Installing lcc

Christopher W. Fraser and David R. Hanson, Microsoft Research
September 2002



lcc is the ANSI C compiler described in our book A Retargetable C Compiler: Design and Implementation (Addison-Wesley, 1995, ISBN 0-8053-1670-1).

If you're installing lcc on a UNIX system, read the remainder of this section and continue with the next section. If you're installing lcc on a Windows system, you should read the rest of this section, the following three sections, and the Windows section.

Extract the distribution into its own directory. All non-absolute paths below are relative to this directory. The distribution holds the following subdirectories.

src source code
etc driver, accessories
lib runtime library source code
cpp preprocessor source code
lburg code-generator generator source code
doc this document, man pages
include/*/* include files
tst test suite
alpha/*/tst ALPHA test outputs
mips/*/tst MIPS test outputs
sparc/*/tst SPARC test outputs
x86/*/tst X86 test outputs

doc/install.html is the HTML file for this document.

The installation makefile is designed so that lcc can be installed from a read-only file system or directory, which is common in networked environments, so the distribution can be unloaded on a central file server. You will need an existing ANSI/ISO C compiler to build and install lcc.

Installation on UNIX

The compilation components (the preprocessor, include files, and compiler proper, etc.) are installed in a single build directory. On multi-platform systems supported by a central file server, it's common to store the build directory in a location specific to the platform and to the version of lcc, and to point a symbolic link to this location. For example,

% ln -s /proj/pkg/lcc/4.2/sparc-solaris /usr/local/lib/lcc

points /usr/local/lib/lcc to a build directory for lcc on the SPARC under Solaris. Links into /usr/local/lib/lcc are created for the programs lcc and bprint. Thus, a new distribution can be installed by building it in its own build directory and changing one symbolic link to point to that directory. If these conventions or their equivalents are followed, the host-specific parts of the driver program, lcc, can be used unmodified.

Installation on a UNIX system involves the following steps. Below, the build directory is referred to as BUILDDIR, and the commands below are executed from the distribution directory.

  1. Create the build directory, using a version- and platform-specific naming convention as suggested above, and record the name of this directory in the BUILDDIR environment variable:
    % setenv BUILDDIR /proj/pkg/lcc/4.2/sparc-solaris
    % mkdir -p $BUILDDIR

    Here and below, commands assume the C shell. Also, you'll need a version of mkdir that supports the -p option, which creates intermediate directories as necessary.

  2. Copy the man pages to the repository for local man pages, e.g.,
    % cp doc/*.1 /usr/local/man/man1

    Some users copy the man pages to the build directory and create the appropriate symbolic links, e.g.,

    % cp doc/*.1 $BUILDDIR
    % ln -s $BUILDDIR/*.1 /usr/local/man/man1
  3. Platform-specific include files are in directories named include/target/os. Create the include directory in the build directory, and copy the include hierarchy for your platform to this directory, e.g.,
    % mkdir $BUILDDIR/include
    % cp -p -R include/sparc/solaris/* $BUILDDIR/include

    Again, some users create a symbolic link to the appropriate directory in the distribution instead of copying the include files. For example, at Princeton, the distributions are stored under /proj/pkg/lcc, so the included files are "installed" by creating one symbolic link:

    % ln -s /proj/pkg/lcc/4.2/include/sparc/solaris $BUILDDIR/include

    If you're installing lcc on Linux, you must also plant a symbolic link named gcc to gcc's library directory, because lcc uses gcc's C preprocessor and most of gcc's header files:

    % ln -s /usr/lib/gcc-lib/i386-redhat-linux/2.96 $BUILDDIR/gcc

    The library directory shown above may be different on your Linux machine; to determine the correct directory, browse /usr/lib/gcc-lib, or execute

    % cc -v tst/8q.c

    and examine the diagnostic output. Make sure that $BUILDDIR/gcc/cpp0 and $BUILDDIR/gcc/include are, respectively, gcc's C preprocessor and header files. On Linux, lcc looks for include files in $BUILDDIR/include, $BUILDDIR/gcc/include, and /usr/include, in that order; see Building the Driver and etc/linux.c for details.

  4. The makefile includes the file named by the CUSTOM macro; the default is, and an empty is included in the distribution. If desired, prepare a site-specification customization file and define CUSTOM to the path of that file when invoking make in steps 5 and 6, e.g.,

    You can, for example, use customization files to record site-specific values for macros instead of using environment variables, and to record targets for the steps in this list.

