Support NEXT_SECTION in ALIGNOF and SIZEOF

This patch is aimed at making __bss_start properly aligned with the
first of any bss-style sections following.  Most of the work here
involves keeping track of the last output section seen when processing
the linker script.

You can almost align __bss_start properly by using
${RELOCATING+. = ALIGN(${DATA_SDATA-${NO_SMALL_DATA-ALIGNOF(.${SBSS_NAME}) != 0 ? ALIGNOF(.${SBSS_NAME}) : }}${BSS_PLT+ALIGNOF(.plt) != 0 ? ALIGNOF(.plt) : }ALIGNOF(.${BSS_NAME}));}
and changing every place that defines NO_SMALL_DATA to use " ", but
having two .plt sections (marked SPECIAL) on some backends foils that
idea.  The problem is that you only want to pick up the following
.plt, not the one preceeding __bss_start in the data segment if the
backend decides that is the proper .plt section.

Perhaps that could be fixed too, but I decided instead to extend the
linker script a little.  THIS_SECTION and PREV_SECTION could easily be
added too.

	* ld.texi (ALIGNOF, SIZEOF): Update and mention NEXT_SECTION.
	* ldexp.c (output_section_find): New function.
	(fold_name <ALIGNOF, SIZEOF>): Use output_section_find.
	(exp_fold_tree): Add os parameter.  Adjust all calls.
	(exp_fold_tree_no_dot, exp_get_vma, exp_get_power): Likewise.
	* ldexp.h (struct ldexp_control): Add last_os.
	(exp_fold_tree, exp_fold_tree_no_dot): Update prototypes.
	(exp_get_vma, exp_get_power): Likewise.
	* ldlang.c: Pass last output section to expression folder
	calls throughout file.
	(open_input_bfds): Add os parameter to track last os seen.
	(lang_size_sections_1): Rename output_section_statement param
	to current_os.  Track last os.
	(lang_do_assignments_1): Track last os.
	* scripttempl/arclinux.sc: Align to ALIGNOF NEXT_SECTION
	before defining __bss_start.
	* scripttempl/elf.sc: Likewise.
	* scripttempl/elf64bpf.sc: Likewise.
	* scripttempl/elf64hppa.sc: Likewise.
	* scripttempl/elf_chaos.sc: Likewise.
	* scripttempl/elfarc.sc: Likewise.
	* scripttempl/elfd10v.sc: Likewise.
	* scripttempl/elfxtensa.sc: Likewise.
	* scripttempl/epiphany_4x4.sc: Likewise.
	* scripttempl/iq2000.sc: Likewise.
	* scripttempl/mep.sc: Likewise.
	* scripttempl/nds32elf.sc: Likewise.
	* scripttempl/xstormy16.sc: Likewise.
	* testsuite/ld-x86-64/pe-x86-64-5.od: Update expected __bss_start.
	* testsuite/ld-x86-64/pe-x86-64-5.rd: Likewise.

