# Installing lcc

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

## Contents

- Introduction
- Installation on UNIX
- Building the Driver
- Building the Compiler and Accessories
- Installation on Windows NT 4.0 and Windows 95/98
- Reporting Bugs
- Keeping in Touch

## Introduction

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 NT 4.0 or Windows 95/98 system, and you intend only to use lcc, you can run the InstallShield executable, which installs the binaries and the documentation. If you want to modify lcc or rebuild it from the source files, you need the complete distribution, and you should read the rest of the section, the following three sections, and the Windows NT/95/98 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. `doc/4.html` describes the internal differences between lcc 3.x and 4.1.

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 /usr/local/lib/lcc-4.1/sparc-solaris /usr/local/lib/lcc

points `/usr/local/lib/lcc` to a build directory for lcc version 4.1 on the SPARC under Solaris. Links into `/usr/local/lib` 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`.

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 /usr/local/lib/lcc-4.1/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/4.1/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/i486-linux/2.7.2.2 $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 `$BUILDDIR/gcc/cpp` and `$BUILDDIR/gcc/include` point to, 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 `custom.mk`, and an empty `custom.mk` 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.,

   >     make CUSTOM=/users/drh/solaris.mk

   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 advantange 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, say, 4.2, can be done by changing `/usr/local/lib/lcc` to point to the 4.2 build directory.

## 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 -DTEMPDIR=\"/tmp\" -o /usr/local/lib/lcc-4.1/sparc-solaris/lcc.o etc/lcc.c
>     cc -g -c -o /usr/local/lib/lcc-4.1/sparc-solaris/host.o etc/solaris.c
>     cc -g -o /usr/local/lib/lcc-4.1/sparc-solaris/lcc /usr/local/lib/lcc-4.1/sparc-solaris/lcc.o /usr/local/lib/lcc-4.1/sparc-solaris/host.o

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/"
>     #endif
>     #ifndef SUNDIR
>     #define SUNDIR "/opt/SUNWspro/SC4.2/lib/"
>     #endif

>     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];
>     	else
>     		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
>     /usr/local/lib/lcc-4.1/lcc $ Id: solaris.c,v 1.10 1998/09/14 20:36:33 drh Exp $
>     foo.c:
>     /usr/local/lib/lcc/cpp -D__STDC__=1 -Dsparc -D__sparc__ -Dsun -D__sun__ -Dunix -D__LCC__ -I/usr/local/lib/lcc/include -I/usr/local/include -I/usr/include foo.c /tmp/lcc266290.i
>     /usr/local/lib/lcc/rcc -target=sparc/solaris -v /tmp/lcc266290.i /tmp/lcc266291.
>     s
>     /usr/ccs/bin/as -Qy -s -o /tmp/lcc266292.o /tmp/lcc266291.s
>     baz.c:
>     /usr/local/lib/lcc/cpp -D__STDC__=1 -Dsparc -D__sparc__ -Dsun -D__sun__ -Dunix -D__LCC__ -I/usr/local/lib/lcc/include -I/usr/local/include -I/usr/include baz.c /tmp/lcc266290.i
>     /usr/local/lib/lcc/rcc -target=sparc/solaris -v /tmp/lcc266290.i /tmp/lcc266291.s
>     /usr/ccs/bin/as -Qy -s -o /tmp/lcc266293.o /tmp/lcc266291.s
>     /usr/ccs/bin/ld -o a.out /opt/SUNWspro/SC4.2/lib/crti.o /opt/SUNWspro/SC4.2/lib/crt1.o /opt/SUNWspro/SC4.2/lib/values-xa.o /tmp/lcc266292.o /tmp/lcc266293.o mylib.a -lX11 -Y P,/opt/SUNWspro/SC4.2/lib/:/usr/ccs/lib:/usr/lib -Qy -L/usr/local/lib/lcc/ -llcc -lm -lc /opt/SUNWspro/SC4.2/lib/crtn.o
>     rm /tmp/lcc266293.o /tmp/lcc266290.i /tmp/lcc266291.s /tmp/lcc266292.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 `-Wo` arg 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. If you're on a DEC 5000 running Ultrix 4.3, use "`make CC=c89 all`".

