Try to improve handling of failures during compilation

The change is mostly about trying to make sure the compiler "fails safe" when it encounters an internal assumption that isn't met.
Most internal errors will now throw exceptions (yes, exceptions are evil, but this will work for now), and these get caught in `spCompile` so that they don't propagate to the user (they just see a message that compilation aborted due to an internal error).

Subsequent changes are going to need to work on diagnosing as many of these situations as possible, so that users can at least know what construct in their code was unexpected or unhandled by the compiler.

1 files changed, 5 insertions, 6 deletions

diff --git a/source/slang/preprocessor.cpp b/source/slang/preprocessor.cpp
index a4cccf4f4..ec38a7214 100644
--- a/source/slang/preprocessor.cpp
+++ b/source/slang/preprocessor.cpp
@@ -705,8 +705,7 @@ static void MaybeBeginMacroExpansion(
             UInt argCount = argIndex;
             if (argCount != paramCount)
             {
-                // TODO: diagnose
-                throw 99;
+                GetSink(preprocessor)->diagnose(PeekLoc(preprocessor), Diagnostics::wrongNumberOfArgumentsToMacro, paramCount, argCount);
             }
 
             // We are ready to expand.
@@ -1006,7 +1005,7 @@ static void beginConditional(
     bool                            enable)
 {
     Preprocessor* preprocessor = context->preprocessor;
-    assert(inputStream);
+    SLANG_ASSERT(inputStream);
 
     PreprocessorConditional* conditional = CreateConditional(preprocessor);
 
@@ -1346,7 +1345,7 @@ static void HandleIfNDefDirective(PreprocessorDirectiveContext* context)
 static void HandleElseDirective(PreprocessorDirectiveContext* context)
 {
     PreprocessorInputStream* inputStream = context->preprocessor->inputStream;
-    assert(inputStream);
+    SLANG_ASSERT(inputStream);
 
     // if we aren't inside a conditional, then error
     PreprocessorConditional* conditional = inputStream->conditional;
@@ -1386,7 +1385,7 @@ static void HandleElifDirective(PreprocessorDirectiveContext* context)
     // Need to grab current input stream *before* we try to parse
     // the conditional expression.
     PreprocessorInputStream* inputStream = context->preprocessor->inputStream;
-    assert(inputStream);
+    SLANG_ASSERT(inputStream);
 
     // HACK(tfoley): handle an empty `elif` like an `else` directive
     //
@@ -1438,7 +1437,7 @@ static void HandleElifDirective(PreprocessorDirectiveContext* context)
 static void HandleEndIfDirective(PreprocessorDirectiveContext* context)
 {
     PreprocessorInputStream* inputStream = context->preprocessor->inputStream;
-    assert(inputStream);
+    SLANG_ASSERT(inputStream);
 
     // if we aren't inside a conditional, then error
     PreprocessorConditional* conditional = inputStream->conditional;