13 files changed, 13 insertions, 5 deletions

diff --git a/ld/scripttempl/arclinux.sc b/ld/scripttempl/arclinux.sc
index 20429df..3c27625 100644
--- a/ld/scripttempl/arclinux.sc
+++ b/ld/scripttempl/arclinux.sc
@@ -613,7 +613,7 @@ cat <<EOF
   ${DATA_SDATA-${SDATA}}
   ${DATA_SDATA-${OTHER_SDATA_SECTIONS}}
   ${RELOCATING+${DATA_END_SYMBOLS-${USER_LABEL_PREFIX}_edata = .; PROVIDE (${USER_LABEL_PREFIX}edata = .);}}
-  ${RELOCATING+. = .;}
+  ${RELOCATING+. = ALIGN(ALIGNOF(NEXT_SECTION));}
   ${RELOCATING+${USER_LABEL_PREFIX}__bss_start = .;}
   ${RELOCATING+${OTHER_BSS_SYMBOLS}}
   ${DATA_SDATA-${SBSS}}
diff --git a/ld/scripttempl/elf.sc b/ld/scripttempl/elf.sc
index 82de4ed..fe921cd 100644
--- a/ld/scripttempl/elf.sc
+++ b/ld/scripttempl/elf.sc
@@ -689,7 +689,7 @@ cat <<EOF
   ${RELOCATING+${SYMBOL_ABI_ALIGNMENT+. = ALIGN(${SYMBOL_ABI_ALIGNMENT});}}
   ${RELOCATING+${DATA_END_SYMBOLS-${CREATE_SHLIB+PROVIDE (}$(def_symbol "_edata")${CREATE_SHLIB+)}; PROVIDE ($(def_symbol "edata"));}}
   ${PERSISTENT}
-  ${RELOCATING+. = .;}
+  ${RELOCATING+. = ALIGN(ALIGNOF(NEXT_SECTION));}
   ${RELOCATING+${CREATE_SHLIB+PROVIDE (}$(def_symbol "__bss_start")${CREATE_SHLIB+)};}
   ${RELOCATING+${OTHER_BSS_SYMBOLS}}
   ${DATA_SDATA-${SBSS}}
diff --git a/ld/scripttempl/elf64bpf.sc b/ld/scripttempl/elf64bpf.sc
index 7415458..07a0726 100644
--- a/ld/scripttempl/elf64bpf.sc
+++ b/ld/scripttempl/elf64bpf.sc
@@ -636,7 +636,7 @@ cat <<EOF
   ${DATA_SDATA-${SDATA}}
   ${DATA_SDATA-${OTHER_SDATA_SECTIONS}}
   ${RELOCATING+${DATA_END_SYMBOLS-${CREATE_SHLIB+PROVIDE (}${USER_LABEL_PREFIX}_edata = .${CREATE_SHLIB+)}; PROVIDE (${USER_LABEL_PREFIX}edata = .);}}
-  ${RELOCATING+. = .;}
+  ${RELOCATING+. = ALIGN(ALIGNOF(NEXT_SECTION));}
   ${RELOCATING+${CREATE_SHLIB+PROVIDE (}${USER_LABEL_PREFIX}__bss_start = .${CREATE_SHLIB+)};}
   ${RELOCATING+${OTHER_BSS_SYMBOLS}}
   ${DATA_SDATA-${SBSS}}
diff --git a/ld/scripttempl/elf64hppa.sc b/ld/scripttempl/elf64hppa.sc
index e85dd39..b3be5a2 100644
--- a/ld/scripttempl/elf64hppa.sc
+++ b/ld/scripttempl/elf64hppa.sc
@@ -490,6 +490,7 @@ cat <<EOF
   ${SDATA}
   ${OTHER_SDATA_SECTIONS}
   ${RELOCATING+${DATA_END_SYMBOLS-${USER_LABEL_PREFIX}_edata = .; PROVIDE (${USER_LABEL_PREFIX}edata = .);}}
+  ${RELOCATING+. = ALIGN(ALIGNOF(NEXT_SECTION));}
   ${RELOCATING+__bss_start = .;}
   ${RELOCATING+${OTHER_BSS_SYMBOLS}}
   ${SBSS}
diff --git a/ld/scripttempl/elf_chaos.sc b/ld/scripttempl/elf_chaos.sc
index 72f91c9..88b573c 100644
--- a/ld/scripttempl/elf_chaos.sc
+++ b/ld/scripttempl/elf_chaos.sc
@@ -303,6 +303,7 @@ cat <<EOF
   ${OTHER_SDATA_SECTIONS}
   ${RELOCATING+_edata = .;}
   ${RELOCATING+PROVIDE (edata = .);}
+  ${RELOCATING+. = ALIGN(ALIGNOF(NEXT_SECTION));}
   ${RELOCATING+__bss_start = .;}
   ${RELOCATING+${OTHER_BSS_SYMBOLS}}
   ${SBSS}
diff --git a/ld/scripttempl/elfarc.sc b/ld/scripttempl/elfarc.sc
index 57cd0a5..1ae0248 100644
--- a/ld/scripttempl/elfarc.sc
+++ b/ld/scripttempl/elfarc.sc
@@ -365,6 +365,7 @@ cat <<EOF
   ${OTHER_SDATA_SECTIONS}
   ${RELOCATING+_edata = .;}
   ${RELOCATING+PROVIDE (edata = .);}
+  ${RELOCATING+. = ALIGN(ALIGNOF(NEXT_SECTION));}
   ${RELOCATING+__bss_start = .;}
   ${RELOCATING+${OTHER_BSS_SYMBOLS}}
   ${SBSS}
diff --git a/ld/scripttempl/elfd10v.sc b/ld/scripttempl/elfd10v.sc
index e52aaed..316fa89 100644
--- a/ld/scripttempl/elfd10v.sc
+++ b/ld/scripttempl/elfd10v.sc
@@ -156,6 +156,7 @@ SECTIONS
 
