[clang] Implement #pragma clang section on COFF targets (#112714)

This patch implements the directive #pragma clang section on COFF targets
with the exact same features available on ELF and Mach-O.

1 files changed, 23 insertions, 31 deletions

diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index be243c0..7db949f 100644
--- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -788,29 +788,35 @@ getGlobalObjectInfo(const GlobalObject *GO, const TargetMachine &TM) {
   return {Group, IsComdat, Flags};
 }
 
-static MCSection *selectExplicitSectionGlobal(
-    const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM,
-    MCContext &Ctx, Mangler &Mang, unsigned &NextUniqueID,
-    bool Retain, bool ForceUnique) {
-  StringRef SectionName = GO->getSection();
-
+static StringRef handlePragmaClangSection(const GlobalObject *GO,
+                                          SectionKind Kind) {
   // Check if '#pragma clang section' name is applicable.
   // Note that pragma directive overrides -ffunction-section, -fdata-section
   // and so section name is exactly as user specified and not uniqued.
   const GlobalVariable *GV = dyn_cast<GlobalVariable>(GO);
   if (GV && GV->hasImplicitSection()) {
     auto Attrs = GV->getAttributes();
-    if (Attrs.hasAttribute("bss-section") && Kind.isBSS()) {
-      SectionName = Attrs.getAttribute("bss-section").getValueAsString();
-    } else if (Attrs.hasAttribute("rodata-section") && Kind.isReadOnly()) {
-      SectionName = Attrs.getAttribute("rodata-section").getValueAsString();
-    } else if (Attrs.hasAttribute("relro-section") && Kind.isReadOnlyWithRel()) {
-      SectionName = Attrs.getAttribute("relro-section").getValueAsString();
-    } else if (Attrs.hasAttribute("data-section") && Kind.isData()) {
-      SectionName = Attrs.getAttribute("data-section").getValueAsString();
-    }
+    if (Attrs.hasAttribute("bss-section") && Kind.isBSS())
+      return Attrs.getAttribute("bss-section").getValueAsString();
+    else if (Attrs.hasAttribute("rodata-section") && Kind.isReadOnly())
+      return Attrs.getAttribute("rodata-section").getValueAsString();
+    else if (Attrs.hasAttribute("relro-section") && Kind.isReadOnlyWithRel())
+      return Attrs.getAttribute("relro-section").getValueAsString();
+    else if (Attrs.hasAttribute("data-section") && Kind.isData())
+      return Attrs.getAttribute("data-section").getValueAsString();
   }
 
+  return GO->getSection();
+}
+
+static MCSection *selectExplicitSectionGlobal(const GlobalObject *GO,
+                                              SectionKind Kind,
+                                              const TargetMachine &TM,
+                                              MCContext &Ctx, Mangler &Mang,
+                                              unsigned &NextUniqueID,
+                                              bool Retain, bool ForceUnique) {
+  StringRef SectionName = handlePragmaClangSection(GO, Kind);
+
   // Infer section flags from the section name if we can.
   Kind = getELFKindForNamedSection(SectionName, Kind);
 
@@ -1291,21 +1297,7 @@ static void checkMachOComdat(const GlobalValue *GV) {
 MCSection *TargetLoweringObjectFileMachO::getExplicitSectionGlobal(
     const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
 
-  StringRef SectionName = GO->getSection();
-
-  const GlobalVariable *GV = dyn_cast<GlobalVariable>(GO);
-  if (GV && GV->hasImplicitSection()) {
-    auto Attrs = GV->getAttributes();
-    if (Attrs.hasAttribute("bss-section") && Kind.isBSS()) {
-      SectionName = Attrs.getAttribute("bss-section").getValueAsString();
-    } else if (Attrs.hasAttribute("rodata-section") && Kind.isReadOnly()) {
-      SectionName = Attrs.getAttribute("rodata-section").getValueAsString();
-    } else if (Attrs.hasAttribute("relro-section") && Kind.isReadOnlyWithRel()) {
-      SectionName = Attrs.getAttribute("relro-section").getValueAsString();
-    } else if (Attrs.hasAttribute("data-section") && Kind.isData()) {
-      SectionName = Attrs.getAttribute("data-section").getValueAsString();
-    }
-  }
+  StringRef SectionName = handlePragmaClangSection(GO, Kind);
 
   // Parse the section specifier and create it if valid.
   StringRef Segment, Section;
@@ -1674,7 +1666,7 @@ static int getSelectionForCOFF(const GlobalValue *GV) {
 
 MCSection *TargetLoweringObjectFileCOFF::getExplicitSectionGlobal(
     const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
-  StringRef Name = GO->getSection();
+  StringRef Name = handlePragmaClangSection(GO, Kind);
   if (Name == getInstrProfSectionName(IPSK_covmap, Triple::COFF,
                                       /*AddSegmentInfo=*/false) ||
       Name == getInstrProfSectionName(IPSK_covfun, Triple::COFF,