[PATCH v1 1/3] mingw: emit end of procedure directive as comment

[Saurabh Jha via Sourceware Forge]

From: Saurabh Jha <saurabh....@arm.com>

For mingw targets, there is no way to identify the end of function using
assembly directives right now.

This patch adds such directive as a comment. This is not a real
directive because some other things, like Structured Exception Handling
(SEH), needs to be supported before we can emit a real directive.

However, emitting an end of function marker now will let us modify
check-function-bodies in scanasm.exp, which in turn enables us to write
dg-compile tests for mingw target.

gcc/ChangeLog:

        * config/aarch64/aarch64-coff.h
        (ASM_COMMENT_START): Specify start of comment.
        (ASM_DECLARE_FUNCTION_SIZE): Specify end of function as comment.

gcc/testsuite/ChangeLog:

        * lib/scanasm.exp: Add support for mingw targets.
---
 gcc/config/aarch64/aarch64-coff.h | 11 +++++++++--
 gcc/testsuite/lib/scanasm.exp     |  2 ++
 2 files changed, 11 insertions(+), 2 deletions(-)


diff --git a/gcc/config/aarch64/aarch64-coff.h b/gcc/config/aarch64/aarch64-coff.h
index 72607262e1b..bcb3a782ba5 100644
--- a/gcc/config/aarch64/aarch64-coff.h
+++ b/gcc/config/aarch64/aarch64-coff.h
@@ -61,10 +61,17 @@
 #define ASM_OUTPUT_SKIP(STREAM, NBYTES) 	\
   fprintf (STREAM, "\t.space\t%d  // skip\n", (int) (NBYTES))
 
-/* Definitions that are not yet supported by binutils for the
+#define ASM_COMMENT_START "//"
+
+/* ASM_OUTPUT_TYPE_DIRECTIVE is not yet supported by binutils for the
    aarch64-w64-mingw32 target.  */
 #define ASM_OUTPUT_TYPE_DIRECTIVE(STREAM, NAME, TYPE)
-#define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL)
+
+/* Structured Exception Handling (SEH) is not yet supported by binutils
+   so adding seh_endproc as an assembly comment to mark the end of a
+   function.  */
+#define ASM_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL) \
+  fprintf (FILE, "\t" ASM_COMMENT_START "  seh_endproc\n")
 
 #define TEXT_SECTION_ASM_OP	"\t.text"
 #define DATA_SECTION_ASM_OP	"\t.data"
diff --git a/gcc/testsuite/lib/scanasm.exp b/gcc/testsuite/lib/scanasm.exp
index 51952a6a7f4..1f9842e7fa3 100644
--- a/gcc/testsuite/lib/scanasm.exp
+++ b/gcc/testsuite/lib/scanasm.exp
@@ -885,6 +885,8 @@ proc configure_check-function-bodies { config } {
 	set up_config(end) {^\}$}
     } elseif { [istarget *-*-darwin*] } {
 	set up_config(end) {^LFE[0-9]+}
+    } elseif { [istarget *-*-mingw32] } {
+	set up_config(end) {seh_endproc}
     } else {
 	set up_config(end) {^\s*\.size}
     }