Module search revamp for pkg managers

The search path listed in an import directive can now be an array.  The
top-level search path is appended.  Null and empty strings in the path
terminate any search.  The "." in "." and "./*" is replaced with the
directory containing the file doing the import (for command-line
programs this is the current directory, though that may be a bad idea).

No version numbers or anything of the sort are gratuitously added to the
search paths.

All this makes external package managers possible by allowing
dependencies to be installed local to dependents.

1 files changed, 24 insertions, 4 deletions

diff --git a/main.c b/main.c
index 1c9b7fe2..a43f8156 100644
--- a/main.c
+++ b/main.c
@@ -10,6 +10,7 @@
 #include "jv.h"
 #include "jq.h"
 #include "jv_alloc.h"
+#include "util.h"
 #include "version.h"
 
 int jq_testsuite(int argc, char* argv[]);
@@ -210,7 +211,7 @@ int main(int argc, char* argv[]) {
   int jq_flags = 0;
   size_t short_opts = 0;
   jv program_arguments = jv_array();
-  jv lib_search_paths = jv_array();
+  jv lib_search_paths = jv_null();
   for (int i=1; i<argc; i++, short_opts = 0) {
     if (further_args_are_files) {
       input_filenames[ninput_files++] = argv[i];
@@ -225,6 +226,8 @@ int main(int argc, char* argv[]) {
       }
     } else {
       if (argv[i][1] == 'L') {
+        if (jv_get_kind(lib_search_paths) == JV_KIND_NULL)
+          lib_search_paths = jv_array();
         if (argv[i][2] != 0) { // -Lname (faster check than strlen)
             lib_search_paths = jv_array_append(lib_search_paths, jv_string(argv[i]+2));
         } else if (i >= argc - 1) {
@@ -376,7 +379,8 @@ int main(int argc, char* argv[]) {
   }
 
   char *penv = getenv("JQ_LIBRARY_PATH");
-  if (penv) {
+  if (penv && jv_get_kind(lib_search_paths) == JV_KIND_NULL) {
+    // Use $JQ_LIBRARY_PATH
 #ifdef WIN32
 #define PATH_ENV_SEPARATOR ";"
 #else
@@ -384,15 +388,22 @@ int main(int argc, char* argv[]) {
 #endif
     lib_search_paths = jv_array_concat(lib_search_paths,jv_string_split(jv_string(penv),jv_string(PATH_ENV_SEPARATOR)));
 #undef PATH_ENV_SEPARATOR
+  } else if (jv_get_kind(lib_search_paths) == JV_KIND_NULL) {
+    // Use compiled-in default JQ_LIBRARY_PATH
+#ifdef WIN32
+    lib_search_paths = JV_ARRAY(jv_string("~/.jq"), jv_string("$ORIGIN/lib"));
+#else
+    lib_search_paths = JV_ARRAY(jv_string("~/.jq"), jv_string("$ORIGIN/../lib/jq"));
+#endif
   }
-  jq_set_attr(jq, jv_string("LIB_DIRS"), lib_search_paths);
+  jq_set_attr(jq, jv_string("JQ_LIBRARY_PATH"), lib_search_paths);
 
   char *origin = strdup(argv[0]);
   if (origin == NULL) {
     fprintf(stderr, "Error: out of memory\n");
     exit(1);
   }
-  jq_set_attr(jq, jv_string("ORIGIN"), jv_string(dirname(origin)));
+  jq_set_attr(jq, jv_string("JQ_ORIGIN"), jv_string(dirname(origin)));
   free(origin);
 
   if (strchr(JQ_VERSION, '-') == NULL)
@@ -436,6 +447,12 @@ int main(int argc, char* argv[]) {
   }
   
   if (options & FROM_FILE) {
+    char *program_origin = strdup(program);
+    if (program_origin == NULL) {
+      perror("malloc");
+      exit(2);
+    }
+
     jv data = jv_load_file(program, 1);
     if (!jv_is_valid(data)) {
       data = jv_invalid_get_msg(data);
@@ -444,9 +461,12 @@ int main(int argc, char* argv[]) {
       ret = 2;
       goto out;
     }
+    jq_set_attr(jq, jv_string("PROGRAM_ORIGIN"), jq_realpath(jv_string(dirname(program_origin))));
     compiled = jq_compile_args(jq, jv_string_value(data), program_arguments);
+    free(program_origin);
     jv_free(data);
   } else {
+    jq_set_attr(jq, jv_string("PROGRAM_ORIGIN"), jq_realpath(jv_string("."))); // XXX is this good?
     compiled = jq_compile_args(jq, program, program_arguments);
   }
   if (!compiled){