slbt_archive_import(): refactor in anticipation of in-memory archive merging.

1 files changed, 163 insertions, 0 deletions

diff --git a/src/fallback/slbt_archive_import_mri.c b/src/fallback/slbt_archive_import_mri.c
new file mode 100644
index 0000000..fb880c2
--- /dev/null
+++ b/src/fallback/slbt_archive_import_mri.c
@@ -0,0 +1,163 @@
+/*******************************************************************/
+/*  slibtool: a skinny libtool implementation, written in C        */
+/*  Copyright (C) 2016--2021  SysDeer Technologies, LLC            */
+/*  Released under the Standard MIT License; see COPYING.SLIBTOOL. */
+/*******************************************************************/
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <limits.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <sys/wait.h>
+
+#include <slibtool/slibtool.h>
+#include "slibtool_driver_impl.h"
+#include "slibtool_spawn_impl.h"
+#include "slibtool_dprintf_impl.h"
+#include "slibtool_symlink_impl.h"
+#include "slibtool_readlink_impl.h"
+#include "slibtool_errinfo_impl.h"
+
+static char * slbt_mri_argument(
+	int	fdat,
+	char *	arg,
+	char *	buf)
+{
+	int	i;
+	char *	lnk;
+	char *	target;
+	char 	mricwd[PATH_MAX];
+	char 	dstbuf[PATH_MAX];
+
+	if ((!(strchr(arg,'+'))) && (!(strchr(arg,'-'))))
+		return arg;
+
+	if (arg[0] == '/')
+		target = arg;
+	else {
+		if (slbt_realpath(fdat,".",O_DIRECTORY,mricwd,sizeof(mricwd)))
+			return 0;
+
+		if ((size_t)snprintf(dstbuf,sizeof(dstbuf),"%s/%s",
+				mricwd,arg) >= sizeof(dstbuf))
+			return 0;
+
+		target = dstbuf;
+	}
+
+	for (i=0,lnk=0; i<1024 && !lnk; i++) {
+		if (!(tmpnam(buf)))
+			return 0;
+
+		if (!(symlinkat(target,fdat,buf)))
+			lnk = buf;
+	}
+
+	return lnk;
+}
+
+static void slbt_archive_import_child(
+	char *	program,
+	int	fd[2])
+{
+	char *	argv[3];
+
+	argv[0] = program;
+	argv[1] = "-M";
+	argv[2] = 0;
+
+	close(fd[1]);
+
+	if (dup2(fd[0],0) == 0)
+		execvp(program,argv);
+
+	_exit(EXIT_FAILURE);
+}
+
+int slbt_archive_import_mri(
+	const struct slbt_driver_ctx *	dctx,
+	struct slbt_exec_ctx *		ectx,
+	char *				dstarchive,
+	char *				srcarchive)
+{
+	int	fdcwd;
+	pid_t	pid;
+	pid_t	rpid;
+	int	fd[2];
+	char *	dst;
+	char *	src;
+	char *	fmt;
+	char	mridst [L_tmpnam];
+	char	mrisrc [L_tmpnam];
+	char	program[PATH_MAX];
+
+	/* fdcwd */
+	fdcwd = slbt_driver_fdcwd(dctx);
+
+	/* not needed? */
+	if (slbt_symlink_is_a_placeholder(fdcwd,srcarchive))
+		return 0;
+
+	/* program */
+	if ((size_t)snprintf(program,sizeof(program),
+				"%s",
+				dctx->cctx->host.ar)
+			>= sizeof(program))
+		return SLBT_BUFFER_ERROR(dctx);
+
+	/* fork */
+	if (pipe(fd))
+		return SLBT_SYSTEM_ERROR(dctx,0);
+
+	if ((pid = fork()) < 0) {
+		close(fd[0]);
+		close(fd[1]);
+		return SLBT_SYSTEM_ERROR(dctx,0);
+	}
+
+	/* child */
+	if (pid == 0)
+		slbt_archive_import_child(
+			program,
+			fd);
+
+	/* parent */
+	close(fd[0]);
+
+	ectx->pid = pid;
+
+	dst = slbt_mri_argument(fdcwd,dstarchive,mridst);
+	src = slbt_mri_argument(fdcwd,srcarchive,mrisrc);
+
+	if (!dst || !src)
+		return SLBT_SYSTEM_ERROR(dctx,0);
+
+	fmt = "OPEN %s\n"
+	      "ADDLIB %s\n"
+	      "SAVE\n"
+	      "END\n";
+
+	if (slbt_dprintf(fd[1],fmt,dst,src) < 0) {
+		close(fd[1]);
+		return SLBT_SYSTEM_ERROR(dctx,0);
+	}
+
+	close(fd[1]);
+
+	rpid = waitpid(
+		pid,
+		&ectx->exitcode,
+		0);
+
+	if (dst == mridst)
+		unlinkat(fdcwd,dst,0);
+
+	if (src == mrisrc)
+		unlinkat(fdcwd,src,0);
+
+	return (rpid == pid) && (ectx->exitcode == 0)
+		? 0 : SLBT_CUSTOM_ERROR(dctx,SLBT_ERR_ARCHIVE_IMPORT);
+}