[gcc r12-4996] gcov-profile: Fix -fcompare-debug with -fprofile-generate [PR100520]

[Martin Liska <marxin@gcc.gnu.org>]

https://gcc.gnu.org/g:7553bd35c876efaf8ab0b6661a6102822b99e6e3

commit r12-4996-g7553bd35c876efaf8ab0b6661a6102822b99e6e3
Author: Martin Liska <mliska@suse.cz>
Date:   Fri Nov 5 16:50:06 2021 +0100

    gcov-profile: Fix -fcompare-debug with -fprofile-generate [PR100520]
    
            PR gcov-profile/100520
    
    gcc/ChangeLog:
    
            * coverage.c (coverage_compute_profile_id): Strip .gk when
            compare debug is used.
            * system.h (endswith): New function.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.dg/pr100520.c: New test.

Diff:
---
 gcc/coverage.c                  |  7 +++++--
 gcc/system.h                    | 13 +++++++++++++
 gcc/testsuite/gcc.dg/pr100520.c |  5 +++++
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/gcc/coverage.c b/gcc/coverage.c
index 4467f1eaa5c..4daa3f9fc30 100644
--- a/gcc/coverage.c
+++ b/gcc/coverage.c
@@ -571,8 +571,11 @@ coverage_compute_profile_id (struct cgraph_node *n)
       if (!use_name_only && first_global_object_name)
 	chksum = coverage_checksum_string
 	  (chksum, first_global_object_name);
-      chksum = coverage_checksum_string
-	(chksum, aux_base_name);
+      char *base_name = xstrdup (aux_base_name);
+      if (endswith (base_name, ".gk"))
+	base_name[strlen (base_name) - 3] = '\0';
+      chksum = coverage_checksum_string (chksum, base_name);
+      free (base_name);
     }
 
   /* Non-negative integers are hopefully small enough to fit in all targets.
diff --git a/gcc/system.h b/gcc/system.h
index adde3e264b6..4ac656c9c3c 100644
--- a/gcc/system.h
+++ b/gcc/system.h
@@ -1305,4 +1305,17 @@ startswith (const char *str, const char *prefix)
   return strncmp (str, prefix, strlen (prefix)) == 0;
 }
 
+/* Return true if STR string ends with SUFFIX.  */
+
+static inline bool
+endswith (const char *str, const char *suffix)
+{
+  size_t str_len = strlen (str);
+  size_t suffix_len = strlen (suffix);
+  if (str_len < suffix_len)
+    return false;
+
+  return memcmp (str + str_len - suffix_len, suffix, suffix_len) == 0;
+}
+
 #endif /* ! GCC_SYSTEM_H */
diff --git a/gcc/testsuite/gcc.dg/pr100520.c b/gcc/testsuite/gcc.dg/pr100520.c
new file mode 100644
index 00000000000..60f79c2b888
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr100520.c
@@ -0,0 +1,5 @@
+/* PR gcov-profile/100520 */
+/* { dg-do compile } */
+/* { dg-options "-fcompare-debug -fprofile-generate" } */
+
+static int f() {}