[gcc r12-1924] fixinc: don't "fix" machine names in __has_include(...) [PR91085]

[gcc r12-1924] fixinc: don't "fix" machine names in __has_include(...) [PR91085]

[Xi Ruoyao]

https://gcc.gnu.org/g:6bf383c37e6131a8e247e8a0997d55d65c830b6d

commit r12-1924-g6bf383c37e6131a8e247e8a0997d55d65c830b6d
Author: Xi Ruoyao <xry111@mengyan1223.wang>
Date:   Mon Jun 28 13:54:58 2021 +0800

    fixinc: don't "fix" machine names in __has_include(...) [PR91085]
    
    fixincludes/
    
            PR other/91085
            * fixfixes.c (check_has_inc): New static function.
              (machine_name_fix): Don't replace header names in
              __has_include(...).
            * inclhack.def (machine_name): Adjust test.
            * tests/base/testing.h: Update.

Diff:
---
 fixincludes/fixfixes.c           | 45 ++++++++++++++++++++++++++++++++++++++--
 fixincludes/inclhack.def         |  3 ++-
 fixincludes/tests/base/testing.h |  2 +-
 3 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/fixincludes/fixfixes.c b/fixincludes/fixfixes.c
index 5b23a8b640d..404b420f302 100644
--- a/fixincludes/fixfixes.c
+++ b/fixincludes/fixfixes.c
@@ -477,6 +477,39 @@ FIX_PROC_HEAD( char_macro_def_fix )
   fputs (text, stdout);
 }
 
+/* Check if the pattern at pos is actually in a "__has_include(...)"
+   directive.  Return the pointer to the ')' of this
+   "__has_include(...)" if it is, NULL otherwise.  */
+static const char *
+check_has_inc (const char *begin, const char *pos, const char *end)
+{
+  static const char has_inc[] = "__has_include";
+  const size_t has_inc_len = sizeof (has_inc) - 1;
+  const char *p;
+
+  for (p = memmem (begin, pos - begin, has_inc, has_inc_len);
+       p != NULL;
+       p = memmem (p, pos - p, has_inc, has_inc_len))
+    {
+      p += has_inc_len;
+      while (p < end && ISSPACE (*p))
+        p++;
+
+      /* "__has_include" may appear as "defined(__has_include)",
+         search for the next appearance then.  */
+      if (*p != '(')
+        continue;
+
+      /* To avoid too much complexity, just hope there is never a
+         ')' in a header name.  */
+      p = memchr (p, ')', end - p);
+      if (p == NULL || p > pos)
+        return p;
+    }
+
+  return NULL;
+}
+
 /* Fix for machine name #ifdefs that are not in the namespace reserved
    by the C standard.  They won't be defined if compiling with -ansi,
    and the headers will break.  We go to some trouble to only change
@@ -524,7 +557,7 @@ FIX_PROC_HEAD( machine_name_fix )
       /* If the 'name_pat' matches in between base and limit, we have
          a bogon.  It is not worth the hassle of excluding comments
          because comments on #if/#ifdef lines are rare, and strings on
-         such lines are illegal.
+         such lines are only legal in a "__has_include" directive.
 
          REG_NOTBOL means 'base' is not at the beginning of a line, which
          shouldn't matter since the name_re has no ^ anchor, but let's
@@ -544,8 +577,16 @@ FIX_PROC_HEAD( machine_name_fix )
             break;
 
           p = base + match[0].rm_so;
-          base += match[0].rm_eo;
 
+          /* Check if the match is in __has_include(...) (PR 91085). */
+          q = check_has_inc (base, p, limit);
+          if (q) 
+            {
+              base = q + 1;
+              goto again;
+            }
+
+          base += match[0].rm_eo;
           /* One more test: if on the same line we have the same string
              with the appropriate underscores, then leave it alone.
              We want exactly two leading and trailing underscores.  */
diff --git a/fixincludes/inclhack.def b/fixincludes/inclhack.def
index 3a4cfe06542..4db311713ef 100644
--- a/fixincludes/inclhack.def
+++ b/fixincludes/inclhack.def
@@ -3151,7 +3151,8 @@ fix = {
     c_fix     = machine_name;
 
     test_text = "/* MACH_DIFF: */\n"
-    "#if defined( i386 ) || defined( sparc ) || defined( vax )"
+    "#if defined( i386 ) || defined( sparc ) || defined( vax ) || "
+    "defined( linux ) || __has_include ( <linux.h> )"
     "\n/* no uniform test, so be careful  :-) */";
 };
 
diff --git a/fixincludes/tests/base/testing.h b/fixincludes/tests/base/testing.h
index cf95321fb86..8b3accaf04e 100644
--- a/fixincludes/tests/base/testing.h
+++ b/fixincludes/tests/base/testing.h
@@ -64,7 +64,7 @@ BSD43__IOWR('T', 1) /* Some are multi-line */
 
 #if defined( MACHINE_NAME_CHECK )
 /* MACH_DIFF: */
-#if defined( i386 ) || defined( sparc ) || defined( vax )
+#if defined( i386 ) || defined( sparc ) || defined( vax ) || defined( linux ) || __has_include ( <linux.h> )
 /* no uniform test, so be careful  :-) */
 #endif  /* MACHINE_NAME_CHECK */