xref: /illumos-gate/usr/src/tools/cw/cw.c (revision 4afe1ab8)

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*
 * Wrapper for the GNU C compiler to make it accept the Sun C compiler
 * arguments where possible.
 *
 * Since the translation is inexact, this is something of a work-in-progress.
 */

/*
 * -#		Verbose mode
 * -###		Show compiler commands built by driver, no compilation
 * -A<name[(tokens)]>	Preprocessor predicate assertion
 * -B<[static|dynamic]>	Specify dynamic or static binding
 * -C		Prevent preprocessor from removing comments
 * -c		Compile only - produce .o files, suppress linking
 * -cg92	Alias for -xtarget=ss1000
 * -D<name[=token]>	Associate name with token as if by #define
 * -d[y|n]	dynamic [-dy] or static [-dn] option to linker
 * -E		Compile source through preprocessor only, output to stdout
 * -erroff=<t>	Suppress warnings specified by tags t(%none, %all, <tag list>)
 * -errtags=<a>	Display messages with tags a(no, yes)
 * -errwarn=<t>	Treats warnings specified by tags t(%none, %all, <tag list>)
 *		as errors
 * -fast	Optimize using a selection of options
 * -fd		Report old-style function definitions and declarations
 * -flags	Show this summary of compiler options
 * -fnonstd	Initialize floating-point hardware to non-standard preferences
 * -fns[=<yes|no>] Select non-standard floating point mode
 * -fprecision=<p> Set FP rounding precision mode p(single, double, extended)
 * -fround=<r>	Select the IEEE rounding mode in effect at startup
 * -fsimple[=<n>] Select floating-point optimization preferences <n>
 * -fsingle	Use single-precision arithmetic (-Xt and -Xs modes only)
 * -ftrap=<t>	Select floating-point trapping mode in effect at startup
 * -fstore	force floating pt. values to target precision on assignment
 * -G		Build a dynamic shared library
 * -g		Compile for debugging
 * -H		Print path name of each file included during compilation
 * -h <name>	Assign <name> to generated dynamic shared library
 * -I<dir>	Add <dir> to preprocessor #include file search path
 * -i		Passed to linker to ignore any LD_LIBRARY_PATH setting
 * -keeptmp	Keep temporary files created during compilation
 * -KPIC	Compile position independent code with 32-bit addresses
 * -Kpic	Compile position independent code
 * -L<dir>	Pass to linker to add <dir> to the library search path
 * -l<name>	Link with library lib<name>.a or lib<name>.so
 * -mc		Remove duplicate strings from .comment section of output files
 * -mr		Remove all strings from .comment section of output files
 * -mr,"string"	Remove all strings and append "string" to .comment section
 * -mt		Specify options needed when compiling multi-threaded code
 * -native	Find available processor, generate code accordingly
 * -nofstore	Do not force floating pt. values to target precision
 *		on assignment
 * -nolib	Same as -xnolib
 * -noqueue	Disable queuing of compiler license requests
 * -norunpath	Do not build in a runtime path for shared libraries
 * -O		Use default optimization level (-xO2 or -xO3. Check man page.)
 * -o <outputfile> Set name of output file to <outputfile>
 * -P		Compile source through preprocessor only, output to .i  file
 * -PIC		Alias for -KPIC or -xcode=pic32
 * -p		Compile for profiling with prof
 * -pic		Alias for -Kpic or -xcode=pic13
 * -Q[y|n]	Emit/don't emit identification info to output file
 * -qp		Compile for profiling with prof
 * -R<dir[:dir]> Build runtime search path list into executable
 * -S		Compile and only generate assembly code (.s)
 * -s		Strip symbol table from the executable file
 * -t		Turn off duplicate symbol warnings when linking
 * -U<name>	Delete initial definition of preprocessor symbol <name>
 * -V		Report version number of each compilation phase
 * -v		Do stricter semantic checking
 * -W<c>,<arg>	Pass <arg> to specified component <c> (a,l,m,p,0,2,h,i,u)
 * -w		Suppress compiler warning messages
 * -Xa		Compile assuming ANSI C conformance, allow K & R extensions
 *		(default mode)
 * -Xc		Compile assuming strict ANSI C conformance
 * -Xs		Compile assuming (pre-ANSI) K & R C style code
 * -Xt		Compile assuming K & R conformance, allow ANSI C
 * -x386	Generate code for the 80386 processor
 * -x486	Generate code for the 80486 processor
 * -xarch=<a>	Specify target architecture instruction set
 * -xbuiltin[=<b>] When profitable inline, or substitute intrinisic functions
 *		for system functions, b={%all,%none}
 * -xCC		Accept C++ style comments
 * -xchar_byte_order=<o> Specify multi-char byte order <o> (default, high, low)
 * -xchip=<c>	Specify the target processor for use by the optimizer
 * -xcode=<c>	Generate different code for forming addresses
 * -xcrossfile[=<n>] Enable optimization and inlining across source files,
 *		n={0|1}
 * -xe		Perform only syntax/semantic checking, no code generation
 * -xF		Compile for later mapfile reordering
 * -xhelp=<f>	Display on-line help information f(flags, readme, errors)
 * -xildoff	Cancel -xildon
 * -xildon	Enable use of the incremental linker, ild
 * -xinline=[<a>,...,<a>]  Attempt inlining of specified user routines,
 *		<a>={%auto,func,no%func}
 * -xlibmieee	Force IEEE 754 return values for math routines in
 *		exceptional cases
 * -xlibmil	Inline selected libm math routines for optimization
 * -xlic_lib=sunperf	Link in the Sun supplied performance libraries
 * -xlicinfo	Show license server information
 * -xM		Generate makefile dependencies
 * -xM1		Generate makefile dependencies, but exclude /usr/include
 * -xmaxopt=[off,1,2,3,4,5] maximum optimization level allowed on #pragma opt
 * -xnolib	Do not link with default system libraries
 * -xnolibmil	Cancel -xlibmil on command line
 * -xO<n>	Generate optimized code (n={1|2|3|4|5})
 * -xP		Print prototypes for function definitions
 * -xpentium	Generate code for the pentium processor
 * -xpg		Compile for profiling with gprof
 * -xprofile=<p> Collect data for a profile or use a profile to optimize
 *		<p>={{collect,use}[:<path>],tcov}
 * -xregs=<r>	Control register allocation
 * -xs		Allow debugging without object (.o) files
 * -xsb		Compile for use with the WorkShop source browser
 * -xsbfast	Generate only WorkShop source browser info, no compilation
 * -xsfpconst	Represent unsuffixed floating point constants as single
 *		precision
 * -xspace	Do not do optimizations that increase code size
 * -xstrconst	Place string literals into read-only data segment
 * -xtarget=<t>	Specify target system for optimization
 * -xtemp=<dir>	Set directory for temporary files to <dir>
 * -xtime	Report the execution time for each compilation phase
 * -xtransition	Emit warnings for differences between K&R C and ANSI C
 * -xtrigraphs[=<yes|no>] Enable|disable trigraph translation
 * -xunroll=n	Enable unrolling loops n times where possible
 * -Y<c>,<dir>	Specify <dir> for location of component <c> (a,l,m,p,0,h,i,u)
 * -YA,<dir>	Change default directory searched for components
 * -YI,<dir>	Change default directory searched for include files
 * -YP,<dir>	Change default directory for finding libraries files
 * -YS,<dir>	Change default directory for startup object files
 */

