Running tests in slang-test process (#740)

* First pass at having an interface to write text to that can be replaced.
Simplifed and made more rigerous the interface used to write formatted strings.

* Added AppContext to simplify setting up and parsing around of streams.

* Added more simplified way to get the std error/out from AppContext.

* Work in progress using dll for tools to speed up testing.

* First pass at ISlangWriter interface.

* Added support for writing VaArgs.
Added NullWriter.

* Use ISlangWriter for output.

* Use ISlangWriter for output - replacing OutputCallback.
Make IRDump go to ISlangWriter

* SlangWriterTargetType -> SlangWriterChannel
Improvements around AppContext

* Shared library working with slang-reflection-test.

* Dll testing working for render-test.

* Include va_list definintion from header.

* Fix errors from clang.

* Fix typo for linux.

* Added -usexes option

* Fix typo.

* Fix arguments problem on linux.

* Fix typo for linux.

* Add windows tool shared library projects.

* Fix warning from x86 win build.
Fix signed warning from slang-test/main.cpp

* First attempt at getting premake to work on travis, and run tests.

* Try moving build out into script.

* Invoke bash scripts so they don't have to be executable.

* Drive configuration/tests from env parameters set by travis

* Try using source to run travis tests.

* Remove the build.linux directory - but doing so will overwrite Makefile.

* Made -fno-delete-null-pointer-checks gcc only.

* Try to fix warning from -fno-delete-null-pointer-checks

* Turn of warnings for unknown switches.

* Try to make premake choose the correct tooling.

* Disabled missing braces warning.

* Disable -Wundefined-var-template on clang.

* -Wunused-function disabled for clang.

* Fix typo due to SlangBool.

* Remove this nullptr tests.

* "-Wno-unused-private-field" for clang.

* Added "-Wno-undefined-bool-conversion"

* Add DominatorList::end fix.

* Split scripts into travis_build.sh travis_test.sh

* Fix gcc/clang template pre-declaration issue around QualType.

* Fix premake to build such that pthread correctly links with slang-glslang

1 files changed, 23 insertions, 16 deletions

diff --git a/source/core/slang-string-util.cpp b/source/core/slang-string-util.cpp
index 6d0d896a1..cb5709759 100644
--- a/source/core/slang-string-util.cpp
+++ b/source/core/slang-string-util.cpp
@@ -39,32 +39,39 @@ static const Guid IID_ISlangBlob = SLANG_UUID_ISlangBlob;
     }
 }
 
-
-/* static */void StringUtil::append(const char* format, va_list args, StringBuilder& buf)
+/* static */size_t StringUtil::calcFormattedSize(const char* format, va_list args)
 {
-    int numChars = 0;
+#if SLANG_WINDOWS_FAMILY
+    return _vscprintf(format, args);
+#else
+     return vsnprintf(nullptr, 0, format, args);
+#endif
+}
 
+/* static */void StringUtil::calcFormatted(const char* format, va_list args, size_t numChars, char* dst)
+{
 #if SLANG_WINDOWS_FAMILY
-    numChars = _vscprintf(format, args);
+    vsnprintf_s(dst, numChars + 1, _TRUNCATE, format, args);
 #else
+    vsnprintf(dst, numChars + 1, format, args);
+#endif
+}
+
+/* static */void StringUtil::append(const char* format, va_list args, StringBuilder& buf)
+{
+    // Calculate the size 
+    size_t numChars;
     {
+        // Create a copy of args, as will be consumed by calcFormattedSize
         va_list argsCopy;
         va_copy(argsCopy, args);
-        numChars = vsnprintf(nullptr, 0, format, argsCopy);
+        numChars = calcFormattedSize(format, argsCopy);
         va_end(argsCopy);
     }
-#endif
-
-    List<char> chars;
-    chars.SetSize(numChars + 1);
-
-#if SLANG_WINDOWS_FAMILY
-    vsnprintf_s(chars.Buffer(), numChars + 1, _TRUNCATE, format, args);
-#else
-    vsnprintf(chars.Buffer(), numChars + 1, format, args);
-#endif
 
-    buf.Append(chars.Buffer(), numChars);
+    char* dst = buf.prepareForAppend(numChars + 1);
+    calcFormatted(format, args, numChars, dst);
+    buf.appendInPlace(dst, numChars);
 }
 
 /* static */void StringUtil::appendFormat(StringBuilder& buf, const char* format, ...)