[COMMITTED] ada: Remove redundant protection against empty lists

Message ID 20230522085018.1726226-1-poulhies@adacore.com
State Accepted
Headers
Series [COMMITTED] ada: Remove redundant protection against empty lists |

Checks

Context Check Description
snail/gcc-patch-check success Github commit url

Commit Message

Marc Poulhiès May 22, 2023, 8:50 a.m. UTC
  From: Piotr Trojanek <trojanek@adacore.com>

Calls to List_Length on No_List intentionally return 0 (and likewise
call to First on No_List intentionally return Empty), so explicit guards
against No_List are unnecessary. Code cleanup; semantics is unaffected.

gcc/ada/

	* exp_aggr.adb (Aggregate_Size): Remove redundant calls to
	Present.
	* exp_ch5.adb (Expand_N_If_Statement): Likewise.
	* sem_prag.adb (Analyze_Pragma): Likewise.
	* sem_warn.adb (Find_Var): Likewise.

Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/ada/exp_aggr.adb |  8 +++-----
 gcc/ada/exp_ch5.adb  |  1 -
 gcc/ada/sem_prag.adb | 25 ++++++++++---------------
 gcc/ada/sem_warn.adb |  2 +-
 4 files changed, 14 insertions(+), 22 deletions(-)
  

Patch

diff --git a/gcc/ada/exp_aggr.adb b/gcc/ada/exp_aggr.adb
index 58831bd51ca..e4b1991f410 100644
--- a/gcc/ada/exp_aggr.adb
+++ b/gcc/ada/exp_aggr.adb
@@ -7397,7 +7397,7 @@  package body Exp_Aggr is
          Comp   : Node_Id;
          Choice : Node_Id;
          Lo, Hi : Node_Id;
-         Siz     : Int := 0;
+         Siz    : Int;
 
          procedure Add_Range_Size;
          --  Compute number of components specified by a component association
@@ -7422,11 +7422,9 @@  package body Exp_Aggr is
          end Add_Range_Size;
 
       begin
-         --  Aggregate is either all positional or all named.
+         --  Aggregate is either all positional or all named
 
-         if Present (Expressions (N)) then
-            Siz := List_Length (Expressions (N));
-         end if;
+         Siz := List_Length (Expressions (N));
 
          if Present (Component_Associations (N)) then
             Comp := First (Component_Associations (N));
diff --git a/gcc/ada/exp_ch5.adb b/gcc/ada/exp_ch5.adb
index 0c89856b58b..dfe1112f341 100644
--- a/gcc/ada/exp_ch5.adb
+++ b/gcc/ada/exp_ch5.adb
@@ -4743,7 +4743,6 @@  package body Exp_Ch5 is
         and then not Opt.Suppress_Control_Flow_Optimizations
         and then Nkind (N) = N_If_Statement
         and then No (Elsif_Parts (N))
-        and then Present (Else_Statements (N))
         and then List_Length (Then_Statements (N)) = 1
         and then List_Length (Else_Statements (N)) = 1
       then
diff --git a/gcc/ada/sem_prag.adb b/gcc/ada/sem_prag.adb
index 36c1add5ea4..5fe5d6a2d0f 100644
--- a/gcc/ada/sem_prag.adb
+++ b/gcc/ada/sem_prag.adb
@@ -11699,29 +11699,24 @@  package body Sem_Prag is
 
       --  Preset arguments
 
-      Arg_Count := 0;
-      Arg1      := Empty;
+      Arg_Count := List_Length (Pragma_Argument_Associations (N));
+      Arg1      := First (Pragma_Argument_Associations (N));
       Arg2      := Empty;
       Arg3      := Empty;
       Arg4      := Empty;
       Arg5      := Empty;
 
-      if Present (Pragma_Argument_Associations (N)) then
-         Arg_Count := List_Length (Pragma_Argument_Associations (N));
-         Arg1 := First (Pragma_Argument_Associations (N));
-
-         if Present (Arg1) then
-            Arg2 := Next (Arg1);
+      if Present (Arg1) then
+         Arg2 := Next (Arg1);
 
-            if Present (Arg2) then
-               Arg3 := Next (Arg2);
+         if Present (Arg2) then
+            Arg3 := Next (Arg2);
 
-               if Present (Arg3) then
-                  Arg4 := Next (Arg3);
+            if Present (Arg3) then
+               Arg4 := Next (Arg3);
 
-                  if Present (Arg4) then
-                     Arg5 := Next (Arg4);
-                  end if;
+               if Present (Arg4) then
+                  Arg5 := Next (Arg4);
                end if;
             end if;
          end if;
diff --git a/gcc/ada/sem_warn.adb b/gcc/ada/sem_warn.adb
index 834d48d311c..5dd7c17d4e2 100644
--- a/gcc/ada/sem_warn.adb
+++ b/gcc/ada/sem_warn.adb
@@ -353,7 +353,7 @@  package body Sem_Warn is
             begin
                --  One argument, so check the argument
 
-               if Present (PA) and then List_Length (PA) = 1 then
+               if List_Length (PA) = 1 then
                   if Nkind (First (PA)) = N_Parameter_Association then
                      Find_Var (Explicit_Actual_Parameter (First (PA)));
                   else