libupkg: Split the upkg_export struct into public/private parts.

[upkg.git] / src / libupkg.c

diff --git a/src/libupkg.c b/src/libupkg.c
index 40b39136f4c3164f22732a73e33adba2b1fae65e..e861bcb7d08c405817ed85d31b19b2de3fab89e5 100644 (file)
--- a/src/libupkg.c
+++ b/src/libupkg.c
@@ -25,16 +25,28 @@
 
 #define MIN(a, b) ((a) < (b) ? (a) : (b))
 
+/*
+ * Print a message and execute some statement(s) if the expression evaluates
+ * to zero.  Intended to help verify that assumed constraints on the file
+ * format actually are not violated.
+ */
+#define format_assert(expr, body) do { \
+       if (!(expr)) { \
+               fprintf(stderr, "%s: %d: %s: format assertion failed: %s\n", \
+                               __FILE__, __LINE__, __func__, #expr); \
+               body; \
+       } \
+} while (0)
+
 struct upkg_name {
        unsigned long flags;
        char *name;
 };
 
-struct upkg_export {
-       const char *name;
+struct upkg_export_priv {
+       struct upkg_export pub;
 
        long package, class, super;
-       unsigned long flags;
        unsigned long size, offset;
 };
 
@@ -50,9 +62,9 @@ struct upkg_private {
 
        struct upkg_file *last_file;
 
-       struct upkg_name   *names;
-       struct upkg_export *exports;
-       struct upkg_import *imports;
+       struct upkg_name        *names;
+       struct upkg_export_priv *exports;
+       struct upkg_import      *imports;
 
        unsigned long name_offset, export_offset, import_offset;
        unsigned char guid[16];
@@ -271,7 +283,7 @@ static int pkg_init_exports(struct upkg *pkg)
                return -1;
 
        while (index < pkg->export_count) {
-               struct upkg_export *export = &pkg->priv->exports[index];
+               struct upkg_export_priv *export = &pkg->priv->exports[index];
                long tmp;
 
                /* Read some data into buffer. */
@@ -297,11 +309,11 @@ static int pkg_init_exports(struct upkg *pkg)
 
                rc = upkg_decode_index(&tmp, buf+len, nbuf-len);
                if (rc == 0 || tmp < 0 || tmp >= pkg->name_count) goto err;
-               export->name = pkg->priv->names[tmp].name;
+               export->pub.name = pkg->priv->names[tmp].name;
                len += rc;
 
                if (nbuf-len < 4) goto err;
-               export->flags = unpack_32_le(buf+len);
+               export->pub.flags = unpack_32_le(buf+len);
                len += 4;
 
                rc = upkg_decode_index(&tmp, buf+len, nbuf-len);
@@ -481,13 +493,17 @@ const char *upkg_get_name(struct upkg *pkg, unsigned long idx)
        return pkg->priv->names[idx].name;
 }
 
-long upkg_export_find(struct upkg *pkg, const char *name)
+long upkg_export_find(struct upkg *pkg, long parent, const char *name)
 {
-       /* This is wrong.
-        * Export names are not necessarily unique within a package. */
-       for (unsigned i = 0; i < pkg->export_count; i++) {
-               struct upkg_export *export = &pkg->priv->exports[i];
-               if (strcmp(export->name, name) == 0) {
+       /* This only makes sense if the assertion below is not violated. */
+       long package = parent < 0 ? 0 : parent + 1;
+
+       for (unsigned long i = 0; i < pkg->export_count; i++) {
+               struct upkg_export_priv *e = &pkg->priv->exports[i];
+
+               /* Assertion: an object's package is an export. */
+               format_assert(e->package >= 0, continue);
+               if (e->package == package && strcmp(e->pub.name, name) == 0) {
                        return i;
                }
        }
@@ -495,24 +511,17 @@ long upkg_export_find(struct upkg *pkg, const char *name)
        return -1;
 }
 
-unsigned long upkg_export_flags(struct upkg *pkg, unsigned long idx)
+const struct upkg_export *upkg_get_export(struct upkg *pkg, unsigned long idx)
 {
        if (idx < pkg->export_count)
-               return pkg->priv->exports[idx].flags;
-       return 0;
-}
-
-const char *upkg_export_name(struct upkg *pkg, unsigned long idx)
-{
-       if (idx < pkg->export_count)
-               return pkg->priv->exports[idx].name;
+               return &pkg->priv->exports[idx].pub;
        return NULL;
 }
 
 const char *upkg_export_class(struct upkg *pkg, unsigned long idx,
                               const char **package)
 {
-       struct upkg_export *export;
+       struct upkg_export_priv *export;
        struct upkg_import *iclass, *ipackage;
        unsigned long pkg_idx;
 
@@ -521,11 +530,8 @@ const char *upkg_export_class(struct upkg *pkg, unsigned long idx,
 
        export = &pkg->priv->exports[idx];
 
-       /* ASSUMPTION: class references are always imports */
-       if (export->class > 0) {
-               fprintf(stderr, "Assumption Violated: class not import\n");
-               return NULL;
-       }
+       /* Assumption: class references are always imports. */
+       format_assert(export->class <= 0, return NULL);
 
        /* Get the class. */
        if (export->class == 0) {
@@ -538,17 +544,12 @@ const char *upkg_export_class(struct upkg *pkg, unsigned long idx,
                return NULL;
        iclass = &pkg->priv->imports[pkg_idx];
 
-       /* ASSUMPTION: Class references are always Core.Class */
-       if (strcmp(iclass->class_name, "Class") || strcmp(iclass->class_package, "Core")) {
-               fprintf(stderr, "Assumption Violated: class not Core.Class\n");
-               return NULL;
-       }
+       /* Assumption: class references are always Core.Class. */
+       format_assert(!strcmp(iclass->class_package, "Core"), return NULL);
+       format_assert(!strcmp(iclass->class_name, "Class"), return NULL);
 
-       /* ASSUMPTION: Package references are always imports */
-       if (iclass->package >= 0) {
-               fprintf(stderr, "Assumption Violated: package not import\n");
-               return NULL;
-       }
+       /* Assumption: package references are always imports. */
+       format_assert(iclass->package <= 0, return NULL);
 
        /* Get the package. */
        pkg_idx = -(iclass->package + 1);
@@ -556,11 +557,9 @@ const char *upkg_export_class(struct upkg *pkg, unsigned long idx,
                return NULL;
        ipackage = &pkg->priv->imports[pkg_idx];
 
-       /* ASSUMPTION: Package references are always Core.Package */
-       if (strcmp(ipackage->class_name, "Package") || strcmp(ipackage->class_package, "Core")) {
-               fprintf(stderr, "Assumption Violated: package not Core.Package\n");
-               return NULL;
-       }
+       /* Assumption: package references are always Core.Package. */
+       format_assert(!strcmp(ipackage->class_package, "Core"), return NULL);
+       format_assert(!strcmp(ipackage->class_name, "Package"), return NULL);
 
        if (package) *package = ipackage->object_name;
        return iclass->object_name;
@@ -581,7 +580,7 @@ struct upkg_file *upkg_export_open(struct upkg *pkg, unsigned long idx)
                .pkg  = pkg,
                .base = pkg->priv->exports[idx].offset,
                .len  = pkg->priv->exports[idx].size,
-               .name = pkg->priv->exports[idx].name,
+               .name = pkg->priv->exports[idx].pub.name,
        };
 
        return f;