| Message ID | 20180508150531.GA16916@kam.mff.cuni.cz |
|---|---|
| State | New |
| Headers | show |
| Series | [RFA] Incremental LTO linking part 1: simple-object bits | expand |
On Tue, 8 May 2018, Jan Hubicka wrote: > Hi, > for incremental linking of LTO objects we need to copy debug sections from > source object files into destination without renaming them from .gnu.debuglto > into the standard debug section (because they will again be LTO debug section > in the resulting object file). > > I have discussed this with Richard on IRC and I hope it is fine to change the > API here becuase lto-wrapper is the only user of this function. I will send > lto-wrapper support in separate patch. > > I have lto-bootstrapped/regtested the whole incremental linking patchet on > x86-64-linux with libbackend being incrementaly linked and also experimented > with extra testcases and tested that debugging works on resulting cc1 binary. > OK? Works for me. Richard. > Honza > > * simple-object.h (simple_object_copy_lto_debug_sections): Add rename > parameter. > * simple-object.c (handle_lto_debug_sections): Add rename parameter. > (handle_lto_debug_sections_rename): New function. > (handle_lto_debug_sections_norename): New function. > (simple_object_copy_lto_debug_sections): Add rename parameter. > Index: include/simple-object.h > =================================================================== > --- include/simple-object.h (revision 260042) > +++ include/simple-object.h (working copy) > @@ -198,12 +198,15 @@ > simple_object_release_write (simple_object_write *); > > /* Copy LTO debug sections from SRC_OBJECT to DEST. > + If RENAME is true, rename LTO debug section into debug section (i.e. > + when producing final binary) and if it is false, keep the sections with > + original names (when incrementally linking). > If an error occurs, return the errno value in ERR and an error string. */ > > extern const char * > simple_object_copy_lto_debug_sections (simple_object_read *src_object, > const char *dest, > - int *err); > + int *err, int rename); > > #ifdef __cplusplus > } > Index: libiberty/simple-object.c > =================================================================== > --- libiberty/simple-object.c (revision 260042) > +++ libiberty/simple-object.c (working copy) > @@ -251,12 +251,15 @@ > } > > /* Callback to identify and rename LTO debug sections by name. > - Returns 1 if NAME is a LTO debug section, 0 if not. */ > + Returns non-NULL if NAME is a LTO debug section, NULL if not. > + If RENAME is true it will rename LTO debug sections to non-LTO > + ones. */ > > static char * > -handle_lto_debug_sections (const char *name) > +handle_lto_debug_sections (const char *name, int rename) > { > - char *newname = XCNEWVEC (char, strlen (name) + 1); > + char *newname = rename ? XCNEWVEC (char, strlen (name) + 1) > + : xstrdup (name); > > /* ??? So we can't use .gnu.lto_ prefixed sections as the assembler > complains about bogus section flags. Which means we need to arrange > @@ -265,12 +268,14 @@ > /* Also include corresponding reloc sections. */ > if (strncmp (name, ".rela", sizeof (".rela") - 1) == 0) > { > - strncpy (newname, name, sizeof (".rela") - 1); > + if (rename) > + strncpy (newname, name, sizeof (".rela") - 1); > name += sizeof (".rela") - 1; > } > else if (strncmp (name, ".rel", sizeof (".rel") - 1) == 0) > { > - strncpy (newname, name, sizeof (".rel") - 1); > + if (rename) > + strncpy (newname, name, sizeof (".rel") - 1); > name += sizeof (".rel") - 1; > } > /* ??? For now this handles both .gnu.lto_ and .gnu.debuglto_ prefixed > @@ -277,10 +282,10 @@ > sections. */ > /* Copy LTO debug sections and rename them to their non-LTO name. */ > if (strncmp (name, ".gnu.debuglto_", sizeof (".gnu.debuglto_") - 1) == 0) > - return strcat (newname, name + sizeof (".gnu.debuglto_") - 1); > + return rename ? strcat (newname, name + sizeof (".gnu.debuglto_") - 1) : newname; > else if (strncmp (name, ".gnu.lto_.debug_", > sizeof (".gnu.lto_.debug_") -1) == 0) > - return strcat (newname, name + sizeof (".gnu.lto_") - 1); > + return rename ? strcat (newname, name + sizeof (".gnu.lto_") - 1) : newname; > /* Copy over .note.GNU-stack section under the same name if present. */ > else if (strcmp (name, ".note.GNU-stack") == 0) > return strcpy (newname, name); > @@ -289,14 +294,31 @@ > COMDAT sections in objects produced by GCC. */ > else if (strcmp (name, ".comment") == 0) > return strcpy (newname, name); > + free (newname); > return NULL; > } > > +/* Wrapper for handle_lto_debug_sections. */ > + > +static char * > +handle_lto_debug_sections_rename (const char *name) > +{ > + return handle_lto_debug_sections (name, 1); > +} > + > +/* Wrapper for handle_lto_debug_sections. */ > + > +static char * > +handle_lto_debug_sections_norename (const char *name) > +{ > + return handle_lto_debug_sections (name, 0); > +} > + > /* Copy LTO debug sections. */ > > const char * > simple_object_copy_lto_debug_sections (simple_object_read *sobj, > - const char *dest, int *err) > + const char *dest, int *err, int rename) > { > const char *errmsg; > simple_object_write *dest_sobj; > @@ -317,9 +339,10 @@ > if (! dest_sobj) > return errmsg; > > - errmsg = sobj->functions->copy_lto_debug_sections (sobj, dest_sobj, > - handle_lto_debug_sections, > - err); > + errmsg = sobj->functions->copy_lto_debug_sections > + (sobj, dest_sobj, > + rename ? handle_lto_debug_sections_rename > + : handle_lto_debug_sections_norename, err); > if (errmsg) > { > simple_object_release_write (dest_sobj); > >
