Check unified/resource heap-stride conflict at option-parse time (#11723)

Per review (@jkwak-work): diagnose the `-spirv-unified-descriptor-heap-stride` /
non-zero `-spirv-resource-heap-stride` mutual exclusivity in OptionsParser's post-parse
validation (alongside ConflictingProfilesSpecifiedForTarget / ConflictingStagesForEntryPoint),
reading both from linkage->m_optionSet, so E57006 fires as soon as the options are parsed --
before any SPIR-V emission and regardless of whether the module declares a resource heap.
An explicit `-spirv-resource-heap-stride 0` selects the default OpConstantSizeOfEXT path
the unified option modifies and is accepted.

Keep diagnoseConflictingDescriptorHeapStrideOptions() at emit time as the compile-API
safety net: SPIRVResourceHeapStride / SPIRVUnifiedDescriptorHeapStride are public API
options, and entries set directly through the compile API do not flow through OptionsParser,
so without the emit-time check that path would silently honor the explicit stride. The two
do not double-diagnose: an E57006 at parse time aborts before emission, so the emit-time
check only fires for the API path.

CONFLICT test variant still produces error[E57006]; build + 4/4 static tests + spirv-val
EXIT=0 for both entries green.

Author: nv-slang-bot[bot]

source/slang/slang-emit-spirv.cpp

@@ -7175,9 +7175,10 @@ struct SPIRVEmitContext : public SourceEmitterBase, public SPIRVEmitSharedContex
     // Returns whether resource descriptor-heap runtime arrays should advertise a single unified
     // maximum `ArrayStride` (opt-in via `-spirv-unified-descriptor-heap-stride`). This only affects
     // the auto stride path, i.e. when `-spirv-resource-heap-stride` is 0. Combining it with a
-    // non-zero `-spirv-resource-heap-stride` is a conflict (the two express contradictory strides)
-    // and is diagnosed in `diagnoseConflictingDescriptorHeapStrideOptions`; an explicit stride of 0
-    // selects that same auto path and is not a conflict.
+    // non-zero `-spirv-resource-heap-stride` is a conflict (the two express contradictory strides),
+    // rejected up front during option processing for the CLI (`OptionsParser` in
+    // `slang-options.cpp`) and re-checked here by `diagnoseConflictingDescriptorHeapStrideOptions`
+    // for the compile-API path; an explicit stride of 0 selects that same auto path, not a conflict.
     bool isUnifiedResourceHeapStrideEnabled()
     {
         return m_targetProgram->getOptionSet().getBoolOption(
@@ -7309,10 +7310,13 @@ struct SPIRVEmitContext : public SourceEmitterBase, public SPIRVEmitSharedContex
         return runtimeArrayType;
     }
 
-    // Diagnoses the mutually-exclusive `-spirv-resource-heap-stride` / unified-stride option pair:
-    // a non-zero explicit literal stride and the unified maximum stride contradict, so combining
-    // them is an error rather than letting one silently win. An explicit stride of 0 selects the
-    // same default `OpConstantSizeOfEXT` path the unified option modifies, so it is not a conflict.
+    // Diagnoses the `-spirv-resource-heap-stride` / `-spirv-unified-descriptor-heap-stride` conflict
+    // for the compile-API path. The CLI rejects this at option-parse time (`OptionsParser` in
+    // `slang-options.cpp`), which aborts before emission; but options set directly through the
+    // public compile API do not flow through that parser, so this re-checks at emit time and fails
+    // loudly rather than silently honoring the explicit stride. The condition matches the parser:
+    // unified enabled and a non-zero `SPIRVResourceHeapStride` (an explicit 0 selects the default
+    // `OpConstantSizeOfEXT` path the unified option modifies, so it is not a conflict).
     void diagnoseConflictingDescriptorHeapStrideOptions()
     {
         if (isUnifiedResourceHeapStrideEnabled() &&

source/slang/slang-options.cpp

@@ -4277,6 +4277,18 @@ SlangResult OptionsParser::_parse(int argc, char const* const* argv)
             }
         }
 
+        // `-spirv-unified-descriptor-heap-stride` and an explicit non-zero
+        // `-spirv-resource-heap-stride` express contradictory strides for the same resource heap,
+        // so reject the combination here, as soon as the options are parsed, rather than waiting
+        // until SPIR-V emission. An explicit stride of 0 selects the default `OpConstantSizeOfEXT`
+        // path that the unified option modifies and is therefore not a conflict.
+        if (linkage->m_optionSet.getBoolOption(
+                CompilerOptionName::SPIRVUnifiedDescriptorHeapStride) &&
+            linkage->m_optionSet.getIntOption(CompilerOptionName::SPIRVResourceHeapStride) != 0)
+        {
+            m_sink->diagnose(Diagnostics::SpirvConflictingDescriptorHeapStrideOptions{});
+        }
+
         // TODO: do we need to require that a target must have a profile specified,
         // or will we continue to allow the profile to be inferred from the target?