  5. Build the host-specific driver, creating a custom host-specific part, if necessary. See Building the Driver.
  6. Build the preprocessor, compiler proper, library, and other accessories. See Building the Compiler.
  7. Plant symbolic links to the build directory and to the installed programs, e.g.,
    % ln -s $BUILDDIR /usr/local/lib/lcc
    % ln -s /usr/local/lib/{lcc,bprint} /usr/local/bin

    Some users copy bprint and lcc into /usr/local/bin instead of creating symbolic links. The advantage of creating the links for lcc and bprint as shown is that, once established, they point indirectly to whatever /usr/local/lib/lcc points to; installing a new version of lcc can be done by changing /usr/local/lib/lcc to point to the build directory for the new version.

Building the Driver

The preprocessor, compiler, assembler, and loader are invoked by a driver program, lcc, which is similar to cc on most systems. It's described in the man page doc/lcc.1. The driver is built by combining the host-independent part, etc/lcc.c, with a small host-specific part. Distributed host-specific parts are named etc/os.c, where os is the name of the operating system for the host on which lcc is being installed. If you're following the installations conventions described above, you can probably use one of the host-specific parts unmodified; otherwise, pick one that is closely related to your platform, copy it to whatever.c, and edit it as described below. You should not have to edit etc/lcc.c.

We'll use etc/solaris.c as an example in describing how the host-specific part works. This example illustrates all the important features. Make sure you have the environment variable BUILDDIR set correctly, and build the driver with a make command, e.g.,

% make HOSTFILE=etc/solaris.c lcc
cc -g -c -o $BUILDDIR/lcc.o etc/lcc.c
cc -g -c -o $BUILDDIR/host.o etc/solaris.c
cc -g -o $BUILDDIR/lcc $BUILDDIR/lcc.o $BUILDDIR/host.o

Of course, the actual value of BUILDDIR will appear in place of $BUILDDIR. The symbolic name HOSTFILE specifies the path to the host-specific part, either one in the distribution or whatever.c. Some versions of make may require the -e option in order to read the environment.

Here's etc/solaris.c:

/* Sparcs running Solaris 2.5.1 at CS Dept., Princeton University */

#include <string.h>

static char rcsid[] = "$ Id: solaris.c,v 1.10 1998/09/14 20:36:33 drh Exp $";

#ifndef LCCDIR
#define LCCDIR "/usr/local/lib/lcc/"
#ifndef SUNDIR
#define SUNDIR "/opt/SUNWspro/SC4.2/lib/"

char *suffixes[] = { ".c", ".i", ".s", ".o", ".out", 0 };
char inputs[256] = "";
char *cpp[] = { LCCDIR "cpp",
	"-D__STDC__=1", "-Dsparc", "-D__sparc__", "-Dsun", "-D__sun__", "-Dunix",
	"$1", "$2", "$3", 0 };
char *include[] = { "-I" LCCDIR "include", "-I/usr/local/include",
	"-I/usr/include", 0 };
char *com[] = { LCCDIR "rcc", "-target=sparc/solaris",
	"$1", "$2", "$3", 0 };
char *as[] = { "/usr/ccs/bin/as", "-Qy", "-s", "-o", "$3", "$1", "$2", 0 };
char *ld[] = { "/usr/ccs/bin/ld", "-o", "$3", "$1",
	SUNDIR "crti.o", SUNDIR "crt1.o",
	SUNDIR "values-xa.o", "$2", "",
	"-Y", "P," SUNDIR ":/usr/ccs/lib:/usr/lib", "-Qy",
	"-L" LCCDIR, "-llcc", "-lm", "-lc", SUNDIR "crtn.o", 0 };

extern char *concat(char *, char *);

int option(char *arg) {
	if (strncmp(arg, "-lccdir=", 8) == 0) {
		cpp[0] = concat(&arg[8], "/cpp");
		include[0] = concat("-I", concat(&arg[8], "/include"));
		ld[12] = concat("-L", &arg[8]);
		com[0] = concat(&arg[8], "/rcc");
	} else if (strcmp(arg, "-p") == 0) {
		ld[5] = SUNDIR "mcrt1.o";
		ld[10] = "P," SUNDIR "libp:/usr/ccs/lib/libp:/usr/lib/libp:"
			 SUNDIR ":/usr/ccs/lib:/usr/lib";
	} else if (strcmp(arg, "-b") == 0)
	else if (strncmp(arg, "-ld=", 4) == 0)
		ld[0] = &arg[4];
		return 0;
	return 1;

LCCDIR defaults to "/usr/local/lib/lcc/" unless it's defined by a -D option as part of CFLAGS in the make command, e.g.,

% make HOSTFILE=etc/solaris.c CFLAGS='-DLCCDIR=\"/v/lib/lcc/\"' lcc

Note the trailing slash; SUNDIR is provided so you can use etc/solaris.c even if you have a different version of the Sun Pro compiler suite. If you're using the gcc compiler tools instead of the Sun Pro tools, see etc/gcc-solaris.c.

