[binutils-gdb] GAS: Add ECOFF `.aent' pseudo-op support

[Maciej W.Rozycki <macro at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=37f9ec62dbead711fe795cff2a95862ea8283c2f

commit 37f9ec62dbead711fe795cff2a95862ea8283c2f
Author: Maciej W. Rozycki <macro@imgtec.com>
Date:   Thu Feb 16 01:50:29 2017 +0000

    GAS: Add ECOFF `.aent' pseudo-op support
    
    Implement the ECOFF `.aent' pseudo-op for ECOFF-style `.mdebug' section
    support with ELF objects and, for consistency, also with ECOFF objects.
    This is so that the same MIPS source can be assembled without and with
    `.mdebug' section generation enabled.
    
    Taking the `gas/testsuite/gas/mips/aent.s' test case source as an
    example and the `mips-linux' target we have:
    
    $ as -o aent.o aent.s
    $ as -mdebug -o aent.o aent.s
    aent.s: Assembler messages:
    aent.s:10: Error: unknown pseudo-op: `.aent'
    $
    
    because for the !ECOFF_DEBUGGING case (which is the default) the
    pseudo-op is already handled by the MIPS backend with `s_mips_ent',
    however no handler is present for the opposite case.
    
    For the MIPS target this is a functional regression introduced with
    commit ecb4347adecd ("Last take: approval for MIPS_STABS_ELF killing"),
    <https://sourceware.org/ml/binutils/2002-06/msg00443.html>, where
    support for the `.mdebug' section was added along with its associated
    `-mdebug'/`-no-mdebug' command-line options, bringing an inconsistency
    between the assembly syntax supported for each of these options as far
    as the `.aent' pseudo-op is concerned.
    
    Assembly language documentation available describes the pseudo-op
    respectively as follows[1]:
    
    "
    .aent name, symno Sets an alternate entry point for the current
                      procedure.  Use this information when you want
                      to generate information for the debugger.  It must
                      appear inside an .ent/.end pair."
    
    and[2]:
    
    "
    .aent name [,symno]
         Sets an alternate entry point for the current procedure.  Use this
         information when you want to generate information for the debugger.
         This directive must appear between a pair of .ent and .end directives.
         (The optional symno is for compiler use only.  It refers to a dense
         number in a .T file (symbol table).)"
    
    Copy the approach from `s_mips_ent' then and add `.aent' support to the
    `.ent' pseudo-op handler shared between the ELF and ECOFF object file
    format backends, by setting BSF_FUNCTION for the symbol requested.
    
    References:
    
    [1] "MIPSpro Assembly Language Programmer's Guide", Silicon Graphics,
        Inc., Document Number 007-2418-004, Section 8.1 "Op-Codes", p. 96
        <http://techpubs.sgi.com/library/manuals/2000/007-2418-004/pdf/007-2418-004.pdf>
    
    [2] "Digital UNIX Assembly Language Programmer's Guide", Digital
        Equipment Corporation, Order Number: AA-PS31D-TE, March 1996,
        Chapter 5 "Assembler Directives", p. 5-2
        <http://h41361.www4.hpe.com/docs/base_doc/DOCUMENTATION/V40G_PDF/APS31DTE.PDF>
    
    	gas/
    	* ecoff.c (ecoff_directive_ent, add_procedure): Handle `.aent'.
    	* config/obj-ecoff.c (obj_pseudo_table): Add "aent" entry.
    	* config/obj-elf.c (ecoff_debug_pseudo_table): Likewise.
    	* testsuite/gas/mips/aent-2.d: New test.
    	* testsuite/gas/mips/aent-mdebug.d: New test.
    	* testsuite/gas/mips/aent-mdebug-2.d: New test.
    	* testsuite/gas/mips/mips.exp: Run the new tests.

Diff:
---
 gas/ChangeLog                          | 10 ++++++++++
 gas/config/obj-ecoff.c                 |  5 +++--
 gas/config/obj-elf.c                   |  1 +
 gas/ecoff.c                            | 26 +++++++++++++++-----------
 gas/testsuite/gas/mips/aent-2.d        | 19 +++++++++++++++++++
 gas/testsuite/gas/mips/aent-mdebug-2.d | 16 ++++++++++++++++
 gas/testsuite/gas/mips/aent-mdebug.d   |  7 +++++++
 gas/testsuite/gas/mips/mips.exp        |  6 +++++-
 8 files changed, 76 insertions(+), 14 deletions(-)

diff --git a/gas/ChangeLog b/gas/ChangeLog
index d494dc7..a15f92e 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,13 @@
+2017-02-17  Maciej W. Rozycki  <macro@imgtec.com>
+
+	* ecoff.c (ecoff_directive_ent, add_procedure): Handle `.aent'.
+	* config/obj-ecoff.c (obj_pseudo_table): Add "aent" entry.
+	* config/obj-elf.c (ecoff_debug_pseudo_table): Likewise.
+	* testsuite/gas/mips/aent-2.d: New test.
+	* testsuite/gas/mips/aent-mdebug.d: New test.
+	* testsuite/gas/mips/aent-mdebug-2.d: New test.
+	* testsuite/gas/mips/mips.exp: Run the new tests.
+
 2017-02-15  Richard Sandiford  <richard.sandiford@arm.com>
 
 	* testsuite/gas/aarch64/sve-sysreg.s,
diff --git a/gas/config/obj-ecoff.c b/gas/config/obj-ecoff.c
index 8458a91..80ae37e 100644
--- a/gas/config/obj-ecoff.c
+++ b/gas/config/obj-ecoff.c
@@ -221,8 +221,8 @@ ecoff_separate_stab_sections (void)
    relating to debugging information are supported here.
 
