From 4c725226c3657adb775af274876de5077b8fbf45 Mon Sep 17 00:00:00 2001
From: Thomas Schwinge <thomas@codesourcery.com>
Date: Thu, 7 Sep 2023 22:15:08 +0200
Subject: [PATCH] More '#ifdef ASM_OUTPUT_DEF' -> 'if
 (TARGET_SUPPORTS_ALIASES)' etc.

Per commit a8b522b483ebb8c972ecfde8779a7a6ec16aecd6 (Subversion r251048)
"Introduce TARGET_SUPPORTS_ALIASES", there is the idea that a back end may or
may not provide symbol aliasing support ('TARGET_SUPPORTS_ALIASES') independent
of '#ifdef ASM_OUTPUT_DEF', and in particular, depending not just on static but
instead on dynamic (run-time) configuration.  There did remain a few instances
where we currently still assume that from '#ifdef ASM_OUTPUT_DEF' follows
'TARGET_SUPPORTS_ALIASES'.  Change these to 'if (TARGET_SUPPORTS_ALIASES)',
similarly, or 'gcc_checking_assert (TARGET_SUPPORTS_ALIASES);'.

	gcc/
	* ipa-icf.cc (sem_item::target_supports_symbol_aliases_p):
	'gcc_checking_assert (TARGET_SUPPORTS_ALIASES);' before
	'return true;'.
	* ipa-visibility.cc (function_and_variable_visibility): Change
	'#ifdef ASM_OUTPUT_DEF' to 'if (TARGET_SUPPORTS_ALIASES)'.
	* varasm.cc (output_constant_pool_contents)
	[#ifdef ASM_OUTPUT_DEF]:
	'gcc_checking_assert (TARGET_SUPPORTS_ALIASES);'.
	(do_assemble_alias) [#ifdef ASM_OUTPUT_DEF]:
	'if (!TARGET_SUPPORTS_ALIASES)',
	'gcc_checking_assert (seen_error ());'.
	(assemble_alias): Change '#if !defined (ASM_OUTPUT_DEF)' to
	'if (!TARGET_SUPPORTS_ALIASES)'.
	(default_asm_output_anchor):
	'gcc_checking_assert (TARGET_SUPPORTS_ALIASES);'.
---
 gcc/ipa-icf.cc        |  1 +
 gcc/ipa-visibility.cc |  8 +++++---
 gcc/varasm.cc         | 13 ++++++++++---
 3 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/gcc/ipa-icf.cc b/gcc/ipa-icf.cc
index 836d0914ded..bbdfd445397 100644
--- a/gcc/ipa-icf.cc
+++ b/gcc/ipa-icf.cc
@@ -218,6 +218,7 @@ sem_item::target_supports_symbol_aliases_p (void)
 #if !defined (ASM_OUTPUT_DEF) || (!defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL))
   return false;
 #else
+  gcc_checking_assert (TARGET_SUPPORTS_ALIASES);
   return true;
 #endif
 }
diff --git a/gcc/ipa-visibility.cc b/gcc/ipa-visibility.cc
index 8ec82bb333e..8ce56114ee3 100644
--- a/gcc/ipa-visibility.cc
+++ b/gcc/ipa-visibility.cc
@@ -622,7 +622,8 @@ function_and_variable_visibility (bool whole_program)
   /* All aliases should be processed at this point.  */
   gcc_checking_assert (!alias_pairs || !alias_pairs->length ());
 
-#ifdef ASM_OUTPUT_DEF
+  if (TARGET_SUPPORTS_ALIASES)
+    {
       FOR_EACH_DEFINED_FUNCTION (node)
 	{
 	  if (node->get_availability () != AVAIL_INTERPOSABLE
@@ -643,7 +644,8 @@ function_and_variable_visibility (bool whole_program)
 
 	      if (!alias)
 		{
-	      alias = dyn_cast<cgraph_node *> (node->noninterposable_alias ());
+		  alias
+		    = dyn_cast<cgraph_node *> (node->noninterposable_alias ());
 		  gcc_assert (alias && alias != node);
 		}
 
@@ -656,7 +658,7 @@ function_and_variable_visibility (bool whole_program)
 		}
 	    }
 	}
-#endif
+    }
 
   FOR_EACH_FUNCTION (node)
     {
diff --git a/gcc/varasm.cc b/gcc/varasm.cc
index 53f0cc61922..40d6081a3fa 100644
--- a/gcc/varasm.cc
+++ b/gcc/varasm.cc
@@ -4300,6 +4300,8 @@ output_constant_pool_contents (struct rtx_constant_pool *pool)
     if (desc->mark < 0)
       {
 #ifdef ASM_OUTPUT_DEF
+	gcc_checking_assert (TARGET_SUPPORTS_ALIASES);
+
 	const char *name = XSTR (desc->sym, 0);
 	char label[256];
 	char buffer[256 + 32];
@@ -6225,6 +6227,10 @@ do_assemble_alias (tree decl, tree target)
 		  IDENTIFIER_POINTER (id),
 		  IDENTIFIER_POINTER (target));
 # endif
+  /* If symbol aliases aren't actually supported...  */
+  if (!TARGET_SUPPORTS_ALIASES)
+    /* ..., 'ASM_OUTPUT_DEF{,_FROM_DECLS}' better have raised an error.  */
+    gcc_checking_assert (seen_error ());
 #elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL)
   {
     const char *name;
@@ -6294,9 +6300,8 @@ assemble_alias (tree decl, tree target)
       if (TREE_PUBLIC (decl))
 	error ("%qs symbol %q+D must have static linkage", "weakref", decl);
     }
-  else
+  else if (!TARGET_SUPPORTS_ALIASES)
     {
-#if !defined (ASM_OUTPUT_DEF)
 # if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL)
       error_at (DECL_SOURCE_LOCATION (decl),
 		"alias definitions not supported in this configuration");
@@ -6317,7 +6322,7 @@ assemble_alias (tree decl, tree target)
 	  return;
 	}
 # endif
-#endif
+      gcc_unreachable ();
     }
   TREE_USED (decl) = 1;
 
@@ -7406,6 +7411,8 @@ default_strip_name_encoding (const char *str)
 void
 default_asm_output_anchor (rtx symbol)
 {
+  gcc_checking_assert (TARGET_SUPPORTS_ALIASES);
+
   char buffer[100];
 
   sprintf (buffer, "*. + " HOST_WIDE_INT_PRINT_DEC,
-- 
2.34.1