Most of the host-specific code is platform-specific data and templates for the commands that invoke the preprocessor, compiler, assembler, and loader. The suffixes array lists the file name suffixes for C source files, preprocessed source files, assembly language source files, object files, and executable files. suffixes must be terminated with a null pointer, as shown above. The initialization of suffixes in etc/solaris.c are the typical ones for UNIX systems. Each element of suffixes is actually a list of suffixes, separated by semicolons; etc/win32.c holds an example:

char *suffixes[] = { ".c;.C", ".i;.I", ".asm;.ASM;.s;.S", ".obj;.OBJ", ".exe", 0 };

When a list is given, the first suffix is used whenever lcc needs to generate a file name. For example, with etc/win32.c, lcc emits the generated assembly code into .asm files.

The inputs array holds a null-terminated string of directories separated by colons or semicolons. These are used as the default value of LCCINPUTS, if the environment variable LCCINPUTS is not set; see the man page.

Each command template is an array of pointers to strings terminated with a null pointer; the strings are full path names of commands, arguments, or argument placeholders, which are described below. Commands are executed in a child process, and templates can contain multiple commands by separating commands with newlines. The driver runs each command in a new process.

The cpp array gives the command for running lcc's preprocessor, cpp. Literal arguments specified in templates, e.g., "-Dsparc" in the cpp command above, are passed to the command as given.

The strings "$1", "$2", and "$3" in templates are placeholders for lists of arguments that are substituted in a copy of the template before the command is executed. $1 is replaced by the options specified by the user; for the preprocessor, this list always contains at least -D__LCC__. $2 is replaced by the input files, and $3 is replaced by the output file.

Zero-length arguments after replacement are removed from the argument list before the command is invoked. So, for example, if the preprocessor is invoked without an output file, "$3" becomes "", which is removed from the final argument list.

The include array is a list of -I options that specify which directives should be searched to satisfy include directives. These directories are searched in the order given. The first directory should be the one to which the ANSI header files were copied as described in UNIX or Windows installation instructions. The driver adds these options to cpp's arguments when it invokes the preprocessor, except when -N is specified.

com gives the command for invoking the compiler. This template can appear as shown above in a custom host-specific part, but the option -target=sparc/solaris should be edited to the target/os for your platform. If com[1] includes the string "win32", the driver assumes it's running on Windows. lcc can generate code for all of the target/os combinations listed in the file src/bind.c. The -target option specifies the default combination. The driver's -Wf option can be used to specify other combinations; the man page elaborates.

as gives the command for invoking the assembler. On Linux, you must be running at least version 2.8.1 of the GNU assembler; earlier versions mis-assemble some instructions emitted by lcc.

ld gives the command for invoking the loader. For the other commands, the list $2 contains a single file; for ld, $2 contains all ".o" files and libraries, and $3 is a.out, unless the -o option is specified. As suggested in the code above, ld must also specify the appropriate startup code and default libraries, including the lcc library, liblcc.a.

The option function is described below; the minimal option function just returns 0.

You can test lcc with the options -v -v to display the commands that would be executed, e.g.,

% $BUILDDIR/lcc -v -v foo.c baz.c mylib.a -lX11
$BUILDDIR/lcc $ Id: lcc.c,v 4.33 2001/06/28 22:19:58 drh $
/usr/local/lib/lcc/cpp -D__STDC__=1 -Dsparc -D__sparc__ -Dsun -D__sun__ -Dunix -D__LCC__i
/usr/local/lib/lcc/rcc -target=sparc/solaris -v /tmp/lcc4060.i /tmp/lcc4061.s
/usr/ccs/bin/as -Qy -s -o /tmp/lcc4062.o /tmp/lcc4061.s
/usr/local/lib/lcc/cpp -D__STDC__=1 -Dsparc -D__sparc__ -Dsun -D__sun__ -Dunix -D__LCC__i
/usr/local/lib/lcc/rcc -target=sparc/solaris -v /tmp/lcc4060.i /tmp/lcc4061.s
/usr/ccs/bin/as -Qy -s -o /tmp/lcc4063.o /tmp/lcc4061.s
/usr/ccs/bin/ld -o a.out /opt/SUNWspro/SC4.2/lib/crti.o /opt/SUNWspro/SC4.2/lib/crt1.o /o
rm /tmp/lcc4063.o /tmp/lcc4060.i /tmp/lcc4061.s /tmp/lcc4062.o

