diff options
Diffstat (limited to 'build/build-clang/llvmorg-17-init-1242-g5de5f66b984a.patch')
| -rw-r--r-- | build/build-clang/llvmorg-17-init-1242-g5de5f66b984a.patch | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/build/build-clang/llvmorg-17-init-1242-g5de5f66b984a.patch b/build/build-clang/llvmorg-17-init-1242-g5de5f66b984a.patch new file mode 100644 index 0000000000..c56bc93f04 --- /dev/null +++ b/build/build-clang/llvmorg-17-init-1242-g5de5f66b984a.patch @@ -0,0 +1,317 @@ +From beb699370963cb347f636435efc8409219c58f5f Mon Sep 17 00:00:00 2001 +From: John Brawn <john.brawn@arm.com> +Date: Mon, 30 Jan 2023 14:34:14 +0000 +Subject: [PATCH] [extract_symbols.py] Better handling of templates + +Since commit 846b676 SmallVectorBase<uint32_t> has been explicitly +instantiated, which means that clang.exe must export it for a plugin +to be able to link against it, but the constructor is not exported as +currently no template constructors or destructors are exported. + +We can't just export all constructors and destructors, as that puts us +over the symbol limit on Windows, so instead rewrite how we decide +which templates need to be exported to be more precise. Currently we +assume that templates instantiated many times have no explicit +instantiations, but this isn't necessarily true and results also in +exporting implicit template instantiations that we don't need +to. Instead check for references to template members, as this +indicates that the template must be explicitly instantiated (as if it +weren't the template would just be implicitly instantiated on use). + +Doing this reduces the number of symbols exported from clang from +66011 to 53993 (in the build configuration that I've been testing). It +also lets us get rid of the special-case handling of Type::getAs, as +its explicit instantiations are now being detected as such. + +Differential Revision: https://reviews.llvm.org/D142989 +--- + llvm/utils/extract_symbols.py | 200 ++++++++++++++++++---------------- + 1 file changed, 104 insertions(+), 96 deletions(-) + +diff --git a/llvm/utils/extract_symbols.py b/llvm/utils/extract_symbols.py +index 298ee6ba4eeb..f64e3d1eebb9 100755 +--- a/llvm/utils/extract_symbols.py ++++ b/llvm/utils/extract_symbols.py +@@ -23,11 +23,11 @@ import subprocess + import multiprocessing + import argparse + +-# Define functions which extract a list of symbols from a library using several +-# different tools. We use subprocess.Popen and yield a symbol at a time instead +-# of using subprocess.check_output and returning a list as, especially on +-# Windows, waiting for the entire output to be ready can take a significant +-# amount of time. ++# Define functions which extract a list of pairs of (symbols, is_def) from a ++# library using several different tools. We use subprocess.Popen and yield a ++# symbol at a time instead of using subprocess.check_output and returning a list ++# as, especially on Windows, waiting for the entire output to be ready can take ++# a significant amount of time. + + def dumpbin_get_symbols(lib): + process = subprocess.Popen(['dumpbin','/symbols',lib], bufsize=1, +@@ -35,10 +35,10 @@ def dumpbin_get_symbols(lib): + universal_newlines=True) + process.stdin.close() + for line in process.stdout: +- # Look for external symbols that are defined in some section +- match = re.match("^.+SECT.+External\s+\|\s+(\S+).*$", line) ++ # Look for external symbols ++ match = re.match("^.+(SECT|UNDEF).+External\s+\|\s+(\S+).*$", line) + if match: +- yield match.group(1) ++ yield (match.group(2), match.group(1) != "UNDEF") + process.wait() + + def nm_get_symbols(lib): +@@ -60,7 +60,11 @@ def nm_get_symbols(lib): + # but \s+ match newline also, so \s+\S* will match the optional size field. + match = re.match("^(\S+)\s+[BDGRSTVW]\s+\S+\s+\S*$", line) + if match: +- yield match.group(1) ++ yield (match.group(1), True) ++ # Look for undefined symbols, which have only name and type (which is U). ++ match = re.match("^(\S+)\s+U\s+$", line) ++ if match: ++ yield (match.group(1), False) + process.wait() + + def readobj_get_symbols(lib): +@@ -71,7 +75,7 @@ def readobj_get_symbols(lib): + for line in process.stdout: + # When looking through the output of llvm-readobj we expect to see Name, + # Section, then StorageClass, so record Name and Section when we see +- # them and decide if this is a defined external symbol when we see ++ # them and decide if this is an external symbol when we see + # StorageClass. + match = re.search('Name: (\S+)', line) + if match: +@@ -83,9 +87,8 @@ def readobj_get_symbols(lib): + if match: + storageclass = match.group(1) + if section != 'IMAGE_SYM_ABSOLUTE' and \ +- section != 'IMAGE_SYM_UNDEFINED' and \ + storageclass == 'External': +- yield name ++ yield (name, section != 'IMAGE_SYM_UNDEFINED') + process.wait() + + # Define functions which determine if the target is 32-bit Windows (as that's +@@ -146,23 +149,11 @@ def should_keep_microsoft_symbol(symbol, calling_convention_decoration): + if symbol.startswith(("__xmm@", "__ymm@", "__real@")): + return None + return symbol +- # Function template instantiations start with ?$; keep the instantiations of +- # clang::Type::getAs, as some of them are explipict specializations that are +- # defined in clang's lib/AST/Type.cpp; discard the rest as it's assumed that +- # the definition is public +- elif re.match('\?\?\$getAs@.+@Type@clang@@', symbol): +- return symbol +- elif symbol.startswith('??$'): +- return None + # Deleting destructors start with ?_G or ?_E and can be discarded because + # link.exe gives you a warning telling you they can't be exported if you + # don't + elif symbol.startswith('??_G') or symbol.startswith('??_E'): + return None +- # Constructors (?0) and destructors (?1) of templates (?$) are assumed to be +- # defined in headers and not required to be kept +- elif symbol.startswith('??0?$') or symbol.startswith('??1?$'): +- return None + # An anonymous namespace is mangled as ?A(maybe hex number)@. Any symbol + # that mentions an anonymous namespace can be discarded, as the anonymous + # namespace doesn't exist outside of that translation unit. +@@ -216,18 +207,6 @@ def should_keep_itanium_symbol(symbol, calling_convention_decoration): + return None + if not names: + return symbol +- # Constructors and destructors of templates classes are assumed to be +- # defined in headers and not required to be kept +- if re.match('[CD][123]', names[-1][0]) and names[-2][1]: +- return None +- # Keep the instantiations of clang::Type::getAs, as some of them are +- # explipict specializations that are defined in clang's lib/AST/Type.cpp; +- # discard any other function template instantiations as it's assumed that +- # the definition is public +- elif symbol.startswith('_ZNK5clang4Type5getAs'): +- return symbol +- elif names[-1][1]: +- return None + # Keep llvm:: and clang:: names + elif names[0][0] == '4llvm' or names[0][0] == '5clang': + return symbol +@@ -338,14 +317,79 @@ def parse_itanium_nested_name(arg): + # If we get here then something went wrong + return None, None + ++# Parse a microsoft mangled symbol and return a list of pairs of ++# (name, is_template). This is very rudimentary and does just enough ++# in order to determine if the first or second component is a template. ++def parse_microsoft_mangling(arg): ++ # If the name doesn't start with ? this isn't a mangled name ++ if not arg.startswith('?'): ++ return [(arg, False)] ++ arg = arg[1:] ++ components = [] ++ while len(arg) > 0: ++ # If we see an empty component we've reached the end ++ if arg.startswith('@'): ++ return components ++ # Check for a simple name ++ match = re.match('(\w+)@(.+)', arg) ++ if match: ++ components.append((match.group(1), False)) ++ arg = match.group(2) ++ continue ++ # Check for a special function name ++ match = re.match('(\?_?\w)(.+)', arg) ++ if match: ++ components.append((match.group(1), False)) ++ arg = match.group(2) ++ continue ++ # Check for a template name ++ match = re.match('\?\$(\w+)@[^@]+@(.+)', arg) ++ if match: ++ components.append((match.group(1), True)) ++ arg = match.group(2) ++ continue ++ # Some other kind of name that we can't handle ++ components.append((arg, False)) ++ return components ++ return components ++ + def extract_symbols(arg): + get_symbols, should_keep_symbol, calling_convention_decoration, lib = arg +- symbols = dict() +- for symbol in get_symbols(lib): ++ symbol_defs = dict() ++ symbol_refs = set() ++ for (symbol, is_def) in get_symbols(lib): + symbol = should_keep_symbol(symbol, calling_convention_decoration) + if symbol: +- symbols[symbol] = 1 + symbols.setdefault(symbol,0) +- return symbols ++ if is_def: ++ symbol_defs[symbol] = 1 + symbol_defs.setdefault(symbol,0) ++ else: ++ symbol_refs.add(symbol) ++ return (symbol_defs, symbol_refs) ++ ++def get_template_name(sym, mangling): ++ # Parse the mangling into a list of (name, is_template) ++ try: ++ if mangling == 'microsoft': ++ names = parse_microsoft_mangling(sym) ++ else: ++ match = re.match('_Z(T[VTIS])?