ad68acb51f2154619e802c8d3d053dd1d6 Mon Sep 17 00:00:00 2001
From: Christoph Moench-Tegeder <cmt@burggraben.net>
Date: Tue, 21 Feb 2023 20:45:27 +0100
Subject: [PATCH] CMakeLists.txt: do not use -ffloat-store on clang

According to it's User Manual, clang does not know about -ffloat-store.
This is corrobated by the FreeBSD i386 build (using LLVM 13 and 15,
depending on the base system version) failing early with an error
message complaining about this parameter being unknown.

See
https://pkg-status.freebsd.org/beefy17/data/main-i386-default/pb27279cba1ca_sed03776ca7/logs/kicad-7.0.0,2.log
for an example of the failure, and
https://clang.llvm.org/docs/UsersManual.html#controlling-floating-point-behavior
for the available floating point options on clang.

(Cherry-picked from 46a59aa2c3e23aa5dd5243e697eb29f8da680e03)
---
 CMakeLists.txt | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7b47135b3e..1007d38de5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -350,12 +350,16 @@ endif(USE_DISTCC)
 # Set flags for GCC, or treat llvm as GCC
 #================================================
 
-if( CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang" )
-
+if( CMAKE_COMPILER_IS_GNUCXX )
     # Set 32-bit flag for GCC to prevent excess precision
+    # clang des not know this flag, so keep this separate
     if( CMAKE_SIZEOF_VOID_P EQUAL 4 )
         set( CMAKE_CXX_FLAGS "-ffloat-store ${CMAKE_CXX_FLAGS}" )
     endif()
+endif( CMAKE_COMPILER_IS_GNUCXX )
+
+
+if( CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang" )
 
     # Link flags in Debug: -g1 and -ggdb1 or -g1 and -ggdb3 can be used.
     # Level 1 produces minimal information, enough for making basic backtraces.