From aa888a29eb3d3fe682ec62d26ea47ea4627636a6 Mon Sep 17 00:00:00 2001
From: Bill Wendling <isanbard@gmail.com>
Date: Mon, 28 May 2012 10:09:01 +0000
Subject: [PATCH] Add support for the GCOV_PREFIX_STRIP env variable which
 tries to strip off the first 'n' directories from the filename.

llvm-svn: 157574
---
 compiler-rt/lib/profile/GCDAProfiling.c | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/compiler-rt/lib/profile/GCDAProfiling.c b/compiler-rt/lib/profile/GCDAProfiling.c
index 4d0c41b40c6c..300985ff45d1 100644
--- a/compiler-rt/lib/profile/GCDAProfiling.c
+++ b/compiler-rt/lib/profile/GCDAProfiling.c
@@ -67,20 +67,39 @@ static void write_string(const char *s) {
 }
 
 static char *mangle_filename(const char *orig_filename) {
-  /* TODO: handle GCOV_PREFIX_STRIP */
   char *filename = 0;
   int prefix_len = 0;
+  int prefix_strip = 0;
+  int level = 0;
+  const char *fname = orig_filename, *ptr = NULL;
   const char *prefix = getenv("GCOV_PREFIX");
+  const char *tmp = getenv("GCOV_PREFIX_STRIP");
 
-  if (!prefix || prefix[0] != '/') /* Ignore non-absolute paths */
+  if (!prefix)
     return strdup(orig_filename);
 
+  if (tmp) {
+    prefix_strip = atoi(tmp);
+
+    /* Negative GCOV_PREFIX_STRIP values are ignored */
+    if (prefix_strip < 0)
+      prefix_strip = 0;
+  }
+
   prefix_len = strlen(prefix);
   filename = malloc(prefix_len + 1 + strlen(orig_filename) + 1);
   strcpy(filename, prefix);
+
   if (prefix[prefix_len - 1] != '/')
     strcat(filename, "/");
-  strcat(filename, orig_filename);
+
+  for (ptr = fname + 1; *ptr != '\0' && level < prefix_strip; ++ptr) {
+    if (*ptr != '/') continue;
+    fname = ptr;
+    ++level;
+  }
+
+  strcat(filename, fname);
 
   return filename;
 }