svn commit: r345593 - head/contrib/elftoolchain/libdwarf

[Mark Johnston]

Author: markj
Date: Wed Mar 27 19:32:21 2019
New Revision: 345593
URL: https://svnweb.freebsd.org/changeset/base/345593

Log:
  Prepend DW_AT_comp_dir to relative line number directory table entries.
  
  Relative directories may appear in the line number program for a CPU if
  files were included via a relative path, for instance with "-I.".
  Previously, dwarf_srclines(3) and dwarf_srcfiles(3) would return the
  relative path, so addr2line, for instance, would do the same.  However,
  we can get an absolute path by prepending the compilation directory, so
  change libdwarf to do that to improve compatibility with GNU binutils
  and since it is more useful in general.
  
  Reviewed by:	jhb
  Discussed with:	emaste
  MFC after:	2 weeks
  Sponsored by:	The FreeBSD Foundation
  Differential Revision:	https://reviews.freebsd.org/D19705

Modified:
  head/contrib/elftoolchain/libdwarf/libdwarf_lineno.c

Modified: head/contrib/elftoolchain/libdwarf/libdwarf_lineno.c
==============================================================================
--- head/contrib/elftoolchain/libdwarf/libdwarf_lineno.c	Wed Mar 27 19:24:37 2019	(r345592)
+++ head/contrib/elftoolchain/libdwarf/libdwarf_lineno.c	Wed Mar 27 19:32:21 2019	(r345593)
@@ -33,9 +33,10 @@ _dwarf_lineno_add_file(Dwarf_LineInfo li, uint8_t **p,
     Dwarf_Error *error, Dwarf_Debug dbg)
 {
 	Dwarf_LineFile lf;
-	const char *dirname;
+	FILE *filepath;
+	const char *incdir;
 	uint8_t *src;
-	int slen;
+	size_t slen;
 
 	src = *p;
 
@@ -54,20 +55,33 @@ _dwarf_lineno_add_file(Dwarf_LineInfo li, uint8_t **p,
 		return (DW_DLE_DIR_INDEX_BAD);
 	}
 
-	/* Make full pathname if need. */
+	/* Make a full pathname if needed. */
 	if (*lf->lf_fname != '/') {
-		dirname = compdir;
+		filepath = open_memstream(&lf->lf_fullpath, &slen);
+		if (filepath == NULL) {
+			free(lf);
+			DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
+			return (DW_DLE_MEMORY);
+		}
+
 		if (lf->lf_dirndx > 0)
-			dirname = li->li_incdirs[lf->lf_dirndx - 1];
-		if (dirname != NULL) {
-			slen = strlen(dirname) + strlen(lf->lf_fname) + 2;
-			if ((lf->lf_fullpath = malloc(slen)) == NULL) {
-				free(lf);
-				DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
-				return (DW_DLE_MEMORY);
-			}
-			snprintf(lf->lf_fullpath, slen, "%s/%s", dirname,
-			    lf->lf_fname);
+			incdir = li->li_incdirs[lf->lf_dirndx - 1];
+		else
+			incdir = NULL;
+
+		/*
+		 * Prepend the compilation directory if the directory table
+		 * entry is relative.
+		 */
+		if (incdir == NULL || *incdir != '/')
+			fprintf(filepath, "%s/", compdir);
+		if (incdir != NULL)
+			fprintf(filepath, "%s/", incdir);
+		fprintf(filepath, "%s", lf->lf_fname);
+		if (fclose(filepath) != 0) {
+			free(lf);
+			DWARF_SET_ERROR(dbg, error, DW_DLE_MEMORY);
+			return (DW_DLE_MEMORY);
 		}
 	}