From d601921b71ed44835e8d4fa6f13ff7aefcf7649d Mon Sep 17 00:00:00 2001
From: Tim Foley <tfoley@nvidia.com>
Date: Wed, 28 Jun 2017 10:20:16 -0700
Subject: Actually respect suffixes on numeric literals.

- Add logic to extract the value and suffix from a numeric literal
  - This duplicates some of the lexing logic, but this is hard to avoid without redundant runtime work

- Note that I'm not using and stdlib string-to-number code. This should be more robust once it is working, but it is obviously error prone in the near term. The main up-sides to this are:
  - We can handle binary integer literals
  - We can handle hexadecimal floating-point literals without stdlib support
  - We can hypothetically support digit separators, if we ever wanted

- The parser looks at the suffix characters sliced off by the lexer, and tries to pick a type to use for a literal
  - It uses `NULL` if there is no suffix, to avoid some nasty order dependencies where the stdlib might need to parse a number before it has seen the definition of `int`
  - Right now I only handle a few cases, so there may be bugs lurking here

- The emit logic needs to handle the fact that a literal node in the AST might have a non-default type attached.
  - Right now I just quickly check for the most likely types, and emit the literal with a matching suffix. This doesn't seem robust if any source language supports a suffix for a type where a target has no corresponding suffix. In the long term some amount of casting is probably required.
---
 source/slang/emit.cpp | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

(limited to 'source/slang/emit.cpp')

diff --git a/source/slang/emit.cpp b/source/slang/emit.cpp
index 5272204f6..9a1d44641 100644
--- a/source/slang/emit.cpp
+++ b/source/slang/emit.cpp
@@ -219,6 +219,8 @@ static void Emit(EmitContext* context, double value)
     Emit(context, buffer);
 }
 
+static void emitTokenWithLocation(EmitContext* context, Token const& token);
+
 // Expressions
 
 // Determine if an expression should not be emitted when it is the base of
@@ -900,14 +902,53 @@ static void EmitExprWithPrecedence(EmitContext* context, RefPtr<ExpressionSyntax
     {
         needClose = MaybeEmitParens(context, outerPrec, kPrecedence_Atomic);
 
+        char const* suffix = "";
+        auto type = litExpr->Type.type;
         switch (litExpr->ConstType)
         {
         case ConstantExpressionSyntaxNode::ConstantType::Int:
+            if(!type)
+            {
+                // Special case for "rewrite" mode
+                emitTokenWithLocation(context, litExpr->token);
+                break;
+            }
+            if(type->Equals(ExpressionType::GetInt()))
+            {}
+            else if(type->Equals(ExpressionType::GetUInt()))
+            {
+                suffix = "u";
+            }
+            else
+            {
+                assert(!"unimplemented");
+            }
             Emit(context, litExpr->IntValue);
+            Emit(context, suffix);
             break;
+
+
         case ConstantExpressionSyntaxNode::ConstantType::Float:
+            if(!type)
+            {
+                // Special case for "rewrite" mode
+                emitTokenWithLocation(context, litExpr->token);
+                break;
+            }
+            if(type->Equals(ExpressionType::GetFloat()))
+            {}
+            else if(type->Equals(ExpressionType::getDoubleType()))
+            {
+                suffix = "l";
+            }
+            else
+            {
+                assert(!"unimplemented");
+            }
             Emit(context, litExpr->FloatValue);
+            Emit(context, suffix);
             break;
+
         case ConstantExpressionSyntaxNode::ConstantType::Bool:
             Emit(context, litExpr->IntValue ? "true" : "false");
             break;
-- 
cgit v1.2.3