From 528799aa1ab548dc649befeb9fa81f0d83f14a50 Mon Sep 17 00:00:00 2001
From: midipix <writeonce@midipix.org>
Date: Mar 10 2016 13:32:39 +0000
Subject: slbt_get_exec_ctx(), slbt_free_exec_ctx(): initial implementation.


---

diff --git a/include/slibtool/slibtool.h b/include/slibtool/slibtool.h
index 312c7cd..97f3b49 100644
--- a/include/slibtool/slibtool.h
+++ b/include/slibtool/slibtool.h
@@ -2,7 +2,9 @@
 #define SOFORT_H
 
 #include <stdint.h>
+#include <stddef.h>
 #include <stdio.h>
+#include <unistd.h>
 
 #include "slibtool_api.h"
 
@@ -76,6 +78,14 @@ struct slbt_input {
 	size_t	size;
 };
 
+struct slbt_exec_ctx {
+	char *	program;
+	char **	argv;
+	char **	envp;
+	pid_t	pid;
+	int	exitcode;
+};
+
 struct slbt_common_ctx {
 	uint64_t			drvflags;
 	uint64_t			actflags;
@@ -115,6 +125,9 @@ slbt_api void slbt_free_driver_ctx	(struct slbt_driver_ctx *);
 slbt_api int  slbt_get_unit_ctx		(const struct slbt_driver_ctx *, const char * path, struct slbt_unit_ctx **);
 slbt_api void slbt_free_unit_ctx	(struct slbt_unit_ctx *);
 
+slbt_api int  slbt_get_exec_ctx		(const struct slbt_driver_ctx *, struct slbt_exec_ctx **);
+slbt_api void slbt_free_exec_ctx	(struct slbt_exec_ctx *);
+
 slbt_api int  slbt_map_input		(int fd, const char * path, int prot, struct slbt_input *);
 slbt_api int  slbt_unmap_input		(struct slbt_input *);
 
diff --git a/project/common.mk b/project/common.mk
index 45a3d8f..0dcdcd6 100644
--- a/project/common.mk
+++ b/project/common.mk
@@ -1,6 +1,7 @@
 COMMON_SRCS = \
 	src/driver/slbt_driver_ctx.c \
 	src/driver/slbt_unit_ctx.c \
+	src/logic/slbt_exec_ctx.c \
 	src/logic/slbt_map_input.c \
 	src/skin/slbt_skin_default.c \
 