On Tue, May 8, 2018 at 8:05 AM, Jan Hubicka <hubicka@ucw.cz> wrote: > Hi, > for incremental linking of LTO objects we need to copy debug sections from > source object files into destination without renaming them from .gnu.debuglto > into the standard debug section (because they will again be LTO debug section > in the resulting object file). > > I have discussed this with Richard on IRC and I hope it is fine to change the > API here becuase lto-wrapper is the only user of this function. I will send > lto-wrapper support in separate patch. > > I have lto-bootstrapped/regtested the whole incremental linking patchet on > x86-64-linux with libbackend being incrementaly linked and also experimented > with extra testcases and tested that debugging works on resulting cc1 binary. > OK? > > Honza > > * simple-object.h (simple_object_copy_lto_debug_sections): Add rename > parameter. > * simple-object.c (handle_lto_debug_sections): Add rename parameter. > (handle_lto_debug_sections_rename): New function. > (handle_lto_debug_sections_norename): New function. > (simple_object_copy_lto_debug_sections): Add rename parameter. > Index: include/simple-object.h > =================================================================== > --- include/simple-object.h (revision 260042) > +++ include/simple-object.h (working copy) > @@ -198,12 +198,15 @@ > simple_object_release_write (simple_object_write *); > > /* Copy LTO debug sections from SRC_OBJECT to DEST. > + If RENAME is true, rename LTO debug section into debug section (i.e. > + when producing final binary) and if it is false, keep the sections with > + original names (when incrementally linking). > If an error occurs, return the errno value in ERR and an error string. */ > > extern const char * > simple_object_copy_lto_debug_sections (simple_object_read *src_object, > const char *dest, > - int *err); > + int *err, int rename); > > #ifdef __cplusplus > } This part is missing from r260956: https://gcc.gnu.org/ml/gcc-cvs/2018-05/msg01177.html
> On Tue, May 8, 2018 at 8:05 AM, Jan Hubicka <hubicka@ucw.cz> wrote: > > Hi, > > for incremental linking of LTO objects we need to copy debug sections from > > source object files into destination without renaming them from .gnu.debuglto > > into the standard debug section (because they will again be LTO debug section > > in the resulting object file). > > > > I have discussed this with Richard on IRC and I hope it is fine to change the > > API here becuase lto-wrapper is the only user of this function. I will send > > lto-wrapper support in separate patch. > > > > I have lto-bootstrapped/regtested the whole incremental linking patchet on > > x86-64-linux with libbackend being incrementaly linked and also experimented > > with extra testcases and tested that debugging works on resulting cc1 binary. > > OK? > > > > Honza > > > > * simple-object.h (simple_object_copy_lto_debug_sections): Add rename > > parameter. > > * simple-object.c (handle_lto_debug_sections): Add rename parameter. > > (handle_lto_debug_sections_rename): New function. > > (handle_lto_debug_sections_norename): New function. > > (simple_object_copy_lto_debug_sections): Add rename parameter. > > Index: include/simple-object.h > > =================================================================== > > --- include/simple-object.h (revision 260042) > > +++ include/simple-object.h (working copy) > > @@ -198,12 +198,15 @@ > > simple_object_release_write (simple_object_write *); > > > > /* Copy LTO debug sections from SRC_OBJECT to DEST. > > + If RENAME is true, rename LTO debug section into debug section (i.e. > > + when producing final binary) and if it is false, keep the sections with > > + original names (when incrementally linking). > > If an error occurs, return the errno value in ERR and an error string. */ > > > > extern const char * > > simple_object_copy_lto_debug_sections (simple_object_read *src_object, > > const char *dest, > > - int *err); > > + int *err, int rename); > > > > #ifdef __cplusplus > > } > > This part is missing from r260956: > > https://gcc.gnu.org/ml/gcc-cvs/2018-05/msg01177.html I have managed to commit partially, it should be fixed now. My apologizes for this! Honza > > -- > H.J.