   ${RELOCATING+_edata = .;}
   ${RELOCATING+PROVIDE (edata = .);}
+  ${RELOCATING+. = ALIGN(ALIGNOF(NEXT_SECTION));}
   ${RELOCATING+__bss_start = .;}
   .sbss    ${RELOCATING-0} : { *(.sbss)${RELOCATING+ *(.scommon)} } ${RELOCATING+ >DATA}
   .bss     ${RELOCATING-0} :
diff --git a/ld/scripttempl/elfxtensa.sc b/ld/scripttempl/elfxtensa.sc
index 7c71525..9c85d15 100644
--- a/ld/scripttempl/elfxtensa.sc
+++ b/ld/scripttempl/elfxtensa.sc
@@ -500,6 +500,7 @@ cat <<EOF
   ${SDATA}
   ${OTHER_SDATA_SECTIONS}
   ${RELOCATING+${DATA_END_SYMBOLS-${USER_LABEL_PREFIX}_edata = .; PROVIDE (${USER_LABEL_PREFIX}edata = .);}}
+  ${RELOCATING+. = ALIGN(ALIGNOF(NEXT_SECTION));}
   ${RELOCATING+__bss_start = .;}
   ${RELOCATING+${OTHER_BSS_SYMBOLS}}
   ${SBSS}
diff --git a/ld/scripttempl/epiphany_4x4.sc b/ld/scripttempl/epiphany_4x4.sc
index 0f4e74f..ee253af 100644
--- a/ld/scripttempl/epiphany_4x4.sc
+++ b/ld/scripttempl/epiphany_4x4.sc
@@ -578,7 +578,7 @@ cat <<EOF
   /* Align ___bss_start and _end to a multiple of 8 so that we can use strd
      to clear bss.  N.B., without adding any extra alignment, we would have
      to clear the bss byte by byte.  */
-  ${RELOCATING+. = ALIGN(8);}
+  ${RELOCATING+. = ALIGN(MAX(8,ALIGNOF(NEXT_SECTION)));}
   ${RELOCATING+___bss_start = .;}
   ${RELOCATING+${OTHER_BSS_SYMBOLS}}
   ${SBSS}
diff --git a/ld/scripttempl/iq2000.sc b/ld/scripttempl/iq2000.sc
index 47bd777..c3d3620 100644
--- a/ld/scripttempl/iq2000.sc
+++ b/ld/scripttempl/iq2000.sc
@@ -373,6 +373,7 @@ cat <<EOF
   ${RELOCATING+${OTHER_SDATA_SECTIONS}}
   ${RELOCATING+_edata = .;}
   ${RELOCATING+PROVIDE (edata = .);}
+  ${RELOCATING+. = ALIGN(ALIGNOF(NEXT_SECTION));}
   ${RELOCATING+__bss_start = .;}
   ${RELOCATING+${OTHER_BSS_SYMBOLS}}
   .sbss    ${RELOCATING-0} :
diff --git a/ld/scripttempl/mep.sc b/ld/scripttempl/mep.sc
index 6b80c36..d49f848 100644
--- a/ld/scripttempl/mep.sc
+++ b/ld/scripttempl/mep.sc
@@ -385,6 +385,7 @@ cat <<EOF
   ${OTHER_SDATA_SECTIONS}
   ${RELOCATING+_edata = .;}
   ${RELOCATING+PROVIDE (edata = .);}
+  ${RELOCATING+. = ALIGN(ALIGNOF(NEXT_SECTION));}
   ${RELOCATING+__bss_start = .;}
   ${RELOCATING+${OTHER_BSS_SYMBOLS}}
   ${SBSS}
diff --git a/ld/scripttempl/nds32elf.sc b/ld/scripttempl/nds32elf.sc
index 9645e80..36d04cd 100644
--- a/ld/scripttempl/nds32elf.sc
+++ b/ld/scripttempl/nds32elf.sc
@@ -557,7 +557,7 @@ cat <<EOF
   ${OTHER_SDATA_SECTIONS}
   ${RELOCATING+. = ALIGN(4);}
   ${RELOCATING+${DATA_END_SYMBOLS-${USER_LABEL_PREFIX}_edata = .; PROVIDE (${USER_LABEL_PREFIX}edata = .);}}
-  ${RELOCATING+. = .;}
+  ${RELOCATING+. = ALIGN(ALIGNOF(NEXT_SECTION));}
   ${RELOCATING+${USER_LABEL_PREFIX}__bss_start = .;}
   ${RELOCATING+${OTHER_BSS_SYMBOLS}}
   ${SBSS}
diff --git a/ld/scripttempl/xstormy16.sc b/ld/scripttempl/xstormy16.sc
index ccae0a2..b29f720 100644
--- a/ld/scripttempl/xstormy16.sc
+++ b/ld/scripttempl/xstormy16.sc
@@ -143,6 +143,7 @@ SECTIONS
   ${RELOCATING+${OTHER_GOT_SECTIONS}}
   ${RELOCATING+_edata = .;}
   ${RELOCATING+PROVIDE (edata = .);}
+  ${RELOCATING+. = ALIGN(ALIGNOF(NEXT_SECTION));}
   ${RELOCATING+__bss_start = .;}
   ${RELOCATING+${OTHER_BSS_SYMBOLS}}
   .bss     ${RELOCATING-0} :