maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

IR: Stop abusing DW_TAG_base_type for compile unit arrays 

The sub-arrays for compile units have for a long time been initialized
to distinct temporary nodes with the `DW_TAG_base_type` tag, with no
other operands.  These invalid `DIBasicType`s are later replaced with
appropriate arrays.

This seems like a poor man's assertion that the arrays do eventually get
replaced.  These days, temporaries in the graph will cause assertions
when writing bitcode or assembly, so this isn't necessary.  Use
temporary empty tuples instead.

Note that the whole idea of using temporaries and then replacing them
later is wasteful here.  We never actually want to merge compile units
by uniquing based on content.  Compile units should use `getDistinct()`
instead of `get()`, and then their operands can be freely replaced later
on.

llvm-svn: 228967
This commit is contained in:
Duncan P. N. Exon Smith 2015-02-12 21:52:11 +00:00
parent 18dd78a8fd
commit b93569d182
1 changed files with 9 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
llvm/lib/IR/DIBuilder.cpp
View File

@ -150,16 +150,14 @@ DICompileUnit DIBuilder::createCompileUnit(unsigned Lang, StringRef Filename,
"Invalid Language tag");
assert(!Filename.empty() &&
"Unable to create compile unit without filename");
Metadata *TElts[] = {HeaderBuilder::get(DW_TAG_base_type).get(VMContext)};
TempEnumTypes = MDNode::getTemporary(VMContext, TElts).release();
TempRetainTypes = MDNode::getTemporary(VMContext, TElts).release();
TempSubprograms = MDNode::getTemporary(VMContext, TElts).release();
TempGVs = MDNode::getTemporary(VMContext, TElts).release();
TempImportedModules = MDNode::getTemporary(VMContext, TElts).release();
// TODO: Once we make MDCompileUnit distinct, stop using temporaries here
// (just start with operands assigned to nullptr).
TempEnumTypes = MDTuple::getTemporary(VMContext, None).release();
TempRetainTypes = MDTuple::getTemporary(VMContext, None).release();
TempSubprograms = MDTuple::getTemporary(VMContext, None).release();
TempGVs = MDTuple::getTemporary(VMContext, None).release();
TempImportedModules = MDTuple::getTemporary(VMContext, None).release();
Metadata *Elts[] = {HeaderBuilder::get(dwarf::DW_TAG_compile_unit)
.concat(Lang)
@ -174,6 +172,8 @@ DICompileUnit DIBuilder::createCompileUnit(unsigned Lang, StringRef Filename,
TempEnumTypes, TempRetainTypes, TempSubprograms, TempGVs,
TempImportedModules};
// TODO: Switch to getDistinct(). We never want to merge compile units based
// on contents.
MDNode *CUNode = MDNode::get(VMContext, Elts);
// Create a named metadata so that it is easier to find cu in a module.