[gcc r14-9133] profile-count: Don't dump through a temporary buffer [PR111960]

[gcc r14-9133] profile-count: Don't dump through a temporary buffer [PR111960]

[Jakub Jelinek]

https://gcc.gnu.org/g:a0782531b8270f0fdb3f3e09b4ce544d5d1eef14

commit r14-9133-ga0782531b8270f0fdb3f3e09b4ce544d5d1eef14
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Thu Feb 22 13:07:25 2024 +0100

    profile-count: Don't dump through a temporary buffer [PR111960]
    
    The profile_count::dump (char *, struct function * = NULL) const;
    method has a single caller, the
    profile_count::dump (FILE *f, struct function *fun) const;
    method and for that going through a temporary buffer is just slower
    and opens doors for buffer overflows, which is exactly why this P1
    was filed.
    The buffer size is 64 bytes, the previous maximum
    "%" PRId64 " (%s)"
    would print up to 61 bytes in there (19 bytes for arbitrary uint64_t:61
    bitfield printed as signed, "estimated locally, globally 0 adjusted"
    i.e. 38 bytes longest %s and 4 other characters).
    Now, after the r14-2389 changes, it can be
    19 + 38 plus 11 other characters + %.4f, which is worst case
    309 chars before decimal point, decimal point and 4 digits after it,
    so total 382 bytes.
    
    So, either we could bump the buffer[64] to buffer[400], or the following
    patch just drops the indirection through buffer and prints it directly to
    stream.  After all, having APIs which fill in some buffer without passing
    down the size of the buffer is just asking for buffer overflows over time.
    
    2024-02-22  Jakub Jelinek  <jakub@redhat.com>
    
            PR ipa/111960
            * profile-count.h (profile_count::dump): Remove overload with
            char * first argument.
            * profile-count.cc (profile_count::dump): Change overload with char *
            first argument which uses sprintf into the overfload with FILE *
            first argument and use fprintf instead.  Remove overload which wrapped
            it.

Diff:
---
 gcc/profile-count.cc | 20 +++++---------------
 gcc/profile-count.h  |  3 ---
 2 files changed, 5 insertions(+), 18 deletions(-)

diff --git a/gcc/profile-count.cc b/gcc/profile-count.cc
index 0cb1220e0785..b26f38e33e47 100644
--- a/gcc/profile-count.cc
+++ b/gcc/profile-count.cc
@@ -84,34 +84,24 @@ const char *profile_quality_display_names[] =
   "precise"
 };
 
-/* Dump THIS to BUFFER.  */
+/* Dump THIS to F.  */
 
 void
-profile_count::dump (char *buffer, struct function *fun) const
+profile_count::dump (FILE *f, struct function *fun) const
 {
   if (!initialized_p ())
-    sprintf (buffer, "uninitialized");
+    fprintf (f, "uninitialized");
   else if (fun && initialized_p ()
 	   && fun->cfg
 	   && ENTRY_BLOCK_PTR_FOR_FN (fun)->count.initialized_p ())
-    sprintf (buffer, "%" PRId64 " (%s, freq %.4f)", m_val,
+    fprintf (f, "%" PRId64 " (%s, freq %.4f)", m_val,
 	     profile_quality_display_names[m_quality],
 	     to_sreal_scale (ENTRY_BLOCK_PTR_FOR_FN (fun)->count).to_double ());
   else
-    sprintf (buffer, "%" PRId64 " (%s)", m_val,
+    fprintf (f, "%" PRId64 " (%s)", m_val,
 	     profile_quality_display_names[m_quality]);
 }
 
-/* Dump THIS to F.  */
-
-void
-profile_count::dump (FILE *f, struct function *fun) const
-{
-  char buffer[64];
-  dump (buffer, fun);
-  fputs (buffer, f);
-}
-
 /* Dump THIS to stderr.  */
 
 void
diff --git a/gcc/profile-count.h b/gcc/profile-count.h
index b773b4ec47c2..b3d776475e2c 100644
--- a/gcc/profile-count.h
+++ b/gcc/profile-count.h
@@ -1299,9 +1299,6 @@ public:
   /* Output THIS to F.  */
   void dump (FILE *f, struct function *fun = NULL) const;
 
-  /* Output THIS to BUFFER.  */
-  void dump (char *buffer, struct function *fun = NULL) const;
-
   /* Print THIS to stderr.  */
   void debug () const;