PR 10757

	* c-pch.c: Include target.h.  Improve comments.
	(struct c_pch_validity): Add target_data_length.
	(pch_init): Add target's validity data.
	(c_common_valid_pch): Check target's validity data.
	* target-def.h (TARGET_GET_PCH_VALIDITY): New.
	(TARGET_PCH_VALID_P): New.
	(TARGET_INITIALIZER): Add new fields.
	* target.h: Include tm.h.
	(struct gcc_target): Add get_pch_validity, pch_valid_p.
	* toplev.h (default_get_pch_validity): New prototype.
	(default_pch_valid_p): New prototype.
	* toplev.c (default_get_pch_validity): New routine.
	(default_pch_valid_p): New routine.
	* Makefile.in (TARGET_H): Add TM_H.  Replace all users of
	target.h with $(TARGET_H).
	(c-pch.o): Add TARGET_H.
	* doc/tm.texi (PCH Target): New node.
	(TARGET_GET_PCH_VALIDITY): Document.
	(TARGET_PCH_VALID_P): Document.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@72909 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 33 insertions, 5 deletions

diff --git a/gcc/c-pch.c b/gcc/c-pch.c
index f7830b2ba27..2a29075d5a3 100644
--- a/gcc/c-pch.c
+++ b/gcc/c-pch.c
@@ -33,6 +33,7 @@ Boston, MA 02111-1307, USA.  */
 #include "ggc.h"
 #include "langhooks.h"
 #include "hosthooks.h"
+#include "target.h"
 
 /* This structure is read very early when validating the PCH, and
    might be read for a PCH which is for a completely different compiler
@@ -40,7 +41,10 @@ Boston, MA 02111-1307, USA.  */
    'unsigned char' entries, at least in the initial entries.  
 
    If you add or change entries before version_length, you should increase
-   the version number in get_ident().  */
+   the version number in get_ident().  
+
+   There are a bunch of fields named *_length; those are lengths of data that
+   follows this structure in the same order as the fields in the structure.  */
 
 struct c_pch_validity
 {
@@ -49,6 +53,7 @@ struct c_pch_validity
   unsigned char version_length;
   unsigned char debug_info_type;
   void (*pch_init) (void);
+  size_t target_data_length;
 };
 
 struct c_pch_header 
@@ -96,6 +101,7 @@ pch_init (void)
 {
   FILE *f;
   struct c_pch_validity v;
+  void *target_validity;
   
   if (! pch_file)
     return;
@@ -112,14 +118,16 @@ pch_init (void)
   v.host_machine_length = strlen (host_machine);
   v.target_machine_length = strlen (target_machine);
   v.version_length = strlen (version_string);
-  
   v.debug_info_type = write_symbols;
   v.pch_init = &pch_init;
+  target_validity = targetm.get_pch_validity (&v.target_data_length);
+  
   if (fwrite (get_ident(), IDENT_LENGTH, 1, f) != 1
       || fwrite (&v, sizeof (v), 1, f) != 1
       || fwrite (host_machine, v.host_machine_length, 1, f) != 1
       || fwrite (target_machine, v.target_machine_length, 1, f) != 1
-      || fwrite (version_string, v.version_length, 1, f) != 1)
+      || fwrite (version_string, v.version_length, 1, f) != 1
+      || fwrite (target_validity, v.target_data_length, 1, f) != 1)
     fatal_error ("can't write to %s: %m", pch_file);
 
   /* We need to be able to re-read the output.  */
@@ -184,8 +192,10 @@ c_common_write_pch (void)
   fclose (pch_outfile);
 }
 
-/* Check the PCH file called NAME, open on FD, to see if it can be used
-   in this compilation.  */
+/* Check the PCH file called NAME, open on FD, to see if it can be
+   used in this compilation.  Return 1 if valid, 0 if the file can't
+   be used now but might be if it's seen later in the compilation, and
+   2 if this file could never be used in the compilation.  */
 
 int
 c_common_valid_pch (cpp_reader *pfile, const char *name, int fd)
@@ -299,6 +309,24 @@ c_common_valid_pch (cpp_reader *pfile, const char *name, int fd)
       return 2;
     }
 
+  /* Check the target-specific validity data.  */
+  {
+    void *this_file_data = xmalloc (v.target_data_length);
+    const char *msg;
+    
+    if ((size_t) read (fd, this_file_data, v.target_data_length)
+	!= v.target_data_length)
+      fatal_error ("can't read %s: %m", name);
+    msg = targetm.pch_valid_p (this_file_data, v.target_data_length);
+    free (this_file_data);
+    if (msg != NULL)
+      {
+	if (cpp_get_options (pfile)->warn_invalid_pch)
+	  cpp_error (pfile, DL_WARNING, "%s: %s", name, msg);
+	return 2;
+      }
+  }
+
   /* Check the preprocessor macros are the same as when the PCH was
      generated.  */