build: pin -std=c11 for instrument-hooks core.c by not-matthias · Pull Request #53 · CodSpeedHQ/codspeed-cpp

not-matthias · 2026-06-22T11:57:47Z

No description provided.

codspeed-hq · 2026-06-22T12:07:14Z

Merging this PR will improve performance by 15.71%

⚠️

Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

⚡ 8 improved benchmarks
✅ 454 untouched benchmarks

Performance Changes

	Mode	Benchmark	`BASE`	`HEAD`	Efficiency
⚡	WallTime	`BM_FibonacciRecursive_Darwin[35]`	37.5 ms	28.3 ms	+32.59%
⚡	WallTime	`BM_Vector_Reserve[10000]`	36.1 µs	31.2 µs	+15.62%
⚡	WallTime	`BM_Vector_PushBack[10000]`	39.3 µs	34 µs	+15.48%
⚡	WallTime	`BM_Vector_PushBack[1000]`	4.3 µs	3.7 µs	+14.94%
⚡	WallTime	`BM_Vector_Reserve[1000]`	3.6 µs	3.2 µs	+13.91%
⚡	WallTime	`BM_FibonacciRecursive_Darwin[35]`	31.6 ms	28.3 ms	+11.68%
⚡	WallTime	`BM_RLE_Decode[10000]`	24.6 µs	22.1 µs	+11.51%
⚡	WallTime	`BM_Vector_Reserve[100]`	390.5 ns	350.7 ns	+11.34%

Tip

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_{Comparing cod-2953-use-stdc11-for-instrument-hooks-in-integrations (76985b6) with main (e47ecff)}

greptile-apps · 2026-06-22T12:18:03Z

Greptile Summary

This PR pins -std=c11 / /std:c11 for the Zig-generated instrument_hooks/dist/core.c in both Bazel and CMake build systems, fixing a build failure introduced by GCC 15's switch to C23 as the default standard (which breaks [[noreturn]] placement in the embedded zig.h).

Bazel (core/BUILD): -std=c11 added to both non-Windows select arms; /std:c11 added to instrument_hooks_cflags_windows so all four select branches (including MSVC, addressing the previously flagged gap) are consistently pinned. -Wno-unknown-warning-option and -Wno-unterminated-string-initialization are added to the shared flag list to handle the new GCC-15-era warning on older Clang toolchains.
CMake (core/CMakeLists.txt): set_target_properties with C_STANDARD 11 / C_STANDARD_REQUIRED ON is used—the idiomatic CMake approach that also translates to /std:c11 on MSVC automatically. The same two warning-suppression flags are added to the GCC/Clang compile-options block.

Confidence Score: 5/5

Safe to merge — the changes are narrowly scoped build-system fixes that pin the C standard for a single prebuilt C file.

Both build systems now consistently pin C11 across all compiler/platform paths. The CMake approach uses the idiomatic C_STANDARD property (which CMake correctly translates to /std:c11 for MSVC), and the Bazel select now covers all four arms including both Windows paths. The newly added warning-suppression flags are ordered correctly (-Wno-unknown-warning-option before -Wno-unterminated-string-initialization) and are safe on GCC because GCC silently ignores unknown -Wno-* flags.

No files require special attention.

Important Files Changed

Filename	Overview
core/BUILD	Adds -std=c11 to non-Windows select arms, /std:c11 to instrument_hooks_cflags_windows, and -Wno-unknown-warning-option/-Wno-unterminated-string-initialization to the common GCC/Clang flag list.
core/CMakeLists.txt	Adds set_target_properties with C_STANDARD 11 / C_STANDARD_REQUIRED ON for instrument_hooks, and the same pair of -Wno-unknown-warning-option/-Wno-unterminated-string-initialization to the GCC/Clang compile options block.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[Build instrument_hooks core.c] --> B{Build System}
    B --> C[CMake]
    B --> D[Bazel]
    C --> E[set_target_properties C_STANDARD 11 C_STANDARD_REQUIRED ON]
    E --> F{Compiler}
    F --> G[GCC or Clang: -std=c11]
    F --> H[MSVC: /std:c11]
    D --> I{Platform select}
    I --> J[windows_strict: /W4 /WX + cflags_windows incl /std:c11]
    I --> K[windows: cflags_windows incl /std:c11]
    I --> L[strict_warnings: -std=c11 -Wall -Werror + cflags]
    I --> M[default: -std=c11 + cflags]
    G --> N[Compiles under GCC 15 C23 default]
    H --> N
    J --> N
    K --> N
    L --> N
    M --> N