(N.+)', sym) ++ if match: ++ names, _ = parse_itanium_nested_name(match.group(2)) ++ else: ++ names = None ++ except TooComplexName: ++ return None ++ ++ if not names: ++ return None ++ ++ # If any component is a template then return it ++ for name, is_template in names: ++ if is_template: ++ return name ++ ++ # Not a template ++ return None + + if __name__ == '__main__': + tool_exes = ['dumpbin','nm','objdump','llvm-readobj'] +@@ -458,68 +502,32 @@ if __name__ == '__main__': + exit(1) + + # Merge everything into a single dict +- symbols = dict() +- for this_lib_symbols in libs_symbols: +- for k,v in list(this_lib_symbols.items()): +- symbols[k] = v + symbols.setdefault(k,0) +- +- # Count instances of member functions of template classes, and map the +- # symbol name to the function+class. We do this under the assumption that if +- # a member function of a template class is instantiated many times it's +- # probably declared in a public header file. +- template_function_count = dict() +- template_function_mapping = dict() +- template_function_count[""] = 0 +- for k in symbols: +- name = None +- if args.mangling == 'microsoft': +- # Member functions of templates start with +- # ?<fn_name>@?$<class_name>@, so we map to <fn_name>@?$<class_name>. +- # As manglings go from the innermost scope to the outermost scope +- # this means: +- # * When we have a function member of a subclass of a template +- # class then <fn_name> will actually contain the mangling of +- # both the subclass and the function member. This is fine. +- # * When we have a function member of a template subclass of a +- # (possibly template) class then it's the innermost template +- # subclass that becomes <class_name>. This should be OK so long +- # as we don't have multiple classes with a template subclass of +- # the same name. +- match = re.search("^\?(\??\w+\@\?\$\w+)\@", k) +- if match: +- name = match.group(1) +- else: +- # Find member functions of templates by demangling the name and +- # checking if the second-to-last name in the list is a template. +- match = re.match('_Z(T[VTIS])?(N.+)', k) +- if match: +- try: +- names, _ = parse_itanium_nested_name(match.group(2)) +- if names and names[-2][1]: +- name = ''.join([x for x,_ in names]) +- except TooComplexName: +- # Manglings that are too complex should already have been +- # filtered out, but if we happen to somehow see one here +- # just leave it as-is. +- pass +- if name: +- old_count = template_function_count.setdefault(name,0) +- template_function_count[name] = old_count + 1 +- template_function_mapping[k] = name +- else: +- template_function_mapping[k] = "" ++ symbol_defs = dict() ++ symbol_refs = set() ++ for (this_lib_defs, this_lib_refs) in libs_symbols: ++ for k,v in list(this_lib_defs.items()): ++ symbol_defs[k] = v + symbol_defs.setdefault(k,0) ++ for sym in list(this_lib_refs): ++ symbol_refs.add(sym) ++ ++ # Find which template instantiations are referenced at least once. ++ template_instantiation_refs = set() ++ for sym in list(symbol_refs): ++ template = get_template_name(sym, args.mangling) ++ if template: ++ template_instantiation_refs.add(template) + + # Print symbols which both: + # * Appear in exactly one input, as symbols defined in multiple + # objects/libraries are assumed to have public definitions. +- # * Aren't instances of member functions of templates which have been +- # instantiated 100 times or more, which are assumed to have public +- # definitions. (100 is an arbitrary guess here.) ++ # * Are not a template instantiation that isn't referenced anywhere. This ++ # is because we need to export any explicitly instantiated templates, ++ # and we expect those to be referenced in some object. + if args.o: + outfile = open(args.o,'w') + else: + outfile = sys.stdout +- for k,v in list(symbols.items()): +- template_count = template_function_count[template_function_mapping[k]] +- if v == 1 and template_count < 100: ++ for k,v in list(symbol_defs.items()): ++ template = get_template_name(k, args.mangling) ++ if v == 1 and (not template or template in template_instantiation_refs): + print(k, file=outfile) +-- +2.39.0.1.g6739ec1790 + |