Rudimentary name mangling support (#4267)

This seems to be enough to avoid naming collisions for functions in any
of the current test cases (verified by asserting that the name of the
`llvm::Function` matches the name passed to create it - not triggering
LLVM's numbering that happens when names collide)

It currently implements mangling for namespace scopes, class scopes, and
impls.
Nothing generic is mangled yet - haven't looked at how that works,
though evidently it's not covered by existing testing, I guess.

Follow-up change will document the current mangling algorithm in
`toolchain/docs/lower.md`

---------

Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
This commit is contained in:
David Blaikie
2024-09-06 23:10:21 +00:00
committed by GitHub
co-authored by Jon Ross-Perkins Carbon Infra Bot
parent 49f2136325
commit a548eff0bb
94 changed files with 657 additions and 498 deletions
@@ -13,7 +13,7 @@ fn Foo(a: i32, b: i32) {}
// CHECK:STDOUT: ; ModuleID = 'params_two.carbon'
// CHECK:STDOUT: source_filename = "params_two.carbon"
// CHECK:STDOUT:
// CHECK:STDOUT: define void @Foo(i32 %a, i32 %b) !dbg !4 {
// CHECK:STDOUT: define void @_CFoo.Main(i32 %a, i32 %b) !dbg !4 {
// CHECK:STDOUT: entry:
// CHECK:STDOUT: ret void, !dbg !7
// CHECK:STDOUT: }
@@ -25,7 +25,7 @@ fn Foo(a: i32, b: i32) {}
// CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
// CHECK:STDOUT: !3 = !DIFile(filename: "params_two.carbon", directory: "")
// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Foo", linkageName: "Foo", scope: null, file: !3, line: 11, type: !5, spFlags: DISPFlagDefinition, unit: !2)
// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "Foo", linkageName: "_CFoo.Main", scope: null, file: !3, line: 11, type: !5, spFlags: DISPFlagDefinition, unit: !2)
// CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
// CHECK:STDOUT: !6 = !{}
// CHECK:STDOUT: !7 = !DILocation(line: 11, column: 1, scope: !4)