Debuginfo for ecj branch

[Andrew Haley <aph at redhat dot com>]

This (mostly) fixes the problem where we lose full pathnames when
compiling with ecj.

Per Bothner's suggestion was to teach ecj to emit SourceDebugExtension
as defined in JSR-45 and to teach gcj to read it.  I haven't followed
that suggestion here, partly because I want to be able to use an
unmodified ecj.  I intend to revisit JSR-45 at some later date.

Instead, this patch causes gcj to pass the same list of sourcefiles
that it passed to ecj to jc1, as an additional command line option.
There are some advantages to this approach.  In particular, if we have
source files we can generate accurate debuginfo when compiling from
.class to .o; we don't need to do recompilation from source to
bytecode with a special compiler.

Andrew.


2006-07-07  Andrew Haley  <aph@redhat.com>

	* java-tree.h (java_read_sourcefilenames): Declare.
	* lang.c (java_handle_option): Call java_read_sourcefilenames().
	* lang.opt (fsource-filename): New opt.
	* lang-specs.h: Add -fsource-filename.
	* jcf-parse.c (num_files, filenames): New variables.
	(reverse, cmpstringp, java_read_sourcefilenames,
	find_sourcefile): New.
	(set_source_filename): Call find_sourcefile to find the real name
	of a source file.

Index: lang-specs.h
===================================================================
--- lang-specs.h	(revision 115149)
+++ lang-specs.h	(working copy)
@@ -47,7 +47,7 @@
       %{!findirect-dispatch:-fzip-dependency=%U.zip}			\
       %{!fsyntax-only:-fzip-target=%U.jar}}\n				\
     %{.class|.zip|.jar|!fsyntax-only:jc1				\
-      %{.java|fsaw-java-file:%U.jar %<ffilelist-file}			\
+      %{.java|fsaw-java-file:%U.jar -fsource-filename=%i %<ffilelist-file} \
       %{.class|.zip|.jar|ffilelist-file|fcompile-resource*:%i}		\
       %(jc1) %(cc1_options) %{I*} %{!findirect-dispatch:-I%U.zip}	\
       %(invoke_as)}",
Index: jcf-parse.c
===================================================================
--- jcf-parse.c	(revision 115149)
+++ jcf-parse.c	(working copy)
@@ -89,6 +89,11 @@
 /* The Java archive that provides main_class;  the main input file. */
 static GTY(()) struct JCF * main_jcf;
 
+/* The number of source files passd to us by -fsource-filename and an
+   array of pointers to each name.  Used by find_sourcefile().  */
+static int num_files = 0;
+static char **filenames;
+
 static struct ZipFile *localToFile;
 
