fbc command-line
Using the fbc command-line.
The official FreeBASIC distribution comes with fbc, FreeBASIC's flagship compiler. fbc is a command line compiler, and can be launched from the console - from DOS, the Windows command prompt or a Linux shell. Running fbc from the console without any arguments displays a list of available options, or command-line switches, that can be used to adjust the behavior of the compiler.
At its simplest, fbc takes a source file as a command-line argument and produces an executable file. It does this by compiling the source file (.bas) into an assembly (.asm) file, then compiling this into an object file (.o) using GAS and finally linking using LD this object file to other object files and libraries it needs to run, producing the final executable file. The assembly and compiled object files are deleted at this point by default. For example, the following command,
produces the executable foo.exe in DOS and Windows, and ./foo in Linux. fbc can accept multiple source files at once, compile and link them all into one executable. For example, the following command,
produces the executable foo.exe in DOS and Windows, and ./foo in Linux. Since foo.bas was listed first, it will be the main entry point into the executable, and also provide its name. To specify a different entry point or executable name, use the "-m" and "-x" switches, respectively. To have, for example, baz.bas provide the main entry point into an executable called foobar.exe, you would use
The "-x" switch names the executable verbatim, so in Linux, the executable produced from the above command would be called ./foobar.exe.
At its simplest, fbc takes a source file as a command-line argument and produces an executable file. It does this by compiling the source file (.bas) into an assembly (.asm) file, then compiling this into an object file (.o) using GAS and finally linking using LD this object file to other object files and libraries it needs to run, producing the final executable file. The assembly and compiled object files are deleted at this point by default. For example, the following command,
fbc foo.bas
produces the executable foo.exe in DOS and Windows, and ./foo in Linux. fbc can accept multiple source files at once, compile and link them all into one executable. For example, the following command,
fbc foo.bas bar.bas baz.bas
produces the executable foo.exe in DOS and Windows, and ./foo in Linux. Since foo.bas was listed first, it will be the main entry point into the executable, and also provide its name. To specify a different entry point or executable name, use the "-m" and "-x" switches, respectively. To have, for example, baz.bas provide the main entry point into an executable called foobar.exe, you would use
fbc -x foobar.exe -m baz foo.bas bar.bas baz.bas
The "-x" switch names the executable verbatim, so in Linux, the executable produced from the above command would be called ./foobar.exe.
Syntax:
fbc [ options ] [ input_list ]
Where input_list is a list of filenames. Accepted files are:
Where input_list is a list of filenames. Accepted files are:
| File extension | Description |
| .bas | FreeBASIC source file |
| .a | Library |
| .o | Object file |
| .rc | Resource script (Windows only) |
| .res | Compiled resource (Windows only) |
| .xpm | X icon pixmap (Linux only) |
Source code
Code generation
Compilation
-b < name >
Add a source file to compilation
-i < name >
Add a path to search for include files
-include < name >
Include a header file on each source compiled
-d < name=val >
Add a preprocessor's define
-lang < name >
Select language mode: fb, fblite, qb, deprecated
-forcelang < name >
Select language mode: fb, fblite, qb, deprecated (overrides statements in code)
Code generation
-target < platform >
Set the target platform for cross compilation
-gen < backend >
Sets the compiler backend (default is 'gas' for x86 and 'gcc' for x86_64)
-asm < format >
Sets the assembler format for Asm block
-arch < type >
Set target architecture
-O < level >
Set the optimization level (-gen gcc)
-vec < level >
Set level of vector optimizations enabled by the compiler (default: 0)
-fpu < type >
Set the floating point arithmetics unit (default: X87)
-fpmode < type >
Select between fast and accurate floating-point operations (default: PRECISE)
-z < value >