/*
 * Translation table:
 */
/*
 * -#				-v
 * -###				error
 * -A<name[(tokens)]>		pass-thru
 * -B<[static|dynamic]>		pass-thru (syntax error for anything else)
 * -C				pass-thru
 * -c				pass-thru
 * -cg92			-m32 -mcpu=v8 -mtune=supersparc (SPARC only)
 * -D<name[=token]>		pass-thru
 * -dy or -dn			-Wl,-dy or -Wl,-dn
 * -E				pass-thru
 * -erroff=E_EMPTY_TRANSLATION_UNIT ignore
 * -errtags=%all		-Wall
 * -errwarn=%all		-Werror else -Wno-error
 * -fast			error
 * -fd				error
 * -flags			--help
 * -fnonstd			error
 * -fns[=<yes|no>]		error
 * -fprecision=<p>		error
 * -fround=<r>			error
 * -fsimple[=<n>]		error
 * -fsingle[=<n>]		error
 * -ftrap=<t>			error
 * -fstore			error
 * -G				pass-thru
 * -g				pass-thru
 * -H				pass-thru
 * -h <name>			pass-thru
 * -I<dir>			pass-thru
 * -i				pass-thru
 * -keeptmp			-save-temps
 * -KPIC			-fPIC
 * -Kpic			-fpic
 * -L<dir>			pass-thru
 * -l<name>			pass-thru
 * -mc				error
 * -mr				error
 * -mr,"string"			error
 * -mt				-D_REENTRANT
 * -native			error
 * -nofstore			error
 * -nolib			-nodefaultlibs
 * -noqueue			ignore
 * -norunpath			ignore
 * -O				-O1 (Check the man page to be certain)
 * -o <outputfile>		pass-thru
 * -P				-E -o filename.i (or error)
 * -PIC				-fPIC (C++ only)
 * -p				pass-thru
 * -pic				-fpic (C++ only)
 * -Q[y|n]			error
 * -qp				-p
 * -R<dir[:dir]>		pass-thru
 * -S				pass-thru
 * -s				-Wl,-s
 * -t				-Wl,-t
 * -U<name>			pass-thru
 * -V				--version
 * -v				-Wall
 * -Wa,<arg>			pass-thru
 * -Wp,<arg>			pass-thru except -xc99=<a>
 * -Wl,<arg>			pass-thru
 * -W{m,0,2,h,i,u>		error/ignore
 * -Wu,-xmodel=kernel		-ffreestanding -mcmodel=kernel -mno-red-zone
 * -Wu,-save_args		-msave-args
 * -w				pass-thru
 * -Xa				-std=iso9899:199409 or -ansi
 * -Xc				-ansi -pedantic
 * -Xt				error
 * -Xs				-traditional -std=c89
 * -x386			-march=i386 (x86 only)
 * -x486			-march=i486 (x86 only)
 * -xarch=<a>			table
 * -xbuiltin[=<b>]		-fbuiltin (-fno-builtin otherwise)
 * -xCC				ignore
 * -xchar_byte_order=<o>	error
 * -xchip=<c>			table
 * -xcode=<c>			table
 * -xdebugformat=<format>	ignore (always use dwarf-2 for gcc)
 * -xcrossfile[=<n>]		ignore
 * -xe				error
 * -xF				error
 * -xhelp=<f>			error
 * -xildoff			ignore
 * -xildon			ignore
 * -xinline			ignore
 * -xlibmieee			error
 * -xlibmil			error
 * -xlic_lib=sunperf		error
 * -xM				-M
 * -xM1				-MM
 * -xmaxopt=[...]		error
 * -xnolib			-nodefaultlibs
 * -xnolibmil			error
 * -xO<n>			-O<n>
 * -xP				error
 * -xpentium			-march=pentium (x86 only)
 * -xpg				error
 * -xprofile=<p>		error
 * -xregs=<r>			table
 * -xs				error
 * -xsb				error
 * -xsbfast			error
 * -xsfpconst			error
 * -xspace			ignore (-not -Os)
 * -xstrconst			ignore
 * -xtarget=<t>			table
 * -xtemp=<dir>			error
 * -xtime			error
 * -xtransition			-Wtransition
 * -xtrigraphs=<yes|no>		-trigraphs -notrigraphs
 * -xunroll=n			error
 * -W0,-xdbggen=no%usedonly	-fno-eliminate-unused-debug-symbols
 *				-fno-eliminate-unused-debug-types
 * -Y<c>,<dir>			error
 * -YA,<dir>			error
 * -YI,<dir>			-nostdinc -I<dir>
 * -YP,<dir>			error
 * -YS,<dir>			error
 */

#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <fcntl.h>
#include <errno.h>
#include <stdarg.h>
#include <sys/utsname.h>
#include <sys/param.h>
#include <sys/isa_defs.h>
#include <sys/wait.h>
#include <sys/stat.h>

#define	CW_F_CXX	0x01
#define	CW_F_SHADOW	0x02
#define	CW_F_EXEC	0x04
#define	CW_F_ECHO	0x08
#define	CW_F_XLATE	0x10
#define	CW_F_PROG	0x20

typedef enum cw_compiler {
	CW_C_CC = 0,
	CW_C_GCC
} cw_compiler_t;

static const char *cmds[] = {
	"cc", "CC",
	"gcc", "g++"
};

static const char *dirs[] = {
	DEFAULT_CC_DIR, DEFAULT_CPLUSPLUS_DIR,
	DEFAULT_GCC_DIR, DEFAULT_GPLUSPLUS_DIR
};

#define	CC(ctx) \
	(((ctx)->i_flags & CW_F_SHADOW) ? \
	    ((ctx)->i_compiler == CW_C_CC ? CW_C_GCC : CW_C_CC) : \
	    (ctx)->i_compiler)