As the output shows, lcc places temporary files in /tmp; if any of the environment variables TMP, TEMP, and TMPDIR are set, they override this default (in the order shown) as does the -tempdir=dir option. The default can be changed by defining TEMPDIR in CFLAGS when building the driver.

The option function is called for the options -Wo, -g, -p, -pg, and -b because these compiler options might also affect the loader's arguments. For these options, the driver calls option(arg) to give the host-specific code an opportunity to edit the ld command, if necessary. option can change ld, if necessary, and return 1 to announce its acceptance of the option. If the option is unsupported, option should return 0.

For example, in response to -g, the option function shown above accepts the option but does nothing else, because the ld and as commands don't need to be modified on the SPARC. -g will also be added to the compiler's options by the host-independent part of the driver. The -p causes option to change the name of the startup code and changed the list of libraries. The -b option turns on lcc's per-expression profiling, the code for which is in liblcc.a, so option need no nothing.

On SPARCs, the driver also recognizes -Bstatic and -Bdynamic as linker options. The driver recognizes but ignores "-target name" option.

The option -Woarg causes the driver to pass arg to option. Such options have no other effect; this mechanism is provided to support system-specific options that affect the commands executed by the driver. As illustrated above, host-specific parts should support the -Wo-lccdir=dir option, which causes lcc's compilation components to be found in dir, because this option is used by the test scripts, and because the driver simulates a -Wo-lccdir option with the value of the environment variable LCCDIR, if it's defined. The code above rebuilds the paths to the include files, preprocessor, compiler, and library by calling concat, which is defined in etc/lcc.c.

Building the Compiler and Accessories

To build the rest of compilation components make sure BUILDDIR is set appropriately and type "make all". This command builds librcc.a (the compiler's private library), rcc (the compiler proper), lburg (the code-generator generator), cpp (the preprocessor), liblcc.a (the runtime library), and bprint (the profile printer), all in BUILDDIR. There may be warnings, but there should be no errors. If you're using an ANSI/ISO compiler other than cc, specify its name with the CC= option, e.g., "make CC=gcc all". If you're running on a DEC ALPHA, use "make CC='cc -std1' all"; the -std1 option is essential on the ALPHA.

Once rcc is built with the host C compiler, run the test suite to verify that rcc is working correctly. If any of the steps below fail, contact us (see Reporting Bugs). The commands in the makefile run the shell script src/ on each C program in the test suite, tst/*.c. It uses the driver, $BUILDDIR/lcc, so you must have the driver in the build directory before testing rcc. The target/os combination is read from the variable TARGET, which must be specified when invoking make:

% make TARGET=sparc/solaris test
mkdir -p $BUILDDIR/sparc/solaris/tst
$BUILDDIR/rcc -target=sparc/solaris $BUILDDIR/sparc/solaris/tst/8q.s:
$BUILDDIR/rcc -target=sparc/solaris $BUILDDIR/sparc/solaris/tst/array.s:
$BUILDDIR/rcc -target=sparc/solaris $BUILDDIR/sparc/solaris/tst/cf.s:
$BUILDDIR/rcc -target=sparc/solaris $BUILDDIR/sparc/solaris/tst/cq.s:
$BUILDDIR/rcc -target=sparc/solaris $BUILDDIR/sparc/solaris/tst/cvt.s:
$BUILDDIR/rcc -target=sparc/solaris $BUILDDIR/sparc/solaris/tst/fields.s:
$BUILDDIR/rcc -target=sparc/solaris $BUILDDIR/sparc/solaris/tst/front.s:
$BUILDDIR/rcc -target=sparc/solaris $BUILDDIR/sparc/solaris/tst/incr.s:
$BUILDDIR/rcc -target=sparc/solaris $BUILDDIR/sparc/solaris/tst/init.s:
$BUILDDIR/rcc -target=sparc/solaris $BUILDDIR/sparc/solaris/tst/limits.s:
$BUILDDIR/rcc -target=sparc/solaris $BUILDDIR/sparc/solaris/tst/paranoia.s:
$BUILDDIR/rcc -target=sparc/solaris $BUILDDIR/sparc/solaris/tst/sort.s:
$BUILDDIR/rcc -target=sparc/solaris $BUILDDIR/sparc/solaris/tst/spill.s:
$BUILDDIR/rcc -target=sparc/solaris $BUILDDIR/sparc/solaris/tst/stdarg.s:
$BUILDDIR/rcc -target=sparc/solaris $BUILDDIR/sparc/solaris/tst/struct.s:
$BUILDDIR/rcc -target=sparc/solaris $BUILDDIR/sparc/solaris/tst/switch.s:
$BUILDDIR/rcc -target=sparc/solaris $BUILDDIR/sparc/solaris/tst/wf1.s:
$BUILDDIR/rcc -target=sparc/solaris $BUILDDIR/sparc/solaris/tst/yacc.s:

