sim: testsuite: rework sim_init usage

The sim_init function was called by runtest for each test when --tool
was set to sim.  When we changed to --tool '' to collapse the testsuite
dir, the init function was no longer called on every test.  However, it
was still being called explicitly by config/default.exp.  It's not clear
why that explicit call ever existed since, in the past, it meant it was
redundant.

Lets drop the single sim_init call in config/default.exp and move it out
to all our tests.  This replicates the runtest behavior so we can setup
variables on a per-test basis which allows us to recollapse the sim_path
logic back.  We'll also leverage this in the future for toolchain setup.

Also add a few comments clarifying the overall runtime behavior.

1 files changed, 21 insertions, 22 deletions

diff --git a/sim/testsuite/lib/sim-defs.exp b/sim/testsuite/lib/sim-defs.exp
index 405f1b7..46a8b3f 100644
--- a/sim/testsuite/lib/sim-defs.exp
+++ b/sim/testsuite/lib/sim-defs.exp
@@ -7,12 +7,22 @@
 set sim_path "unknown-run"
 
 # Initialize the testrun.
-# Required by dejagnu.
+#
+# Normally dejagnu will execute ${tool}_init automatically, but since we set
+# --tool '' (for a simpler testsuite/ layout), we have each test call this
+# itself.
 
 proc sim_init { args } {
+    global builddir
+    global subdir
     global sim_path
-    set sim_path [board_info target sim]
-    # Need to return an empty string (copied from GAS).
+
+    # Find the path to the simulator for executing.
+    set arch "$subdir"
+    while { [file dirname $arch] != "." } {
+	set arch [file dirname $arch]
+    }
+    set sim_path "$builddir/$arch/run"
 
     # As gross as it is, we unset the linker script specified by the target
     # board.  The simulator board file mips-sim.exp, sets ldscript to the
@@ -23,6 +33,8 @@ proc sim_init { args } {
     # all simulators.
     unset_currtarget_info ldscript
 
+    # Need to return an empty string.  This tells dejagnu to *not* re-run us
+    # with the exact test that we're about to run.
     return ""
 }
 
@@ -35,22 +47,6 @@ proc sim_version {} {
     clone_output "$sim_path $version\n"
 }
 
-# Find the path to the simulator for executing.
-proc sim_tool_path {} {
-    global sim_path
-    set sim "$sim_path"
-    if [string equal "" $sim] {
-	global builddir
-	global subdir
-	set arch "$subdir"
-	while { [file dirname $arch] != "." } {
-	    set arch [file dirname $arch]
-	}
-	return "$builddir/$arch/run"
-    }
-    return "$sim"
-}
-
 # Run a program on the simulator.
 # Required by dejagnu (at least ${tool}_run used to be).
 #
@@ -73,6 +69,8 @@ proc sim_tool_path {} {
 # simulator (not the simulated program, the simulator) with sim_load.
 
 proc sim_run { prog sim_opts prog_opts redir options } {
+    global sim_path
+
     # Set the default value of the timeout.
     # FIXME: The timeout value we actually want is a function of
     # host, target, and testcase.
@@ -99,7 +97,7 @@ proc sim_run { prog sim_opts prog_opts redir options } {
 	
     verbose "testcase timeout is set to $testcase_timeout" 1
 
-    set sim [sim_tool_path]
+    set sim $sim_path
 
     if [is_remote host] {
 	set prog [remote_download host $prog]
@@ -182,13 +180,14 @@ proc sim_run { prog sim_opts prog_opts redir options } {
 
 proc run_sim_test { name requested_machs } {
     global subdir srcdir objdir
+    global sim_path
     global opts
     global cpu_option
     global cpu_option_sep
     global SIMFLAGS_FOR_TARGET
 
-    if ![file exists [sim_tool_path]] {
-	unsupported "$name: missing simulator [sim_tool_path]"
+    if ![file exists $sim_path] {
+	unsupported "$name: missing simulator $sim_path"
 	return
     }