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-rw-r--r--docs/LangRef.html137
-rw-r--r--lib/CodeGen/AsmPrinter/AsmPrinter.cpp65
-rw-r--r--lib/Target/X86/X86FrameLowering.cpp19
3 files changed, 208 insertions, 13 deletions
diff --git a/docs/LangRef.html b/docs/LangRef.html
index 2799083748..6881620cbc 100644
--- a/docs/LangRef.html
+++ b/docs/LangRef.html
@@ -106,6 +106,11 @@
<li><a href="#fpaccuracy">'<tt>fpaccuracy</tt>' Metadata</a></li>
</ol>
</li>
+ <li><a href="#module_flags">Module Flags Metadata</a>
+ <ol>
+ <li><a href="#objc_metadata">Objective-C Metadata</a></li>
+ </ol>
+ </li>
</ol>
</li>
<li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
@@ -3026,6 +3031,138 @@ call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
</div>
+<!-- ======================================================================= -->
+<h3>
+ <a name="module_flags">Module Flags Metadata</a>
+</h3>
+
+<div>
+
+<p>Occasionally, the front-end needs to transmit data to the linker which
+ affects its behavior. The LLVM IR isn't sufficient to transmit this
+ information, so one should use the <tt>llvm.module.flags</tt> named
+ metadata.</p>
+
+<p>The <tt>llvm.module.flags</tt> metadata is a named metadata, whose elements
+ consist of metadata triplets. For example:</p>
+
+<pre class="doc_code">
+!0 = metadata !{ i32 0, metadata !"foo", i32 1 }
+!1 = metadata !{ i32 1, metadata !"bar", i32 37 }
+
+!llvm.module.flags = !{ !0, !1 }
+</pre>
+
+<p>The first field specifies the behavior of the linker upon encountering two of
+ the same values. Behavior could range from: emitting an error if some of the
+ modules' flags disagree, emitting a warning, etc. The second field is the
+ name of the metadata. The third field is the value of the metadata.</p>
+
+<p>When two modules are linked together, the <tt>llvm.module.flags</tt> metadata
+ are unioned together.</p>
+
+</div>
+
+<!-- _______________________________________________________________________ -->
+<h4>
+ <a name="objc_metadata">Objective-C Metadata</a>
+</h4>
+
+<div>
+
+<p>The following module flags are used to convey Objective-C metadata to the
+ linker.</p>
+
+<table border="1" cellspacing="0" cellpadding="4">
+ <tbody>
+ <tr>
+ <th>Value</th>
+ <th>Behavior</th>
+ </tr>
+ <tr>
+ <td>1</td>
+ <td align="left">
+ <dl>
+ <dt><tt>Error</tt></dt>
+ <dd>Causes the linker to emit an error when two values disagree.</dd>
+ </dl>
+ </td>
+ </tr>
+ <tr>
+ <td>2</td>
+ <td align="left">
+ <dl>
+ <dt><tt>Require</tt></dt>
+ <dd>Causes the linker to emit an error when the specified value is not
+ present.</dd>
+ </dl>
+ </td>
+ </tr>
+ <tr>
+ <td>3</td>
+ <td align="left">
+ <dl>
+ <dt><tt>Override</tt></dt>
+ <dd>Causes the linker to use the specified value if the two values
+ disagree. It's an error if two pieces of the same metadata have
+ the <tt>Override</tt> behavior but different values.</dd>
+ </dl>
+ </td>
+ </tr>
+ </tbody>
+</table>
+
+<p>The names are:</p>
+
+<ul>
+ <li><tt>Objective-C Version</tt></li>
+ <li><tt>Objective-C Garbage Collection</tt></li>
+ <li><tt>Objective-C GC Only</tt></li>
+ <li><tt>Objective-C Image Info Section</tt></li>
+</ul>
+
+<p>
+
+<p>Here is an example of how to use the Objective-C metadata:</p>
+
+<pre class="doc_code">
+<u>Module A</u>
+!0 = metadata !{ i32 1, metadata !"Objective-C Version", i32 2 }
+!1 = metadata !{ i32 1, metadata !"Objective-C Garbage Collection", i32 2 }
+!2 = metadata !{ i32 1, metadata !"Objective-C Image Info Section",
+ metadata !"__DATA, __objc_imageinfo, regular, no_dead_strip" }
+!llvm.module.flags = !{ !0, !1, !2 }
+
+<u>Module B</u>
+!0 = metadata !{ i32 1, metadata !"Objective-C Version", i32 2 }
+!1 = metadata !{ i32 1, metadata !"Objective-C Garbage Collection", i32 2 }
+!2 = metadata !{ i32 1, metadata !"Objective-C GC Only", i32 4 }
+!3 = metadata !{ i32 1, metadata !"Objective-C Image Info Section",
+ metadata !"__DATA, __objc_imageinfo, regular, no_dead_strip" }
+!4 = metadata !{ i32 2, metadata !"Objective-C GC Only",
+ metadata !{
+ metadata !"Objective-C Garbage Collection", i32 2
+ }
+}
+!llvm.module.flags = !{ !0, !1, !2, !3, !4 }
+
+<u>Linked Module</u>
+!0 = metadata !{ i32 1, metadata !"Objective-C Version", i32 2 }
+!1 = metadata !{ i32 3, metadata !"Objective-C Garbage Collection", i32 2 }
+!2 = metadata !{ i32 1, metadata !"Objective-C GC Only", i32 4 }
+!3 = metadata !{ i32 1, metadata !"Objective-C Image Info Section",
+ metadata !"__DATA, __objc_imageinfo, regular, no_dead_strip" }
+!4 = metadata !{ i32 2, metadata !"Objective-C GC Only",
+ metadata !{
+ metadata !"Objective-C Garbage Collection", i32 2
+ }
+}
+!llvm.module.flags = !{ !0, !1, !2, !3, !4 }
+</pre>
+
+
+</div>
+
</div>
<!-- *********************************************************************** -->
diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 82860c2657..1b15cdcc81 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -930,6 +930,71 @@ bool AsmPrinter::doFinalization(Module &M) {
if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
OutStreamer.SwitchSection(S);
+ // If we have module flags, then emit them.