#define	CIDX(compiler, flags)	\
	((int)(compiler) << 1) + ((flags) & CW_F_CXX ? 1 : 0)

typedef enum cw_op {
	CW_O_NONE = 0,
	CW_O_PREPROCESS,
	CW_O_COMPILE,
	CW_O_LINK
} cw_op_t;

struct aelist {
	struct ae {
		struct ae *ae_next;
		char *ae_arg;
	} *ael_head, *ael_tail;
	int ael_argc;
};

typedef struct cw_ictx {
	cw_compiler_t	i_compiler;
	struct aelist	*i_ae;
	uint32_t	i_flags;
	int		i_oldargc;
	char		**i_oldargv;
	pid_t		i_pid;
	char		i_discard[MAXPATHLEN];
	char		*i_stderr;
} cw_ictx_t;

static const char *progname;

static const char *xarch_tbl[] = {
#if defined(__x86)
	"generic",	NULL,
	"generic64",	"-m64", "-mtune=opteron", NULL,
	"amd64",	"-m64", "-mtune=opteron", NULL,
	"386",		"-march=i386", NULL,
	"pentium_pro",	"-march=pentiumpro", NULL,
#elif defined(__sparc)
	"generic",	"-m32", "-mcpu=v8", NULL,
	"generic64",	"-m64", "-mcpu=v9", NULL,
	"v8",		"-m32", "-mcpu=v8", "-mno-v8plus", NULL,
	"v8plus",	"-m32", "-mcpu=v9", "-mv8plus", NULL,
	"v8plusa",	"-m32", "-mcpu=ultrasparc", "-mv8plus", "-mvis", NULL,
	"v8plusb",	"-m32", "-mcpu=ultrasparc3", "-mv8plus", "-mvis", NULL,
	"v9",		"-m64", "-mcpu=v9", NULL,
	"v9a",		"-m64", "-mcpu=ultrasparc", "-mvis", NULL,
	"v9b",		"-m64", "-mcpu=ultrasparc3", "-mvis", NULL,
#endif
	NULL,		NULL
};

static const char *xchip_tbl[] = {
#if defined(__x86)
	"386",		"-mtune=i386", NULL,
	"486",		"-mtune=i486", NULL,
	"pentium",	"-mtune=pentium", NULL,
	"pentium_pro",  "-mtune=pentiumpro", NULL,
#elif defined(__sparc)
	"super",	"-mtune=supersparc", NULL,
	"ultra",	"-mtune=ultrasparc", NULL,
	"ultra3",	"-mtune=ultrasparc3", NULL,
#endif
	NULL,		NULL
};

static const char *xcode_tbl[] = {
#if defined(__sparc)
	"abs32",	"-fno-pic", "-mcmodel=medlow", NULL,
	"abs44",	"-fno-pic", "-mcmodel=medmid", NULL,
	"abs64",	"-fno-pic", "-mcmodel=medany", NULL,
	"pic13",	"-fpic", NULL,
	"pic32",	"-fPIC", NULL,
#endif
	NULL,		NULL
};

static const char *xtarget_tbl[] = {
#if defined(__x86)
	"pentium_pro",	"-march=pentiumpro", NULL,
#endif	/* __x86 */
	NULL,		NULL
};

static const char *xregs_tbl[] = {
#if defined(__sparc)
	"appl",		"-mapp-regs", NULL,
	"no%appl",	"-mno-app-regs", NULL,
	"float",	"-mfpu", NULL,
	"no%float",	"-mno-fpu", NULL,
#endif	/* __sparc */
	NULL,		NULL
};

static void
nomem(void)
{
	(void) fprintf(stderr, "%s: error: out of memory\n", progname);
	exit(1);
}

static void
cw_perror(const char *fmt, ...)
{
	va_list ap;
	int saved_errno = errno;

	(void) fprintf(stderr, "%s: error: ", progname);

	va_start(ap, fmt);
	(void) vfprintf(stderr, fmt, ap);
	va_end(ap);

	(void) fprintf(stderr, " (%s)\n", strerror(saved_errno));
}

static void
newae(struct aelist *ael, const char *arg)
{
	struct ae *ae;

	if ((ae = calloc(sizeof (*ae), 1)) == NULL)
		nomem();
	ae->ae_arg = strdup(arg);
	if (ael->ael_tail == NULL)
		ael->ael_head = ae;
	else
		ael->ael_tail->ae_next = ae;
	ael->ael_tail = ae;
	ael->ael_argc++;
}

static cw_ictx_t *
newictx(void)
{
	cw_ictx_t *ctx = calloc(sizeof (cw_ictx_t), 1);
	if (ctx)
		if ((ctx->i_ae = calloc(sizeof (struct aelist), 1)) == NULL) {
			free(ctx);
			return (NULL);
		}

	return (ctx);
}

static void
error(const char *arg)
{
	(void) fprintf(stderr,
	    "%s: error: mapping failed at or near arg '%s'\n", progname, arg);
	exit(2);
}

/*
 * Add the current favourite set of warnings to the gcc invocation.
 */
static void
warnings(struct aelist *h)
{
	static int warningsonce;

	if (warningsonce++)
		return;

	newae(h, "-Wall");
	newae(h, "-Wno-unknown-pragmas");
	newae(h, "-Wno-missing-braces");
	newae(h, "-Wno-sign-compare");
	newae(h, "-Wno-parentheses");
	newae(h, "-Wno-uninitialized");
	newae(h, "-Wno-implicit-function-declaration");
	newae(h, "-Wno-unused");
	newae(h, "-Wno-trigraphs");
	newae(h, "-Wno-char-subscripts");
	newae(h, "-Wno-switch");
}

static void
optim_disable(struct aelist *h, int level)
{
	if (level >= 2) {
		newae(h, "-fno-strict-aliasing");
		newae(h, "-fno-unit-at-a-time");
		newae(h, "-fno-optimize-sibling-calls");
	}
}

/* ARGSUSED */
static void
Xamode(struct aelist *h)
{
}

static void
Xcmode(struct aelist *h)
{
	static int xconce;

	if (xconce++)
		return;

	newae(h, "-ansi");
	newae(h, "-pedantic-errors");
}

static void
Xsmode(struct aelist *h)
{
	static int xsonce;

	if (xsonce++)
		return;

	newae(h, "-traditional");
	newae(h, "-traditional-cpp");
}

static void
usage()
{
	(void) fprintf(stderr,
	    "usage: %s { -_cc | -_gcc | -_CC | -_g++ } [ -_compiler | ... ]\n",
	    progname);
	exit(2);
}

static void
xlate(struct aelist *h, const char *xarg, const char **table)
{
	while (*table != NULL && strcmp(xarg, *table) != 0) {
		while (*table != NULL)
			table++;
		table++;
	}

	if (*table == NULL)
		error(xarg);

	table++;

	while (*table != NULL) {
		newae(h, *table);
		table++;
	}
}

static void
do_gcc(cw_ictx_t *ctx)
{
	int c;
	int pic = 0, nolibc = 0;
	int in_output = 0, seen_o = 0, c_files = 0;
	cw_op_t op = CW_O_LINK;
	char *model = NULL;

	if (ctx->i_flags & CW_F_PROG) {
		newae(ctx->i_ae, "--version");
		return;
	}

	newae(ctx->i_ae, "-fident");
	newae(ctx->i_ae, "-finline");
	newae(ctx->i_ae, "-fno-inline-functions");
	newae(ctx->i_ae, "-fno-builtin");
	newae(ctx->i_ae, "-fno-asm");
	newae(ctx->i_ae, "-nodefaultlibs");