%%{init: {'theme': 'base', 'themeVariables': {"darkMode": true, "background": "#0d1117", "primaryColor": "#21262d", "primaryTextColor": "#e6edf3", "primaryBorderColor": "#8b949e", "lineColor": "#8b949e", "textColor": "#e6edf3", "edgeLabelBackground": "#161b22", "actorBkg": "#21262d", "actorBorder": "#8b949e", "actorTextColor": "#e6edf3", "actorLineColor": "#8b949e", "signalColor": "#8b949e", "signalTextColor": "#e6edf3", "noteBkgColor": "#373320", "noteBorderColor": "#d4a72c", "noteTextColor": "#f0e6c0", "labelBoxBkgColor": "#21262d", "labelBoxBorderColor": "#8b949e", "labelTextColor": "#e6edf3", "loopTextColor": "#e6edf3", "activationBkgColor": "#30363d", "activationBorderColor": "#8b949e"}}}%%
flowchart TD
    A[Build instrument_hooks core.c] --> B{Build System}
    B --> C[CMake]
    B --> D[Bazel]
    C --> E[set_target_properties C_STANDARD 11 C_STANDARD_REQUIRED ON]
    E --> F{Compiler}
    F --> G[GCC or Clang: -std=c11]
    F --> H[MSVC: /std:c11]
    D --> I{Platform select}
    I --> J[windows_strict: /W4 /WX + cflags_windows incl /std:c11]
    I --> K[windows: cflags_windows incl /std:c11]
    I --> L[strict_warnings: -std=c11 -Wall -Werror + cflags]
    I --> M[default: -std=c11 + cflags]
    G --> N[Compiles under GCC 15 C23 default]
    H --> N
    J --> N
    K --> N
    L --> N
    M --> N

_{Reviews (4): Last reviewed commit: "build: suppress -Wunterminated-string-in..." | Re-trigger Greptile}

The Zig-generated dist/core.c is rejected under C23 (GCC 15's default), so pin C11 in both the Bazel and CMake builds.

…ooks core.c

not-matthias requested a review from GuillaumeLagrange June 22, 2026 12:14

not-matthias marked this pull request as ready for review June 22, 2026 12:14

greptile-apps Bot reviewed Jun 22, 2026

View reviewed changes

Comment thread core/BUILD

GuillaumeLagrange approved these changes Jun 23, 2026

View reviewed changes

build: pin -std=c11 for instrument-hooks core.c

9a88d80

The Zig-generated dist/core.c is rejected under C23 (GCC 15's default), so pin C11 in both the Bazel and CMake builds.

not-matthias force-pushed the cod-2953-use-stdc11-for-instrument-hooks-in-integrations branch from 1d6f615 to 9a88d80 Compare June 24, 2026 09:52

build: suppress -Wunterminated-string-initialization for instrument-h…

76985b6

…ooks core.c

not-matthias force-pushed the cod-2953-use-stdc11-for-instrument-hooks-in-integrations branch from 297b3c6 to 76985b6 Compare June 24, 2026 10:07

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build: pin -std=c11 for instrument-hooks core.c#53

build: pin -std=c11 for instrument-hooks core.c#53
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cod-2953-use-stdc11-for-instrument-hooks-in-integrations

not-matthias commented Jun 22, 2026

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not-matthias commented Jun 22, 2026

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Merging this PR will improve performance by 15.71%

Performance Changes

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Greptile Summary

Confidence Score: 5/5

Important Files Changed

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codspeed-hq Bot commented Jun 22, 2026 •

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