[PATCH v2 12/16] testsuite, fortran: fix info-types for intel compilers

[Nils-Christian Kempke <nils-christian.kempke@intel.com>]

This info-types.exp test case had a few issues that this patch fixes.

First, the emitted symbol character(kind=1)/character*1 (different
compilers use different naming converntions here) which is checkedin the
test is not actually expected given the test program.  There is no
variable of that type in the test.  Still, gfortran emits it for every
Fortran program there is.  The reason is the way gfortran handles Fortran's
named main program.  It generates a wrapper around the Fortran program
that is quite similar to a C main function.  This C-like wrapper has
argc and argv arguments for command line argument passing and the argv
pointer type has a base type character(kind=1) DIE emitted at CU scope.

Given the program

  program prog
  end program prog

the degbug info gfortran emits looks somewhat like

   <0><c>: Abbrev Number: 3 (DW_TAG_compile_unit)
      ...
   <1><2f>: Abbrev Number: 4 (DW_TAG_subprogram)
      <30>   DW_AT_external    : 1
      <30>   DW_AT_name        : (indirect string, ...): main
      ...
   <2><51>: Abbrev Number: 1 (DW_TAG_formal_parameter)
      <52>   DW_AT_name        : (indirect string, ...): argc
      ...
   <2><5d>: Abbrev Number: 1 (DW_TAG_formal_parameter)
      <5e>   DW_AT_name        : (indirect string, ...): argv
      ...
      <62>   DW_AT_type        : <0x77>
      ...
   <2><6a>: Abbrev Number: 0
   ...
   <1><77>: Abbrev Number: 6 (DW_TAG_pointer_type)
      <78>   DW_AT_byte_size   : 8
      <79>   DW_AT_type        : <0x7d>
   <1><7d>: Abbrev Number: 2 (DW_TAG_base_type)
      <7e>   DW_AT_byte_size   : 1
      <7f>   DW_AT_encoding    : 8        (unsigned char)
      <80>   DW_AT_name        : (indirect string, ...): character(kind=1)
   <1><84>: Abbrev Number: 7 (DW_TAG_subprogram)
      <85>   DW_AT_name        : (indirect string, ...): prog
   ...

Ifx and flang do not emit any debug info for a wrapper main method so
the type is missing here.  There was the possibility of actually adding
a character*1 type variable to the Fortran executable, but both, ifx and
gfortran chose to emit this variable's type as a DW_TAG_string_type of
length one (instead of a character(kind=1), or whatever the respective
compiler naming convention is).  While string types are printed as
character*LENGHT in the fortran language part (e.g. when issuing a
'ptype') they do not generate any symbols inside GDB.  In read.c it says

   /* These dies have a type, but processing them does not create
      a symbol or recurse to process the children.  Therefore we can
      read them on-demand through read_type_die.  */

So they did not add any output to 'info types'.  Only flang did emit a
character type here.
As adding a type would have a) not solved the problem for ifx and would
have b) somehow hidden the curious behavior of gfortran, instead, the
check for this character type was chagened to optional with the
check_optional_entry to allow for the symbols's absence and to allow
flang and ifx to pass this test as well.

Second, the line checked for s1 was hardcoded as 37 in the test.  Given
that the type is actually defined on line 41 (which is what is emitted by
ifx) it even seems wrong.  The line check for s1 was changed to actually
check for 41 and a gfortran bug has been filed here

   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105454

The test is now marked as xfail for gfortran.

Third, the whole test of checking for the 'Type s1' in info types seemed
questionable.  The type s1 is declared iside the scope of the Fortran
program info_types_test.  Its DIE however is emitted as a child of the
whole compilation unit making it visible outside of the program's scope.
The 'info types' command checks for types stored in the GLOBAL_BLOCK,
or STATIC_BLOCKm wgucm according to block.h

   The GLOBAL_BLOCK contains all the symbols defined in this compilation
   whose scope is the entire program linked together.
   The STATIC_BLOCK contains all the symbols whose scope is the
   entire compilation excluding other separate compilations.

so for gfortran, the type shows up in the output of 'info types'.  For
flang and ifx on the other hand this is not the case.  The two compilers
emit the type (correctly) as a child of the Fortran program, thus not
adding it to either, the GLOBAL_BLOCK nor the LOCAL_BLOCK.  A bug has
been opened for the gfortran scoping issue:

   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105454

While the most correct change might have been removing the check for s1,
the change made here was to only check for this type in case of gfortran
being used as the compiler, as this check also covers the declaration
line issue mentioned above.  A comment was added to maybe remove this
check once the scoping issue is resolved (and it starts to fail with
newer gfortran versions).  The one used to test these changes was 13.0.
---
 gdb/testsuite/gdb.fortran/info-types.exp | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/gdb/testsuite/gdb.fortran/info-types.exp b/gdb/testsuite/gdb.fortran/info-types.exp
index 9a388dd1a1..527f9fead3 100644
--- a/gdb/testsuite/gdb.fortran/info-types.exp
+++ b/gdb/testsuite/gdb.fortran/info-types.exp
@@ -41,12 +41,26 @@ set real4 [fortran_real4]
 GDBInfoSymbols::run_command "info types"
 GDBInfoSymbols::check_header "All defined types:"
 
-GDBInfoSymbols::check_entry "${srcfile}" "" "${character1}"
+GDBInfoSymbols::check_optional_entry "${srcfile}" "" "${character1}"
 GDBInfoSymbols::check_entry "${srcfile}" "" "${integer4}"
 GDBInfoSymbols::check_entry "${srcfile}" "" "${logical4}"
 GDBInfoSymbols::check_entry "${srcfile}" "$decimal" "Type m1t1;"
 GDBInfoSymbols::check_entry "${srcfile}" "" "${real4}"
-GDBInfoSymbols::check_entry "${srcfile}" "37" "Type s1;"
+
+# The emission of the 'Type s1' at global scope is actually not expected.  The
+# type is defined inside the Fortran program and thus scoped to it as well.
+# However, gfortran (13) emits its DIE as a child of the whole cu, while flang
+# and ifx emit the DIE as a child of the main program info_types_test.  As
+# 'info types' only checks for types stored in the GLOBAL_BLOCK, or
+# STATIC_BLOCK we should not expect this type as an output here.  Still, we
+# leave the test here for now (for gfortarn only) as it also covers a line info
+# bug (see gcc/105454).  The bug for the type scoping can be found at
+# gcc/105785.  Should gfortran fix this in some future version this test will
+# start to fail and should be removed.
+if { [test_compiler_info {gfortran-*} f90] } {
+    setup_xfail *-*-* gcc/105454
+    GDBInfoSymbols::check_entry "${srcfile}" "41" "Type s1;"
+}
 
 return 0
 
@@ -62,5 +76,5 @@ gdb_test "info types" \
 	 "(35:\[\t \]+Type __vtype_mod1_M1t1;" \
 	 ")?$decimal:\[\t \]+Type m1t1;" \
 	 "\[\t \]+${real4}" \
-	 "37:\[\t \]+Type s1;(" \
+	 "41:\[\t \]+Type s1;(" \
 	 ".*)?"]
-- 
2.25.1

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