Re: [PATCH 5/5] gdb: native target invalid architecture detection

[Pedro Alves <pedro@palves.net>]

On 2022-06-07 19:42, Pedro Alves wrote:

>     When we use gcc for arm-linux target, its file name can be different,
>     arm-linux-gnueabihf-gcc, arm-linux-gnueabi-gcc, or arm-none-linux-gnueabi-gcc,
>     so I add a variable ARM_CC_FOR_TARGET, so that user can set the name
>     of gcc for arm-linux target on aarch64, like:

...

> Maybe it would be possible to come up with a way to default ARM_CC_FOR_TARGET to
> something that works for most people when testing aarch64, somehow.

Maybe something like this?  Completely untested, other than hacking it such that
the aarch64 linux path is taken on my x86-64 box, to ensure the tcl at least parses
as expected.

I left arm-linux-gnueabihf-gcc last on the theory that binaries produced by
arm-linux-gnueabi-gcc and arm-none-linux-gnueabi-gcc would run everywhere, but
arm-linux-gnueabihf-gcc might now.  I am not really sure about that, I may be
making that up.

gdb.multi/multi-arch-exec.exp also uses ARM_CC_FOR_TARGET.  If something like
this works, then we could do the same to that testcase.  Even better if we
manage to factor this out to a shared procedure used by both testcases.

From 56cdd32a54b236d35c433809fcb015f20487dc4b Mon Sep 17 00:00:00 2001
From: Pedro Alves <pedro@palves.net>
Date: Tue, 7 Jun 2022 20:11:32 +0100
Subject: [PATCH] aarch64: gdb.multi/multi-arch.exp: Add fallback if
 ARM_CC_FOR_TARGET not set

On Aarch64, you can set ARM_CC_FOR_TARGET to the 32-bit compiler to
use when testing gdb.multi/multi-arch.exp.  If you set it, then the
testcase doesn't run.

I guess that approximately nobody remembers to set ARM_CC_FOR_TARGET.

This commit adds a fallback.  If ARM_CC_FOR_TARGET is not set, and
testing for Linux, try arm-linux-gnueabi-gcc,
arm-none-linux-gnueabi-gcc, arm-linux-gnueabihf-gcc.

Change-Id: Iefe5865d5fc84b4032eaff7f4c5c61582bf75c39
---
 gdb/testsuite/gdb.multi/multi-arch.exp | 39 ++++++++++++++++++++++----
 1 file changed, 34 insertions(+), 5 deletions(-)

diff --git a/gdb/testsuite/gdb.multi/multi-arch.exp b/gdb/testsuite/gdb.multi/multi-arch.exp
index e5c2d9cc161..a9d442d89ad 100644
--- a/gdb/testsuite/gdb.multi/multi-arch.exp
+++ b/gdb/testsuite/gdb.multi/multi-arch.exp
@@ -61,18 +61,47 @@ set options [list debug]
 
 if [istarget "aarch64*-*-*"] {
     if {[info exists ARM_CC_FOR_TARGET]} {
-	lappend options "compiler=${ARM_CC_FOR_TARGET}"
+	set compilers [list ${ARM_CC_FOR_TARGET}]
+    } elseif [istarget "*-linux*-*"] {
+	# Try a few common compiler names.
+	set compilers {
+	    arm-linux-gnueabi-gcc
+	    arm-none-linux-gnueabi-gcc
+	    arm-linux-gnueabihf-gcc
+	}
     } else {
+	set compilers {}
+    }
+
+    set ok 0
+    foreach compiler $compilers {
+	set arm_options $options
+	lappend arm_options "compiler=$compiler"
+
+	if {![is_remote host] && [which $compiler] == 0} {
+	    # Avoid "default_target_compile: Can't find
+	    # $compiler." warning issued from gdb_compile.
+	    continue
+	}
+
+	if { [gdb_compile "${srcdir}/${subdir}/${srcfile2}" ${exec2} \
+		  executable $arm_options] == "" } {
+	    set ok 1
+	    break
+	}
+    }
+
+    if {!$ok} {
 	unsupported "ARM compiler is not known"
 	return -1
     }
 } else {
     lappend options "additional_flags=${march2}"
-}
 
-if { [build_executable "failed to prepare" ${exec2} "${srcfile2}" \
-	 $options]} {
-    return -1
+    if { [build_executable "failed to prepare" ${exec2} "${srcfile2}" \
+	      $options]} {
+	return -1
+    }
 }
 
 # Start inferior 1

base-commit: 0c8cd1de90b97f12b27b40c2922a03a68932eea1
-- 
2.36.0