MSL: Refactor member reference in terms of one boolean.

ptr_chain was really just masking the proper i == 0 check.
Be more explicit about what the check is actually doing and comment
this.

6 files changed, 64 insertions, 9 deletions

diff --git a/reference/shaders-msl-no-opt/comp/buffer-device-address-from-pointer-complex-chain.msl23.comp b/reference/shaders-msl-no-opt/comp/buffer-device-address-from-pointer-complex-chain.msl23.comp
new file mode 100644
index 00000000..7864e0fb
--- /dev/null
+++ b/reference/shaders-msl-no-opt/comp/buffer-device-address-from-pointer-complex-chain.msl23.comp
@@ -0,0 +1,28 @@
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct SSBO;
+
+struct S
+{
+    float3 v;
+};
+
+struct SSBO
+{
+    S s[1];
+};
+
+struct PC
+{
+    uint2 ptr;
+};
+
+kernel void main0(constant PC& pc [[buffer(0)]])
+{
+    device SSBO* ssbo = reinterpret_cast<device SSBO*>(as_type<ulong>(pc.ptr));
+    ssbo->s[0].v = float3(1.0);
+}
+
diff --git a/shaders-msl-no-opt/comp/buffer-device-address-from-pointer-complex-chain.msl23.comp b/shaders-msl-no-opt/comp/buffer-device-address-from-pointer-complex-chain.msl23.comp
new file mode 100644
index 00000000..56c11bbb
--- /dev/null
+++ b/shaders-msl-no-opt/comp/buffer-device-address-from-pointer-complex-chain.msl23.comp
@@ -0,0 +1,21 @@
+#version 460
+
+#extension GL_EXT_buffer_reference: enable
+#extension GL_EXT_buffer_reference_uvec2: enable
+
+struct S {
+    vec3 v;
+};
+
+layout(buffer_reference) buffer SSBO{
+    S s[];
+};
+
+layout(push_constant) uniform PC {
+    uvec2 ptr;
+} pc;
+
+void main(){
+    SSBO ssbo = SSBO(pc.ptr);
+    ssbo.s[0].v = vec3(1.0);
+}
diff --git a/spirv_glsl.cpp b/spirv_glsl.cpp
index 5ae845a9..0dadd7d7 100644
--- a/spirv_glsl.cpp
+++ b/spirv_glsl.cpp
@@ -9421,7 +9421,13 @@ string CompilerGLSL::access_chain_internal(uint32_t base, const uint32_t *indice
 				else if (flatten_member_reference)
 					expr += join("_", to_member_name(*type, index));
 				else
-					expr += to_member_reference(base, *type, index, i, ptr_chain);
+				{
+					// Any pointer de-refences for values are handled in the first access chain.
+					// For pointer chains, the pointer-ness is resolved through an array access.
+					// The only time this is not true is when accessing array of SSBO/UBO.
+					// This case is explicitly handled.
+					expr += to_member_reference(base, *type, index, ptr_chain || i != 0);
+				}
 			}
 
 			if (has_member_decoration(type->self, index, DecorationInvariant))
@@ -13843,9 +13849,9 @@ string CompilerGLSL::to_member_name(const SPIRType &type, uint32_t index)
 		return join("_m", index);
 }
 
-string CompilerGLSL::to_member_reference(uint32_t, const SPIRType &type, uint32_t member_index, uint32_t chain_index, bool)
+string CompilerGLSL::to_member_reference(uint32_t, const SPIRType &type, uint32_t index, bool)
 {
-	return join(".", to_member_name(type, member_index));
+	return join(".", to_member_name(type, index));
 }
 
 string CompilerGLSL::to_multi_member_reference(const SPIRType &type, const SmallVector<uint32_t> &indices)
diff --git a/spirv_glsl.hpp b/spirv_glsl.hpp
index 67bf8d80..69d323e8 100644
--- a/spirv_glsl.hpp
+++ b/spirv_glsl.hpp
@@ -770,7 +770,7 @@ protected:
 	std::string address_of_expression(const std::string &expr);
 	void strip_enclosed_expression(std::string &expr);
 	std::string to_member_name(const SPIRType &type, uint32_t index);
-	virtual std::string to_member_reference(uint32_t base, const SPIRType &type, uint32_t member_index, uint32_t chain_index, bool ptr_chain);
+	virtual std::string to_member_reference(uint32_t base, const SPIRType &type, uint32_t index, bool ptr_chain_is_resolved);
 	std::string to_multi_member_reference(const SPIRType &type, const SmallVector<uint32_t> &indices);
 	std::string type_to_glsl_constructor(const SPIRType &type);
 	std::string argument_decl(const SPIRFunction::Parameter &arg);
diff --git a/spirv_msl.cpp b/spirv_msl.cpp
index 004fc597..9ac6f067 100644
--- a/spirv_msl.cpp
+++ b/spirv_msl.cpp
@@ -14432,7 +14432,7 @@ void CompilerMSL::sync_entry_point_aliases_and_names()
 		entry.second.name = ir.meta[entry.first].decoration.alias;
 }
 
-string CompilerMSL::to_member_reference(uint32_t base, const SPIRType &type, uint32_t member_index, uint32_t chain_index, bool ptr_chain)
+string CompilerMSL::to_member_reference(uint32_t base, const SPIRType &type, uint32_t index, bool ptr_chain_is_resolved)
 {
 	auto *var = maybe_get_backing_variable(base);
 	// If this is a buffer array, we have to dereference the buffer pointers.
@@ -14451,10 +14451,10 @@ string CompilerMSL::to_member_reference(uint32_t base, const SPIRType &type, uin
 		declared_as_pointer = is_buffer_variable && is_array(get<SPIRType>(var->basetype));
 	}
 
-	if (declared_as_pointer || (!ptr_chain && should_dereference(base) && chain_index == 0))
-		return join("->", to_member_name(type, member_index));
+	if (declared_as_pointer || (!ptr_chain_is_resolved && should_dereference(base)))
+		return join("->", to_member_name(type, index));
 	else
-		return join(".", to_member_name(type, member_index));
+		return join(".", to_member_name(type, index));
 }
 
 string CompilerMSL::to_qualifiers_glsl(uint32_t id)
diff --git a/spirv_msl.hpp b/spirv_msl.hpp
index 78534528..72fb043e 100644
--- a/spirv_msl.hpp
+++ b/spirv_msl.hpp
@@ -831,7 +831,7 @@ protected:
 	std::string bitcast_glsl_op(const SPIRType &result_type, const SPIRType &argument_type) override;
 	bool emit_complex_bitcast(uint32_t result_id, uint32_t id, uint32_t op0) override;
 	bool skip_argument(uint32_t id) const override;
-	std::string to_member_reference(uint32_t base, const SPIRType &type, uint32_t member_index, uint32_t chain_index, bool ptr_chain) override;
+	std::string to_member_reference(uint32_t base, const SPIRType &type, uint32_t index, bool ptr_chain_is_resolved) override;
 	std::string to_qualifiers_glsl(uint32_t id) override;
 	void replace_illegal_names() override;
 	void declare_undefined_values() override;