+ NamedMDNode *ModFlags = M.getNamedMetadata("llvm.module.flags");
+ if (ModFlags) {
+ const char *ObjCGCName = "Objective-C Garbage Collection";
+ const char *ObjCGCOnlyName = "Objective-C GC Only";
+ const char *ObjCImageInfoVersion = "Objective-C Image Info Version";
+ const char *ObjCImageInfoSec = "Objective-C Image Info Section";
+
+ MDNode *GC = 0;
+ MDNode *GCOnly = 0;
+ MDNode *ImageInfoVersion = 0;
+ MDNode *ImageInfoSec = 0;
+
+ for (unsigned I = 0, E = ModFlags->getNumOperands(); I != E; ++I) {
+ MDNode *MD = ModFlags->getOperand(I);
+ unsigned Behavior = cast<ConstantInt>(MD->getOperand(0))->getZExtValue();
+ (void) Behavior;
+ MDString *Str = cast<MDString>(MD->getOperand(1));
+
+ if (Str->getString() == ObjCImageInfoVersion) {
+ assert(Behavior == 1 && "Invalid behavior for module flag!");
+ ImageInfoVersion = MD;
+ } else if (Str->getString() == ObjCGCName) {
+ assert((Behavior == 1 || Behavior == 3) &&
+ "Invalid behavior for module flag!");
+ GC = MD;
+ } else if (Str->getString() == ObjCGCOnlyName) {
+ if (Behavior == 2) continue; // Ignore the 'require' clause.
+ GCOnly = MD;
+ } else if (Str->getString() == ObjCImageInfoSec) {
+ assert(Behavior == 1 && "Invalid behavior for module flag!");
+ ImageInfoSec = MD;
+ }
+ }
+
+ if (ImageInfoVersion || GC || GCOnly || ImageInfoSec) {
+ // FIXME: Duh!
+ unsigned version = 0;
+ unsigned flags = 0;
+
+ version =
+ cast<ConstantInt>(ImageInfoVersion->getOperand(2))->getZExtValue();
+ if (GC)
+ flags |= cast<ConstantInt>(GC->getOperand(2))->getZExtValue();
+ if (GCOnly)
+ flags |= cast<ConstantInt>(GCOnly->getOperand(2))->getZExtValue();
+
+ Type *Int32Ty = Type::getInt32Ty(M.getContext());
+ Constant *values[2] = {
+ ConstantInt::get(Int32Ty, version),
+ ConstantInt::get(Int32Ty, flags)
+ };
+ ArrayType *AT = ArrayType::get(Int32Ty, 2);
+ StringRef Sec = cast<MDString>(ImageInfoSec->getOperand(2))->getString();
+
+ GlobalVariable *GV =
+ cast<GlobalVariable>(M.getOrInsertGlobal("L_OBJC_IMAGE_INFO", AT));
+ GV->setConstant(true);
+ GV->setSection(Sec);
+ GV->setInitializer(ConstantArray::get(AT, values));
+
+ EmitGlobalVariable(GV);
+ }
+ }
+
// Allow the target to emit any magic that it wants at the end of the file,
// after everything else has gone out.
EmitEndOfAsmFile(M);
diff --git a/lib/Target/X86/X86FrameLowering.cpp b/lib/Target/X86/X86FrameLowering.cpp
index e5f6752614..5dfc0bb85d 100644
--- a/lib/Target/X86/X86FrameLowering.cpp
+++ b/lib/Target/X86/X86FrameLowering.cpp
@@ -455,26 +455,19 @@ encodeCompactUnwindRegistersWithFrame(unsigned SavedRegs[CU_NUM_SAVED_REGS],
};
const unsigned *CURegs = (Is64Bit ? CU64BitRegs : CU32BitRegs);
- // FIXME: The code below is WRONG and breaks tests on i386, see
- // SingleSource/Regression/C++/EH/ctor_dtor_count.exec
- // SingleSource/Regression/C++/EH/exception_spec_test.exec
- // SingleSource/Regression/C++/EH/function_try_block.exec
- // SingleSource/Regression/C++/EH/throw_rethrow_test.exec
- return ~0U;
-
// Encode the registers in the order they were saved, 3-bits per register. The
- // registers are numbered from 1 to 6.
+ // registers are numbered from 1 to CU_NUM_SAVED_REGS.
uint32_t RegEnc = 0;
- for (int I = 0; I != 6; ++I) {
+ for (int I = CU_NUM_SAVED_REGS, Idx = 0; I != -1; --I) {
unsigned Reg = SavedRegs[I];
- if (Reg == 0) break;
+ if (Reg == 0) continue;
+
int CURegNum = getCompactUnwindRegNum(CURegs, Reg);
- if (CURegNum == -1)
- return ~0U;
+ if (CURegNum == -1) return ~0U;
// Encode the 3-bit register number in order, skipping over 3-bits for each
// register.
- RegEnc |= (CURegNum & 0x7) << ((5 - I) * 3);
+ RegEnc |= (CURegNum & 0x7) << (Idx++ * 3);
}
assert((RegEnc & 0x3FFFF) == RegEnc && "Invalid compact register encoding!");
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2025-06-27 15:14:26 +0000