[DebugInfo] Fix bug in multi-entry procedures

When the compiler generates debuginfo for a procedure, it does not consider
that if is an ENTRY statement, the number of arguments will increase
by one. We can fix this problem by using the new number of arguments as
returned by the process_ll_abi_func_ftn_mod function.

Author: liuyunlong16

test/debug_info/entry_argument_1.f90

@@ -0,0 +1,20 @@
+!RUN: %flang -g -S -emit-llvm %s -o - | FileCheck %s
+
+!CHECK: [[N1:![0-9]+]] = distinct !DISubprogram
+!CHECK: !DILocalVariable(arg: 1, scope: [[N1]]
+!CHECK: !DILocalVariable(arg: 2, scope: [[N1]]
+!CHECK: !DILocalVariable(name: "a", arg: 3, scope: [[N1]]
+
+module test
+contains
+  subroutine sub(a)
+    implicit none
+    integer(kind = 4) :: m
+    real(kind = 8), intent(inout) :: a(:,:)
+    m = size(a, 1)
+    entry subsub(a)
+    m = size(a, 1) + 1
+    entry subsub1(a)
+    m = size(a, 1) + 2
+  end subroutine sub
+end module

tools/flang2/flang2exe/cgmain.cpp

@@ -275,6 +275,7 @@ typedef struct ComplexResultList_t {
   unsigned entries;
 } ComplexResultList_t;
 static ComplexResultList_t complexResultList;
+LL_ABI_Info *entry_abi;
 
 /* ---  static prototypes (exported prototypes belong in cgllvm.h) --- */
 
@@ -1613,11 +1614,12 @@ schedule(void)
 
   /* Build up the additional items/dummys needed for the master sptr if there
      are entries, and call process_formal_arguments on that information. */
-  if (has_multiple_entries(gbl.currsub) && get_entries_argnum())
-    process_formal_arguments(
-        process_ll_abi_func_ftn_mod(current_module, get_master_sptr(), 1));
-  else
+  if (has_multiple_entries(gbl.currsub) && get_entries_argnum()) {
+    entry_abi = process_ll_abi_func_ftn_mod(current_module, get_master_sptr(), 1);
+    process_formal_arguments(entry_abi);
+  } else {
     process_formal_arguments(llvm_info.abi_info);
+  }
   made_return = false;
 
   get_local_overlap_size();
@@ -14574,3 +14576,15 @@ get_parnum(SPTR sptr)
 
   return 0;
 }
+
+int
+get_entry_parnum(SPTR sptr)
+{
+  for (unsigned parnum = 1; parnum <= entry_abi->nargs; parnum++) {
+    if (entry_abi->arg[parnum].sptr == sptr) {
+      return parnum;
+    }
+  }
+
+  return 0;
+}

tools/flang2/flang2exe/cgmain.h

@@ -303,4 +303,6 @@ void insert_llvm_dbg_value(OPERAND *load, LL_MDRef mdnode, SPTR sptr,
 bool pointer_scalar_need_debug_info(SPTR sptr);
 
 int get_parnum(SPTR sptr);
+
+int get_entry_parnum(SPTR sptr);
 #endif

tools/flang2/flang2exe/lldebug.cpp

@@ -3253,10 +3253,15 @@ lldbg_emit_type(LL_DebugInfo *db, DTYPE dtype, SPTR sptr, int findex,
               if (SCG(data_sptr) == SC_DUMMY) {
                 LL_MDRef type_mdnode = lldbg_emit_type(
                     db, __POINT_T, data_sptr, findex, false, false, false);
+                int parnum_lldbg = 0;
+                if (has_multiple_entries(gbl.currsub))
+                  parnum_lldbg = get_entry_parnum(data_sptr);
+                else
+                  parnum_lldbg = get_parnum(data_sptr);
                 dataloc = lldbg_create_local_variable_mdnode(
                     db, DW_TAG_arg_variable, db->cur_subprogram_mdnode, NULL,
                     file_mdnode, db->cur_subprogram_lineno,
-                    get_parnum(data_sptr), type_mdnode,
+                    parnum_lldbg, type_mdnode,
                     set_dilocalvariable_flags(data_sptr), ll_get_md_null());
                 lldbg_register_param_mdnode(db, dataloc, data_sptr);
 
@@ -3317,10 +3322,15 @@ lldbg_emit_type(LL_DebugInfo *db, DTYPE dtype, SPTR sptr, int findex,
                   if (SCG(datasptr) == SC_DUMMY) {
                     LL_MDRef type_mdnode = lldbg_emit_type(
                         db, __POINT_T, datasptr, findex, false, false, false);
+                    int parnum_lldbg = 0;
+                    if (has_multiple_entries(gbl.currsub))
+                      parnum_lldbg = get_entry_parnum(data_sptr);
+                    else
+                      parnum_lldbg = get_parnum(data_sptr);
                     dataloc = lldbg_create_local_variable_mdnode(
                         db, DW_TAG_arg_variable, db->cur_subprogram_mdnode,
                         NULL, file_mdnode, db->cur_subprogram_lineno,
-                        get_parnum(sptr), type_mdnode,
+                        parnum_lldbg, type_mdnode,
                         set_dilocalvariable_flags(datasptr), ll_get_md_null());
                     lldbg_register_param_mdnode(db, dataloc, datasptr);
                   } else
@@ -3975,12 +3985,18 @@ lldbg_emit_param_variable(LL_DebugInfo *db, SPTR sptr, int findex, int parnum,
     if ((ASSUMRANKG(sptr) || ASSUMSHPG(sptr)) && SDSCG(sptr)) {
       type_mdnode = lldbg_emit_type(db, dtype, SDSCG(sptr), findex,
                                     is_reference, true, false, sptr);
-      parnum = get_parnum(SDSCG(sptr));
+      if (has_multiple_entries(gbl.currsub))
+        parnum = get_entry_parnum(SDSCG(sptr));
+      else
+        parnum = get_parnum(SDSCG(sptr));
     } else if (STYPEG(sptr) == ST_ARRAY &&
                (ALLOCATTRG(sptr) || POINTERG(sptr)) && SDSCG(sptr)) {
       type_mdnode = lldbg_emit_type(db, dtype, sptr, findex, is_reference, true,
                                     false, MIDNUMG(sptr));
-      parnum = get_parnum(SDSCG(sptr));
+      if (has_multiple_entries(gbl.currsub))
+        parnum = get_entry_parnum(SDSCG(sptr));
+      else
+        parnum = get_parnum(SDSCG(sptr));
     } else {
       type_mdnode =
           lldbg_emit_type(db, dtype, sptr, findex, is_reference, true, false);