    The following pseudo-ops from the Kane and Heinrich MIPS book
-   should be defined here, but are currently unsupported: .aent,
-   .bgnb, .endb, .verstamp, .vreg.
+   should be defined here, but are currently unsupported: .bgnb,
+   .endb, .verstamp, .vreg.
 
    The following pseudo-ops from the Kane and Heinrich MIPS book are
    MIPS CPU specific, and should be defined by tc-mips.c: .alias,
@@ -253,6 +253,7 @@ const pseudo_typeS obj_pseudo_table[] =
   { "val",	ecoff_directive_val,	0 },
 
   /* ECOFF specific debugging information.  */
+  { "aent",	ecoff_directive_ent,	1 },
   { "begin",	ecoff_directive_begin,	0 },
   { "bend",	ecoff_directive_bend,	0 },
   { "end",	ecoff_directive_end,	0 },
diff --git a/gas/config/obj-elf.c b/gas/config/obj-elf.c
index 165fc8b..1d59fc0 100644
--- a/gas/config/obj-elf.c
+++ b/gas/config/obj-elf.c
@@ -164,6 +164,7 @@ static const pseudo_typeS ecoff_debug_pseudo_table[] =
   { "etype",	ecoff_directive_type,	0 },
 
   /* ECOFF specific debugging information.  */
+  { "aent",	ecoff_directive_ent,	1 },
   { "begin",	ecoff_directive_begin,	0 },
   { "bend",	ecoff_directive_bend,	0 },
   { "end",	ecoff_directive_end,	0 },
diff --git a/gas/ecoff.c b/gas/ecoff.c
index 171f2db..5c37312 100644
--- a/gas/ecoff.c
+++ b/gas/ecoff.c
@@ -1422,7 +1422,7 @@ static symint_t add_aux_sym_tir (type_info_t *t,
 				 thash_t **hash_tbl);
 static tag_t *get_tag (const char *tag, localsym_t *sym, bt_t basic_type);
 static void add_unknown_tag (tag_t *ptag);
-static void add_procedure (char *func);
+static void add_procedure (char *func, int aent);
 static void add_file (const char *file_name, int indx, int fake);
 #ifdef ECOFF_DEBUG
 static char *sc_to_string (sc_t storage_class);
@@ -2109,10 +2109,11 @@ add_unknown_tag (tag_t *ptag /* pointer to tag information */)
 }
 
 /* Add a procedure to the current file's list of procedures, and record
-   this is the current procedure.  */
+   this is the current procedure.  If AENT, then only set the requested
+   symbol's function type.  */
 
 static void
-add_procedure (char *func /* func name */)
+add_procedure (char *func /* func name */, int aent)
 {
   varray_t *vp;
   proc_t *new_proc_ptr;
@@ -2123,6 +2124,13 @@ add_procedure (char *func /* func name */)
     fputc ('\n', stderr);
 #endif
 
+  /* Set the BSF_FUNCTION flag for the symbol.  */
+  sym = symbol_find_or_make (func);
+  symbol_get_bfdsym (sym)->flags |= BSF_FUNCTION;
+
+  if (aent)
+    return;
+
   if (cur_file_ptr == (efdr_t *) NULL)
     as_fatal (_("no current file pointer"));
 
@@ -2143,10 +2151,6 @@ add_procedure (char *func /* func name */)
   new_proc_ptr->pdr.lnLow = -1;
   new_proc_ptr->pdr.lnHigh = -1;
 
-  /* Set the BSF_FUNCTION flag for the symbol.  */
-  sym = symbol_find_or_make (func);
-  symbol_get_bfdsym (sym)->flags |= BSF_FUNCTION;
-
   /* Push the start of the function.  */
   new_proc_ptr->sym = add_ecoff_symbol ((const char *) NULL, st_Proc, sc_Text,
 					sym, (bfd_vma) 0, (symint_t) 0,
@@ -3030,7 +3034,7 @@ ecoff_directive_end (int ignore ATTRIBUTE_UNUSED)
 /* Parse .ent directives.  */
 
 void
-ecoff_directive_ent (int ignore ATTRIBUTE_UNUSED)
+ecoff_directive_ent (int aent)
 {
   char *name;
   char name_end;
@@ -3038,7 +3042,7 @@ ecoff_directive_ent (int ignore ATTRIBUTE_UNUSED)
   if (cur_file_ptr == (efdr_t *) NULL)
     add_file ((const char *) NULL, 0, 1);
 
