re PR c++/90010 (valgrind error with snprintf and -Wall)

	PR c++/90010
	* gimple-ssa-sprintf.c (target_to_host): Fix handling of targstr
	with strlen in between hostsz-3 and hostsz-1 inclusive when no
	translation is needed, and when translation is needed, only append
	... if the string length is hostsz or more bytes long.  Avoid using
	strncpy or strcat.

	* gcc.dg/pr90010.c: New test.

From-SVN: r270246

4 files changed, 51 insertions, 6 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 9d21ce3..84d1205 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2019-04-10  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/90010
+	* gimple-ssa-sprintf.c (target_to_host): Fix handling of targstr
+	with strlen in between hostsz-3 and hostsz-1 inclusive when no
+	translation is needed, and when translation is needed, only append
+	... if the string length is hostsz or more bytes long.  Avoid using
+	strncpy or strcat.
+
 2019-04-09  Matthew Malcomson  <matthew.malcomson@arm.com>
 
 	PR target/90024
diff --git a/gcc/gimple-ssa-sprintf.c b/gcc/gimple-ssa-sprintf.c
index de60241..b6527bf 100644
--- a/gcc/gimple-ssa-sprintf.c
+++ b/gcc/gimple-ssa-sprintf.c
@@ -383,9 +383,14 @@ target_to_host (char *hostr, size_t hostsz, const char *targstr)
      overlong strings just like the translated strings are.  */
   if (target_to_host_charmap['\0'] == 1)
     {
-      strncpy (hostr, targstr, hostsz - 4);
-      if (strlen (targstr) >= hostsz)
-	strcpy (hostr + hostsz - 4, "...");
+      size_t len = strlen (targstr);
+      if (len >= hostsz)
+	{
+	  memcpy (hostr, targstr, hostsz - 4);
+	  strcpy (hostr + hostsz - 4, "...");
+	}
+      else
+	memcpy (hostr, targstr, len + 1);
       return hostr;
     }
 
@@ -399,10 +404,9 @@ target_to_host (char *hostr, size_t hostsz, const char *targstr)
       if (!*targstr)
 	break;
 
-      if (size_t (ph - hostr) == hostsz - 4)
+      if (size_t (ph - hostr) == hostsz)
 	{
-	  *ph = '\0';
-	  strcat (ph, "...");
+	  strcpy (ph - 4, "...");
 	  break;
 	}
     }
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index d8349c5..2f6bda8 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2019-04-10  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/90010
+	* gcc.dg/pr90010.c: New test.
+
 2019-04-09  Uroš Bizjak  <ubizjak@gmail.com>
 
 	* gcc.target/i386/ifcvt-onecmpl-abs-1.c
diff --git a/gcc/testsuite/gcc.dg/pr90010.c b/gcc/testsuite/gcc.dg/pr90010.c
new file mode 100644
index 0000000..5cd5dd2
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr90010.c
@@ -0,0 +1,27 @@
+/* PR c++/90010 */
+/* { dg-do compile } */
+/* { dg-options "-Wall" } */
+
+char b[4096] = "abc";
+void bar (char *);
+
+void
+foo ()
+{
+  char d[4096];
+  __builtin_snprintf (d, sizeof d, "%sfoobarbazquxquuxquuzthudfred", b);	/* { dg-warning "'foobarbazquxquuxquuzthudfred' directive output may be truncated writing 28 bytes into a region of size between 1 and 4096" } */
+  /* { dg-message "'__builtin_snprintf' output between 29 and 4124 bytes into a destination of size 4096" "" { target *-*-* } .-1 } */
+  bar (d);
+  __builtin_snprintf (d, sizeof d, "%sfoobarbazquxquuxquuzcorgefred", b);	/* { dg-warning "'foobarbazquxquuxquuzcorgefred' directive output may be truncated writing 29 bytes into a region of size between 1 and 4096" } */
+  /* { dg-message "'__builtin_snprintf' output between 30 and 4125 bytes into a destination of size 4096" "" { target *-*-* } .-1 } */
+  bar (d);
+  __builtin_snprintf (d, sizeof d, "%sfoobarbazquxquuxquuzcorgewaldo", b);	/* { dg-warning "'foobarbazquxquuxquuzcorgewaldo' directive output may be truncated writing 30 bytes into a region of size between 1 and 4096" } */
+  /* { dg-message "'__builtin_snprintf' output between 31 and 4126 bytes into a destination of size 4096" "" { target *-*-* } .-1 } */
+  bar (d);
+  __builtin_snprintf (d, sizeof d, "%sfoobarbazquxquuxquuzcorgegarply", b);	/* { dg-warning "'foobarbazquxquuxquuzcorgegarply' directive output may be truncated writing 31 bytes into a region of size between 1 and 4096" } */
+  /* { dg-message "'__builtin_snprintf' output between 32 and 4127 bytes into a destination of size 4096" "" { target *-*-* } .-1 } */
+  bar (d);
+  __builtin_snprintf (d, sizeof d, "%sfoobarfredquxquuxquuzcorgegarply", b);	/* { dg-warning "'foobarfredquxquuxquuzcorgega\.\.\.' directive output may be truncated writing 32 bytes into a region of size between 1 and 4096" } */
+  /* { dg-message "'__builtin_snprintf' output between 33 and 4128 bytes into a destination of size 4096" "" { target *-*-* } .-1 } */
+  bar (d);
+}