This patch adds a new Clang compiler flag "-gline-tables-only".

It reduces the amount of emitted debug information:
1) DIEs in .debug_info have types DW_TAG_compile_unit, DW_TAG_subprogram,
DW_TAG_inlined_subroutine (for opt builds) and DW_TAG_lexical_block only.
2) .debug_str contains only function names.
3) No debug data for types/namespaces/variables is emitted.
4) The data in .debug_line is enough to produce valid stack traces with
function names and line numbers.

Reviewed by Eric Christopher.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@156160 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 20 insertions, 10 deletions

diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp
index 644777963b..4d4b57904c 100644
--- a/lib/CodeGen/CGDecl.cpp
+++ b/lib/CodeGen/CGDecl.cpp
@@ -326,7 +326,8 @@ void CodeGenFunction::EmitStaticVarDecl(const VarDecl &D,
 
   // Emit global variable debug descriptor for static vars.
   CGDebugInfo *DI = getDebugInfo();
-  if (DI) {
+  if (DI &&
+      CGM.getCodeGenOpts().DebugInfo >= CodeGenOptions::LimitedDebugInfo) {
     DI->setLocation(D.getLocation());
     DI->EmitGlobalVariable(var, &D);
   }
@@ -897,11 +898,14 @@ CodeGenFunction::EmitAutoVarAlloca(const VarDecl &D) {
   // Emit debug info for local var declaration.
   if (HaveInsertPoint())
     if (CGDebugInfo *DI = getDebugInfo()) {
-      DI->setLocation(D.getLocation());
-      if (Target.useGlobalsForAutomaticVariables()) {
-        DI->EmitGlobalVariable(static_cast<llvm::GlobalVariable *>(DeclPtr), &D);
-      } else
-        DI->EmitDeclareOfAutoVariable(&D, DeclPtr, Builder);
+      if (CGM.getCodeGenOpts().DebugInfo >= CodeGenOptions::LimitedDebugInfo) {
+        DI->setLocation(D.getLocation());
+        if (Target.useGlobalsForAutomaticVariables()) {
+          DI->EmitGlobalVariable(static_cast<llvm::GlobalVariable *>(DeclPtr),
+                                 &D);
+        } else
+          DI->EmitDeclareOfAutoVariable(&D, DeclPtr, Builder);
+      }
     }
 
   if (D.hasAttr<AnnotateAttr>())
@@ -1477,8 +1481,11 @@ void CodeGenFunction::EmitParmDecl(const VarDecl &D, llvm::Value *Arg,
       LocalDeclMap[&D] = Arg;
 
       if (CGDebugInfo *DI = getDebugInfo()) {
-        DI->setLocation(D.getLocation());
-        DI->EmitDeclareOfBlockLiteralArgVariable(*BlockInfo, Arg, Builder);
+        if (CGM.getCodeGenOpts().DebugInfo >=
+            CodeGenOptions::LimitedDebugInfo) {
+          DI->setLocation(D.getLocation());
+          DI->EmitDeclareOfBlockLiteralArgVariable(*BlockInfo, Arg, Builder);
+        }
       }
 
       return;
@@ -1556,8 +1563,11 @@ void CodeGenFunction::EmitParmDecl(const VarDecl &D, llvm::Value *Arg,
   DMEntry = DeclPtr;
 
   // Emit debug info for param declaration.
-  if (CGDebugInfo *DI = getDebugInfo())
-    DI->EmitDeclareOfArgVariable(&D, DeclPtr, ArgNo, Builder);
+  if (CGDebugInfo *DI = getDebugInfo()) {
+    if (CGM.getCodeGenOpts().DebugInfo >= CodeGenOptions::LimitedDebugInfo) {
+      DI->EmitDeclareOfArgVariable(&D, DeclPtr, ArgNo, Builder);
+    }
+  }
 
   if (D.hasAttr<AnnotateAttr>())
       EmitVarAnnotations(&D, DeclPtr);