#if defined(__sparc)
	/*
	 * The SPARC ldd and std instructions require 8-byte alignment of
	 * their address operand.  gcc correctly uses them only when the
	 * ABI requires 8-byte alignment; unfortunately we have a number of
	 * pieces of buggy code that doesn't conform to the ABI.  This
	 * flag makes gcc work more like Studio with -xmemalign=4.
	 */
	newae(ctx->i_ae, "-mno-integer-ldd-std");
#endif

	/*
	 * This is needed because 'u' is defined
	 * under a conditional on 'sun'.  Should
	 * probably just remove the conditional,
	 * or make it be dependent on '__sun'.
	 *
	 * -Dunix is also missing in enhanced ANSI mode
	 */
	newae(ctx->i_ae, "-D__sun");

	/*
	 * Walk the argument list, translating as we go ..
	 */

	while (--ctx->i_oldargc > 0) {
		char *arg = *++ctx->i_oldargv;
		size_t arglen = strlen(arg);

		if (*arg == '-') {
			arglen--;
		} else {
			/*
			 * Discard inline files that gcc doesn't grok
			 */
			if (!in_output && arglen > 3 &&
			    strcmp(arg + arglen - 3, ".il") == 0)
				continue;

			if (!in_output && arglen > 2 &&
			    arg[arglen - 2] == '.' &&
			    (arg[arglen - 1] == 'S' || arg[arglen - 1] == 's' ||
			    arg[arglen - 1] == 'c' || arg[arglen - 1] == 'i'))
				c_files++;

			/*
			 * Otherwise, filenames and partial arguments
			 * are passed through for gcc to chew on.  However,
			 * output is always discarded for the secondary
			 * compiler.
			 */
			if ((ctx->i_flags & CW_F_SHADOW) && in_output)
				newae(ctx->i_ae, ctx->i_discard);
			else
				newae(ctx->i_ae, arg);
			in_output = 0;
			continue;
		}

		if (ctx->i_flags & CW_F_CXX) {
			if (strncmp(arg, "-compat=", 8) == 0) {
				/* discard -compat=4 and -compat=5 */
				continue;
			}
			if (strcmp(arg, "-Qoption") == 0) {
				/* discard -Qoption and its two arguments */
				if (ctx->i_oldargc < 3)
					error(arg);
				ctx->i_oldargc -= 2;
				ctx->i_oldargv += 2;
				continue;
			}
			if (strcmp(arg, "-xwe") == 0) {
				/* turn warnings into errors */
				newae(ctx->i_ae, "-Werror");
				continue;
			}
			if (strcmp(arg, "-noex") == 0) {
				/* no exceptions */
				newae(ctx->i_ae, "-fno-exceptions");
				/* no run time type descriptor information */
				newae(ctx->i_ae, "-fno-rtti");
				continue;
			}
			if (strcmp(arg, "-pic") == 0) {
				newae(ctx->i_ae, "-fpic");
				pic = 1;
				continue;
			}
			if (strcmp(arg, "-PIC") == 0) {
				newae(ctx->i_ae, "-fPIC");
				pic = 1;
				continue;
			}
			if (strcmp(arg, "-norunpath") == 0) {
				/* gcc has no corresponding option */
				continue;
			}
			if (strcmp(arg, "-nolib") == 0) {
				/* -nodefaultlibs is on by default */
				nolibc = 1;
				continue;
			}
#if defined(__sparc)
			if (strcmp(arg, "-cg92") == 0) {
				xlate(ctx->i_ae, "v8", xarch_tbl);
				xlate(ctx->i_ae, "super", xchip_tbl);
				continue;
			}
#endif	/* __sparc */
		}

		switch ((c = arg[1])) {
		case '_':
			if (strcmp(arg, "-_noecho") == 0)
				ctx->i_flags &= ~CW_F_ECHO;
			else if (strncmp(arg, "-_cc=", 5) == 0 ||
			    strncmp(arg, "-_CC=", 5) == 0)
				/* EMPTY */;
			else if (strncmp(arg, "-_gcc=", 6) == 0 ||
			    strncmp(arg, "-_g++=", 6) == 0)
				newae(ctx->i_ae, arg + 6);
			else
				error(arg);
			break;
		case '#':
			if (arglen == 1) {
				newae(ctx->i_ae, "-v");
				break;
			}
			error(arg);
			break;
		case 'g':
			newae(ctx->i_ae, "-gdwarf-2");
			break;
		case 'E':
			if (arglen == 1) {
				newae(ctx->i_ae, "-xc");
				newae(ctx->i_ae, arg);
				op = CW_O_PREPROCESS;
				nolibc = 1;
				break;
			}
			error(arg);
			break;
		case 'c':
		case 'S':
			if (arglen == 1) {
				op = CW_O_COMPILE;
				nolibc = 1;
			}
			/* FALLTHROUGH */
		case 'C':
		case 'H':
		case 'p':
			if (arglen == 1) {
				newae(ctx->i_ae, arg);
				break;
			}
			error(arg);
			break;
		case 'A':
		case 'h':
		case 'I':
		case 'i':
		case 'L':
		case 'l':
		case 'R':
		case 'U':
		case 'u':
		case 'w':
			newae(ctx->i_ae, arg);
			break;
		case 'o':
			seen_o = 1;
			if (arglen == 1) {
				in_output = 1;
				newae(ctx->i_ae, arg);
			} else if (ctx->i_flags & CW_F_SHADOW) {
				newae(ctx->i_ae, "-o");
				newae(ctx->i_ae, ctx->i_discard);
			} else {
				newae(ctx->i_ae, arg);
			}
			break;
		case 'D':
			newae(ctx->i_ae, arg);
			/*
			 * XXX	Clearly a hack ... do we need _KADB too?
			 */
			if (strcmp(arg, "-D_KERNEL") == 0 ||
			    strcmp(arg, "-D_BOOT") == 0)
				newae(ctx->i_ae, "-ffreestanding");
			break;
		case 'd':
			if (arglen == 2) {
				if (strcmp(arg, "-dy") == 0) {
					newae(ctx->i_ae, "-Wl,-dy");
					break;
				}
				if (strcmp(arg, "-dn") == 0) {
					newae(ctx->i_ae, "-Wl,-dn");
					break;
				}
			}
			if (strcmp(arg, "-dalign") == 0) {
				/*
				 * -dalign forces alignment in some cases;
				 * gcc does not need any flag to do this.
				 */
				break;
			}
			error(arg);
			break;
		case 'e':
			if (strcmp(arg,
			    "-erroff=E_EMPTY_TRANSLATION_UNIT") == 0) {
				/*
				 * Accept but ignore this -- gcc doesn't
				 * seem to complain about empty translation
				 * units
				 */
				break;
			}
			/* XX64 -- ignore all -erroff= options, for now */
			if (strncmp(arg, "-erroff=", 8) == 0)
				break;
			if (strcmp(arg, "-errtags=yes") == 0) {
				warnings(ctx->i_ae);
				break;
			}
			if (strcmp(arg, "-errwarn=%all") == 0) {
				newae(ctx->i_ae, "-Werror");
				break;
			}
			error(arg);
			break;
		case 'f':
			if (strcmp(arg, "-flags") == 0) {
				newae(ctx->i_ae, "--help");
				break;
			}
			error(arg);
			break;
		case 'G':
			newae(ctx->i_ae, "-shared");
			nolibc = 1;
			break;
		case 'k':
			if (strcmp(arg, "-keeptmp") == 0) {
				newae(ctx->i_ae, "-save-temps");
				break;
			}
			error(arg);
			break;
		case 'K':
			if (arglen == 1) {
				if ((arg = *++ctx->i_oldargv) == NULL ||
				    *arg == '\0')
					error("-K");
				ctx->i_oldargc--;
			} else {
				arg += 2;
			}
			if (strcmp(arg, "pic") == 0) {
				newae(ctx->i_ae, "-fpic");
				pic = 1;
				break;
			}
			if (strcmp(arg, "PIC") == 0) {
				newae(ctx->i_ae, "-fPIC");
				pic = 1;
				break;
			}
			error("-K");
			break;
		case 'm':
			if (strcmp(arg, "-mt") == 0) {
				newae(ctx->i_ae, "-D_REENTRANT");
				break;
			}
			error(arg);
			break;
		case 'B':	/* linker options */
		case 'M':
		case 'z':
			{
				char *opt;
				size_t len;
				char *s;