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/run.sh` 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 /usr/local/lib/lcc-4.1/sparc-solaris/sparc/solaris/tst
>     /usr/local/lib/lcc-4.1/sparc-solaris/rcc -target=sparc/solaris /usr/local/lib/lcc-4.1/sparc-solaris/sparc/solaris/tst/8q.s:
>     /usr/local/lib/lcc-4.1/sparc-solaris/rcc -target=sparc/solaris /usr/local/lib/lcc-4.1/sparc-solaris/sparc/solaris/tst/array.s:
>     /usr/local/lib/lcc-4.1/sparc-solaris/rcc -target=sparc/solaris /usr/local/lib/lcc-4.1/sparc-solaris/sparc/solaris/tst/cf.s:
>     /usr/local/lib/lcc-4.1/sparc-solaris/rcc -target=sparc/solaris /usr/local/lib/lcc-4.1/sparc-solaris/sparc/solaris/tst/cq.s:
>     /usr/local/lib/lcc-4.1/sparc-solaris/rcc -target=sparc/solaris /usr/local/lib/lcc-4.1/sparc-solaris/sparc/solaris/tst/cvt.s:
>     /usr/local/lib/lcc-4.1/sparc-solaris/rcc -target=sparc/solaris /usr/local/lib/lcc-4.1/sparc-solaris/sparc/solaris/tst/fields.s:
>     /usr/local/lib/lcc-4.1/sparc-solaris/rcc -target=sparc/solaris /usr/local/lib/lcc-4.1/sparc-solaris/sparc/solaris/tst/front.s:
>     /usr/local/lib/lcc-4.1/sparc-solaris/rcc -target=sparc/solaris /usr/local/lib/lcc-4.1/sparc-solaris/sparc/solaris/tst/incr.s:
>     /usr/local/lib/lcc-4.1/sparc-solaris/rcc -target=sparc/solaris /usr/local/lib/lcc-4.1/sparc-solaris/sparc/solaris/tst/init.s:
>     /usr/local/lib/lcc-4.1/sparc-solaris/rcc -target=sparc/solaris /usr/local/lib/lcc-4.1/sparc-solaris/sparc/solaris/tst/limits.s:
>     /usr/local/lib/lcc-4.1/sparc-solaris/rcc -target=sparc/solaris /usr/local/lib/lcc-4.1/sparc-solaris/sparc/solaris/tst/paranoia.s:
>     /usr/local/lib/lcc-4.1/sparc-solaris/rcc -target=sparc/solaris /usr/local/lib/lcc-4.1/sparc-solaris/sparc/solaris/tst/sort.s:
>     /usr/local/lib/lcc-4.1/sparc-solaris/rcc -target=sparc/solaris /usr/local/lib/lcc-4.1/sparc-solaris/sparc/solaris/tst/spill.s:
>     /usr/local/lib/lcc-4.1/sparc-solaris/rcc -target=sparc/solaris /usr/local/lib/lcc-4.1/sparc-solaris/sparc/solaris/tst/stdarg.s:
>     /usr/local/lib/lcc-4.1/sparc-solaris/rcc -target=sparc/solaris /usr/local/lib/lcc-4.1/sparc-solaris/sparc/solaris/tst/struct.s:
>     /usr/local/lib/lcc-4.1/sparc-solaris/rcc -target=sparc/solaris /usr/local/lib/lcc-4.1/sparc-solaris/sparc/solaris/tst/switch.s:
>     /usr/local/lib/lcc-4.1/sparc-solaris/rcc -target=sparc/solaris /usr/local/lib/lcc-4.1/sparc-solaris/sparc/solaris/tst/wf1.s:
>     /usr/local/lib/lcc-4.1/sparc-solaris/rcc -target=sparc/solaris /usr/local/lib/lcc-4.1/sparc-solaris/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. 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/run.sh` 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
>     /usr/local/lib/lcc-4.1/sparc-solaris/lcc -o /usr/local/lib/lcc-4.1/sparc-solaris/1rcc -d0.6 -Wo-lccdir=/usr/local/lib/lcc-4.1/sparc-solaris -B/usr/local/lib/lcc-4.1/sparc-solaris/  -Isrc src/*.c
>     src/alloc.c:
>     ...
>     src/x86.c:
>     /usr/local/lib/lcc-4.1/sparc-solaris/lcc -o /usr/local/lib/lcc-4.1/sparc-solaris/1rcc -d0.6 -Wo-lccdir=/usr/local/lib/lcc-4.1/sparc-solaris -B/usr/local/lib/lcc-4.1/sparc-solaris/  -Isrc src/*.c
>     src/alloc.c:
>     ...
>     src/x86.c:
>     strip /usr/local/lib/lcc-4.1/sparc-solaris/[12]rcc
>     dd if=/usr/local/lib/lcc-4.1/sparc-solaris/1rcc of=/usr/local/lib/lcc-4.1/sparc-solaris/rcc1 bs=512 skip=1
>     769+1 records in
>     769+1 records out
>     dd if=/usr/local/lib/lcc-4.1/sparc-solaris/2rcc of=/usr/local/lib/lcc-4.1/sparc-solaris/rcc2 bs=512 skip=1
>     769+1 records in
>     769+1 records out
>     if cmp /usr/local/lib/lcc-4.1/sparc-solaris/rcc[12]; then \
>             mv /usr/local/lib/lcc-4.1/sparc-solaris/2rcc /usr/local/lib/lcc-4.1/sparc-solaris/rcc; \
>             rm -f /usr/local/lib/lcc-4.1/sparc-solaris/1rcc /usr/local/lib/lcc-4.1/sparc-solaris/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/run.sh` does. For example, to test the MIPS code generator, type

