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chore: bump clang to v20 #6009

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239fdb5
chore: bump `clang` to v20
ggreif Apr 12, 2026
b2845ba
Updating `test/bench` numbers
github-actions[bot] Apr 17, 2026
d9c425b
test(ld): accept clang-20 \`wasm-ld\` output for representative.wat
ggreif Apr 25, 2026
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8 changes: 4 additions & 4 deletions flake.nix
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Original file line number Diff line number Diff line change
Expand Up @@ -86,17 +86,17 @@
llvmEnv = ''
# When compiling to wasm, we want to have more control over the flags,
# so we do not use the nix-provided wrapper in clang
export WASM_CLANG="clang-19"
export WASM_CLANG="clang-20"
export WASM_LD=wasm-ld
# because we use the unwrapped clang, we have to pass in some flags/paths
# that otherwise the wrapped clang would take care for us
export WASM_CLANG_LIB="${pkgs.llvmPackages_19.clang-unwrapped.lib}"
export WASM_CLANG_LIB="${pkgs.llvmPackages_20.clang-unwrapped.lib}"

# When compiling natively, we want to use `clang` (which is a nixpkgs
# provided wrapper that sets various include paths etc).
# But for some reason it does not handle building for Wasm well, so
# there we use plain clang-19. There is no stdlib there anyways.
export CLANG="${pkgs.clang_19}/bin/clang"
# there we use plain clang-20. There is no stdlib there anyways.
export CLANG="${pkgs.clang_20}/bin/clang"
'';

rts = import ./nix/rts.nix { inherit pkgs llvmEnv; };
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2 changes: 1 addition & 1 deletion nix/ic-wasm.nix
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@@ -1,4 +1,4 @@
pkgs: with pkgs.llvmPackages_19; pkgs.rustPlatform.buildRustPackage rec {
pkgs: with pkgs.llvmPackages_20; pkgs.rustPlatform.buildRustPackage rec {
pname = "ic-wasm";
version = builtins.substring 0 7 src.rev;
src = pkgs.sources.ic-wasm-src;
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4 changes: 2 additions & 2 deletions nix/rts.nix
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Expand Up @@ -56,8 +56,8 @@ pkgs.stdenv.mkDerivation {
nativeBuildInputs = [ pkgs.makeWrapper pkgs.removeReferencesTo pkgs.cacert ];

buildInputs = with pkgs; [
llvmPackages_19.clang
llvmPackages_19.bintools
llvmPackages_20.clang
llvmPackages_20.bintools
rust-nightly
wasmtime
rust-bindgen
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2 changes: 1 addition & 1 deletion nix/tests.nix
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Expand Up @@ -26,7 +26,7 @@ let

# extra deps for test/ld
ldTestDeps =
with pkgs.llvmPackages_19; [ lld clang ];
with pkgs.llvmPackages_20; [ lld clang ];

testDerivation = args:
pkgs.stdenv.mkDerivation (testDerivationArgs // args);
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13 changes: 9 additions & 4 deletions rts/Makefile
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@@ -1,9 +1,9 @@
SHELL:=bash -O globstar

CLANG ?= clang-19
CLANG ?= clang-20
LLVM_LINK = llvm-link
WASM_CLANG ?= clang-19
WASM_LD ?= wasm-ld-19
WASM_CLANG ?= clang-20
WASM_LD ?= wasm-ld-20

#
# We manually list all the .c files of libtommath that we care about.
Expand Down Expand Up @@ -270,7 +270,6 @@ test64: $(TEST_DEPENDENCIES_64)

EXPORTED_SYMBOLS=\
__wasm_call_ctors \
__wasm_apply_data_relocs \
memcmp \
tan \
asin \
Expand All @@ -286,6 +285,12 @@ EXPORTED_SYMBOLS=\
fmodf \
log

EXPORTED_SYMBOLS_64=\
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@ggreif ggreif Apr 12, 2026

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This is dead code. None of our RTS libraries export it.

