[PATCH] D92952: [WebAssembly] Support COMDAT sections in assembly syntax

[Derek Schuff via Phabricator via llvm-commits]

dschuff updated this revision to Diff 310735.
dschuff added a comment.

Simplify WebAssemblyAsmParser, add test for its behavior, add TODO


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D92952/new/

https://reviews.llvm.org/D92952

Files:
  llvm/lib/MC/MCParser/WasmAsmParser.cpp
  llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp
  llvm/test/MC/WebAssembly/comdat-sections.s


Index: llvm/test/MC/WebAssembly/comdat-sections.s
===================================================================
--- llvm/test/MC/WebAssembly/comdat-sections.s
+++ llvm/test/MC/WebAssembly/comdat-sections.s
@@ -7,12 +7,22 @@
         .functype foo () -> ()
         return
         end_function
+
+        .globl bar
+        .type bar, at function
+bar:
+        .functype bar () -> ()
+        return
+        end_function
+
         .section .debug_foo,"G",@,abc123,comdat
         .int32 42
         .section .debug_foo,"G",@,duplicate,comdat
         .int64 234
 
 
+
+
 # Check that there are 2 identically-named custom sections, with the desired
 # contents
 # CHECK:  - Type:            CUSTOM
@@ -31,6 +41,11 @@
 # CHECK-NEXT:        Entries:
 # CHECK-NEXT:          - Kind:            FUNCTION
 # CHECK-NEXT:            Index:           0
+
+# If the user forgets to create a new section for a function, one is created for
+# them by the assembler. Check that it is also in the same group.
+# CHECK-NEXT:          - Kind:            FUNCTION
+# CHECK-NEXT:            Index:           1
 # CHECK-NEXT:          - Kind:            SECTION
 # CHECK-NEXT:            Index:           4
 # CHECK-NEXT:      - Name:            duplicate
Index: llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp
===================================================================
--- llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp
+++ llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp
@@ -971,23 +971,21 @@
     auto SymName = Symbol->getName();
     if (SymName.startswith(".L"))
       return; // Local Symbol.
+
     // Only create a new text section if we're already in one.
+    // TODO: If the user explicitly creates a new function section, we ignore
+    // its name when we create this one. It would be nice to honor their
+    // choice, while still ensuring that we create one if they forget.
+    // (that requires coordination with WasmAsmParser::parseSectionDirective)
     auto CWS = cast<MCSectionWasm>(getStreamer().getCurrentSection().first);
     if (!CWS || !CWS->getKind().isText())
       return;
     auto SecName = ".text." + SymName;
 
-    MCSectionWasm *WS = CWS;
-    if (cast<MCSymbolWasm>(Symbol)->isComdat()) {
-      // If the function is a comdat function, then the user must have already
-      // declared the section as such (because that's the only way the asm
-      // parser can tell). In that case, just use the current section.
-      assert(CWS->getGroup() &&
-             "Current section for comdat function has no group");
-    } else {
-      WS = getContext().getWasmSection(SecName, SectionKind::getText());
-      getStreamer().SwitchSection(WS);
-    }
+    auto WS = getContext().getWasmSection(SecName, SectionKind::getText(),
+                                          CWS->getGroup(),
+                                          MCContext::GenericSectionID, nullptr);
+    getStreamer().SwitchSection(WS);
     // Also generate DWARF for this section if requested.
     if (getContext().getGenDwarfForAssembly())
       getContext().addGenDwarfSection(WS);
Index: llvm/lib/MC/MCParser/WasmAsmParser.cpp
===================================================================
--- llvm/lib/MC/MCParser/WasmAsmParser.cpp
+++ llvm/lib/MC/MCParser/WasmAsmParser.cpp
@@ -185,7 +185,6 @@
                              "Only data sections can be passive");
       WS->setPassive();
     }
-
     getStreamer().SwitchSection(WS);
     return false;
   }


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