imrsh: Properly handle errors v1 PROPOSED

Sebastian: 1
 Properly handle errors

 4 files changed, 46 insertions(+), 8 deletions(-)

[PATCH imrsh] Properly handle errors Export this patch

1. `assert` is no longer used to check that a function succeeded. A new
   function, `err`, is used instead to exit when a fatal error is
   encountered.
2. Calls to `calloc` are replaced by calls to `xcalloc`, which checks
   that the allocation succeeded.

Signed-off-by: Sebastian <sebastian@sebsite.pw>
---
 include/imrsh.h   |  8 ++++++++
 src/history.c     |  5 +++--
 src/interactive.c | 17 +++++++++++++----
 src/main.c        | 24 ++++++++++++++++++++++--
 4 files changed, 46 insertions(+), 8 deletions(-)
 create mode 100644 include/imrsh.h

diff --git a/include/imrsh.h b/include/imrsh.h
new file mode 100644
index 0000000..1e9d4a4
--- /dev/null
+++ b/include/imrsh.h
@@ -0,0 +1,8 @@
+#ifndef _IMRSH_H
+#define _IMRSH_H
+#include <stddef.h>
+
+void err(const char *s);
+void *xcalloc(size_t n, size_t s);
+
+#endif
diff --git a/src/history.c b/src/history.c
index 16c024e..cb151da 100644
--- a/src/history.c
+++ b/src/history.c
@@ -8,6 +8,7 @@
 #include <sys/stat.h>
 #include <wordexp.h>
 #include "history.h"
+#include "imrsh.h"
 
 static void
 posix_dirname(char *path, char *dname)
@@ -87,7 +88,7 @@ imrsh_history_load(struct imrsh_history *history)
 			}
 		}
 		size_t l = strlen(line);
-		tail = calloc(1, sizeof(struct imrsh_history_entry));
+		tail = xcalloc(1, sizeof(struct imrsh_history_entry));
 		tail->cmd = strdup(line);
 		if (tail->cmd[l - 1] == '\n') {
 			tail->cmd[l - 1] = '\0';
@@ -123,7 +124,7 @@ imrsh_history_append(struct imrsh_history *history, const char *cmd)
 		return;
 	}
 	struct imrsh_history_entry *next =
-		calloc(1, sizeof(struct imrsh_history_entry));
+		xcalloc(1, sizeof(struct imrsh_history_entry));
 	next->cmd = strdup(cmd);
 	if (history->tail) {
 		history->tail->next = next;
diff --git a/src/interactive.c b/src/interactive.c
index 0643f29..d615825 100644
--- a/src/interactive.c
+++ b/src/interactive.c
@@ -5,6 +5,7 @@
 #include <string.h>
 #include <tickit.h>
 #include <unistd.h>
+#include "imrsh.h"
 #include "interactive.h"
 #include "history.h"
 
@@ -12,7 +13,9 @@ static char *
 buffer_insert(struct mrsh_buffer *buf, int at, size_t n)
 {
 	char *b = mrsh_buffer_add(buf, n);
-	assert(b);
+	if (!b) {
+		err("mrsh_buffer_add");
+	}
 	memmove(&buf->data[at + n], &buf->data[at], buf->len - at + n);
 	return &buf->data[at];
 }
@@ -221,7 +224,9 @@ imrsh_set_cmd(struct imrsh_interactive *imrsh, const char *cmd)
 	if (imrsh->read_buffer->len < l + 1) {
 		char *_ = mrsh_buffer_add(imrsh->read_buffer,
 				l + 1 - imrsh->read_buffer->len);
-		assert(_);
+		if (!_) {
+			err("mrsh_buffer_add");
+		}
 	}
 	int diff = (int)_l - (int)l;
 	strcpy(imrsh->read_buffer->data, cmd);
@@ -350,11 +355,15 @@ void
 interactive_init(struct imrsh_interactive *imrsh)
 {
 	imrsh->tt = tickit_term_new();
-	assert(imrsh->tt);
+	if (!imrsh->tt) {
+		err("tickit_term_new");
+	}
 	imrsh->pens._default = tickit_pen_new_attrs(
 			TICKIT_PEN_FG, -1, TICKIT_PEN_BG, -1, 0);
+	if (!imrsh->pens._default) {
+		err("tickit_pen_new_attrs");
+	}
 	imrsh->pens.typeahead = tickit_pen_new_attrs(TICKIT_PEN_FG, 240, 0);
-	assert(imrsh->pens._default);
 
 	tickit_term_set_input_fd(imrsh->tt, STDIN_FILENO);
 	tickit_term_set_output_fd(imrsh->tt, STDOUT_FILENO);
diff --git a/src/main.c b/src/main.c
index f1d627a..fcfce66 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,4 +1,3 @@
-#include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <mrsh/ast.h>
@@ -7,14 +6,33 @@
 #include <mrsh/entry.h>
 #include <mrsh/parser.h>
 #include <mrsh/shell.h>
+#include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
 #include <unistd.h>
+#include "imrsh.h"
 #include "history.h"
 #include "interactive.h"
 
 extern char **environ;
 
+void
+err(const char *s)
+{
+	perror(s);
+	exit(EXIT_FAILURE);
+}
+
+void *
+xcalloc(size_t n, size_t s)
+{
+	void *p = calloc(n, s);
+	if (!p) {
+		err("calloc");
+	}
+	return p;
+}
+
 static int
 noninteractive_init(struct mrsh_init_args *init_args,
 		struct mrsh_parser **parser)
@@ -44,7 +62,9 @@ int
 main(int argc, char *argv[])
 {
 	struct mrsh_state *state = mrsh_state_create();
-	assert(state);
+	if (!state) {
+		err("mrsh_state_create");
+	}
 	struct imrsh_history history = { 0 };
 	struct mrsh_buffer read_buffer = { 0 };
 	struct imrsh_interactive istate = {
-- 
2.34.1