a68: handle Darwin's #1/NN archive members

In Darwin archives use an extension to encode the member names
off-header, in the first bytes of the contents.  The name in the
header proper is then #1/NN... where NN... is an ascii-encoded number
in decimal with the length of the name, which is encoded right after
the header as part of the contents.

This patch fixes the Algol 68 module importing from archives in Darwin
by acknowledging this extension.  Note that, for the moment, we don't
bother to fetch the actual member name.  This can lead to poor
diagnostics, so we probably will fix that at some point.

Signed-off-by: Jose E. Marchesi <jemarch@gnu.org>
gcc/algol68/ChangeLog

	* a68-imports-archive.cc (Archive_file): Handle Darwin #1/NN
	archive members.

diff --git a/gcc/algol68/a68-imports-archive.cc b/gcc/algol68/a68-imports-archive.cc
index ab8982268220bc4da8c229063b5d6654c9799948..e6951a3f2eca2962ff82a928f7c7be4367f3f76d 100644 (file)
--- a/gcc/algol68/a68-imports-archive.cc
+++ b/gcc/algol68/a68-imports-archive.cc
@@ -138,7 +138,8 @@ class Archive_file
 {
  public:
   Archive_file(const std::string& filename, int fd, location_t location)
-    : filename_(filename), fd_(fd), filesize_(-1), first_member_offset_(0),
+    : filename_(filename), fd_(fd), offset_to_member_contents_(0),
+    filesize_(-1), first_member_offset_(0),
       extended_names_(), is_thin_archive_(false), is_big_archive_(false),
       location_(location), nested_archives_()
   { }
@@ -197,7 +198,8 @@ class Archive_file
   // *NESTED_OFF to the offset in a nested archive.
   bool
   interpret_header(const Archive_header* hdr, off_t off,
-                  std::string* pname, off_t* size, off_t* nested_off) const;
+                  std::string* pname, off_t* size,
+                  off_t* nested_off, off_t* offset_to_contents) const;
 
   // Get the file and offset for an archive member.
   bool
@@ -232,6 +234,9 @@ class Archive_file
   std::string filename_;
   // The file descriptor.
   int fd_;
+  // Offset to the archive contents, to accommodate some Darwin
+  // extensions.
+  off_t offset_to_member_contents_;
   // The file size;
   off_t filesize_;
   // The first member offset;
@@ -518,8 +523,11 @@ Archive_file::read_archive_header(off_t off, std::string* pname, off_t* size,
                   this->filename_.c_str(), static_cast<long>(off));
     }
   off_t local_nested_off;
-  if (!this->interpret_header(&hdr, off, pname, size, &local_nested_off))
+  off_t offset_to_contents;
+  if (!this->interpret_header(&hdr, off, pname, size, &local_nested_off,
+                             &offset_to_contents))
     return false;
+  this->offset_to_member_contents_ = offset_to_contents;
   if (nested_off != NULL)
     *nested_off = local_nested_off;
 
@@ -541,8 +549,10 @@ Archive_file::read_archive_header(off_t off, std::string* pname, off_t* size,
 
 bool
 Archive_file::interpret_header(const Archive_header* hdr, off_t off,
-                              std::string* pname, off_t* size,
-                              off_t* nested_off) const
+                              std::string* pname,
+                              off_t* size,
+                              off_t* nested_off,
+                              off_t* offset_to_contents) const
 {
   if (memcmp(hdr->ar_fmag, arfmag, sizeof arfmag) != 0)
     {
@@ -560,8 +570,28 @@ Archive_file::interpret_header(const Archive_header* hdr, off_t off,
     }
   *size = local_size;
 
+  *offset_to_contents = 0;
   *nested_off = 0;
-  if (hdr->ar_name[0] != '/')
+  if (hdr->ar_name[0] == '#'
+          && hdr->ar_name[1] == '1'
+          && hdr->ar_name[2] == '/')
+    {
+      // This is an entry with a long name in Darwin, which gets actually
+      // stored in the first bytes of the archive member contents. For now,
+      // don't bother to decode the name, but we need to annotate the offset to
+      // the actual contents.
+      *pname = "#1";
+      char *end;
+      long y = strtol (hdr->ar_name + 3, &end, 10);
+      if (*end != ' ' || y < 0 || (y == LONG_MAX && errno == ERANGE))
+       {
+         a68_error (NO_NODE, "%s: bad Darwin extended name size at %lu",
+                    this->filename_.c_str(), static_cast<unsigned long>(off));
+         return false;
+       }
+      *offset_to_contents = y;
+    }
+  else if (hdr->ar_name[0] != '/')
     {
       const char* name_end = strchr(hdr->ar_name, '/');
       if (name_end == NULL
@@ -648,7 +678,7 @@ Archive_file::get_file_and_offset(off_t off, const std::string& hdrname,
   else if (!this->is_thin_archive_)
     {
       *memfd = this->fd_;
-      *memoff = off + sizeof(Archive_header);
+      *memoff = off + sizeof(Archive_header) + this->offset_to_member_contents_;
       *memname = this->filename_ + '(' + hdrname + ')';
       return true;
     }