From 60856b5cdafc520538688258a8ce4ae8be2a8477 Mon Sep 17 00:00:00 2001
From: Vladislav Belov <vladislav.belov@syntacore.com>
Date: Wed, 28 Feb 2024 16:36:37 +0000
Subject: Fix implementation of SUBALIGN.

---
 ld/ldlang.c                        | 13 ++++++++-----
 ld/testsuite/ld-scripts/align.exp  |  8 ++++++++
 ld/testsuite/ld-scripts/subalign.d | 12 ++++++++++++
 ld/testsuite/ld-scripts/subalign.s | 20 ++++++++++++++++++++
 ld/testsuite/ld-scripts/subalign.t | 20 ++++++++++++++++++++
 5 files changed, 68 insertions(+), 5 deletions(-)
 create mode 100644 ld/testsuite/ld-scripts/subalign.d
 create mode 100644 ld/testsuite/ld-scripts/subalign.s
 create mode 100644 ld/testsuite/ld-scripts/subalign.t

(limited to 'ld')

diff --git a/ld/ldlang.c b/ld/ldlang.c
index 229401c..54d1af6 100644
--- a/ld/ldlang.c
+++ b/ld/ldlang.c
@@ -5468,13 +5468,16 @@ size_input_section
       /* Align this section first to the input sections requirement,
 	 then to the output section's requirement.  If this alignment
 	 is greater than any seen before, then record it too.  Perform
-	 the alignment by inserting a magic 'padding' statement.  */
+	 the alignment by inserting a magic 'padding' statement.
+         We can force input section alignment within an output section 
+         by using SUBALIGN.  The value specified overrides any alignment 
+         given by input sections, whether larger or smaller.  */
 
       if (output_section_statement->subsection_alignment != NULL)
-	i->alignment_power
-	  = exp_get_power (output_section_statement->subsection_alignment,
-			   output_section_statement,
-			   "subsection alignment");
+	o->alignment_power = i->alignment_power =
+	  exp_get_power (output_section_statement->subsection_alignment,
+			 output_section_statement,
+			 "subsection alignment");
 
       if (o->alignment_power < i->alignment_power)
 	o->alignment_power = i->alignment_power;
diff --git a/ld/testsuite/ld-scripts/align.exp b/ld/testsuite/ld-scripts/align.exp
index ea0500d..e34825e 100644
--- a/ld/testsuite/ld-scripts/align.exp
+++ b/ld/testsuite/ld-scripts/align.exp
@@ -48,6 +48,14 @@ if ![is_aout_format] {
     run_dump_test align5
 }
 run_dump_test align2c
+
+if { [is_elf_format] } {
+    # FIXME: Currently this test is only run for ELF targets as other formats
+    # do not necessarily support these large alignments.  It could be tweaked
+    # to work with other formats.
+    run_dump_test subalign
+}
+
 set LDFLAGS "$saved_LDFLAGS"
 
 if { [is_elf_format] && ![uses_genelf] } {
diff --git a/ld/testsuite/ld-scripts/subalign.d b/ld/testsuite/ld-scripts/subalign.d
new file mode 100644
index 0000000..37483a3
--- /dev/null
+++ b/ld/testsuite/ld-scripts/subalign.d
@@ -0,0 +1,12 @@
+# ld: -T subalign.t --no-error-rwx-segments -e 0
+# objdump: -h --wide
+# Ensure that SUBALIGN fixes the alignment of the output section.
+# Check that ALIGN provides a minimum alignment, although allow the target to require a larger value.
+
+#...
+  . .mysection1.*2\*\*2.*
+#...
+  . .mysection2.*2\*\*[4-9].*
+#...
+  . .mysection3.*2\*\*[3-9].*
+#...
diff --git a/ld/testsuite/ld-scripts/subalign.s b/ld/testsuite/ld-scripts/subalign.s
new file mode 100644
index 0000000..5589570
--- /dev/null
+++ b/ld/testsuite/ld-scripts/subalign.s
@@ -0,0 +1,20 @@
+	.file	"subalign.c"
+	.text
+	.globl		a_one
+	.section	.mysection1,"aw"
+	.align 8
+a_one:
+	.zero		1
+
+	.globl		b_one
+	.section	.mysection2,"aw"
+	.align 		8
+b_one:
+	.zero	1
+
+	.globl		c_one
+	.section	.mysection3,"aw"
+	.align 		8
+c_one:
+	.zero	1
+
diff --git a/ld/testsuite/ld-scripts/subalign.t b/ld/testsuite/ld-scripts/subalign.t
new file mode 100644
index 0000000..36ee259
--- /dev/null
+++ b/ld/testsuite/ld-scripts/subalign.t
@@ -0,0 +1,20 @@
+SECTIONS
+{
+    . = 0x10024;
+
+    .mysection1 : SUBALIGN(4) {
+        *(.mysection1)
+    }
+
+    .mysection2 : ALIGN(16) {
+        *(.mysection2)
+    }
+  
+    .mysection3 : {
+        *(.mysection3)
+    }
+  
+    /DISCARD/ : {
+      *(*)
+    }
+}
-- 
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