Re: [PATCH 4/4] gdb/testsuite: allow_hipcc_tests tests the hipcc compiler

[Lancelot SIX <Lancelot.Six@amd.com>]

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On 07/02/2023 14:12, Simon Marchi wrote:
> Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
> 
> 
> On 2/7/23 08:28, Lancelot SIX via Gdb-patches wrote:
>> Update allow_hipcc_tests so all gdb.rocm tests are skipped if we do not
>> have a working hipcc compiler available.
>>
>> To achieve this, adjust gdb_simple_compile to ensure that the hip
>> program is saved in a ".cpp" file before calling hipcc otherwise
>> compilation will fail.
>>
>> One thing to note is that it is possible to have a hipcc installed with
>> a CUDA backend.  Compiling with this back-end will successfully result
>> in an application, but GDB cannot debug it (at least for the offload
>> part). In the context of the gdb.rocm tests, we want to detect such
>> situation where gdb_simple_compile would give a false positive.
>>
>> To achieve this, this patch checks that there is at least one AMDGPU
>> device available and that hipcc can compile for this or those targets.
>> Detecting the device is done using the rocm_agent_enumerator tool which
>> is installed with the all ROCm installations (it is used by hipcc to
>> detect identify targets if this is not specified on the comand line).
>>
>> This patch also makes the allow_hipcc_tests proc a cached proc.
>> ---
>>   gdb/testsuite/lib/gdb.exp  |  4 +++
>>   gdb/testsuite/lib/rocm.exp | 69 +++++++++++++++++++++++++++++++++++++-
>>   2 files changed, 72 insertions(+), 1 deletion(-)
>>
>> diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
>> index faa0ac05a9a..6333728f71e 100644
>> --- a/gdb/testsuite/lib/gdb.exp
>> +++ b/gdb/testsuite/lib/gdb.exp
>> @@ -4581,6 +4581,10 @@ proc gdb_simple_compile {name code {type object} {compile_flags {}} {object obj}
>>            set ext "go"
>>            break
>>        }
>> +     if { "$flag" eq "hip" } {
>> +         set ext "cpp"
>> +         break
>> +     }
>>       }
>>       set src [standard_temp_file $name-[pid].$ext]
>>       set obj [standard_temp_file $name-[pid].$postfix]
>> diff --git a/gdb/testsuite/lib/rocm.exp b/gdb/testsuite/lib/rocm.exp
>> index b5b59748c27..06d5b3988b8 100644
>> --- a/gdb/testsuite/lib/rocm.exp
>> +++ b/gdb/testsuite/lib/rocm.exp
>> @@ -15,7 +15,51 @@
>>   #
>>   # Support library for testing ROCm (AMD GPU) GDB features.
>>
>> -proc allow_hipcc_tests { } {
>> +# Get the list of gpu targets to compile for.
>> +#
>> +# If HCC_AMDGPU_TARGET is set in the environment, use it.  Otherwise,
>> +# try reading it from the system using the rocm_agent_enumerator
>> +# utility.
>> +
>> +proc hcc_amdgpu_targets {} {
>> +    # Look for HCC_AMDGPU_TARGET (same env var hipcc uses).  If
>> +    # that fails, try using rocm_agent_enumerator (again, same as
>> +    # hipcc does).
>> +    if {[info exists ::env(HCC_AMDGPU_TARGET)]} {
>> +     return [split $::env(HCC_AMDGPU_TARGET) ","]
>> +    }
>> +
>> +    set rocm_agent_enumerator "rocm_agent_enumerator"
>> +
>> +    # If available, use ROCM_PATH to locate rocm_agent_enumerator.
>> +    if { [info exists ::env(ROCM_PATH)] } {
>> +     set rocm_agent_enumerator \
>> +         "$::env(ROCM_PATH)/bin/rocm_agent_enumerator"
>> +    }
>> +
>> +    # If we fail to locate the rocm_agent_enumerator, just return an empty
>> +    # list of targets and let the caller decide if this should be an error.
>> +    if { [which $rocm_agent_enumerator] == 0 } {
>> +     return [list]
>> +    }
>> +
>> +    set result [remote_exec host $rocm_agent_enumerator]
>> +    if { [lindex $result 0] != 0 } {
>> +     error "rocm_agent_enumerator failed"
>> +    }
>> +
>> +    set targets [list]
>> +    foreach target [lindex $result 1] {
>> +     # Ignore gfx000 which is the host CPU.
>> +     if { $target ne "gfx000" } {
>> +         lappend targets $target
>> +     }
>> +    }
>> +
>> +    return $targets
> 
> I typically don't have ROCM_PATH set, and I don't add /opt/rocm/bin to
> my PATH, so rocm_agent_enumerator will not be found by default here.
> However, gdb_find_hipcc does fall back on /opt/rocm/bin, so it does find
> my hipcc.  I think we should use similar strategies for both cases.  I
> don't mind having to set ROCM_PATH or adding /opt/rocm/bin to my PATH if
> needed, as long as we're consistent about it.
> 

When installing the pre-built packages, at least on Ubuntu, there should 
be symlinks from /usr/bin to /etc/alternavites to 
/opt/rocm-$VERSION/bin.   I expect that when those tools start to be 
packaged by the various distributions, they will be available in PATH.