Each line in the output above is of the form

$BUILDDIR/rcc -target=target/os $BUILDDIR/target/os/X.s:

where X is the base name of the C program X.c in the test suite. The actual value of BUILDDIR will, of course, appear in place of $BUILDDIR. This output identifies the compiler and the target, e.g., "$BUILDDIR/rcc is generating code for a sparc running the solaris operating system."

For each program in the test suite, src/ compiles the program, drops the generated assembly language code in BUILDDIR/target/os, and uses diff to compare the generated assembly code with the expected code (the code expected for tst/8q.c on the SPARC under Solaris is in sparc/solaris/tst/8q.sbk, etc.). If there are differences, the script executes the generated code with the input given in tst (the input for tst/8q.c is in tst/8q.0, etc.) and compares the output with the expected output (the expected output from tst/8q.c on the SPARC under Solaris is in sparc/solaris/tst/8q.1bk, etc.). The script also compares the diagnostics from the compiler with the expected diagnostics.

On some systems, there may be a few differences between the generated code and the expected code. These differences occur because the expected code is generated by cross compilation and the least significant bits of some floating-point constants differ from those bits in constants generated on your system. On Linux, there may be differences because of differences in the header files between our system and yours. There should be no differences in the output from executing the test programs.

Next, run the "triple test", which builds rcc using itself:

% make triple
$BUILDDIR/lcc -A -d0.6 -Wo-lccdir=$(BUILDDIR) -Isrc -I$(BUILDDIR) -o $BUILDDIR/1rcc -B$BUILDDIR/ src/alloc.c ...
$BUILDDIR/lcc -A -d0.6 -Wo-lccdir=$(BUILDDIR) -Isrc -I$(BUILDDIR) -o $BUILDDIR/2rcc -B$BUILDDIR/1 src/alloc.c ...
strip $BUILDDIR/[12]rcc
dd if=$BUILDDIR/1rcc of=$BUILDDIR/rcc1 bs=512 skip=1
1270+1 records in
1270+1 records out
dd if=$BUILDDIR/2rcc of=$BUILDDIR/rcc2 bs=512 skip=1
1270+1 records in
1270+1 records out
if cmp $BUILDDIR/rcc[12]; then \
        mv $BUILDDIR/2rcc $BUILDDIR/rcc; \
        rm -f $BUILDDIR/1rcc $BUILDDIR/rcc[12]; fi

This command builds rcc twice; once using the rcc built by cc and again using the rcc built by lcc. The resulting binaries are compared. They should be identical, as shown at the end of the output above. If they aren't, our compiler is generating incorrect code; contact us.

The final version of rcc should also pass the test suite; that is, the output from

% make TARGET=sparc/solaris test

should be identical to that from the previous make test.

The command "make clean" cleans up, but does not remove rcc, etc., and "make clobber" cleans up and removes lcc, rcc, and the other accessories. Test directories under BUILDDIR are not removed; you'll need to remove these by hand, e.g.,

% rm -fr $BUILDDIR/sparc

The code generators for the other targets can be tested by specifying the desired target/os and setting an environment variable that controls what src/ does. For example, to test the MIPS code generator, type

% setenv REMOTEHOST noexecute
% make TARGET=mips/irix test

As above, src/ compares the MIPS code generated with what's expected. There should be no differences. Setting REMOTEHOST to noexecute suppresses the assembly and execution of the generated code. If you set REMOTEHOST to the name of a MIPS machine to which you can rlogin, src/ will rcp the generated code to that machine and execute it there, if necessary. See src/ for the details.

