Signed-off-by: Max Schillinger <max@mxsr.de>
---
Currently, error locations are printed relative to dependencies' root
directories. This can't be processed easily automatically (p.e. by vim's
:make). Also see
<https://lists.sr.ht/~sircmpwn/hare-users/%3CCWQ9IWWELP77.2TIL8M24VF5F5%40mxsr.de%3E>.

 include/util.h |  2 ++
 src/main.c     | 11 ++---------
 src/util.c     | 44 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 48 insertions(+), 9 deletions(-)

diff --git a/include/util.h b/include/util.h
index 42127c4..b29cc3e 100644
--- a/include/util.h
+++ b/include/util.h
@@ -28,6 +28,8 @@ char *xstrdup(const char *s);
 
 char *gen_name(int *id, const char *fmt);
 
+const char *relpath(const char *dir);
+
 void errline(struct location loc);
 
 #endif
diff --git a/src/main.c b/src/main.c
index 313e462..62d2667 100644
--- a/src/main.c
+++ b/src/main.c
@@ -70,7 +70,6 @@ main(int argc, char *argv[])
 {
 	const char *output = NULL, *typedefs = NULL;
 	const char *target = DEFAULT_TARGET;
-	const char *modpath = NULL;
 	const char *mainsym = "main";
 	bool is_test = false;
 	struct unit unit = {0};
@@ -91,7 +90,6 @@ main(int argc, char *argv[])
 			usage(argv[0]);
 			return EXIT_SUCCESS;
 		case 'M':
-			modpath = optarg;
 			break;
 		case 'm':
 			mainsym = optarg;
@@ -144,13 +142,8 @@ main(int argc, char *argv[])
 	memcpy((char **)sources + 1, argv + optind, sizeof(char **) * nsources);
 	sources[0] = "<unknown>";
 
-	if (modpath) {
-		size_t modlen = strlen(modpath);
-		for (size_t i = 1; i <= nsources; i++) {
-			if (strncmp(sources[i], modpath, modlen) == 0) {
-				sources[i] += modlen;
-			}
-		}
+	for (size_t i = 1; i <= nsources; i++) {
+		sources[i] = relpath(sources[i]);
 	}
 
 	for (size_t i = 0; i < nsources; ++i) {
diff --git a/src/util.c b/src/util.c
index c3691bb..fd62264 100644
--- a/src/util.c
+++ b/src/util.c
@@ -1,3 +1,4 @@
+#include <limits.h>
 #include <sys/stat.h>
 #include <stdarg.h>
 #include <stdbool.h>
@@ -113,6 +114,49 @@ gen_name(int *id, const char *fmt)
 	return str;
 }
 
+const char *
+relpath(const char *dir)
+{
+	if (dir[0] != '/') {
+		return dir;
+	}
+	char cwd[PATH_MAX];
+	if (getcwd(cwd, sizeof(cwd)) == NULL) {
+		return dir;
+	}
+	size_t cwdlen = strlen(cwd);
+	if (strncmp(dir, cwd, cwdlen) == 0) {
+		return dir + cwdlen + 1;
+	}
+	int common_prefix = -1;
+	for (int i = 0; dir[i] != '\0' && dir[i] == cwd[i]; i++) {
+		if (dir[i] == '/') {
+			common_prefix = i;
+		}
+	}
+	if (common_prefix == -1) {
+		return dir;
+	}
+	int dirs_up = 1;
+	for (int i = common_prefix + 1; cwd[i] != '\0'; i++) {
+		if (cwd[i] == '/') {
+			dirs_up++;
+		}
+	}
+	const char *unique_part = dir + common_prefix + 1;
+	char dir_up[] = "../";
+	size_t l_dir_up = strlen(dir_up);
+	size_t l_reldir = dirs_up * l_dir_up + strlen(unique_part) + 1;
+	char *reldir = xcalloc(1, l_reldir);
+	int i = 0;
+	for (int d = 0; d < dirs_up; d++) {
+		strcpy(reldir + i, dir_up);
+		i += l_dir_up;
+	}
+	strcpy(reldir + i, unique_part);
+	return reldir;
+}
+
 void
 errline(struct location loc)
 {
-- 
2.43.0

harec/patches: SUCCESS in 58s

[Print paths relative to cwd on errors][0] from [Max Schillinger][1]