$(EXPORTED_SYMBOLS) \
__wasm_apply_data_relocs



WASM_A_DEPENDENCIES_32=$(TOMMATH_WASM_32_A)
LINKER_OPTIONS_32=\
--import-memory --shared --no-entry --gc-sections \
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4 changes: 2 additions & 2 deletions rts/README.md
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Expand Up @@ -20,8 +20,8 @@ Running `make` should produce RTS Wasm files (different versions).

If run within the Nix shell, the environment variables `WASM_CLANG` and `WASM_LD`
should point to suitable binaries (we track a specific unreleased version of
`llvm`). If not present, the `Makefile` will try to use `clang-19` and
`wasm-ld-19`.
`llvm`). If not present, the `Makefile` will try to use `clang-20` and
`wasm-ld-20`.

The runtime compiles and links in [libtommath]. It needs the source, so
`nix build` and `nix develop` will set the environment variable `TOMMATHSRC` to
Expand Down
2 changes: 1 addition & 1 deletion test/bench/ok/bignum.drun-run.ok
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@@ -1,6 +1,6 @@
ingress Completed: Reply: 0x4449444c016c01b3c4b1f204680100010a00000000000000000101
ingress Completed: Reply: 0x4449444c0000
debug.print: {cycles = 2_503_853; size = +25_528}
debug.print: {cycles = 2_464_174; size = +25_528}
ingress Completed: Reply: 0x4449444c0000
debug.print: {cycles = 54_911_669; size = +830_464}
ingress Completed: Reply: 0x4449444c0000
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4 changes: 2 additions & 2 deletions test/bench/ok/heap-32.drun-run.ok
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@@ -1,6 +1,6 @@
ingress Completed: Reply: 0x4449444c016c01b3c4b1f204680100010a00000000000000000101
ingress Completed: Reply: 0x4449444c0000
debug.print: (50_227, +75_320_504, 1_137_727_438)
debug.print: (50_070, +86_221_288, 1_237_464_268)
debug.print: (50_227, +75_320_504, 1_137_089_459)
debug.print: (50_070, +86_221_288, 1_236_660_755)
ingress Completed: Reply: 0x4449444c0000
ingress Completed: Reply: 0x4449444c0000
4 changes: 2 additions & 2 deletions test/bench/ok/heap-64.drun-run.ok
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@@ -1,6 +1,6 @@
ingress Completed: Reply: 0x4449444c016c01b3c4b1f204680100010a00000000000000000101
ingress Completed: Reply: 0x4449444c0000
debug.print: (49_965, +88_051_888, 1_309_249_302)
debug.print: (49_806, +86_432_120, 1_281_944_210)
debug.print: (49_965, +88_051_888, 1_307_891_851)
debug.print: (49_806, +86_432_120, 1_280_591_180)
ingress Completed: Reply: 0x4449444c0000
ingress Completed: Reply: 0x4449444c0000
4 changes: 2 additions & 2 deletions test/ld/Makefile
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Expand Up @@ -9,8 +9,8 @@ accept:
clean:
rm -rf _out

WASM_CLANG?=clang-19
WASM_LD?=wasm-ld-19
WASM_CLANG?=clang-20
WASM_LD?=wasm-ld-20
MO_LD?=../../src/mo-ld

_out/%.lib.o: %.c | _out
Expand Down
6 changes: 1 addition & 5 deletions test/ld/ok/representative.linked.wat.ok
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Expand Up @@ -12,7 +12,6 @@
call $not_yet_imported2)
(func $resolved_export (type 0))
(func $__wasm_call_ctors (type 0))
(func $__wasm_apply_data_relocs (type 0))
(func $square (type 1) (param i32) (result i32)
call $resolved_export
call $unresolved_import
Expand All @@ -21,10 +20,7 @@
i32.mul)
(func $link_start (type 0)
call $__wasm_call_ctors)
(func $link_start.1 (type 0)
call $__wasm_apply_data_relocs
call $link_start)
(table (;0;) i64 1 1 funcref)
(memory (;0;) i64 2)
(global (;0;) i64 (i64.const 65536))
(start $link_start.1))
(start $link_start))
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