Allow pragmas to customize throwing mode for try/catch

Signed-off-by: Danila Fedorin <daniel.fedorin@hpe.com>

Author: DanilaFe

frontend/include/chpl/parsing/parsing-queries.h

@@ -596,6 +596,12 @@ const uast::AstNode* parentAst(Context* context, const uast::AstNode* node);
  */
 ID idToParentModule(Context* context, ID id);
 
+/**
+  Return the ID for the module containing the given ID,
+  unless the ID itself is a module, in which case return the ID itself.
+ */
+ID idToModule(Context* context, ID id);
+
 /**
   Given an ID 'id', attempt to lookup the declared linkage of the composite
   type associated with 'id'. Returns 'DEFAULT_LINKAGE' if no such AST was

frontend/lib/parsing/parsing-queries.cpp

@@ -1597,6 +1597,10 @@ ID idToParentModule(Context* context, ID id) {
   return getModuleForId(context, parentSymId);
 }
 
+ID idToModule(Context* context, ID id) {
+  return getModuleForId(context, id);
+}
+
 bool idIsToplevelModule(Context* context, ID id) {
   if (idIsModule(context, id)) {
     ID parentSymId = id.parentSymbolId(context);

frontend/lib/resolution/try-catch-analysis.cpp

@@ -409,6 +409,20 @@ namespace resolution {
   // PERMIT_UNHANDLED_MODULE_ERRORS compiler flag to determine the handling mode
   static ErrorCheckingMode computeErrorCheckingMode(Context* context,
                                                     const AstNode* node) {
+    // pragmas on modules override the default error checking mode.
+    auto moduleId = parsing::idToModule(context, node->id());
+    auto ag = parsing::idToAttributeGroup(context, moduleId);
+    if (!ag) {
+      // fall through to figuring out the mode from the module kind
+    } else if (ag->hasPragma(pragmatags::PRAGMA_ERROR_MODE_FATAL)) {
+      return ErrorCheckingMode::FATAL;
+    } else if (ag->hasPragma(pragmatags::PRAGMA_ERROR_MODE_STRICT)) {
+      CHPL_UNIMPL("strict error checking mode not implemented");
+      return ErrorCheckingMode::RELAXED;
+    } else if (ag->hasPragma(pragmatags::PRAGMA_ERROR_MODE_RELAXED)) {
+      return ErrorCheckingMode::RELAXED;
+    }
+
     auto mode = ErrorCheckingMode::UNKNOWN;
     auto moduleKind = parsing::idToModuleKind(context, node->id());
     if (moduleKind == Module::Kind::PROTOTYPE ||