I'm refactoring my library by mostly moving functions between modules and I get DMD crashes pretty often. The latest example:

(No debugging symbols found in /usr/bin/dmd)
(gdb) r  -c -of.dub/build/argparse-test-library-unittest-linux.posix-x86_64-dmd_v2.100.0-85E634C9744FC817BD0D2766A2B6CFD9/argparse-test-library.o -debug -g -unittest -w -version=Have_argparse -Isource/ .dub/code/argparse-test-library-unittest-linux.posix-x86_64-dmd_v2.100.0-662575AE9496601C3D84B10DCD65DAFE_dub_test_root.d source/argparse/ansi.d source/argparse/internal/arguments.d source/argparse/internal/completer.d source/argparse/internal/help.d source/argparse/internal/lazystring.d source/argparse/internal/package.d source/argparse/internal/parser.d source/argparse/internal/subcommands.d source/argparse/internal/utils.d source/argparse/package.d -vcolumns
Starting program: /usr/bin/dmd -c -of.dub/build/argparse-test-library-unittest-linux.posix-x86_64-dmd_v2.100.0-85E634C9744FC817BD0D2766A2B6CFD9/argparse-test-library.o -debug -g -unittest -w -version=Have_argparse -Isource/ .dub/code/argparse-test-library-unittest-linux.posix-x86_64-dmd_v2.100.0-662575AE9496601C3D84B10DCD65DAFE_dub_test_root.d source/argparse/ansi.d source/argparse/internal/arguments.d source/argparse/internal/completer.d source/argparse/internal/help.d source/argparse/internal/lazystring.d source/argparse/internal/package.d source/argparse/internal/parser.d source/argparse/internal/subcommands.d source/argparse/internal/utils.d source/argparse/package.d -vcolumns
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Program received signal SIGSEGV, Segmentation fault.
0x0000555555822ee6 in getTypePointerBitmap::PointerBitmapVisitor::visit(TypeStruct*) ()

(gdb) where
#0  0x0000555555822ee6 in getTypePointerBitmap::PointerBitmapVisitor::visit(TypeStruct*) ()
#1  0x0000555555822bc9 in dmd.traits.getTypePointerBitmap(dmd.globals.Loc, dmd.mtype.Type, dmd.root.array.Array!(ulong).Array*) ()
#2  0x000055555581d832 in dmd.traits.semanticTraits(dmd.expression.TraitsExp, dmd.dscope.Scope*) ()
#3  0x00005555557d4ded in ExpressionSemanticVisitor::visit(TraitsExp*) ()
#4  0x00005555558499af in dmd.initsem.inferType(dmd.init.Initializer, dmd.dscope.Scope*) ()
#5  0x000055555582b965 in DsymbolSemanticVisitor::visit(VarDeclaration*) ()
#6  0x00005555556f06ad in dmd.dsymbolsem.templateInstanceSemantic(dmd.dtemplate.TemplateInstance, dmd.dscope.Scope*, dmd.root.array.Array!(dmd.expression.Expression).(gdb)
#7  0x00005555556c7ee4 in Semantic3Visitor::visit(AggregateDeclaration*) ()
#8  0x00005555556c83fc in Semantic3Visitor::visit(TemplateInstance*) ()
#9  0x00005555558e317e in dmd.mars.tryMain(ulong, const(char)**, ref dmd.globals.Param) ()
#10 0x00005555558f27d1 in D main ()

How do you debug and fix these things?

On Wednesday, 28 September 2022 at 22:48:47 UTC, Andrey Zherikov wrote:

Program received signal SIGSEGV, Segmentation fault.
0x0000555555822ee6 in getTypePointerBitmap::PointerBitmapVisitor::visit(TypeStruct*) ()

(gdb) where
#0  0x0000555555822ee6 in getTypePointerBitmap::PointerBitmapVisitor::visit(TypeStruct*) ()
#1  0x0000555555822bc9 in dmd.traits.getTypePointerBitmap(dmd.globals.Loc, dmd.mtype.Type, dmd.root.array.Array!(ulong).Array*) ()

This seems to stem from use of __traits(getPointerBitmap, T), with a T that is not handled properly. If you can get a reduced test case that will make things much easier. dustmite (which should come with dmd, is useful for automatic reduction, otherwise if you have few uses of __traits(getPointerBitmap, T), it might be easier to synthesise an example that crashes the compiler.