				if (arglen == 1) {
					opt = *++ctx->i_oldargv;
					if (opt == NULL || *opt == '\0')
						error(arg);
					ctx->i_oldargc--;
				} else {
					opt = arg + 2;
				}
				len = strlen(opt) + 7;
				if ((s = malloc(len)) == NULL)
					nomem();
				(void) snprintf(s, len, "-Wl,-%c%s", c, opt);
				newae(ctx->i_ae, s);
				free(s);
			}
			break;
		case 'n':
			if (strcmp(arg, "-noqueue") == 0) {
				/*
				 * Horrid license server stuff - n/a
				 */
				break;
			}
			error(arg);
			break;
		case 'O':
			if (arglen == 1) {
				newae(ctx->i_ae, "-O");
				break;
			}
			error(arg);
			break;
		case 'P':
			/*
			 * We could do '-E -o filename.i', but that's hard,
			 * and we don't need it for the case that's triggering
			 * this addition.  We'll require the user to specify
			 * -o in the Makefile.  If they don't they'll find out
			 * in a hurry.
			 */
			newae(ctx->i_ae, "-E");
			op = CW_O_PREPROCESS;
			nolibc = 1;
			break;
		case 'q':
			if (strcmp(arg, "-qp") == 0) {
				newae(ctx->i_ae, "-p");
				break;
			}
			error(arg);
			break;
		case 's':
			if (arglen == 1) {
				newae(ctx->i_ae, "-Wl,-s");
				break;
			}
			error(arg);
			break;
		case 't':
			if (arglen == 1) {
				newae(ctx->i_ae, "-Wl,-t");
				break;
			}
			error(arg);
			break;
		case 'V':
			if (arglen == 1) {
				ctx->i_flags &= ~CW_F_ECHO;
				newae(ctx->i_ae, "--version");
				break;
			}
			error(arg);
			break;
		case 'v':
			if (arglen == 1) {
				warnings(ctx->i_ae);
				break;
			}
			error(arg);
			break;
		case 'W':
			if (strncmp(arg, "-Wp,-xc99", 9) == 0) {
				/*
				 * gcc's preprocessor will accept c99
				 * regardless, so accept and ignore.
				 */
				break;
			}
			if (strncmp(arg, "-Wa,", 4) == 0 ||
			    strncmp(arg, "-Wp,", 4) == 0 ||
			    strncmp(arg, "-Wl,", 4) == 0) {
				newae(ctx->i_ae, arg);
				break;
			}
			if (strcmp(arg, "-W0,-xc99=pragma") == 0) {
				/* (undocumented) enables _Pragma */
				break;
			}
			if (strcmp(arg, "-W0,-xc99=%none") == 0) {
				/*
				 * This is a polite way of saying
				 * "no c99 constructs allowed!"
				 * For now, just accept and ignore this.
				 */
				break;
			}
			if (strcmp(arg, "-W0,-noglobal") == 0 ||
			    strcmp(arg, "-W0,-xglobalstatic") == 0) {
				/*
				 * gcc doesn't prefix local symbols
				 * in debug mode, so this is not needed.
				 */
				break;
			}
			if (strcmp(arg, "-W0,-Lt") == 0) {
				/*
				 * Generate tests at the top of loops.
				 * There is no direct gcc equivalent, ignore.
				 */
				break;
			}
			if (strcmp(arg, "-W0,-xdbggen=no%usedonly") == 0) {
				newae(ctx->i_ae,
				    "-fno-eliminate-unused-debug-symbols");
				newae(ctx->i_ae,
				    "-fno-eliminate-unused-debug-types");
				break;
			}
			if (strcmp(arg, "-W2,-Rcond_elim") == 0) {
				/*
				 * Elimination and expansion of conditionals;
				 * gcc has no direct equivalent.
				 */
				break;
			}
			if (strcmp(arg, "-Wd,-xsafe=unboundsym") == 0) {
				/*
				 * Prevents optimizing away checks for
				 * unbound weak symbol addresses.  gcc does
				 * not do this, so it's not needed.
				 */
				break;
			}
			if (strncmp(arg, "-Wc,-xcode=", 11) == 0) {
				xlate(ctx->i_ae, arg + 11, xcode_tbl);
				if (strncmp(arg + 11, "pic", 3) == 0)
					pic = 1;
				break;
			}
			if (strncmp(arg, "-Wc,-Qiselect", 13) == 0) {
				/*
				 * Prevents insertion of register symbols.
				 * gcc doesn't do this, so ignore it.
				 */
				break;
			}
#if defined(__x86)
			if (strcmp(arg, "-Wu,-no_got_reloc") == 0) {
				newae(ctx->i_ae, "-fno-jump-tables");
				newae(ctx->i_ae, "-fno-constant-pools");
				break;
			}
			if (strcmp(arg, "-Wu,-xmodel=kernel") == 0) {
				newae(ctx->i_ae, "-ffreestanding");
				newae(ctx->i_ae, "-mno-red-zone");
				model = "-mcmodel=kernel";
				nolibc = 1;
				break;
			}
			if (strcmp(arg, "-Wu,-save_args") == 0) {
				newae(ctx->i_ae, "-msave-args");
				break;
			}
#endif	/* __x86 */
			error(arg);
			break;
		case 'X':
			if (strcmp(arg, "-Xa") == 0 ||
			    strcmp(arg, "-Xt") == 0) {
				Xamode(ctx->i_ae);
				break;
			}
			if (strcmp(arg, "-Xc") == 0) {
				Xcmode(ctx->i_ae);
				break;
			}
			if (strcmp(arg, "-Xs") == 0) {
				Xsmode(ctx->i_ae);
				break;
			}
			error(arg);
			break;
		case 'x':
			if (arglen == 1)
				error(arg);
			switch (arg[2]) {
#if defined(__x86)
			case '3':
				if (strcmp(arg, "-x386") == 0) {
					newae(ctx->i_ae, "-march=i386");
					break;
				}
				error(arg);
				break;
			case '4':
				if (strcmp(arg, "-x486") == 0) {
					newae(ctx->i_ae, "-march=i486");
					break;
				}
				error(arg);
				break;
#endif	/* __x86 */
			case 'a':
				if (strncmp(arg, "-xarch=", 7) == 0) {
					xlate(ctx->i_ae, arg + 7, xarch_tbl);
					break;
				}
				error(arg);
				break;
			case 'b':
				if (strncmp(arg, "-xbuiltin=", 10) == 0) {
					if (strcmp(arg + 10, "%all"))
						newae(ctx->i_ae, "-fbuiltin");
					break;
				}
				error(arg);
				break;
			case 'C':
				/* Accept C++ style comments -- ignore */
				if (strcmp(arg, "-xCC") == 0)
					break;
				error(arg);
				break;
			case 'c':
				if (strncmp(arg, "-xc99=%all", 10) == 0) {
					newae(ctx->i_ae, "-std=gnu99");
					break;
				}
				if (strncmp(arg, "-xc99=%none", 11) == 0) {
					newae(ctx->i_ae, "-std=gnu89");
					break;
				}
				if (strncmp(arg, "-xchip=", 7) == 0) {
					xlate(ctx->i_ae, arg + 7, xchip_tbl);
					break;
				}
				if (strncmp(arg, "-xcode=", 7) == 0) {
					xlate(ctx->i_ae, arg + 7, xcode_tbl);
					if (strncmp(arg + 7, "pic", 3) == 0)
						pic = 1;
					break;
				}
				if (strncmp(arg, "-xcache=", 8) == 0)
					break;
				if (strncmp(arg, "-xcrossfile", 11) == 0)
					break;
				error(arg);
				break;
			case 'd':
				if (strcmp(arg, "-xdepend") == 0)
					break;
				if (strncmp(arg, "-xdebugformat=", 14) == 0)
					break;
				error(arg);
				break;
			case 'F':
				/* compile for mapfile reordering -- ignore */
				if (strcmp(arg, "-xF") == 0)
					break;
				error(arg);
				break;
			case 'i':
				if (strncmp(arg, "-xinline", 8) == 0)
					/* No inlining; ignore */
					break;
				if (strcmp(arg, "-xildon") == 0 ||
				    strcmp(arg, "-xildoff") == 0)
					/* No incremental linking; ignore */
					break;
				error(arg);
				break;
			case 'M':
				if (strcmp(arg, "-xM") == 0) {
					newae(ctx->i_ae, "-M");
					break;
				}
				if (strcmp(arg, "-xM1") == 0) {
					newae(ctx->i_ae, "-MM");
					break;
				}
				error(arg);
				break;
			case 'n':
				if (strcmp(arg, "-xnolib") == 0) {
					nolibc = 1;
					break;
				}
				error(arg);
				break;
			case 'O':
				if (strncmp(arg, "-xO", 3) == 0) {
					size_t len = strlen(arg);
					char *s;
					int c = *(arg + 3);
					int level;