-  if (cur_proc_ptr != (proc_t *) NULL)
+  if (!aent && cur_proc_ptr != (proc_t *) NULL)
     {
       as_warn (_("second .ent directive found before .end directive"));
       demand_empty_rest_of_line ();
@@ -3049,13 +3053,13 @@ ecoff_directive_ent (int ignore ATTRIBUTE_UNUSED)
 
   if (name == input_line_pointer)
     {
-      as_warn (_(".ent directive has no name"));
+      as_warn (_("%s directive has no name"), aent ? ".aent" : ".ent");
       (void) restore_line_pointer (name_end);
       demand_empty_rest_of_line ();
       return;
     }
 
-  add_procedure (name);
+  add_procedure (name, aent);
 
   (void) restore_line_pointer (name_end);
 
diff --git a/gas/testsuite/gas/mips/aent-2.d b/gas/testsuite/gas/mips/aent-2.d
new file mode 100644
index 0000000..4115919
--- /dev/null
+++ b/gas/testsuite/gas/mips/aent-2.d
@@ -0,0 +1,19 @@
+#PROG: readelf
+#readelf: -s
+#name: MIPS .aent directive 2
+#as: -32
+#source: aent.s
+
+# Verify that the .aent directive retains function symbol type annotation,
+# e.g.:
+#    Num:    Value  Size Type    Bind   Vis      Ndx Name
+#      8: 00000000    16 FUNC    GLOBAL DEFAULT    1 foo
+#      9: 00000008     0 FUNC    GLOBAL DEFAULT    1 bar
+# vs:
+#    Num:    Value  Size Type    Bind   Vis      Ndx Name
+#      8: 00000000    16 FUNC    GLOBAL DEFAULT    1 foo
+#      9: 00000008     0 OBJECT  GLOBAL DEFAULT    1 bar
+#...
+ *[0-9]+: +[0-9]+ +[0-9]+ +FUNC +GLOBAL +DEFAULT(?: +\[[^]]*\])? +[0-9]+ foo
+ *[0-9]+: +[0-9]+ +[0-9]+ +FUNC +GLOBAL +DEFAULT(?: +\[[^]]*\])? +[0-9]+ bar
+#pass
diff --git a/gas/testsuite/gas/mips/aent-mdebug-2.d b/gas/testsuite/gas/mips/aent-mdebug-2.d
new file mode 100644
index 0000000..eea4115
--- /dev/null
+++ b/gas/testsuite/gas/mips/aent-mdebug-2.d
@@ -0,0 +1,16 @@
+#PROG: readelf
+#readelf: -s
+#name: MIPS .aent directive with ECOFF debug 2
+#as: -32 -mdebug
+#source: aent.s
+#dump: aent-2.d
+
+# Verify that the .aent directive retains function symbol type annotation,
+# e.g.:
+#    Num:    Value  Size Type    Bind   Vis      Ndx Name
+#      8: 00000000    16 FUNC    GLOBAL DEFAULT    1 foo
+#      9: 00000008     0 FUNC    GLOBAL DEFAULT    1 bar
+# vs:
+#    Num:    Value  Size Type    Bind   Vis      Ndx Name
+#      8: 00000000    16 FUNC    GLOBAL DEFAULT    1 foo
+#      9: 00000008     0 OBJECT  GLOBAL DEFAULT    1 bar
diff --git a/gas/testsuite/gas/mips/aent-mdebug.d b/gas/testsuite/gas/mips/aent-mdebug.d
new file mode 100644
index 0000000..1a373c6
--- /dev/null
+++ b/gas/testsuite/gas/mips/aent-mdebug.d
@@ -0,0 +1,7 @@
+#objdump: -dr --prefix-addresses
+#name: MIPS .aent directive with ECOFF debug
+#as: -32 -mdebug
+#source: aent.s
+#dump: aent.d
+
+# Test the .aent directive retains function symbol type annotation.
diff --git a/gas/testsuite/gas/mips/mips.exp b/gas/testsuite/gas/mips/mips.exp
index 5a69542..8a9f9f1 100644
--- a/gas/testsuite/gas/mips/mips.exp
+++ b/gas/testsuite/gas/mips/mips.exp
@@ -1191,7 +1191,11 @@ if { [istarget mips*-*-vxworks*] } {
 					    !micromips]
     }
 
-    run_dump_test_arches "aent"	[mips_arch_list_matching mips1]
+    run_dump_test_arches "aent"		[mips_arch_list_matching mips1]
+    run_dump_test_arches "aent-2"	[mips_arch_list_matching mips1]
+    run_dump_test_arches "aent-mdebug"	[mips_arch_list_matching mips1]
+    run_dump_test_arches "aent-mdebug-2" \
+					[mips_arch_list_matching mips1]
 
     run_dump_test_arches "loc-swap"	[mips_arch_list_all]
     run_dump_test_arches "loc-swap-dis"	[mips_arch_list_all]