Replace ErrorHandler with Errors and FormatErrors*

`ErrorHandler` complicated all error handling in wabt, since it was
callback-based. Callbacks would be useful if we ever wanted to change
behavior when an error occurred, but instead all that the handler ever
did was write the errors to stdout/stderr or to a buffer.

This change adds a new class `Error`, which contains an `ErrorLevel`, a
`Location` and an error message. It also replaces ErrorHandler with
`Errors` (a typedef for `std::vector<Error>`), and adds a couple of
functions that can format a list of `Errors` for output:
`FormatErrorsTo{String,File}`.

1 files changed, 2 insertions, 3 deletions

diff --git a/src/binary-reader-objdump.cc b/src/binary-reader-objdump.cc
index cec37772..420940f5 100644
--- a/src/binary-reader-objdump.cc
+++ b/src/binary-reader-objdump.cc
@@ -38,7 +38,7 @@ class BinaryReaderObjdumpBase : public BinaryReaderNop {
                           ObjdumpOptions* options,
                           ObjdumpState* state);
 
-  bool OnError(ErrorLevel, const char* message) override;
+  bool OnError(const Error&) override;
 
   Result BeginModule(uint32_t version) override;
   Result BeginSection(BinarySection section_type, Offset size) override;
@@ -86,8 +86,7 @@ Result BinaryReaderObjdumpBase::BeginSection(BinarySection section_code,
   return Result::Ok;
 }
 
-bool BinaryReaderObjdumpBase::OnError(ErrorLevel error_level,
-                                      const char* message) {
+bool BinaryReaderObjdumpBase::OnError(const Error&) {
   // Tell the BinaryReader that this error is "handled" for all passes other
   // than the prepass. When the error is handled the default message will be
   // suppressed.