Fixes FreeBSD build on 12.2

- Fix compiler warning with Clang
- Fix usage of libiconv
- Fix an incorrect SSE macro in NVTT for SSE

Patch by: @madpilot and Stan
Fixes: #5255
Differential Revision: https://code.wildfiregames.com/D3421
This was SVN commit r24704.

build/premake/extern_libs5.lua

@@ -351,8 +351,8 @@ extern_lib_defs = {
 				add_default_include_paths("iconv")
 				defines { "LIBICONV_STATIC" }
 			elseif os.getversion().description == "FreeBSD" then
-				defines { "HAVE_ICONV_CONST" }
-				defines { "ICONV_CONST=const" }
+				-- On FreeBSD you need this flag to tell it to use the BSD libc iconv
+				defines { "LIBICONV_PLUG" }
 			end
 		end,
 		link_settings = function()
@@ -366,14 +366,6 @@ extern_lib_defs = {
 				no_delayload = 1,
 			})
 			-- glibc (used on Linux and GNU/kFreeBSD) has iconv
-			-- FreeBSD 10+ has iconv as a part of libc
-			if os.istarget("bsd")
-			   and not (os.getversion().description == "FreeBSD" and os.getversion().majorversion >= 10
-			            or os.getversion().description == "GNU/kFreeBSD") then
-				add_default_links({
-					bsd_names = { "iconv" },
-				})
-			end
 		end,
 	},
 	icu = {

build/premake/premake5.lua

@@ -42,6 +42,8 @@ if os.istarget("macosx") then
 	cc = "clang"
 elseif os.istarget("linux") and _OPTIONS["icc"] then
 	cc = "icc"
+elseif os.istarget("bsd") and os.getversion().description == "FreeBSD" then
+	cc = "clang"
 elseif not os.istarget("windows") then
 	cc = os.getenv("CC")
 	if cc == nil or cc == "" then
@@ -1103,8 +1105,13 @@ function setup_atlas_project(project_name, target_type, rel_source_dirs, rel_inc
 		links { "winmm", "delayimp" }
 
 	elseif os.istarget("linux") or os.istarget("bsd") then
-		buildoptions { "-rdynamic", "-fPIC" }
-		linkoptions { "-fPIC", "-rdynamic" }
+		if os.getversion().description == "FreeBSD" then
+			buildoptions { "-fPIC" }
+			linkoptions { "-fPIC" }
+		else
+			buildoptions { "-rdynamic", "-fPIC" }
+			linkoptions { "-fPIC", "-rdynamic" }
+		end
 
 		-- warnings triggered by wxWidgets
 		buildoptions { "-Wno-unused-local-typedefs" }
@@ -1252,9 +1259,10 @@ function setup_collada_project(project_name, target_type, rel_source_dirs, rel_i
 		-- FCollada is not aliasing-safe, so disallow dangerous optimisations
 		-- (TODO: It'd be nice to fix FCollada, but that looks hard)
 		buildoptions { "-fno-strict-aliasing" }
-
-		buildoptions { "-rdynamic" }
-		linkoptions { "-rdynamic" }
+		if os.getversion().description ~= "FreeBSD" then
+			buildoptions { "-rdynamic" }
+			linkoptions { "-rdynamic" }
+		end
 
 	elseif os.istarget("bsd") then
 		if os.getversion().description == "OpenBSD" then