From 01c284ecf81d34d027161e822ecde23f81fd9f48 Mon Sep 17 00:00:00 2001
From: Arnaud Giersch <arnaud.giersch@univ-fcomte.fr>
Date: Thu, 26 Oct 2017 10:25:12 +0200
Subject: [PATCH 1/1] Try to improve coverage for mrealloc.

---
 teshsuite/xbt/mmalloc/mmalloc_32.tesh  |  1 +
 teshsuite/xbt/mmalloc/mmalloc_64.tesh  |  1 +
 teshsuite/xbt/mmalloc/mmalloc_test.cpp | 24 ++++++++++++++++++++++++
 3 files changed, 26 insertions(+)

diff --git a/teshsuite/xbt/mmalloc/mmalloc_32.tesh b/teshsuite/xbt/mmalloc/mmalloc_32.tesh
index 449049d43b..e40a03f31b 100644
--- a/teshsuite/xbt/mmalloc/mmalloc_32.tesh
+++ b/teshsuite/xbt/mmalloc/mmalloc_32.tesh
@@ -106,4 +106,5 @@ $ ${bindir:=.}/mmalloc_test --log=root.fmt:%m%n
 > Re-allocate every second block
 > free all blocks (each one twice, to check that double free are correctly catched)
 > free again all blocks (to really check that double free are correctly catched)
+> Let's try different codepaths for mrealloc
 > Damnit, I cannot break mmalloc this time. That's SO disappointing.
diff --git a/teshsuite/xbt/mmalloc/mmalloc_64.tesh b/teshsuite/xbt/mmalloc/mmalloc_64.tesh
index 343e2a4a98..90e01ff2f1 100644
--- a/teshsuite/xbt/mmalloc/mmalloc_64.tesh
+++ b/teshsuite/xbt/mmalloc/mmalloc_64.tesh
@@ -106,4 +106,5 @@ $ ${bindir:=.}/mmalloc_test --log=root.fmt:%m%n
 > Re-allocate every second block
 > free all blocks (each one twice, to check that double free are correctly catched)
 > free again all blocks (to really check that double free are correctly catched)
+> Let's try different codepaths for mrealloc
 > Damnit, I cannot break mmalloc this time. That's SO disappointing.
diff --git a/teshsuite/xbt/mmalloc/mmalloc_test.cpp b/teshsuite/xbt/mmalloc/mmalloc_test.cpp
index 759f09e473..a20ee38dbf 100644
--- a/teshsuite/xbt/mmalloc/mmalloc_test.cpp
+++ b/teshsuite/xbt/mmalloc/mmalloc_test.cpp
@@ -22,6 +22,15 @@ XBT_LOG_NEW_DEFAULT_CATEGORY(test,"this test");
 #define TESTSIZE 100
 #define size_of_block(i) (((i % 50)+1)* 100)
 
+static void check_block(const void* s, int c, int n)
+{
+  const unsigned char* p = static_cast<const unsigned char*>(s);
+  unsigned char b        = static_cast<unsigned char>(c);
+  for (int i = 0; i < n; i++)
+    if (p[i] != b)
+      xbt_die("value mismatch: %p[%d] = %#hhx, expected %#hhx", p, i, p[i], b);
+}
+
 int main(int argc, char**argv)
 {
   xbt_mheap_t heapA = nullptr;
@@ -87,6 +96,21 @@ int main(int argc, char**argv)
       xbt_die("FAIL: A double-free went undetected (for size:%d)",size_of_block(i));
   }
 
+  XBT_INFO("Let's try different codepaths for mrealloc");
+  for (i = 0; i < TESTSIZE; i++) {
+    const std::vector<std::pair<int, int>> requests = {
+        {size_of_block(i) / 2, 0x77}, {size_of_block(i) * 2, 0xaa}, {1, 0xc0}, {0, 0}};
+    pointers[i] = nullptr;
+    for (unsigned k = 0; k < requests.size(); ++k) {
+      size        = requests[k].first;
+      pointers[i] = mrealloc(heapA, pointers[i], size);
+      if (k > 0)
+        check_block(pointers[i], requests[k - 1].second, std::min(size, requests[k - 1].first));
+      if (size > 0)
+        memset(pointers[i], requests[k].second, size);
+    }
+  }
+
   XBT_INFO("Damnit, I cannot break mmalloc this time. That's SO disappointing.");
   return 0;
 }
-- 
2.20.1