 /* Declarations of some functions used here.  */
@@ -124,6 +129,181 @@
     }
 }
 
+
+
+/* Reverse a string.  */
+static char *
+reverse (const char *s)
+{
+  if (s == NULL)
+    return NULL;
+  else
+    {
+      int len = strlen (s);
+      char *d = xmalloc (len + 1);
+      const char *sp;
+      char *dp;
+      
+      d[len] = 0;
+      for (dp = &d[0], sp = &s[len-1]; sp >= s; dp++, sp--)
+	*dp = *sp;
+
+      return d;
+    }
+}
+
+/* Compare two strings for qsort().  */
+static int
+cmpstringp (const void *p1, const void *p2)
+{
+  /* The arguments to this function are "pointers to
+     pointers to char", but strcmp() arguments are "pointers
+     to char", hence the following cast plus dereference */
+
+  return strcmp(*(char **) p1, *(char **) p2);
+}
+
+/* Create an array of strings, one for each source file that we've
+   seen.  fsource_filename can either be the name of a single .java
+   file or a file that contains a list of filenames separated by
+   newlines.  */
+void 
+java_read_sourcefilenames (const char *fsource_filename)
+{
+  if (fsource_filename 
+      && filenames == 0
+      && strlen (fsource_filename) > strlen (".java")
+      && strcmp ((fsource_filename 
+		  + strlen (fsource_filename)
+		  - strlen (".java")),
+		 ".java") != 0)
+    {
+      // fsource_filename isn't a .java file but a list of filenames
+      // separated by newlines
+      FILE *finput = fopen (fsource_filename, "r");
+      int len = 0;
+      int longest_line = 0;
+
+      gcc_assert (finput);
+
+      /* Find out how many files there are, and how long the filenames are.  */
+      while (! feof (finput))
+	{
+	  int ch = getc (finput);
+	  if (ch == '\n')
+	    {
+	      num_files++;
+	      if (len > longest_line)
+		longest_line = len;
+	      len = 0;
+	      continue;
+	    }
+	  if (ch == EOF)
+	    break;
+	  len++;
+	}
+
+      rewind (finput);
+
+      /* Read the filenames.  Put a pointer to each filename into the
+	 array FILENAMES.  */
+      {
+	char *linebuf = alloca (longest_line + 1);
+	int i = 0;
+	int charpos;
+
+	filenames = xmalloc (num_files * sizeof (char*));
+
+	charpos = 0;
+	for (;;)
+	  {
+	    int ch = getc (finput);
+	    if (ch == EOF)
+	      break;
+	    if (ch == '\n')
+	      {
+		linebuf[charpos] = 0;
+		gcc_assert (i < num_files);		
+		/* ???  Perhaps we should use lrealpath() here.  Doing
+		   so would tidy up things like /../ but the rest of
+		   gcc seems to assume relative pathnames, not
+		   absolute pathnames.  */
+/* 		realname = lrealpath (linebuf); */
+		filenames[i++] = reverse (linebuf);
+		charpos = 0;
+		continue;
+	      }
+	    gcc_assert (charpos < longest_line);
+	    linebuf[charpos++] = ch;
+	  }
+
+	if (num_files > 1)
+	  qsort (filenames, num_files, sizeof (char *), cmpstringp);
+      }
+      fclose (finput);
+    }
+  else
+    {
+      filenames = xmalloc (sizeof (char*));      
+      filenames[0] = reverse (fsource_filename);
+      num_files = 1;
+    }
+}
+
+/* Given a relative pathname such as foo/bar.java, attempt to find a
+   longer pathname with the same suffix.  
+
+   This is a best guess heuristic; with some weird class hierarcies we
+   may fail to pick the correct source file.  For example, if we have
+   the filenames foo/bar.java and also foo/foo/bar.java, we do not
+   have enough information to know which one is the right match for
+   foo/bar.java.  */
+
+static const char *
+find_sourcefile (const char *name)
+{
+  int i = 0, j = num_files-1;
+  char *found = NULL;
+  
+  if (filenames)
+    {
+      char *revname = reverse (name);
+
+      do
+	{
+	  int k = (i+j) / 2;
+	  int cmp = strncmp (revname, filenames[k], strlen (revname));
+	  if (cmp == 0)
+	    {
+	      /*  OK, so we found one.  But is it a unique match?  */
+	      if ((k > i
+		   && strncmp (revname, filenames[k-1], strlen (revname)) == 0)
+		  || (k < j
+		      && (strncmp (revname, filenames[k+1], strlen (revname)) 
+			  == 0)))
+		;
+	      else
+		found = filenames[k];
+	      break;
+	    }
+	  if (cmp > 0)
+	    i = k+1;
+	  else
+	    j = k-1;
+	}
+      while (i <= j);
+
+      free (revname);
+    }
+
+  if (found && strlen (found) > strlen (name))
+    return reverse (found);
+  else
+    return name;
+}
+
+
+
 /* Handle "SourceFile" attribute. */
 
 static void
@@ -144,6 +324,10 @@
 	      || old_filename[old_len - new_len - 1] == '\\'))
 	{
 #ifndef USE_MAPPED_LOCATION
+	  if (CLASS_FROM_CURRENTLY_COMPILED_P (current_class))
+	    // if we're generating code for this class, try to find
+	    // its full pathname
+	    input_filename = find_sourcefile (input_filename);
 	  DECL_SOURCE_LOCATION (TYPE_NAME (current_class)) = input_location;
 	  file_start_location = input_location;
 #endif
@@ -177,6 +361,10 @@
 	}
     }
       
+  if (CLASS_FROM_CURRENTLY_COMPILED_P (current_class))
+    // if we're generating code for this class, try to find its full
+    // pathname
+    sfname = find_sourcefile (sfname);
 #ifdef USE_MAPPED_LOCATION
   line_table.maps[line_table.used-1].to_file = sfname;
 #else
Index: lang.opt
===================================================================
--- lang.opt	(revision 115149)
+++ lang.opt	(working copy)
@@ -134,6 +134,9 @@
 Java Joined RejectNegative
 --extdirs=<path>	Set the extension directory path
 
+fsource-filename=
+Java Joined Undocumented 
+
 ffilelist-file
 Java Var(flag_filelist_file)
 Input file is a file with a list of filenames to compile
Index: lang.c
===================================================================
--- lang.c	(revision 115149)
+++ lang.c	(working copy)
@@ -343,6 +343,10 @@
       v_flag = 1;
       break;
       
+    case OPT_fsource_filename_:
+      java_read_sourcefilenames (arg);
+      break;
+      
     default:
       if (cl_options[code].flags & CL_Java)
 	break;
Index: java-tree.h
===================================================================
--- java-tree.h	(revision 115149)
+++ java-tree.h	(working copy)
@@ -1405,6 +1405,9 @@
 extern tree builtin_function (const char *, tree, int, enum built_in_class,
 			      const char *, tree);
 
+extern void java_read_sourcefilenames (const char *fsource_filename);
+
+
 #define DECL_FINAL(DECL) DECL_LANG_FLAG_3 (DECL)
 
 /* Access flags etc for a method (a FUNCTION_DECL): */