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

As above, `src/run.sh` 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/run.sh` will `rcp` the generated code to that machine and execute it there, if necessary. See `src/run.sh` 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 NT 4.0 or Windows 95/98

On Windows NT 4.0 and Windows 95/98, lcc is designed to work with Microsoft's Visual C++ 5.0 (VC) and Microsoft's Assembler, MASM 6.11d. It uses the VC header files, libraries, and command-line tools, and it uses MASM to assemble the code it generates. If you have MASM 6.11, make sure you upgrade to 6.11d, because earlier 6.11 releases do not generate correct COFF object files.

Building the distribution components from the ground up requires Microsoft's Visual C/C++ 5.0 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\4.1`.

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\4.1>set BUILDDIR=\progra~1\lcc\4.1\bin
   >     C:\dist\lcc\4.1>mkdir %BUILDDIR%

   The default build, or installation, directory is `\Program Files\lcc\4.1\bin`, 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\4.1>nmake -f makefile.nt TEMPDIR=\\temp HOSTFILE=etc/win32.c lcc
   >     ...
   >             cl -nologo -Zi -MLd -Fd\progra~1\lcc\4.1\bin\ -c -DTEMPDIR=\"\\temp\" -Fo\progra~1\lcc\4.1\bin\lcc.obj etc/lcc.c
   >     lcc.c
   >             cl -nologo -Zi -MLd -Fd\progra~1\lcc\4.1\bin\ -c -Fo\progra~1\lcc\4.1\bin\host.obj etc/win32.c
   >     win32.c
   >             cl -nologo -Zi -MLd -Fd\progra~1\lcc\4.1\bin\ -Fe\progra~1\lcc\4.1\bin\lcc.exe \progra~1\lcc\4.1\bin\lcc.obj \progra~1\lcc\4.1\bin\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\4.1>nmake -f makefile.nt TEMPDIR=\\temp HOSTFILE=%BUILDDIR%\win32.c lcc

3. Build the preprocessor, compiler proper, library, and other accessories (see Building the Compiler):

   >     C:\dist\lcc\4.1>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\4.1>mkdir %BUILDDIR%\x86\win32\tst
   >     C:\dist\lcc\4.1>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\4.1>nmake -f makefile.nt triple
   >     ...
   >     \progra~1\lcc\4.1\bin\x86.c:
   >      Assembling: C:/TEMP/lcc2001.asm
   >             fc /b \progra~1\lcc\4.1\bin\1rcc.exe \progra~1\lcc\4.1\bin\2rcc.exe
   >     Comparing files \progra~1\lcc\4.1\bin\1rcc.exe and \progra~1\lcc\4.1\bin\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. If they aren't, 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\4.1>copy %BUILDDIR%\lcc.exe \bin
   >             1 file(s) copied.

   >     C:\dist\lcc\4.1>copy %BUILDDIR%\bprint.exe \bin
   >             1 file(s) copied.

7. Finally, clean up:

   >     C:\dist\lcc\4.1>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\4.1>rmdir %BUILDDIR%\x86 /s
   >     \progra~1\lcc\4.1\bin\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 an 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, Appendix A in The C Programming Language, 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 always available for anonymous `ftp` from `ftp.cs.princeton.edu` in `pub/lcc`. A `README` file there gives acquistion details, and the `LOG` file reports what errors were fixed and when they were fixed. If you report an error that's been fixed, you might get a canned reply.
7. Send your program by electronic mail to `lcc-bugs@cs.princeton.edu`. Please send only valid C programs; put all remarks in C comments so that we can process reports semiautomatically.

## Keeping in Touch

There is an lcc mailing list for general information about lcc. To be added to the list, send a message with the 1-line body

>     subscribe lcc

to `majordomo@cs.princeton.edu`. This line must appear in the message body; "Subject:" lines are ignored. To learn more about mailing lists served by `majordomo`, send a message with the 1-word body "`help`" to `majordomo@cs.princeton.edu`. Mail sent to `lcc@cs.princeton.edu` is forwarded to everyone on the mailing list.

There is also an `lcc-bugs` mailing list for reporting bugs; subscribe to it by sending a message with the 1-line body

>     subscribe lcc-bugs

to `majordomo@cs.princeton.edu`. Mail addressed to lcc-bugs@cs.princeton.edu is forwarded to everyone on this list.