diff --git a/src/logic/slbt_exec_ctx.c b/src/logic/slbt_exec_ctx.c
new file mode 100644
index 0000000..87d8412
--- /dev/null
+++ b/src/logic/slbt_exec_ctx.c
@@ -0,0 +1,164 @@
+/*******************************************************************/
+/*  slibtool: a skinny libtool implementation, written in C        */
+/*  Copyright (C) 2016  Z. Gilboa                                  */
+/*  Released under the Standard MIT License; see COPYING.SLIBTOOL. */
+/*******************************************************************/
+
+#include <stdint.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <slibtool/slibtool.h>
+
+#define SLBT_ARGV_SPARE_PTRS	16
+
+struct slbt_exec_ctx_impl {
+	int			argc;
+	char *			args;
+	struct slbt_exec_ctx	ctx;
+	char *			buffer[];
+};
+
+
+static size_t slbt_parse_comma_separated_flags(
+	const char *	str,
+	int *		argc)
+{
+	const char * ch;
+
+	for (ch=str; *ch; ch++)
+		if (*ch == ',')
+			(*argc)++;
+
+	return ch - str;
+}
+
+
+static struct slbt_exec_ctx_impl * slbt_exec_ctx_alloc(
+	const struct slbt_driver_ctx *	dctx)
+{
+	struct slbt_exec_ctx_impl *	ictx;
+	size_t				size;
+	int				argc;
+	char *				args;
+	char **				parg;
+
+	size = argc = 0;
+
+	/* buffer size (cargv, -Wc) */
+	for (parg=dctx->cctx->cargv; *parg; parg++, argc++)
+		if (!(strncmp("-Wc,",*parg,4)))
+			size += sizeof('\0') + slbt_parse_comma_separated_flags(
+					parg[4],&argc);
+		else
+			size += sizeof('\0') + strlen(*parg);
+
+	/* alloc */
+	if (!(args = malloc(size + strlen(".libs/")
+				 + strlen(".lo")
+				 + strlen(dctx->cctx->output))))
+		return 0;
+
+	size = sizeof(*ictx) + (argc+SLBT_ARGV_SPARE_PTRS)*sizeof(char *);
+
+	if (!(ictx = calloc(1,size))) {
+		free(args);
+		return 0;
+	}
+
+	ictx->args = args;
+	ictx->argc = argc;
+
+	return ictx;
+}
+
+
+int  slbt_get_exec_ctx(
+	const struct slbt_driver_ctx *	dctx,
+	struct slbt_exec_ctx **		ectx)
+{
+	struct slbt_exec_ctx_impl *	ictx;
+	char **				parg;
+	char *				ch;
+	char *				slash;
+	int				i;
+
+	/* alloc */
+	if (!(ictx = slbt_exec_ctx_alloc(dctx)))
+		return -1;
+
+	/* init with guard for later .lo check */
+	ch                = ictx->args + strlen(".lo");
+	ictx->ctx.argv    = ictx->buffer;
+
+	/* <compiler> */
+	ictx->ctx.program = dctx->cctx->cargv[0];
+
+	/* cargv, -Wc */
+	for (i=0, parg=dctx->cctx->cargv; *parg; parg++, ch++) {
+		if (!(strncmp("-Wc,",*parg,4))) {
+			strcpy(ch,parg[4]);
+			ictx->ctx.argv[i++] = ch;
+
+			for (; *ch; ch++)
+				if (*ch == ',') {
+					*ch = '\0';
+					ictx->ctx.argv[i++] = ch+1;
+				}
+		} else {
+			ictx->ctx.argv[i++] = ch;
+			ch += sprintf(ch,"%s",*parg);
+		}
+	}
+
+	if (dctx->cctx->mode == SLBT_MODE_COMPILE) {
+		if (dctx->cctx->drvflags & SLBT_DRIVER_SHARED) {
+			ictx->ctx.argv[i++] = "-DPIC";
+			ictx->ctx.argv[i++] = "-fPIC";
+		}
+
+		ictx->ctx.argv[i++] = "-c";
+		ictx->ctx.argv[i++] = "-o";
+		ictx->ctx.argv[i++] = ch;
+
+		if ((slash = strrchr(dctx->cctx->output,'/'))) {
+			sprintf(ch,"%s",dctx->cctx->output);
+			ch += slash - dctx->cctx->output;
+			ch += sprintf(ch,"/.libs%s",slash);
+		} else
+			ch += sprintf(ch,".libs/%s",dctx->cctx->output);
+
+		if ((ch[-3] == '.') && (ch[-2] == 'l') && (ch[-1] == 'o')) {
+			ch[-2] = 'o';
+			ch[-1] = '\0';
+			ch--;
+		}
+	}
+
+	*ectx = &ictx->ctx;
+	return 0;
+}
+
+
+static int slbt_free_exec_ctx_impl(
+	struct slbt_exec_ctx_impl *	ictx,
+	int				status)
+{
+	free(ictx->args);
+	free (ictx);
+	return status;
+}
+
+
+void slbt_free_exec_ctx(struct slbt_exec_ctx * ctx)
+{
+	struct slbt_exec_ctx_impl *	ictx;
+	uintptr_t			addr;
+
+	if (ctx) {
+		addr = (uintptr_t)ctx - offsetof(struct slbt_exec_ctx_impl,ctx);
+		ictx = (struct slbt_exec_ctx_impl *)addr;
+		slbt_free_exec_ctx_impl(ictx,0);
+	}
+}