Sets miscellaneous or experimental options
-pic
Generate position-independent code (non-x86 Unix shared libs)
Compilation
-m < name >
Define main file (without extension), the entry point (default is the first .bas file on the command line)
-entry < name >
Override public exported name of implicit user main function
-g
Add debug info
-profgen < profiler >
Enable function profiling by selecting a specific profiler
-profile
Enable function profiling for gmon/gprof
-e
Add error checking
-ex
Add error checking with RESUME support
-exx
Same as -ex, plus array bounds and dimensions, null-pointer, and error location reporting
-eunwind
Enable stack unwind information
-Wa < opt >
Pass options to GAS (separated by commas)
-Wc < opt >
Pass options to GCC (separated by commas)
-o < name >
Set object file path/name (must be passed after the .bas file)
-earray
Enable array bounds checking
-earraydims
Enable array dimensions checking
-eassert
Enable assert() and assertwarn() checking
-edebug
Enable __FB_DEBUG__
-edebuginfo
Add debug information
-elocation
Enable full error location reporting
-enullptr
Enable null-pointer checking
Linking
Behaviour
Target specific
Meta
-a < name >
Add an object file to linker's list
-l < name >
Add a library file to linker's list
-p < name >
Add a path to search for libraries
-mt
Link with thread-safe runtime library
-nodeflibs
Do not include the default libraries
-nolib < name(s) >
Do not include specific library(s)
-static
Prefer static libraries over dynamic ones when linking
-map < name >
Save the linking map to file name
-Wl < opt >
Pass options to LD (separated by commas)
-export
Export symbols for dynamic linkage
-lib
Create a static library
-dylib
Create a DLL, including the import library
-dll
Create a DLL, including the import library. (Same as -dylib)
-x < name >
Set executable/library path/name
-nostrip
Do not strip symbol information from the output file
-strip
Omit all symbol information from the output file
-sysroot < path >
Tell the linker where to find libraries (needed by some toolchains)
Behaviour
-prefix < path >
Set the compiler prefix path
-buildprefix < name >
Set the internal buildprefix option
-version
Show compiler version on the command line, do not compile or link
-v
Be verbose
-print < option >
Display certain information (fblibdir, host, target, x)
-pp
Emit the preprocessed input file only, do not compile
-r
Compile into intermediate file(s) only, do not assemble or link
-rr
Compile into asm file(s) only, do not assemble or link
-c
Compile and assemble source file only, do not link
-R
Do not delete the intermediate file(s)
-RR
Do not delete the asm file(s)
-C
Do not delete the object file(s)
-w < value >
Set min warning level: all, none, param, escape, pedantic, next, funcptr, constness, suffix, error, upcast or a value
-maxerr < val >
Only stop parsing if <val> errors occurred
-noerrline
Do not show source line where error occurred
-noobjinfo
Do not read/write compile-time info from/to .o and .a files
-showincludes
Display a tree of file names of #included files
Target specific
-s < name >
Set subsystem (gui, console)
-t < value >
Set stack size in kbytes (default: 1 MB or 2 MB)
Meta
@< file >
Read (additional) command-line options from a file
Examples:
fbc myfile.bas
(With DOS version of FBC, compile and link a DOS executable MYFILE.EXE.)
fbc -s gui myfile.bas
(With Windows version of FBC, compile and link a Windows executable myfile.exe. Running the program will not show the console window ("MS-DOS Prompt"))
fbc -lib module1.bas module2.bas module3.bas -x libmylib.a
(Compile and link a static library libmylib.a from the three source files)
fbc -m main_module -c main_module.bas
(Compile an object file main_module.o and mark it as an entry point)
fbc -c sub_module.bas
(Compile an object file sub_module.o)
fbc -x application.exe main_module.o sub_module.o
(Link an executable application.exe)
Note: How to include an icon in a FB executable program
There is a simple command line option to compile a FB program into an executable with an Icon:
- Create a *.rc file, for example appicon.rc, with this info:
- Then when compiling program, add appicon.rc in the list of files to compile.
FB_PROGRAM_ICON ICON "appicon.ico"
(where appicon.ico is the name of icon)
See also:
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