					if (len != 4 || !isdigit(c))
						error(arg);

					if ((s = malloc(len)) == NULL)
						nomem();

					level = atoi(arg + 3);
					if (level > 5)
						error(arg);
					if (level >= 2) {
						/*
						 * For gcc-3.4.x at -O2 we
						 * need to disable optimizations
						 * that break ON.
						 */
						optim_disable(ctx->i_ae, level);
						/*
						 * limit -xO3 to -O2 as well.
						 */
						level = 2;
					}
					(void) snprintf(s, len, "-O%d", level);
					newae(ctx->i_ae, s);
					free(s);
					break;
				}
				error(arg);
				break;
			case 'p':
				if (strcmp(arg, "-xpentium") == 0) {
					newae(ctx->i_ae, "-march=pentium");
					break;
				}
				if (strcmp(arg, "-xpg") == 0) {
					newae(ctx->i_ae, "-pg");
					break;
				}
				error(arg);
				break;
			case 'r':
				if (strncmp(arg, "-xregs=", 7) == 0) {
					xlate(ctx->i_ae, arg + 7, xregs_tbl);
					break;
				}
				error(arg);
				break;
			case 's':
				if (strcmp(arg, "-xs") == 0 ||
				    strcmp(arg, "-xspace") == 0 ||
				    strcmp(arg, "-xstrconst") == 0)
					break;
				error(arg);
				break;
			case 't':
				if (strcmp(arg, "-xtransition") == 0) {
					newae(ctx->i_ae, "-Wtransition");
					break;
				}
				if (strcmp(arg, "-xtrigraphs=yes") == 0) {
					newae(ctx->i_ae, "-trigraphs");
					break;
				}
				if (strcmp(arg, "-xtrigraphs=no") == 0) {
					newae(ctx->i_ae, "-notrigraphs");
					break;
				}
				if (strncmp(arg, "-xtarget=", 9) == 0) {
					xlate(ctx->i_ae, arg + 9, xtarget_tbl);
					break;
				}
				error(arg);
				break;
			case 'e':
			case 'h':
			case 'l':
			default:
				error(arg);
				break;
			}
			break;
		case 'Y':
			if (arglen == 1) {
				if ((arg = *++ctx->i_oldargv) == NULL ||
				    *arg == '\0')
					error("-Y");
				ctx->i_oldargc--;
				arglen = strlen(arg + 1);
			} else {
				arg += 2;
			}
			/* Just ignore -YS,... for now */
			if (strncmp(arg, "S,", 2) == 0)
				break;
			if (strncmp(arg, "l,", 2) == 0) {
				char *s = strdup(arg);
				s[0] = '-';
				s[1] = 'B';
				newae(ctx->i_ae, s);
				free(s);
				break;
			}
			if (strncmp(arg, "I,", 2) == 0) {
				char *s = strdup(arg);
				s[0] = '-';
				s[1] = 'I';
				newae(ctx->i_ae, "-nostdinc");
				newae(ctx->i_ae, s);
				free(s);
				break;
			}
			error(arg);
			break;
		case 'Q':
			/*
			 * We could map -Qy into -Wl,-Qy etc.
			 */
		default:
			error(arg);
			break;
		}
	}