You can use lcc as a cross compiler. The options -S and -Wf-target=target/os generate assembly code for the specified target, which is any of those listed in the file src/bind.c. For example,

% lcc -Wf-target=mips/irix -S tst/8q.c

generates MIPS code for tst/8q.c in 8q.s.

lcc can also generate code for a "symbolic" target. This target is used routinely in front-end development, and its output is a printable representation of the input program, e.g., the dags constructed by the front end are printed, and other interface functions print their arguments. You can specify this target with the option -Wf-target=symbolic. For example,

% lcc -Wf-target=symbolic -S tst/8q.c

generates symbolic output for tst/8q.c in 8q.s. Adding -Wf-html causes the symbolic target to emit HTML instead of plain text. Finally, the option -Wf-target=null specifies the "null" target for which lcc emits nothing and thus only checks the syntax and semantics of its input files.

Installation on Windows

On Windows, lcc is designed to work with Microsoft's Visual C++ (VC), version 5.0 and above, and Microsoft's Assembler, MASM. It uses the VC header files, libraries, and command-line tools, and it uses MASM to assemble the code it generates. You must use MASM 6.11d or later, because earlier releases generate incorrect COFF object files. MASM 6.15 is available as part of the free Visual C++ 6.0 Processor Pack.

Building the distribution components from the ground up requires Microsoft's Visual C/C++ compiler, Microsoft's make, nmake, and the standard Windows command interpreter. makefile.nt is written to use only nmake. As on UNIX systems, the compilation components are installed in a single build directory, and the top-level programs, lcc.exe and bprint.exe, are installed in a directory on the PATH. If the conventions used below are followed, the Windows-specific parts of the driver program, lcc.exe, can be used unmodified.

Building from the source distribution on a Windows system involves the following steps. Below, the build directory is referred to as BUILDDIR, and the distribution is in \dist\lcc.

  1. Create the build directory, perhaps using a version- and platform-specific naming convention as suggested in Installation on UNIX, and record the name of this directory in the BUILDDIR environment variable:
    C:\dist\lcc>set BUILDDIR=\progra~1\lcc\version\bin
    C:\dist\lcc>mkdir %BUILDDIR%

    The default build, or installation, directory is \Program Files\lcc\version\bin, where version is the version number, e.g., 4.2, but the nmake commands require that you use the corresponding 8.3 file name, progra~1, instead of Program Files.

  2. etc\win32.c is the Windows-specific part of the driver. It assumes that environment variable include gives the locations of the VC header files and that the linker (link.exe) and the assembler (ml.exe) are on the PATH. It also assumes that the macro LCCDIR gives the build directory. If necessary, revise a copy of etc\win32.c to reflect the conventions on your computer (see Building the Driver), then build the driver, specifying the default temporary directory, if necessary:
    C:\dist\lcc>nmake -f makefile.nt HOSTFILE=etc/win32.c lcc
            cl -nologo -Zi -MLd -Fd%BUILDDIR%\ -c -Fo%BUILDDIR%\lcc.obj etc/lcc.c
            cl -nologo -Zi -MLd -Fd%BUILDDIR%\ -c -Fo%BUILDDIR%\host.obj etc/win32.c
            cl -nologo -Zi -MLd -Fd%BUILDDIR%\ -Fe%BUILDDIR%\lcc.exe %BUILDDIR%\lcc.obj %BUILDDIR%\host.obj

    If you make a copy of etc\win32.c, specify the path of the copy as the value of HOSTFILE. For example, if you copy etc\win32.c to BUILDDIR and edit it, use the command

    C:\dist\lcc>nmake -f makefile.nt HOSTFILE=%BUILDDIR%\win32.c lcc
  3. Build the preprocessor, compiler proper, library, and other accessories (see Building the Compiler):
    C:\dist\lcc>nmake -f makefile.nt all

    This command uses the VC command-line tools cl and lib to build bprint.exe, cpp.exe, lburg.exe, liblcc.lib, librcc.lib, and rcc.exe, all in BUILDDIR. There may be some warnings, but there should be no warnings.