On Wednesday, 28 September 2022 at 23:07:34 UTC, Nicholas Wilson wrote:

I don't use getPointerBitmap in my code:

$ grep -r --include=*.d getPointerBitmap
$

On Wednesday, 28 September 2022 at 23:15:42 UTC, Andrey Zherikov wrote:

$ grep -r --include=*.d getPointerBitmap
$

It's used in druntime, by RTInfo:

https://github.com/dlang/druntime/blob/v2.100.2/src/object.d#L3695-L3702

I actually see that DMD is very unstable.
Here are three consequtive calls of dub test --coverage -v --build-mode singleFile without any change in source files:

Failed:

C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d-mixin-2084(2084,7): Error: unterminated string constant starting at C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d-mixin-2084(2084,14)
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d-mixin-2084(2084,14): Error: no identifier for declarator `handler`
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d-mixin-2084(2084,14): Error: semicolon expected to close `alias` declaration
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d(2096,32): Error: incomplete mixin expression `handler`(args[`].get!(SumTypes[`].Types[`])(), )`
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d(2096,32): Error: incomplete mixin expression `handler`(args[`].get!(SumTypes[`].Types[1])(), )`
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d(2096,32): Error: incomplete mixin expression `handler`(args[`].get!(SumTypes[`].Types[2])(), )`
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d(2096,32): Error: incomplete mixin expression `handler`(args[`].get!(SumTypes[`].Types[3])(), )`
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d(2096,32): Error: incomplete mixin expression `handler`(args[`].get!(SumTypes[`].Types[4])(), )`
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d(1662,52): Error: template instance `argparse.internal.parser.Parser.parse!(false, Init).parse.matchImpl!(SumType!(Unknown, EndOfArgs, Positional, NamedShort, NamedLong))` error instantiating
source\argparse\internal\parser.d(234,19):        instantiated from here: `match!(SumType!(Unknown, EndOfArgs, Positional, NamedShort, NamedLong))`
source\argparse\internal\subcommands.d(138,47):        instantiated from here: `parse!(false, Init)`
source\argparse\internal\subcommands.d(103,17):        instantiated from here: `ParsingSubCommandArgument!(Config('=', '\xff', '-', "--", false, false, true, StylingMode.autodetect, null, Style(TextStyle([cast(ubyte)1u]), TextStyle([cast(ubyte)1u]), TextStyle([cast(ubyte)1u, cast(ubyte)4u]), TextStyle([cast(ubyte)93u]), TextStyle([cast(ubyte)3u]), TextStyle([cast(ubyte)93u])), null), Init, CommandInfo(["init"], LazyString(SumType(Storage(null, ), cast(ubyte)0u)), LazyString(SumType(Storage("Print initialization script for shell completion.", ), cast(ubyte)0u)), LazyString(SumType(Storage("Print initialization script.", ), cast(ubyte)0u)), LazyString(SumType(Storage(null, ), cast(ubyte)0u))), Complete!(T), "cmd", false)`
source\argparse\internal\package.d(402,32):        ... (4 instantiations, -v to show) ...
source\argparse\package.d(999,46):        instantiated from here: `callParser!(Config('=', '\xff', '-', "--", false, false, true, StylingMode.autodetect, null, Style(TextStyle([cast(ubyte)1u]), TextStyle([cast(ubyte)1u]), TextStyle([cast(ubyte)1u, cast(ubyte)4u]), TextStyle([cast(ubyte)93u]), TextStyle([cast(ubyte)3u]), TextStyle([cast(ubyte)93u])), null), false, Complete!(T))`
source\argparse\package.d(794,12):        instantiated from here: `CLI!(Config('=', '\xff', '-', "--", false, false, true, StylingMode.autodetect, null, Style(TextStyle([cast(ubyte)1u]), TextStyle([cast(ubyte)1u]), TextStyle([cast(ubyte)1u, cast(ubyte)4u]), TextStyle([cast(ubyte)93u]), TextStyle([cast(ubyte)3u]), TextStyle([cast(ubyte)93u])), null), T)`
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d-mixin-2084(2084,7): Error: unterminated string constant starting at C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d-mixin-2084(2084,14)
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d-mixin-2084(2084,14): Error: no identifier for declarator `handler`
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d-mixin-2084(2084,14): Error: semicolon expected to close `alias` declaration
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d(2096,32): Error: incomplete mixin expression `handler`(args[`].get!(SumTypes[`].Types[`])(), )`
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d(2096,32): Error: incomplete mixin expression `handler`(args[`].get!(SumTypes[`].Types[1])(), )`
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d(2096,32): Error: incomplete mixin expression `handler`(args[`].get!(SumTypes[`].Types[2])(), )`
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d(2096,32): Error: incomplete mixin expression `handler`(args[`].get!(SumTypes[`].Types[3])(), )`
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d(2096,32): Error: incomplete mixin expression `handler`(args[`].get!(SumTypes[`].Types[4])(), )`
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d(1662,52): Error: template instance `argparse.internal.parser.Parser.parse!(true, Init).parse.matchImpl!(SumType!(Unknown, EndOfArgs, Positional, NamedShort, NamedLong))` error instantiating
source\argparse\internal\parser.d(234,19):        instantiated from here: `match!(SumType!(Unknown, EndOfArgs, Positional, NamedShort, NamedLong))`
source\argparse\internal\subcommands.d(138,47):        instantiated from here: `parse!(true, Init)`
source\argparse\internal\subcommands.d(104,17):        instantiated from here: `ParsingSubCommandArgument!(Config('=', '\xff', '-', "--", false, false, true, StylingMode.autodetect, null, Style(TextStyle([cast(ubyte)1u]), TextStyle([cast(ubyte)1u]), TextStyle([cast(ubyte)1u, cast(ubyte)4u]), TextStyle([cast(ubyte)93u]), TextStyle([cast(ubyte)3u]), TextStyle([cast(ubyte)93u])), null), Init, CommandInfo(["init"], LazyString(SumType(Storage(null, ), cast(ubyte)0u)), LazyString(SumType(Storage("Print initialization script for shell completion.", ), cast(ubyte)0u)), LazyString(SumType(Storage("Print initialization script.", ), cast(ubyte)0u)), LazyString(SumType(Storage(null, ), cast(ubyte)0u))), Complete!(T), "cmd", true)`
source\argparse\internal\package.d(402,32):        ... (4 instantiations, -v to show) ...
source\argparse\package.d(999,46):        instantiated from here: `callParser!(Config('=', '\xff', '-', "--", false, false, true, StylingMode.autodetect, null, Style(TextStyle([cast(ubyte)1u]), TextStyle([cast(ubyte)1u]), TextStyle([cast(ubyte)1u, cast(ubyte)4u]), TextStyle([cast(ubyte)93u]), TextStyle([cast(ubyte)3u]), TextStyle([cast(ubyte)93u])), null), false, Complete!(T))`
source\argparse\package.d(794,12):        instantiated from here: `CLI!(Config('=', '\xff', '-', "--", false, false, true, StylingMode.autodetect, null, Style(TextStyle([cast(ubyte)1u]), TextStyle([cast(ubyte)1u]), TextStyle([cast(ubyte)1u, cast(ubyte)4u]), TextStyle([cast(ubyte)93u]), TextStyle([cast(ubyte)3u]), TextStyle([cast(ubyte)93u])), null), T)`
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d-mixin-2084(2084,7): Error: unterminated string constant starting at C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d-mixin-2084(2084,14)
C:\D\dmd2\windows\bin\..\..\src\phobos\std\sumtype.d-mixin-2084(2084,14): Error: no identifier for declarator `handler`
C:\D\dmd2\windows\bin\dmd.exe failed with exit code 1.