	if (c_files > 1 && (ctx->i_flags & CW_F_SHADOW) &&
	    op != CW_O_PREPROCESS) {
		(void) fprintf(stderr, "%s: error: multiple source files are "
		    "allowed only with -E or -P\n", progname);
		exit(2);
	}
	if (op == CW_O_LINK && (ctx->i_flags & CW_F_SHADOW))
		exit(0);

	if (model && !pic)
		newae(ctx->i_ae, model);
	if (!nolibc)
		newae(ctx->i_ae, "-lc");
	if (!seen_o && (ctx->i_flags & CW_F_SHADOW)) {
		newae(ctx->i_ae, "-o");
		newae(ctx->i_ae, ctx->i_discard);
	}
}

static void
do_cc(cw_ictx_t *ctx)
{
	int in_output = 0, seen_o = 0;
	cw_op_t op = CW_O_LINK;

	if (ctx->i_flags & CW_F_PROG) {
		newae(ctx->i_ae, "-V");
		return;
	}

	while (--ctx->i_oldargc > 0) {
		char *arg = *++ctx->i_oldargv;

		if (*arg != '-') {
			if (in_output == 0 || !(ctx->i_flags & CW_F_SHADOW)) {
				newae(ctx->i_ae, arg);
			} else {
				in_output = 0;
				newae(ctx->i_ae, ctx->i_discard);
			}
			continue;
		}
		switch (*(arg + 1)) {
		case '_':
			if (strcmp(arg, "-_noecho") == 0) {
				ctx->i_flags &= ~CW_F_ECHO;
			} else if (strncmp(arg, "-_cc=", 5) == 0 ||
			    strncmp(arg, "-_CC=", 5) == 0) {
				newae(ctx->i_ae, arg + 5);
			} else if (strncmp(arg, "-_gcc=", 6) != 0 &&
			    strncmp(arg, "-_g++=", 6) != 0) {
				(void) fprintf(stderr,
				    "%s: invalid argument '%s'\n", progname,
				    arg);
				exit(2);
			}
			break;
		case 'V':
			ctx->i_flags &= ~CW_F_ECHO;
			newae(ctx->i_ae, arg);
			break;
		case 'o':
			seen_o = 1;
			if (strlen(arg) == 2) {
				in_output = 1;
				newae(ctx->i_ae, arg);
			} else if (ctx->i_flags & CW_F_SHADOW) {
				newae(ctx->i_ae, "-o");
				newae(ctx->i_ae, ctx->i_discard);
			} else {
				newae(ctx->i_ae, arg);
			}
			break;
		case 'c':
		case 'S':
			op = CW_O_COMPILE;
			newae(ctx->i_ae, arg);
			break;
		case 'E':
		case 'P':
			op = CW_O_PREPROCESS;
		/*FALLTHROUGH*/
		default:
			newae(ctx->i_ae, arg);
		}
	}

	if ((op == CW_O_LINK || op == CW_O_PREPROCESS) &&
	    (ctx->i_flags & CW_F_SHADOW))
		exit(0);

	if (!seen_o && (ctx->i_flags & CW_F_SHADOW)) {
		newae(ctx->i_ae, "-o");
		newae(ctx->i_ae, ctx->i_discard);
	}
}

static void
prepctx(cw_ictx_t *ctx)
{
	const char *dir, *cmd;
	char *program;
	size_t len;

	dir = dirs[CIDX(CC(ctx), ctx->i_flags)];
	cmd = cmds[CIDX(CC(ctx), ctx->i_flags)];
	len = strlen(dir) + strlen(cmd) + 2;
	if ((program = malloc(len)) == NULL)
		nomem();
	(void) snprintf(program, len, "%s/%s", dir, cmd);

	newae(ctx->i_ae, program);

	if (ctx->i_flags & CW_F_PROG) {
		(void) printf("%s: %s\n", (ctx->i_flags & CW_F_SHADOW) ?
		    "shadow" : "primary", program);
		(void) fflush(stdout);
	}

	if (!(ctx->i_flags & CW_F_XLATE))
		return;

	switch (CC(ctx)) {
	case CW_C_CC:
		do_cc(ctx);
		break;
	case CW_C_GCC:
		do_gcc(ctx);
		break;
	}
}

static int
invoke(cw_ictx_t *ctx)
{
	char **newargv;
	int ac;
	struct ae *a;

	if ((newargv = calloc(sizeof (*newargv), ctx->i_ae->ael_argc + 1)) ==
	    NULL)
		nomem();

	if (ctx->i_flags & CW_F_ECHO)
		(void) fprintf(stderr, "+ ");

	for (ac = 0, a = ctx->i_ae->ael_head; a; a = a->ae_next, ac++) {
		newargv[ac] = a->ae_arg;
		if (ctx->i_flags & CW_F_ECHO)
			(void) fprintf(stderr, "%s ", a->ae_arg);
		if (a == ctx->i_ae->ael_tail)
			break;
	}

	if (ctx->i_flags & CW_F_ECHO) {
		(void) fprintf(stderr, "\n");
		(void) fflush(stderr);
	}

	if (!(ctx->i_flags & CW_F_EXEC))
		return (0);

	/*
	 * We must fix up the environment here so that the
	 * dependency files are not trampled by the shadow compiler.
	 */
	if ((ctx->i_flags & CW_F_SHADOW) &&
	    (unsetenv("SUNPRO_DEPENDENCIES") != 0 ||
	    unsetenv("DEPENDENCIES_OUTPUT") != 0)) {
		(void) fprintf(stderr, "error: environment setup failed: %s\n",
		    strerror(errno));
		return (-1);
	}

	(void) execv(newargv[0], newargv);
	cw_perror("couldn't run %s", newargv[0]);

	return (-1);
}

static int
reap(cw_ictx_t *ctx)
{
	int status, ret = 0;
	char buf[1024];
	struct stat s;

	do {
		(void) waitpid(ctx->i_pid, &status, 0);
		if (status != 0) {
			if (WIFSIGNALED(status)) {
				ret = -WTERMSIG(status);
				break;
			} else if (WIFEXITED(status)) {
				ret = WEXITSTATUS(status);
				break;
			}
		}
	} while (!WIFEXITED(status) && !WIFSIGNALED(status));

	(void) unlink(ctx->i_discard);

	if (stat(ctx->i_stderr, &s) < 0) {
		cw_perror("stat failed on child cleanup");
		return (-1);
	}
	if (s.st_size != 0) {
		FILE *f;

		if ((f = fopen(ctx->i_stderr, "r")) != NULL) {
			while (fgets(buf, sizeof (buf), f))
				(void) fprintf(stderr, "%s", buf);
			(void) fflush(stderr);
			(void) fclose(f);
		}
	}
	(void) unlink(ctx->i_stderr);
	free(ctx->i_stderr);