Hi Jan, >> > Index: include/simple-object.h >> > =================================================================== >> > --- include/simple-object.h (revision 260042) >> > +++ include/simple-object.h (working copy) >> > @@ -198,12 +198,15 @@ >> > simple_object_release_write (simple_object_write *); >> > >> > /* Copy LTO debug sections from SRC_OBJECT to DEST. >> > + If RENAME is true, rename LTO debug section into debug section (i.e. >> > + when producing final binary) and if it is false, keep the sections with >> > + original names (when incrementally linking). >> > If an error occurs, return the errno value in ERR and an error string. */ >> > >> > extern const char * >> > simple_object_copy_lto_debug_sections (simple_object_read *src_object, >> > const char *dest, >> > - int *err); >> > + int *err, int rename); >> > >> > #ifdef __cplusplus >> > } >> >> This part is missing from r260956: >> >> https://gcc.gnu.org/ml/gcc-cvs/2018-05/msg01177.html > > I have managed to commit partially, it should be fixed now. My apologizes > for this! unfortunately, it isn't: the include/simple-object.h part is still missing. Rainer
Index: include/simple-object.h =================================================================== --- include/simple-object.h (revision 260042) +++ include/simple-object.h (working copy) @@ -198,12 +198,15 @@ simple_object_release_write (simple_object_write *); /* Copy LTO debug sections from SRC_OBJECT to DEST. + If RENAME is true, rename LTO debug section into debug section (i.e. + when producing final binary) and if it is false, keep the sections with + original names (when incrementally linking). If an error occurs, return the errno value in ERR and an error string. */ extern const char * simple_object_copy_lto_debug_sections (simple_object_read *src_object, const char *dest, - int *err); + int *err, int rename); #ifdef __cplusplus } Index: libiberty/simple-object.c =================================================================== --- libiberty/simple-object.c (revision 260042) +++ libiberty/simple-object.c (working copy) @@ -251,12 +251,15 @@ } /* Callback to identify and rename LTO debug sections by name. - Returns 1 if NAME is a LTO debug section, 0 if not. */ + Returns non-NULL if NAME is a LTO debug section, NULL if not. + If RENAME is true it will rename LTO debug sections to non-LTO + ones. */ static char * -handle_lto_debug_sections (const char *name) +handle_lto_debug_sections (const char *name, int rename) { - char *newname = XCNEWVEC (char, strlen (name) + 1); + char *newname = rename ? XCNEWVEC (char, strlen (name) + 1) + : xstrdup (name); /* ??? So we can't use .gnu.lto_ prefixed sections as the assembler complains about bogus section flags. Which means we need to arrange @@ -265,12 +268,14 @@ /* Also include corresponding reloc sections. */ if (strncmp (name, ".rela", sizeof (".rela") - 1) == 0) { - strncpy (newname, name, sizeof (".rela") - 1); + if (rename) + strncpy (newname, name, sizeof (".rela") - 1); name += sizeof (".rela") - 1; } else if (strncmp (name, ".rel", sizeof (".rel") - 1) == 0) { - strncpy (newname, name, sizeof (".rel") - 1); + if (rename) + strncpy (newname, name, sizeof (".rel") - 1); name += sizeof (".rel") - 1; } /* ??? For now this handles both .gnu.lto_ and .gnu.debuglto_ prefixed @@ -277,10 +282,10 @@ sections. */ /* Copy LTO debug sections and rename them to their non-LTO name. */ if (strncmp (name, ".gnu.debuglto_", sizeof (".gnu.debuglto_") - 1) == 0) - return strcat (newname, name + sizeof (".gnu.debuglto_") - 1); + return rename ? strcat (newname, name + sizeof (".gnu.debuglto_") - 1) : newname; else if (strncmp (name, ".gnu.lto_.debug_", sizeof (".gnu.lto_.debug_") -1) == 0) - return strcat (newname, name + sizeof (".gnu.lto_") - 1); + return rename ? strcat (newname, name + sizeof (".gnu.lto_") - 1) : newname; /* Copy over .note.GNU-stack section under the same name if present. */ else if (strcmp (name, ".note.GNU-stack") == 0) return strcpy (newname, name); @@ -289,14 +294,31 @@ COMDAT sections in objects produced by GCC. */ else if (strcmp (name, ".comment") == 0) return strcpy (newname, name); + free (newname); return NULL; } +/* Wrapper for handle_lto_debug_sections. */ + +static char * +handle_lto_debug_sections_rename (const char *name) +{ + return handle_lto_debug_sections (name, 1); +} + +/* Wrapper for handle_lto_debug_sections. */ + +static char * +handle_lto_debug_sections_norename (const char *name) +{ + return handle_lto_debug_sections (name, 0); +} + /* Copy LTO debug sections. */ const char * simple_object_copy_lto_debug_sections (simple_object_read *sobj, - const char *dest, int *err) + const char *dest, int *err, int rename) { const char *errmsg; simple_object_write *dest_sobj; @@ -317,9 +339,10 @@ if (! dest_sobj) return errmsg; - errmsg = sobj->functions->copy_lto_debug_sections (sobj, dest_sobj, - handle_lto_debug_sections, - err); + errmsg = sobj->functions->copy_lto_debug_sections + (sobj, dest_sobj, + rename ? handle_lto_debug_sections_rename + : handle_lto_debug_sections_norename, err); if (errmsg) { simple_object_release_write (dest_sobj);