Revision: 126685
Author: clattner
Date: 2007-04-28 21:24:20 -0700 (Sat, 28 Apr 2007)
Log Message:
---
Add alias support to llvm-gcc
Patch by Anton K!
Modified Paths:
--
apple-local/branches/llvm/gcc/llvm-backend.cpp
apple-local/branches/llvm/gcc/llvm.h
apple-local/branches/llvm/gcc/varasm.c
Modified: apple-local/branches/llvm/gcc/llvm-backend.cpp
===
--- apple-local/branches/llvm/gcc/llvm-backend.cpp 2007-04-28 17:04:47 UTC
(rev 126684)
+++ apple-local/branches/llvm/gcc/llvm-backend.cpp 2007-04-29 04:24:20 UTC
(rev 126685)
@@ -28,6 +28,7 @@
#include "llvm/Module.h"
#include "llvm/ModuleProvider.h"
#include "llvm/PassManager.h"
+#include "llvm/ValueSymbolTable.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Analysis/Verifier.h"
#include "llvm/Assembly/Writer.h"
@@ -57,6 +58,7 @@
#include "coretypes.h"
#include "flags.h"
#include "tree.h"
+#include "c-tree.h" // For aliases
#include "diagnostic.h"
#include "output.h"
#include "toplev.h"
@@ -532,6 +534,86 @@
timevar_pop(TV_LLVM_FUNCS);
}
+// emit_alias_to_llvm - Given decl and target emit alias to target. gcc is
+// little bit insane, it can ask us for alias emission in many places. Such
+// places are divided into two stages: it's allowed to have unresolved target
at
+// stage 0 (hence result code -1), but not on stage 1 (error). Zero is returned
+// if alias was emitted.
+int emit_alias_to_llvm(tree decl, tree target, unsigned stage) {
+ if (errorcount || sorrycount) return -2;
+
+ timevar_push(TV_LLVM_GLOBALS);
+
+ // Get or create LLVM global for our alias.
+ GlobalValue *V = cast(DECL_LLVM(decl));
+
+ // Try to grab decl from IDENTIFIER_NODE
+ GlobalValue *Aliasee = 0;
+ if (tree c_decl = lookup_name(target))
+Aliasee = cast(DECL_LLVM(c_decl));
+
+ // Query SymTab for aliasee
+ const char* AliaseeName = IDENTIFIER_POINTER(target);
+ if (!Aliasee) {
+Aliasee =
+ dyn_cast_or_null(TheModule->
+getValueSymbolTable().lookup(AliaseeName));
+ }
+
+ // Last resort. Query for name set via __asm__
+ if (!Aliasee) {
+std::string starred = std::string("\001") + AliaseeName;
+Aliasee =
+ dyn_cast_or_null(TheModule->
+getValueSymbolTable().lookup(starred));
+ }
+
+ if (!Aliasee) {
+if (stage)
+ error ("%J%qD aliased to undefined symbol %qE",
+ decl, decl, target);
+timevar_pop(TV_LLVM_GLOBALS);
+return -1;
+ }
+
+ GlobalValue::LinkageTypes Linkage;
+ GlobalValue::VisibilityTypes Visibility;
+
+ // Check for external weak linkage
+ if (DECL_EXTERNAL(decl) && DECL_WEAK(decl))
+Linkage = GlobalValue::WeakLinkage;
+ else if (!TREE_PUBLIC(decl))
+Linkage = GlobalValue::InternalLinkage;
+ else
+Linkage = GlobalValue::ExternalLinkage;
+
+ GlobalAlias* GA = new GlobalAlias(Aliasee->getType(), Linkage, "",
+Aliasee, TheModule);
+ // Handle visibility style
+ if (TREE_PUBLIC(decl) && DECL_VISIBILITY(decl) == VISIBILITY_HIDDEN)
+GA->setVisibility(GlobalValue::HiddenVisibility);
+
+ if (V->getType() == GA->getType())
+V->replaceAllUsesWith(GA);
+ else if (!V->use_empty())
+error ("%J% Alias %qD used with invalid type!", decl, decl);
+
+ changeLLVMValue(V, GA);
+ GA->takeName(V);
+ if (GlobalVariable *GV = dyn_cast(V))
+GV->eraseFromParent();
+ else if (GlobalAlias *GA = dyn_cast(V))
+GA->eraseFromParent();
+ else if (Function *F = dyn_cast(V))
+F->eraseFromParent();
+ else
+assert(0 && "Unsuported global value");
+
+ timevar_pop(TV_LLVM_GLOBALS);
+ return 0;
+}
+
+
/// emit_global_to_llvm - Emit the specified VAR_DECL or aggregate CONST_DECL
to
/// LLVM as a global variable. This function implements the end of
/// assemble_variable.
@@ -845,12 +927,12 @@
// Update the decl that points to F.
changeLLVMValue(F, FInNewType);
+
+ // Now we can give GV the proper name.
+ GV->takeName(F);
// F is now dead, nuke it.
F->eraseFromParent();
-
- // Now we can give GV the proper name.
- GV->setName(Name);
}
} else {
Modified: apple-local/branches/llvm/gcc/llvm.h
===
--- apple-local/branches/llvm/gcc/llvm.h2007-04-28 17:04:47 UTC (rev
126684)
+++ apple-local/branches/llvm/gcc/llvm.h2007-04-29 04:24:20 UTC (rev
126685)
@@ -49,6 +49,10 @@
*/
void emit_global_to_llvm(union tree_node*);
+/* emit_global_to_llvm - Emit the specified alias to LLVM
+ */
+int emit_alias_to_llvm(union tree_node*, union tree_node*, unsigned);
+
/* llvm_get_decl_name - Used by varasm.c, returns the specified declaration's
* name.
*/
Modified: apple-local/branches/llvm/gcc/varasm.c
==
