[gcc r16-2646] Report read errors when reading auto-profile

[Jan Hubicka via Gcc-cvs]

https://gcc.gnu.org/g:994feb9edd8a243283d5996667f89351c2c66e26

commit r16-2646-g994feb9edd8a243283d5996667f89351c2c66e26
Author: Jan Hubicka <j...@suse.cz>
Date:   Wed Jul 30 16:09:12 2025 +0200

    Report read errors when reading auto-profile
    
    currently -fauto-profile will happily read truncated file without any 
warning
    and interpret it as a zero profile which will in turn result in slow code.
    This patch exports gcov_is_error and adds checks so truncated files are 
detected.
    
    gcc/ChangeLog:
    
            * auto-profile.cc (string_table::read): Check gcov_is_error.
            (read_profile): Likewise.
            * gcov-io.cc (gcov_is_error): Export for gcc linkage.
            * gcov-io.h (gcov_is_error): Declare.

Diff:
---
 gcc/auto-profile.cc | 12 +++++++++++-
 gcc/gcov-io.cc      |  2 +-
 gcc/gcov-io.h       |  1 +
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/gcc/auto-profile.cc b/gcc/auto-profile.cc
index 53e7b51e8832..7ff952632c35 100644
--- a/gcc/auto-profile.cc
+++ b/gcc/auto-profile.cc
@@ -885,6 +885,8 @@ string_table::read ()
     {
       vector_.quick_push (xstrdup (gcov_read_string ()));
       map_[vector_.last ()] = i;
+      if (gcov_is_error ())
+       return false;
     }
   return true;
 }
@@ -2747,14 +2749,22 @@ read_profile (void)
 
   /* autofdo_source_profile.  */
   afdo_source_profile = autofdo_source_profile::create ();
-  if (afdo_source_profile == NULL)
+  if (afdo_source_profile == NULL
+      || gcov_is_error ())
     {
       error ("cannot read function profile from %s", auto_profile_file);
+      delete afdo_source_profile;
+      afdo_source_profile = NULL;
       return;
     }
 
   /* autofdo_module_profile.  */
   fake_read_autofdo_module_profile ();
+  if (gcov_is_error ())
+    {
+      error ("cannot read module profile from %s", auto_profile_file);
+      return;
+    }
 }
 
 /* From AutoFDO profiles, find values inside STMT for that we want to measure
diff --git a/gcc/gcov-io.cc b/gcc/gcov-io.cc
index f39b4bd565ad..dd3fc88f4b51 100644
--- a/gcc/gcov-io.cc
+++ b/gcc/gcov-io.cc
@@ -69,7 +69,7 @@ gcov_position (void)
 
 /* Return nonzero if the error flag is set.  */
 /* We need to expose this function when compiling for gcov-tool.  */
-#ifndef IN_GCOV_TOOL
+#if !defined (IN_GCOV_TOOL) && !defined (IN_GCC)
 static inline
 #endif
 int
diff --git a/gcc/gcov-io.h b/gcc/gcov-io.h
index f3e3a1c08da8..313c15cecbb8 100644
--- a/gcc/gcov-io.h
+++ b/gcc/gcov-io.h
@@ -387,6 +387,7 @@ char *mangle_path (char const *base);
 /* Available outside gcov */
 GCOV_LINKAGE void gcov_write (const void *, unsigned) ATTRIBUTE_HIDDEN;
 GCOV_LINKAGE void gcov_write_unsigned (gcov_unsigned_t) ATTRIBUTE_HIDDEN;
+GCOV_LINKAGE int gcov_is_error (void);
 #endif
 
 #if !IN_GCOV && !IN_LIBGCOV