Failed:

C:\D\dmd2\windows\bin\dmd.exe failed with exit code -1073741819.

Succeeded:

Linking...
LINK : .dub\build\argparse-test-library-unittest-cov-windows-x86_64-dmd_v2.100.2-dirty-54DD8361E221F5FB88F9291F67344057\argparse-test-library.exe not found or not built by the last incremental link; performing full link
Running argparse-test-library.exe

On Thursday, 29 September 2022 at 00:07:41 UTC, Paul Backus wrote:

$ grep -r --include=*.d getPointerBitmap
$

getPointerBitmap needs to be completely rewritten.

Currently it uses the visitor pattern and doesn't cache anything so a N element static array gets walked N times which is very very very slow even ignoring that each one has the same result.

On Thursday, 29 September 2022 at 00:48:03 UTC, Andrey Zherikov wrote:

The same code fails to build on Ubuntu:

Starting program: /usr/bin/dmd -debug -cov -g -unittest -w -version=Have_argparse -Isource/ source/argparse/package.d -c -of.dub/build/argparse-test-library-unittest-cov-linux.posix-x86_64-dmd_v2.100.0-2270E3354D7B3AAE3038EDF467033FBF/package_bcdb8bae.o -vcolumns
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Program received signal SIGILL, Illegal instruction.
0x00005555556b67c0 in ParseTimeVisitor<ASTCodegen>::visit(Expression*) ()

(gdb) where
#0  0x00005555556b67c0 in ParseTimeVisitor<ASTCodegen>::visit(Expression*) ()
#1  0x000055555587361a in S2irVisitor::visit(CompoundStatement*) ()
#2  0x0000555555869fea in S2irVisitor::visit(ScopeStatement*) ()
#3  0x000055555586c396 in S2irVisitor::visit(IfStatement*) ()
#4  0x000055555586c528 in S2irVisitor::visit(IfStatement*) ()
#5  0x000055555587361a in S2irVisitor::visit(CompoundStatement*) ()
#6  0x0000555555869fea in S2irVisitor::visit(ScopeStatement*) ()
#7  0x000055555586b477 in S2irVisitor::visit(ForStatement*) ()
#8  0x000055555587361a in S2irVisitor::visit(CompoundStatement*) ()
#9  0x000055555587361a in S2irVisitor::visit(CompoundStatement*) ()
#10 0x00005555558679da in FuncDeclaration_toObjFile(FuncDeclaration*, bool) ()
#11 0x000055555584e0b1 in toObjFile::ToObjFile::visit(TemplateInstance*) ()
#12 0x00005555558ce23e in genObjFile(Module*, bool) ()
#13 0x00005555558e584e in dmd.mars.tryMain(ulong, const(char)**, ref dmd.globals.Param) ()
#14 0x00005555558f27d1 in D main ()

On 9/28/22 9:01 PM, Andrey Zherikov wrote:

This seems like it might be an out of memory problem. When the compiler runs out of memory, any of a number of things might happen, including segfaults.

-Steve

On Thursday, 29 September 2022 at 03:19:08 UTC, Steven Schveighoffer wrote:

Why doesn't it fail with "out of memory exception"? I remember it did in previous versions (I use 2.100.2 now).