build: build the vendored Capstone from the autotools build

[moha-bekh]

Callgrind's cycle estimation links a static Capstone, which until now had to be built by hand before Valgrind: configure hard-failed unless it was given --with-capstone=PATH or CAPSTONE_DIR. That put the same cmake invocation in a wrapper script and in a CI action, where the two copies of the required compiler flags could drift apart, and every new consumer had to repeat it.

This compiles the submodule as an automake convenience library instead, so a plain ./autogen.sh && ./configure && make && make install is the whole build. --with-capstone stays as an override for the Debian packaging, but nothing needs it any more.

The CodSpeed logic lives in files of its own (m4/codspeed_capstone.m4 and third_party/Makefile.am), leaving three one-line touch points in upstream files -- the macro call, an AC_CONFIG_FILES entry and a SUBDIRS entry -- in place of the 28-line block this removes from configure.ac, so rebasing onto upstream conflicts on single lines.

The submodule checkout is left untouched by a build: the sources are compiled by explicit rules that write every object and dependency file under third_party/capstone-obj/ in the build directory, rather than through _SOURCES, which would have automake drop objects, .deps and .dirstamp next to the sources.

Two things the wrapper script was hiding, now handled by the build system

• The tool CFLAGS pass -fno-builtin, so GCC no longer folds Capstone's fprintf(stderr, "...") guard into fwrite, nor expands strcat into strlen+strcpy. The tool shimmed only fwrite and thus only linked by accident of those optimisations; this shims fprintf and strcat explicitly, and compiles Capstone -DNDEBUG as its own Release build does so assert() does not pull in __assert_fail.
• CFLAGS=-std=gnu17 was passed by the script alone, so builds through debian/rules never got it. AC_PROG_CC picks gnu23 on GCC 15+, under which glibc 2.42+ defines strchr/strrchr/strstr as _Generic macros that clash with Callgrind's own definitions. configure now exports it as CODSPEED_C_STD and applies it to the primary Callgrind tool only, so the rest of the tree keeps the compiler's own default.

CI: the inline-crossfile failure on ubuntu-22.04 is not caused by this PR

The same commit is green on workflow_dispatch and red on pull_request, reproducibly on both sides, on the same runner image. Comparing a red run with a green one: third_party/libcapstone.a and the inline-crossfile test binary are identical bit for bit, configure's output and the tool's link command line are identical line for line, and only callgrind-amd64-linux differs -- built from coregrind/VEX/callgrind objects this PR does not touch.

That is enough to flip the expectation, because cfni=??? is not a marker of inlined code: callgrind/dump.c emits it when leaving an inlined range, guarded by a file-static last_inline_fn that is never reset between dumps and is compared by pointer rather than by string. Its presence therefore depends on the order in which functions are dumped, i.e. on the tool binary's layout. Tracked separately.

[greptile-apps]

Greptile Summary

This PR moves the vendored Capstone build into Autotools, retains support for an external Capstone installation, pins C compilation to GNU17, and adds the libc shims needed by the newly integrated static library.

• Adds a conditional Automake convenience library containing Capstone’s x86 and AArch64 sources.
• Replaces the inline configure logic with dedicated Capstone and C-standard macros.
• Removes the standalone CMake build action from CI and release workflows.
• Updates source-distribution inputs and Callgrind’s libc compatibility shims.

Confidence Score: 4/5

The external-Capstone build path should be fixed before merging because an offline Git checkout can fail during autogen even though vendoring was explicitly bypassed.

The new fatal submodule update runs before the configuration layer honors CAPSTONE_DIR, making the supported prebuilt-library override unusable when the checkout lacks initialized submodules and cannot access the network.

Files Needing Attention: autogen.sh and m4/codspeed_capstone.m4

Important Files Changed

Filename	Overview
autogen.sh	Adds fatal, unconditional submodule initialization for Git worktrees, preventing offline external-Capstone builds when the submodule is absent.
m4/codspeed_capstone.m4	Defines vendored-versus-external Capstone configuration and pins GNU17, but its override is evaluated too late to prevent autogen.sh from cloning.
third_party/Makefile.am	Builds a primary-platform x86/AArch64 Capstone convenience archive and declares the vendored distribution inputs.
callgrind/cycledecode_capstone.c	Adds fprintf and strcat shims required by Capstone when compiled under Valgrind’s tool flags.
configure.ac	Integrates the new configuration macros and generates the third-party Makefile.
.github/workflows/release.yml	Removes the redundant standalone CMake Capstone build and relies on the integrated Autotools path.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart LR
  A[Git checkout] --> B[autogen.sh]
  B --> C[Configure]
  C --> D{External Capstone supplied?}
  D -- No --> E[Build vendored libcapstone.a]
  D -- Yes --> F[Use prebuilt libcapstone.a]
  E --> G[Link primary Callgrind]
  F --> G

Loading

Prompt To Fix All With AI

### Issue 1
autogen.sh:25
**Override still initializes submodule**

When a Git checkout has no initialized Capstone submodule and runs offline with `CAPSTONE_DIR` set, this fatal update attempts to clone the vendored source before configure can honor the external-library override, causing `autogen.sh` to exit and preventing the supported prebuilt-Capstone build.

---

For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

_{Reviews (1): Last reviewed commit: "build: build the vendored Capstone from ..." | Re-trigger Greptile}

[greptile-apps]

Override still initializes submodule

When a Git checkout has no initialized Capstone submodule and runs offline with CAPSTONE_DIR set, this fatal update attempts to clone the vendored source before configure can honor the external-library override, causing autogen.sh to exit and preventing the supported prebuilt-Capstone build.

Knowledge Base Used:

• Build, platform, and testing infrastructure
• Build and packaging workflows

Prompt To Fix With AI

This is a comment left during a code review.
Path: autogen.sh
Line: 25

Comment:
**Override still initializes submodule**

When a Git checkout has no initialized Capstone submodule and runs offline with `CAPSTONE_DIR` set, this fatal update attempts to clone the vendored source before configure can honor the external-library override, causing `autogen.sh` to exit and preventing the supported prebuilt-Capstone build.

**Knowledge Base Used:**
- [Build, platform, and testing infrastructure](https://app.greptile.com/codspeed/-/custom-context/knowledge-base/codspeedhq/valgrind-codspeed/-/docs/build-platform-and-testing.md)
- [Build and packaging workflows](https://app.greptile.com/codspeed/-/custom-context/knowledge-base/codspeedhq/valgrind-codspeed/-/docs/build-and-packaging.md)

---

For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

[GuillaumeLagrange]

We should not run this unconditionnally IMO, especially if people provide a CAPSTONE_DIR argument

[greptile-apps]

Agreed. Making the update non-fatal still causes an unnecessary network attempt, and it can fail before configure gets a chance to honor CAPSTONE_DIR. The submodule initialization should be conditional on CAPSTONE_DIR being unset. --with-capstone=PATH is only parsed by configure, so autogen.sh cannot detect that form unless configure arguments are explicitly passed through to it.

Tip: You can customize Greptile's behavior for this repo with .greptile/rules.md and .greptile/config.json.

[codspeed]

Merging this PR will not alter performance

✅ 84 untouched benchmarks
⏩ 60 skipped benchmarks¹

---

_{Comparing cod-3465-create-a-self-contained-valgrind-build-script (b5f6cba) with master (aaa0946)}

Footnotes

1. 60 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