[0]: https://lists.sr.ht/~sircmpwn/hare-dev/patches/47004
[1]: max@mxsr.de

✓ #1100918 SUCCESS harec/patches/freebsd.yml https://builds.sr.ht/~sircmpwn/job/1100918
✓ #1100919 SUCCESS harec/patches/netbsd.yml  https://builds.sr.ht/~sircmpwn/job/1100919
✓ #1100917 SUCCESS harec/patches/alpine.yml  https://builds.sr.ht/~sircmpwn/job/1100917

comments inline

On Sat, Nov 25, 2023 at 08:10:59PM +0100, Max Schillinger wrote:
> Signed-off-by: Max Schillinger <max@mxsr.de>
> ---
> Currently, error locations are printed relative to dependencies' root
> directories. This can't be processed easily automatically (p.e. by vim's
> :make). Also see
> <https://lists.sr.ht/~sircmpwn/hare-users/%3CCWQ9IWWELP77.2TIL8M24VF5F5%40mxsr.de%3E>.
> 
>  include/util.h |  2 ++
>  src/main.c     | 11 ++---------
>  src/util.c     | 44 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 48 insertions(+), 9 deletions(-)
> 
> diff --git a/include/util.h b/include/util.h
> index 42127c4..b29cc3e 100644
> --- a/include/util.h
> +++ b/include/util.h
> @@ -28,6 +28,8 @@ char *xstrdup(const char *s);
>  
>  char *gen_name(int *id, const char *fmt);
>  
> +const char *relpath(const char *dir);
> +
>  void errline(struct location loc);
>  
>  #endif
> diff --git a/src/main.c b/src/main.c
> index 313e462..62d2667 100644
> --- a/src/main.c
> +++ b/src/main.c
> @@ -70,7 +70,6 @@ main(int argc, char *argv[])
>  {
>  	const char *output = NULL, *typedefs = NULL;
>  	const char *target = DEFAULT_TARGET;
> -	const char *modpath = NULL;
>  	const char *mainsym = "main";
>  	bool is_test = false;
>  	struct unit unit = {0};
> @@ -91,7 +90,6 @@ main(int argc, char *argv[])
>  			usage(argv[0]);
>  			return EXIT_SUCCESS;
>  		case 'M':
> -			modpath = optarg;
>  			break;
>  		case 'm':
>  			mainsym = optarg;
> @@ -144,13 +142,8 @@ main(int argc, char *argv[])
>  	memcpy((char **)sources + 1, argv + optind, sizeof(char **) * nsources);
>  	sources[0] = "<unknown>";
>  
> -	if (modpath) {
> -		size_t modlen = strlen(modpath);
> -		for (size_t i = 1; i <= nsources; i++) {
> -			if (strncmp(sources[i], modpath, modlen) == 0) {
> -				sources[i] += modlen;
> -			}
> -		}
> +	for (size_t i = 1; i <= nsources; i++) {
> +		sources[i] = relpath(sources[i]);
>  	}
>  
>  	for (size_t i = 0; i < nsources; ++i) {
> diff --git a/src/util.c b/src/util.c
> index c3691bb..fd62264 100644
> --- a/src/util.c
> +++ b/src/util.c
> @@ -1,3 +1,4 @@
> +#include <limits.h>
>  #include <sys/stat.h>
>  #include <stdarg.h>
>  #include <stdbool.h>
> @@ -113,6 +114,49 @@ gen_name(int *id, const char *fmt)
>  	return str;
>  }
>  
> +const char *
> +relpath(const char *dir)
> +{
> +	if (dir[0] != '/') {
> +		return dir;
> +	}
> +	char cwd[PATH_MAX];
> +	if (getcwd(cwd, sizeof(cwd)) == NULL) {
> +		return dir;
> +	}
> +	size_t cwdlen = strlen(cwd);
> +	if (strncmp(dir, cwd, cwdlen) == 0) {
> +		return dir + cwdlen + 1;

this is out of bounds if cwdlen == strlen(dir) (although this function
will never be called this way?)

> +	}
> +	int common_prefix = -1;
> +	for (int i = 0; dir[i] != '\0' && dir[i] == cwd[i]; i++) {
> +		if (dir[i] == '/') {
> +			common_prefix = i;
> +		}
> +	}
> +	if (common_prefix == -1) {
> +		return dir;
> +	}
> +	int dirs_up = 1;
> +	for (int i = common_prefix + 1; cwd[i] != '\0'; i++) {
> +		if (cwd[i] == '/') {
> +			dirs_up++;
> +		}
> +	}
> +	const char *unique_part = dir + common_prefix + 1;

note that unique_part might be '\0' here, again, just when this function
is called in a way that it wont be? (yet)

> +	char dir_up[] = "../";
> +	size_t l_dir_up = strlen(dir_up);
> +	size_t l_reldir = dirs_up * l_dir_up + strlen(unique_part) + 1;
> +	char *reldir = xcalloc(1, l_reldir);
> +	int i = 0;
> +	for (int d = 0; d < dirs_up; d++) {
> +		strcpy(reldir + i, dir_up);
> +		i += l_dir_up;
> +	}
> +	strcpy(reldir + i, unique_part);
> +	return reldir;
> +}
> +
>  void
>  errline(struct location loc)
>  {

True. Actually, the input variable is a file, not a directory. I'll 
rename it. This means, this case should indeed never happen. But I'll 
fix it anyway.

> note that unique_part might be '\0' here, again, just when this function
> is called in a way that it wont be? (yet)

Same as for your other comment: It shouldn't happen because the file 
name should have a length >= 1 but I'll fix it to be on the safe side.

@Lorenz: Thanks for your comments. I have fixed this in v2: 
<https://lists.sr.ht/~sircmpwn/hare-dev/patches/47009>