Fix importing from "../../" (#526)

runtests.sh

@@ -202,10 +202,13 @@ function run_test()
     # jou flags start with space when non-empty
     command="$command$jou_flags"
 
-    if [[ "$joufile" =~ ^examples/aoc ]]; then
+    if [[ "$joufile" =~ ^examples/aoc ]] || [[ $joufile == *double_dotdot_import* ]]; then
         # AoC files use fopen("sampleinput.txt", "r").
         # We don't do this for all files, because I like relative paths in error messages.
         # jou_flags starts with a space whenever it isn't empty.
+        #
+        # Also, double_dotdot_import test had a bug that was reproducible only with
+        # relative path.
         command="cd $(dirname $joufile) && $command $(basename $joufile)"
     else
         command="$command $joufile"
@@ -236,7 +239,7 @@ function run_test()
 counter=0
 skipped=0
 
-for joufile in examples/*.jou examples/aoc*/day*/part*.jou tests/*/*.jou; do
+for joufile in examples/*.jou examples/aoc*/day*/part*.jou tests/*/*.jou tests/should_succeed/double_dotdot_import/*/*.jou; do
     if ! [[ $joufile == *"$file_filter"* ]]; then
         # Skip silently, without showing that this is skipped.
         # This produces less noisy output when you select only a few tests.

src/util.c

@@ -35,6 +35,39 @@ void trim_whitespace(char *s)
     delete_slice(s, start);
 }
 
+/*
+In paths, "foo/../" is usually unnecessary, because it goes to a folder "foo" and then
+immediately back up. However, it makes a difference in a few cases:
+
+1. folder "foo" doesn't exist
+2. folder "foo" is a symlink to a different place
+3. we are actually looking at "../../" (so "foo" is "..")
+
+Special cases 1 and 2 are not relevant in the Jou compiler, but special case 3 is relevant
+when importing from "../../file.jou" (bad style, but should work).
+
+This function deletes one unnecessary "foo/../", and may be called recursively to delete
+all of them.
+*/
+static bool simplify_dotdot_once(char *path)
+{
+    assert(!strstr(path, "\\"));  // should be already taken care of when calling this
+
+    for (char *p = strstr(path, "/../"); p != NULL; p = strstr(p+1, "/../")) {
+        char *end = p+4;
+        char *start = p;
+        while (start > path && start[-1] != '/')
+            start--;
+
+        if (strncmp(start, "../", 3)) {
+            delete_slice(start, end);
+            return true;
+        }
+    }
+
+    return false;
+}
+
 void simplify_path(char *path)
 {
 #ifdef _WIN32
@@ -52,12 +85,7 @@ void simplify_path(char *path)
         delete_slice(p, p+2);
 
     // Delete unnecessary ".." components.
-    while ((p = strstr(path, "/../"))) {
-        char *delstart = p;
-        while (delstart > path && delstart[-1] != '/')
-            delstart--;
-        delete_slice(delstart, p+4);
-    }
+    while (simplify_dotdot_once(path)) {}
 }
 
 

tests/should_succeed/deep_import.jou

@@ -0,0 +1,5 @@
+import "./imported/level1/level2/deep.jou"
+
+def main() -> int:
+    do_deep_stuff()  # Output: Deep stuff... Bar Bar 123 456
+    return 0

tests/should_succeed/double_dotdot_import/more_nesting/double_dotdot_import.jou

@@ -0,0 +1,9 @@
+# This file tests "../../" imports, which were previously broken.
+
+import "stdlib/io.jou"
+import "../../imported/bar.jou"
+
+def main() -> int:
+    printf("It runs\n")  # Output: It runs
+    bar(Point{x = 123, y = 456})  # Output: Bar Bar 123 456
+    return 0

tests/should_succeed/imported/level1/level2/deep.jou

@@ -0,0 +1,8 @@
+# This file tests "../../" imports, which were previously broken.
+
+import "stdlib/io.jou"
+import "../../bar.jou"
+
+def do_deep_stuff() -> None:
+    printf("Deep stuff... ")
+    bar(Point{x = 123, y = 456})