	/*
	 * cc returns an error code when given -V; we want that to succeed.
	 */
	if (ctx->i_flags & CW_F_PROG)
		return (0);

	return (ret);
}

static int
exec_ctx(cw_ictx_t *ctx, int block)
{
	char *file;

	/*
	 * To avoid offending cc's sensibilities, the name of its output
	 * file must end in '.o'.
	 */
	if ((file = tempnam(NULL, ".cw")) == NULL) {
		nomem();
		return (-1);
	}
	(void) strlcpy(ctx->i_discard, file, MAXPATHLEN);
	(void) strlcat(ctx->i_discard, ".o", MAXPATHLEN);
	free(file);

	if ((ctx->i_stderr = tempnam(NULL, ".cw")) == NULL) {
		nomem();
		return (-1);
	}

	if ((ctx->i_pid = fork()) == 0) {
		int fd;

		(void) fclose(stderr);
		if ((fd = open(ctx->i_stderr, O_WRONLY | O_CREAT | O_EXCL,
		    0666)) < 0) {
			cw_perror("open failed for standard error");
			exit(1);
		}
		if (dup2(fd, 2) < 0) {
			cw_perror("dup2 failed for standard error");
			exit(1);
		}
		if (fd != 2)
			(void) close(fd);
		if (freopen("/dev/fd/2", "w", stderr) == NULL) {
			cw_perror("freopen failed for /dev/fd/2");
			exit(1);
		}
		prepctx(ctx);
		exit(invoke(ctx));
	}

	if (ctx->i_pid < 0) {
		cw_perror("fork failed");
		return (1);
	}

	if (block)
		return (reap(ctx));

	return (0);
}

int
main(int argc, char **argv)
{
	cw_ictx_t *ctx = newictx();
	cw_ictx_t *ctx_shadow = newictx();
	const char *dir;
	char cc_buf[MAXPATHLEN], gcc_buf[MAXPATHLEN];
	int do_serial, do_shadow;
	int ret = 0;

	if ((progname = strrchr(argv[0], '/')) == NULL)
		progname = argv[0];
	else
		progname++;

	if (ctx == NULL || ctx_shadow == NULL)
		nomem();

	ctx->i_flags = CW_F_ECHO|CW_F_XLATE;

	/*
	 * Figure out where to get our tools from.  This depends on
	 * the environment variables set at run time.
	 */
	if ((dir = getenv("SPRO_VROOT")) != NULL) {
		(void) snprintf(cc_buf, MAXPATHLEN, "%s/bin", dir);
	} else if ((dir = getenv("SPRO_ROOT")) != NULL) {
		(void) snprintf(cc_buf, MAXPATHLEN, "%s/SOS10/bin", dir);
	} else if ((dir = getenv("BUILD_TOOLS")) != NULL) {
		(void) snprintf(cc_buf, MAXPATHLEN,
		    "%s/SUNWspro/SOS10/bin", dir);
	}
	if (dir != NULL) {
		dirs[CIDX(CW_C_CC, 0)] = (const char *)cc_buf;
		dirs[CIDX(CW_C_CC, CW_F_CXX)] = (const char *)cc_buf;
	}

	if ((dir = getenv("GNU_ROOT")) != NULL) {
		(void) snprintf(gcc_buf, MAXPATHLEN, "%s/bin", dir);
		dirs[CIDX(CW_C_GCC, 0)] = (const char *)gcc_buf;
		dirs[CIDX(CW_C_GCC, CW_F_CXX)] = (const char *)gcc_buf;
	}

	if ((dir = getenv("CW_CC_DIR")) != NULL)
		dirs[CIDX(CW_C_CC, 0)] = dir;
	if ((dir = getenv("CW_CPLUSPLUS_DIR")) != NULL)
		dirs[CIDX(CW_C_CC, CW_F_CXX)] = dir;
	if ((dir = getenv("CW_GCC_DIR")) != NULL)
		dirs[CIDX(CW_C_GCC, 0)] = dir;
	if ((dir = getenv("CW_GPLUSPLUS_DIR")) != NULL)
		dirs[CIDX(CW_C_GCC, CW_F_CXX)] = dir;

	do_shadow = (getenv("CW_NO_SHADOW") ? 0 : 1);
	do_serial = (getenv("CW_SHADOW_SERIAL") ? 1 : 0);

	if (getenv("CW_NO_EXEC") == NULL)
		ctx->i_flags |= CW_F_EXEC;

	/*
	 * The first argument must be one of "-_cc", "-_gcc", "-_CC", or "-_g++"
	 */
	if (argc == 1)
		usage();
	argc--;
	argv++;
	if (strcmp(argv[0], "-_cc") == 0) {
		ctx->i_compiler = CW_C_CC;
	} else if (strcmp(argv[0], "-_gcc") == 0) {
		ctx->i_compiler = CW_C_GCC;
	} else if (strcmp(argv[0], "-_CC") == 0) {
		ctx->i_compiler = CW_C_CC;
		ctx->i_flags |= CW_F_CXX;
	} else if (strcmp(argv[0], "-_g++") == 0) {
		ctx->i_compiler = CW_C_GCC;
		ctx->i_flags |= CW_F_CXX;
	} else {
		/* assume "-_gcc" by default */
		argc++;
		argv--;
		ctx->i_compiler = CW_C_GCC;
	}

	/*
	 * -_compiler - tell us the path to the primary compiler only
	 */
	if (argc > 1 && strcmp(argv[1], "-_compiler") == 0) {
		ctx->i_flags &= ~CW_F_XLATE;
		prepctx(ctx);
		(void) printf("%s\n", ctx->i_ae->ael_head->ae_arg);
		return (0);
	}

	/*
	 * -_versions - tell us the cw version, paths to all compilers, and
	 *		ask each for its version if we know how.
	 */
	if (argc > 1 && strcmp(argv[1], "-_versions") == 0) {
		(void) printf("%s", "cw version %I%");
		if (!do_shadow)
			(void) printf(" (SHADOW MODE DISABLED)");
		(void) printf("\n");
		(void) fflush(stdout);
		ctx->i_flags &= ~CW_F_ECHO;
		ctx->i_flags |= CW_F_PROG|CW_F_EXEC;
		argc--;
		argv++;
		do_serial = 1;
	}

	ctx->i_oldargc = argc;
	ctx->i_oldargv = argv;

	ret |= exec_ctx(ctx, do_serial);

	if (do_shadow) {
		(void) memcpy(ctx_shadow, ctx, sizeof (cw_ictx_t));
		ctx_shadow->i_flags |= CW_F_SHADOW;
		ret |= exec_ctx(ctx_shadow, 1);
	}

	if (!do_serial)
		ret |= reap(ctx);

	return (ret);
}