As I am not a big fan of the hard-coded /opt/rocm prefix, especially in 
the context of upstream, I would prefer to update gdb_find_hipcc.

Would something like this be OK?  It search for hipcc in dejagnu's 
tool_root_dir, $::env(ROCM_PATH) (if set) and fallbacks to "hipcc" if 
none of the above worked to search in PATH.

 From b8638cafabd36bc9316591da3c8326e10277372a Mon Sep 17 00:00:00 2001
From: Lancelot SIX <lancelot.six@amd.com>
Date: Tue, 7 Feb 2023 15:13:47 +0000
Subject: [PATCH] gdb/testsuite: look for hipcc in env(ROCM_PATH)

If the hipcc compiler cannot be found in dejagnu's tool_root_dir, look
for it in $::env(ROCM_PATH) (if set).  If hipcc is still not found,
fallback to "hipcc" so the compiler will be searched in the PATH.  This
removes the fallback to the hard-coded "/opt/rocm/bin" prefix.

This change is done so ROCM tools are searched in a uniform manner.
---
  gdb/testsuite/lib/future.exp | 5 ++++-
  1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/gdb/testsuite/lib/future.exp b/gdb/testsuite/lib/future.exp
index 5720d3837d5..2e8315bbfe1 100644
--- a/gdb/testsuite/lib/future.exp
+++ b/gdb/testsuite/lib/future.exp
@@ -125,8 +125,11 @@ proc gdb_find_hipcc {} {
      global tool_root_dir
      if {![is_remote host]} {
  	set hipcc [lookfor_file $tool_root_dir hipcc]
+	if {$hipcc == "" && [info exists ::env(ROCM_PATH)]} {
+	    set hipcc [lookfor_file $::env(ROCM_PATH)/bin hipcc]
+	}
  	if {$hipcc == ""} {
-	    set hipcc [lookfor_file /opt/rocm/bin hipcc]
+	    set hipcc hipcc
  	}
      } else {
  	set hipcc ""
-- 
2.34.1


>> +}
>> +
>> +gdb_caching_proc allow_hipcc_tests {
>>       # Only the native target supports ROCm debugging.  E.g., when
>>       # testing against GDBserver, there's no point in running the ROCm
>>       # tests.
>> @@ -29,6 +73,29 @@ proc allow_hipcc_tests { } {
>>        return 0
>>       }
>>
>> +    # Check we have a working hipcc compiler available.
>> +    set targets [hcc_amdgpu_targets]
>> +    if { [llength $targets] == 0} {
>> +     return 0
>> +    }
>> +
>> +    set flags [list hip additional_flags=--offload-arch=[join $targets ","]]
>> +    if {![gdb_simple_compile hipprobe {
>> +         #include <hip/hip_runtime.h>
>> +         __global__ void
>> +         kern () {}
>> +
>> +         int
>> +         main ()
>> +         {
>> +             kern<<<1, 1>>> ();
>> +             hipDeviceSynchronize ();
>> +             return 0;
>> +         }
>> +     } executable $flags]} {
>> +     return 0
>> +    }
> 
> So, this last part ensures we don't have a "CUDA hipcc false
> positive"?  It would be good to put a comment above it to indicate the
> precise intent.

Yes, if -offload-arch=gfxXX is passed, I expect the cuda backend to 
complain at this is not a valid NVIDIA architecture.  I'll add a comment 
to explain this.

Thanks for the review.
Lancelot.

> 
> Simon

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From b8638cafabd36bc9316591da3c8326e10277372a Mon Sep 17 00:00:00 2001
From: Lancelot SIX <lancelot.six@amd.com>
Date: Tue, 7 Feb 2023 15:13:47 +0000
Subject: [PATCH] gdb/testsuite: look for hipcc in env(ROCM_PATH)

If the hipcc compiler cannot be found in dejagnu's tool_root_dir, look
for it in $::env(ROCM_PATH) (if set).  If hipcc is still not found,
fallback to "hipcc" so the compiler will be searched in the PATH.  This
removes the fallback to the hard-coded "/opt/rocm/bin" prefix.

This change is done so ROCM tools are searched in a uniform manner.
---
 gdb/testsuite/lib/future.exp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/gdb/testsuite/lib/future.exp b/gdb/testsuite/lib/future.exp
index 5720d3837d5..2e8315bbfe1 100644
--- a/gdb/testsuite/lib/future.exp
+++ b/gdb/testsuite/lib/future.exp
@@ -125,8 +125,11 @@ proc gdb_find_hipcc {} {
     global tool_root_dir
     if {![is_remote host]} {
 	set hipcc [lookfor_file $tool_root_dir hipcc]
+	if {$hipcc == "" && [info exists ::env(ROCM_PATH)]} {
+	    set hipcc [lookfor_file $::env(ROCM_PATH)/bin hipcc]
+	}
 	if {$hipcc == ""} {
-	    set hipcc [lookfor_file /opt/rocm/bin hipcc]
+	    set hipcc hipcc
 	}
     } else {
 	set hipcc ""
-- 
2.34.1