From 36c9858b3b1df3f636a2478050da3e721cbdf8f9 Mon Sep 17 00:00:00 2001
From: Kyle Huey <khuey@kylehuey.com>
Date: Fri, 10 Jun 2022 21:50:04 -0700
Subject: [PATCH] When traversing the scope chain, account for the size of the
 earlier scopes.

Closes #269
---
 src/ast.rs     | 30 +++++++++++++++++++++++++++++-
 tests/tests.rs |  5 +++++
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/src/ast.rs b/src/ast.rs
index c9d68cd..3064aef 100644
--- a/src/ast.rs
+++ b/src/ast.rs
@@ -343,6 +343,9 @@ trait ArgScope<'me, 'ctx>: fmt::Debug {
     fn get_template_arg(&'me self, index: usize)
         -> Result<(&'ctx TemplateArg, &'ctx TemplateArgs)>;
 
+    /// Get the current scope's count of template arguments.
+    fn template_arg_count(&'me self) -> usize;
+
     /// Get the current scope's `index`th function argument's type.
     fn get_function_arg(&'me self, index: usize) -> Result<&'ctx Type>;
 }
@@ -408,7 +411,7 @@ impl<'prev, 'subs> ArgScope<'prev, 'subs> for Option<ArgScopeStack<'prev, 'subs>
 
     fn get_template_arg(
         &'prev self,
-        idx: usize,
+        mut idx: usize,
     ) -> Result<(&'subs TemplateArg, &'subs TemplateArgs)> {
         let mut scope = self.as_ref();
         while let Some(s) = scope {
@@ -423,11 +426,16 @@ impl<'prev, 'subs> ArgScope<'prev, 'subs> for Option<ArgScopeStack<'prev, 'subs>
                 return Ok((arg, args));
             }
             scope = s.prev;
+            idx = idx.checked_sub(s.item.template_arg_count()).unwrap();
         }
 
         Err(error::Error::BadTemplateArgReference)
     }
 
+    fn template_arg_count(&self) -> usize {
+        self.as_ref().map(|s| s.item.template_arg_count()).unwrap_or(0)
+    }
+
     fn get_function_arg(&'prev self, idx: usize) -> Result<&'subs Type> {
         let mut scope = self.as_ref();
         while let Some(s) = scope {
@@ -2624,6 +2632,10 @@ impl<'subs> ArgScope<'subs, 'subs> for SourceName {
         Err(error::Error::BadTemplateArgReference)
     }
 
+    fn template_arg_count(&self) -> usize {
+        0
+    }
+
     fn get_function_arg(&'subs self, _: usize) -> Result<&'subs Type> {
         Err(error::Error::BadFunctionArgReference)
     }
@@ -4569,6 +4581,10 @@ impl<'subs> ArgScope<'subs, 'subs> for UnnamedTypeName {
         Err(error::Error::BadTemplateArgReference)
     }
 
+    fn template_arg_count(&self) -> usize {
+        0
+    }
+
     fn get_function_arg(&'subs self, _: usize) -> Result<&'subs Type> {
         Err(error::Error::BadFunctionArgReference)
     }
@@ -5173,6 +5189,10 @@ impl<'subs> ArgScope<'subs, 'subs> for TemplateArgs {
             .map(|v| (v, self))
     }
 
+    fn template_arg_count(&self) -> usize {
+        self.0.len()
+    }
+
     fn get_function_arg(&'subs self, _: usize) -> Result<&'subs Type> {
         Err(error::Error::BadFunctionArgReference)
     }
@@ -7017,6 +7037,10 @@ impl<'subs> ArgScope<'subs, 'subs> for ClosureTypeName {
         Err(error::Error::BadTemplateArgReference)
     }
 
+    fn template_arg_count(&self) -> usize {
+        0
+    }
+
     fn get_function_arg(&'subs self, _: usize) -> Result<&'subs Type> {
         Err(error::Error::BadFunctionArgReference)
     }
@@ -7245,6 +7269,10 @@ impl<'a> ArgScope<'a, 'a> for WellKnownComponent {
         Err(error::Error::BadTemplateArgReference)
     }
 
+    fn template_arg_count(&self) -> usize {
+        0
+    }
+
     fn get_function_arg(&'a self, _: usize) -> Result<&'a Type> {
         Err(error::Error::BadFunctionArgReference)
     }
diff --git a/tests/tests.rs b/tests/tests.rs
index 8e908e1..a694cb7 100755
--- a/tests/tests.rs
+++ b/tests/tests.rs
@@ -600,3 +600,8 @@ demangles!(
     _ZN4glslL7combineIhLi2EEEDvmlT0_Li4E_T_DvT0__S1_S3_S3_S3_,
     "unsigned char __vector((2)*(4)) glsl::combine<unsigned char, 2>(unsigned char __vector(2), unsigned char __vector(2), unsigned char __vector(2), unsigned char __vector(2))"
 );
+
+demangles!(
+    __ZZZN3jkj9dragonbox10to_decimalIfNS0_20default_float_traitsIfEEJNS0_6detail11policy_impl4sign6ignoreENS5_13trailing_zero6removeEEEEDaNS0_23signed_significand_bitsIT_T0_EEjDpT1_ENKUlSC_E_clINS5_26decimal_to_binary_rounding15nearest_to_evenEEESA_SC_ENKUlDpT_E_clIJEEESA_SM_,
+    "jkj::dragonbox::signed_significand_bits jkj::dragonbox::signed_significand_bits auto jkj::dragonbox::to_decimal<float, jkj::dragonbox::default_float_traits<float>, jkj::dragonbox::detail::policy_impl::sign::ignore, jkj::dragonbox::detail::policy_impl::trailing_zero::remove>(jkj::dragonbox::signed_significand_bits<float, jkj::dragonbox::default_float_traits<float> >, unsigned int, jkj::dragonbox::detail::policy_impl::sign::ignore, jkj::dragonbox::detail::policy_impl::trailing_zero::remove)::{lambda(auto:2)#1}::operator()<jkj::dragonbox::detail::policy_impl::decimal_to_binary_rounding::nearest_to_even>(jkj::dragonbox::detail::policy_impl::decimal_to_binary_rounding::nearest_to_even) const::{lambda(auto:1)#1}::operator()<>({lambda(auto:1)#1}) const"
+);