[asan] Add lit feature to indicate compiler_rt's shadow scale value

[waltl]

Summary

This will be used to mark tests that require a specific shadow scale.

[waltl]

Change approach to only override shadow scale in compiler_rt

[vitalybuka]

compiler-rt/test/lit.common.cfg

332 ↗

(On Diff #122459)

can we see a patch where it's used?

[waltl]

compiler-rt/test/lit.common.cfg

332 ↗

(On Diff #122459)

https://reviews.llvm.org/D39774

[vitalybuka]

compiler-rt/test/lit.common.cfg

332 ↗

(On Diff #122459)

WDYT about "config.available_features.add("shadow-scale-%s" % (config.asan_shadow_scale if not empty else 3))"?

So you can replace " UNSUPPORTED: custom-shadow-scale" with " REQUIRES: shadow-scale-3"
This allows to add some scale-5 specific tests

[waltl]

compiler-rt/test/lit.common.cfg

332 ↗

(On Diff #122459)

That sounds much better. Thanks.

[waltl]

Address CR comments

compiler-rt/test/asan/CMakeLists.txt

 endif()
 set(ASAN_DYNAMIC_TEST_DEPS ${ASAN_TEST_DEPS})
 
 set(ASAN_TEST_ARCH ${ASAN_SUPPORTED_ARCH})
 if(APPLE)
   darwin_filter_host_archs(ASAN_SUPPORTED_ARCH ASAN_TEST_ARCH)
 endif()
 
+set(ASAN_TEST_SHADOW_SCALE ${LLVM_ASAN_SHADOW_SCALE})
+
 foreach(arch ${ASAN_TEST_ARCH})
   if(ANDROID)
     set(ASAN_TEST_TARGET_ARCH ${arch}-android)
   else()
     set(ASAN_TEST_TARGET_ARCH ${arch})
   endif()
 
   set(ASAN_TEST_IOS "0")

compiler-rt/test/asan/lit.cfg

 config.substitutions.append( ("%sancov ", python_exec + " " + sancov + " ") )
 
 # Determine kernel bitness
 if config.host_arch.find('64') != -1 and not config.android:
   kernel_bits = '64'
 else:
   kernel_bits = '32'
 
+# Detect custom shadow scale
+if config.asan_shadow_scale != '3':
+  config.available_features.add("custom-shadow-scale")
+
 config.substitutions.append( ('CHECK-%kernel_bits', ("CHECK-kernel-" + kernel_bits + "-bits")))
 
 config.substitutions.append( ("%libdl", libdl_flag) )
 
 config.available_features.add("asan-" + config.bits + "-bits")
 
 # Fast unwinder doesn't work with Thumb
 if re.search('mthumb', config.target_cflags) is not None:

compiler-rt/test/asan/lit.site.cfg.in

 @LIT_SITE_CFG_IN_HEADER@
 
 # Tool-specific config options.
 config.name_suffix = "@ASAN_TEST_CONFIG_SUFFIX@"
 config.target_cflags = "@ASAN_TEST_TARGET_CFLAGS@"
 config.clang = "@ASAN_TEST_TARGET_CC@"
 config.bits = "@ASAN_TEST_BITS@"
 config.ios = @ASAN_TEST_IOS_PYBOOL@
 config.iossim = @ASAN_TEST_IOSSIM_PYBOOL@
 config.asan_dynamic = @ASAN_TEST_DYNAMIC@
 config.target_arch = "@ASAN_TEST_TARGET_ARCH@"
+config.asan_shadow_scale = "@ASAN_TEST_SHADOW_SCALE@"
 
 # Load common config for all compiler-rt lit tests.
 lit_config.load_config(config, "@COMPILER_RT_BINARY_DIR@/test/lit.common.configured")
 
 # Load tool-specific config that would do the real work.
 lit_config.load_config(config, "@ASAN_LIT_SOURCE_DIR@/lit.cfg")