Feature/file unique identity (#789)

* * Fix memory bug around expanding va_args - needed buffer to have space for terminating 0
* Fix problem with FileWriter defaults being globals, as memory they allocate, will only be freed after return from main - work around by making StdWriters RefObject derived, and kept in scope such the writers are destroyed before checks for leaks is found
* Added SimplifyPathAndHash mode for CacheFileSystem - will simplify the path and see if simplified path is in cache before reading file (limiting amout of underlying file requests)

* * Added calcReplaceChar
* Renamed DefaultFileSystem to OSFileSystem
* Made OSFileSystem convert windows \ to / on linux

* Simplified logic for caching in CacheFileSystem.

* Added pragma-once-c to add extra test, but also so there is an 'include' directory in preprocessor tests.

* Small fixes in pragma once test.

* Simplified cache handling path, so that paths/simplified paths area always added.

* Improve naming of methods for different caches.

* Removed references to 'canonicalPath' and made 'uniqueIdentity'

* * Re-add support for canonicalPath to ISlangFileSystem -> not for uniqueIdentifier but as a way to display 'canonicalPath'
* Added peliminary support for being able to display verbose paths in a diagnostic
* Added 'clearCache' support
* Added verbose path support to SourceManager (now needs a ISlangFileSystemExt to do this)

* Added support for '-verbose-path' option to slangc and slang-test.

3 files changed, 27 insertions, 8 deletions

diff --git a/tools/slang-test/options.cpp b/tools/slang-test/options.cpp
index 0a6023733..70b7a4533 100644
--- a/tools/slang-test/options.cpp
+++ b/tools/slang-test/options.cpp
@@ -134,6 +134,10 @@ static bool _isSubCommand(const char* arg)
         {
             optionsOut->shouldBeVerbose = true;
         }
+        else if (strcmp(arg, "-verbose-paths") == 0)
+        {
+            optionsOut->verbosePaths = true;
+        }
         else if (strcmp(arg, "-generate-hlsl-baselines") == 0)
         {
             optionsOut->generateHLSLBaselines = true;
diff --git a/tools/slang-test/options.h b/tools/slang-test/options.h
index 4858ffd03..77460e190 100644
--- a/tools/slang-test/options.h
+++ b/tools/slang-test/options.h
@@ -49,6 +49,9 @@ struct Options
     // generate extra output (notably: command lines we run)
     bool shouldBeVerbose = false;
 
+    // Use verbose paths
+    bool verbosePaths = false;
+
     // force generation of baselines for HLSL tests
     bool generateHLSLBaselines = false;
 
diff --git a/tools/slang-test/slang-test-main.cpp b/tools/slang-test/slang-test-main.cpp
index d0da4fc61..cbd2974da 100644
--- a/tools/slang-test/slang-test-main.cpp
+++ b/tools/slang-test/slang-test-main.cpp
@@ -519,6 +519,15 @@ String findExpectedPath(const TestInput& input, const char* postFix)
     return "";
 }
 
+static void _initSlangCompiler(TestContext* context, OSProcessSpawner& spawnerOut)
+{
+    spawnerOut.pushExecutablePath(String(context->options.binDir) + "slangc" + osGetExecutableSuffix());
+
+    if (context->options.verbosePaths)
+    {
+        spawnerOut.pushArgument("-verbose-paths");
+    }
+}
 
 TestResult runSimpleTest(TestContext* context, TestInput& input)
 {
@@ -528,8 +537,8 @@ TestResult runSimpleTest(TestContext* context, TestInput& input)
     auto outputStem = input.outputStem;
 
     OSProcessSpawner spawner;
+    _initSlangCompiler(context, spawner);
 
-    spawner.pushExecutablePath(String(context->options.binDir) + "slangc" + osGetExecutableSuffix());
     spawner.pushArgument(filePath999);
 
     for( auto arg : input.testOptions->args )
@@ -699,6 +708,8 @@ static SlangCompileTarget _getCompileTarget(const UnownedStringSlice& name)
     return SLANG_TARGET_UNKNOWN;
 }
 
+
+
 TestResult runCrossCompilerTest(TestContext* context, TestInput& input)
 {
     // need to execute the stand-alone Slang compiler on the file
@@ -710,11 +721,11 @@ TestResult runCrossCompilerTest(TestContext* context, TestInput& input)
     OSProcessSpawner actualSpawner;
     OSProcessSpawner expectedSpawner;
 
-    actualSpawner.pushExecutablePath(String(context->options.binDir) + "slangc" + osGetExecutableSuffix());
-    expectedSpawner.pushExecutablePath(String(context->options.binDir) + "slangc" + osGetExecutableSuffix());
-
+    _initSlangCompiler(context, actualSpawner);
+    _initSlangCompiler(context, expectedSpawner);
+    
     actualSpawner.pushArgument(filePath);
-
+    
     const auto& args = input.testOptions->args;
 
     const UInt targetIndex = args.IndexOf("-target");
@@ -821,7 +832,8 @@ TestResult generateHLSLBaseline(TestContext* context, TestInput& input)
     auto outputStem = input.outputStem;
 
     OSProcessSpawner spawner;
-    spawner.pushExecutablePath(String(context->options.binDir) + "slangc" + osGetExecutableSuffix());
+    _initSlangCompiler(context, spawner);
+
     spawner.pushArgument(filePath999);
 
     for( auto arg : input.testOptions->args )
@@ -866,8 +878,8 @@ TestResult runHLSLComparisonTest(TestContext* context, TestInput& input)
     // need to execute the stand-alone Slang compiler on the file, and compare its output to what we expect
 
     OSProcessSpawner spawner;
+    _initSlangCompiler(context, spawner);
 
-    spawner.pushExecutablePath(String(context->options.binDir) + "slangc" + osGetExecutableSuffix());
     spawner.pushArgument(filePath999);
 
     for( auto arg : input.testOptions->args )
@@ -967,8 +979,8 @@ TestResult doGLSLComparisonTestRun(TestContext* context,
     auto outputStem = input.outputStem;
 
     OSProcessSpawner spawner;
+    _initSlangCompiler(context, spawner);
 
-    spawner.pushExecutablePath(String(context->options.binDir) + "slangc" + osGetExecutableSuffix());
     spawner.pushArgument(filePath999);
 
     if( langDefine )