fbc: add -gfx command line arg to link against libfbgfx

This already existed as an internal flag, I simply exposed it.  It's useful
under emscripten where we can't write objinfo to wasm (nor js) files. Of course
if you're using emscripten you'd know that you (currently) need libfbgfx.a
specifically, but this is a lot cleaner for portable build systems and
future-proof.

changelog.txt

@@ -3,6 +3,7 @@ Version 1.10.1
 [changed]
 
 [added]
+- fbc: '-gfx' command line option to link against correct libfbgfx variant, for platforms (emscripten) where it's not automatic due to missing objinfo support
 
 [fixed]
 - sf.net #982: Array descriptors emitted incorrectly in gcc backend 

src/compiler/fbc.bas

@@ -1717,6 +1717,7 @@ enum
 	OPT_FPU
 	OPT_G
 	OPT_GEN
+	OPT_GFX
 	OPT_HELP
 	OPT_I
 	OPT_INCLUDE
@@ -1799,6 +1800,7 @@ dim shared as FBC_CMDLINE_OPTION cmdlineOptionTB(0 to (OPT__COUNT - 1)) = _
 	( TRUE , TRUE , TRUE , TRUE  ), _ '' OPT_FPU          affects major initialization,affects code generation, affects second stage compile, affects link
 	( FALSE, TRUE , TRUE , FALSE ), _ '' OPT_G            affects code generation, affects link
 	( TRUE , TRUE , TRUE , TRUE  ), _ '' OPT_GEN          affects major initialization
+	( FALSE, TRUE , FALSE, FALSE ), _ '' OPT_GFX          affects link
 	( FALSE, FALSE, FALSE, FALSE ), _ '' OPT_HELP         never allow, real command line only, makes no sense to have in source
 	( TRUE , TRUE , TRUE , TRUE  ), _ '' OPT_I            add include path before the default one
 	( TRUE , TRUE , TRUE , TRUE  ), _ '' OPT_INCLUDE      restart required to inject preInclude
@@ -2007,6 +2009,9 @@ private sub handleOpt _
 			hFatalInvalidOption( arg, is_source )
 		end select
 
+	case OPT_GFX
+		fbSetOption( FB_COMPOPT_GFX, TRUE )
+
 	case OPT_HELP
 		fbc.showhelp = TRUE
 
@@ -2390,6 +2395,7 @@ private function parseOption(byval opt as zstring ptr) as integer
 	case asc("g")
 		ONECHAR(OPT_G)
 		CHECK("gen", OPT_GEN)
+		CHECK("gfx", OPT_GFX)
 
 	case asc( "h" )
 		CHECK( "help", OPT_HELP )
@@ -4094,14 +4100,15 @@ private sub hPrintOptions( byval verbose as integer )
 	if( verbose ) then
 	print "  -fpmode fast|precise  Select floating-point math accuracy/speed"
 	print "  -fpu x87|sse     Set target FPU"
-	endif
+	end if
 	print "  -g               Add debug info, enable __FB_DEBUG__, and enable assert()"
 
 	if( verbose ) then
 	print "  -gen gas         Select GNU gas 32-bit assembler backend"
 	print "  -gen gas64       Select GNU gas 64-bit assembler backend"
 	print "  -gen gcc         Select GNU gcc C backend"
 	print "  -gen llvm        Select LLVM backend"
+	print "  -gfx             Link to the appropriate libfbgfx variant (normally automatic)"
 	else
 	print "  -gen gas|gas64|gcc|llvm  Select code generation backend"
 	end if

tests/unit-tests.mk

@@ -105,7 +105,7 @@ ifneq ($(GEN),)
 	FBC_CFLAGS += -gen $(GEN)
 endif
 
-FBC_LFLAGS := $(FBCU_LIBS) -p $(FBCU_LIB) -x $(MAINEXE)
+FBC_LFLAGS := $(FBCU_LIBS) -p $(FBCU_LIB) -x $(MAINEXE) -v
 ifdef DEBUG
 	FBC_LFLAGS += -g
 endif