  4. Create a test directory and run the test suite:
    C:\dist\lcc>mkdir %BUILDDIR%\x86\win32\tst
    C:\dist\lcc>nmake -f makefile.nt test

    This command compiles each program in tst, compares the generated assembly code and diagnostics with the expected assembly code and diagnostics, executes the program, and compares the output with the expected output (using fc). For example, when the nmake command compiles tst\8q.c, it leaves the generated assembly code and diagnostic output in %BUILDDIR%\x86\win32\tst\8q.s and %BUILDDIR%\x86\win32\tst\8q.2, and it compares them with the expected results in x86\win32\tst\8q.sbk. It builds the executable program in %BUILDDIR%\x86\win32\tst\8q.exe, runs it, and redirects the output to %BUILDDIR%\x86\win32\tst\8q.1, which it compares with x86\win32\tst\8q.1bk. The output from this step is voluminous, but there should be no differences and no errors.

  5. Run the "triple" test, which compiles rcc with itself and verifies the results:
    C:\dist\lcc>nmake -f makefile.nt triple
     Assembling: C:/TEMP/lcc2001.asm
            fc /b %BUILDDIR%\1rcc.exe %BUILDDIR%\2rcc.exe
    Comparing files %BUILDDIR%\1rcc.exe and %BUILDDIR%\2RCC.EXE
    00000088: B4 D5

    This command builds rcc twice; once using the rcc built by VC and again using the rcc built by lcc. The resulting binaries are compared using fc. They should be identical, except for one or two bytes of timestamp data, as shown at the end of the output above (which will be different on your system). If 1rcc.exe and 2rcc.exe aren't identical, our compiler is generating incorrect code; contact us.

  6. Copy lcc.exe and bprint.exe to a directory on your PATH, e.g.,
    C:\dist\lcc>copy %BUILDDIR%\lcc.exe \bin
            1 file(s) copied.
    C:\dist\lcc>copy %BUILDDIR%\bprint.exe \bin
            1 file(s) copied.
  7. Finally, clean up:
    C:\dist\lcc>nmake -f makefile.nt clean

    This command removes the derived files in BUILDDIR, but does not remove rcc.exe, etc.; "nmake -f makefile.nt clobber" cleans up and removes all executables and libraries. Test directories under BUILDDIR are not removed; you'll need to remove these by hand, e.g.,

    C:\dist\lcc>rmdir %BUILDDIR%\x86 /s
    %BUILDDIR%\x86, Are you sure (Y/N)? y

Reporting Bugs

lcc is a large, complex program. We find and repair errors routinely. If you think that you've found a error, follow the steps below, which are adapted from the instructions in Chapter 1 of A Retargetable C Compiler: Design and Implementation.

  1. If you don't have a source file that displays the error, create one. Most errors are exposed when programmers try to compile a program they think is valid, so you probably have a demonstration program already.
  2. Preprocess the source file and capture the preprocessor output. Discard the original code.
  3. Prune your source code until it can be pruned no more without sending the error into hiding. We prune most error demonstrations to fewer than five lines.
  4. Confirm that the source file displays the error with the distributed version of lcc. If you've changed lcc and the error appears only in your version, then you'll have to chase the error yourself, even if it turns out to be our fault, because we can't work on your code.
  5. Annotate your code with comments that explain why you think that lcc is wrong. If lcc dies with an assertion failure, please tell us where it died. If lcc crashes, please report the last part of the call chain if you can. If lcc is rejecting a program you think is valid, please tell us why you think it's valid, and include supporting page numbers in the ANSI Standard or the appropriate section in C: A Reference Manual, 4th edition by S. B. Harbison and G. L. Steele, Jr. (Prentice Hall, 1995). If lcc silently generates incorrect code for some construct, please include the corrupt assembly code in the comments and flag the incorrect instructions if you can.
  6. Confirm that your error hasn't been fixed already. The latest version of lcc is available at The LOG file there reports what errors were fixed and when they were fixed. If you report a error that's been fixed, you might get a canned reply.
  7. Post your program to the newsgroup comp.compilers.lcc using a USENET newsreader like those at and Please post only valid C programs; put all remarks in C comments so that we can process reports semi automatically.

Keeping in Touch

The USENET newsgroup comp.compilers.lcc is an unmoderated newsgroup that serves as a forum for all topics related to the installation, use, and development of lcc. You can post messages to comp.compilers.lcc using any USENET newsreader or by visiting, which also includes an archive of recent postings.

Chris Fraser
David Hanson