preliminary support for Emacs

.cirrus.yml

@@ -4,39 +4,6 @@ task:
   only_if: $CIRRUS_BRANCH == "main" || $CIRRUS_PR != ""
 
   matrix:
-    - name: Linux
-      container:
-        image: gcc:15.1
-      environment:
-        DEBIAN_FRONTEND: noninteractive
-        CFLAGS: -Werror -g -fno-omit-frame-pointer -fsanitize=address,undefined -fno-sanitize-recover=undefined -fuse-ld=gold
-        LC_ALL: C.UTF-8
-        UBSAN_OPTIONS: print_stacktrace=1
-      install_script: apt-get update -y && apt-get install --no-install-recommends -y cmake cscope libclang-dev llvm python3-pytest sqlite3 xxd vim
-      test_script: ./misc/ci.sh
-
-    - name: Linux, release build
-      container:
-        image: gcc:15.1
-      environment:
-        DEBIAN_FRONTEND: noninteractive
-        CFLAGS: -Werror -g -fno-omit-frame-pointer -fsanitize=address,undefined -fno-sanitize-recover=undefined -fuse-ld=gold
-        CMAKE_FLAGS: -DCMAKE_BUILD_TYPE=Release
-        LC_ALL: C.UTF-8
-        UBSAN_OPTIONS: print_stacktrace=1
-      install_script: apt-get update -y && apt-get install --no-install-recommends -y cmake cscope libclang-dev llvm python3-pytest sqlite3 xxd vim
-      test_script: ./misc/ci.sh
-
-    - name: macOS
-      macos_instance:
-        image: ghcr.io/cirruslabs/macos-runner:sequoia
-      environment:
-        CFLAGS: -Werror -g -fno-omit-frame-pointer -fsanitize=address,undefined -fno-sanitize-recover=undefined
-        PATH: /opt/homebrew/opt/llvm/bin:${PATH}
-        UBSAN_OPTIONS: print_stacktrace=1
-      install_script: brew update && brew install coreutils cscope llvm && env PIP_BREAK_SYSTEM_PACKAGES=1 python3 -m pip install pytest
-      test_script: ./misc/ci.sh
-
     - name: C formatting
       container:
         image: silkeh/clang:19

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
           set -u
           set -x
           uname -rms
-          pkg install -y bash cmake cscope git llvm python3 py311-pytest sqlite3 py311-sqlite3 vim
+          pkg install -y bash cmake cscope git llvm python3 devel/py-pytest sqlite3 databases/py-sqlite3 vim
           python3 --version
           git clone --no-checkout --recurse-submodules -- ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY} wd
           cd wd
@@ -37,3 +37,59 @@ jobs:
           printf "find-me says: "
           ./build/test/find-me/find-me
           cmake --install build
+
+  macos26:
+    name: macOS
+    runs-on: macos-26-intel
+    env:
+      CFLAGS: -Werror -g -fno-omit-frame-pointer -fsanitize=address,undefined -fno-sanitize-recover=address,undefined
+      UBSAN_OPTIONS: print_stacktrace=1
+    steps:
+      - run: python3 --version
+      - run: brew update
+      - run: brew install coreutils cscope llvm
+      - run: env PIP_BREAK_SYSTEM_PACKAGES=1 python3 -m pip install pytest
+      - run: echo "cloning ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}"
+      - run: git clone --no-checkout --recurse-submodules -- ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY} wd
+      - run: >
+          cd wd &&
+          git fetch -- origin ${{ github.event.pull_request.head.sha }} &&
+          git checkout FETCH_HEAD &&
+          ./misc/ci.sh
+
+  ubuntu2604:
+    name: Linux
+    runs-on: ubuntu-26.04
+    env:
+      DEBIAN_FRONTEND: noninteractive
+      CFLAGS: -Werror -g -fno-omit-frame-pointer -fsanitize=address,undefined -fno-sanitize-recover=address,undefined
+      UBSAN_OPTIONS: print_stacktrace=1
+    steps:
+      - run: sudo apt-get update
+      - run: sudo apt-get install --no-install-recommends -y cscope libclang-dev llvm python3-pytest xxd vim
+      - run: echo "cloning ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}"
+      - run: git clone --no-checkout --recurse-submodules -- ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY} wd
+      - run: >
+          cd wd &&
+          git fetch -- origin ${{ github.event.pull_request.head.sha }} &&
+          git checkout FETCH_HEAD &&
+          ./misc/ci.sh
+
+  ubuntu2604_release:
+    name: Linux, release build
+    runs-on: ubuntu-26.04
+    env:
+      DEBIAN_FRONTEND: noninteractive
+      CFLAGS: -Werror -g -fno-omit-frame-pointer -fsanitize=address,undefined -fno-sanitize-recover=address,undefined
+      CMAKE_FLAGS: -DCMAKE_BUILD_TYPE=Release
+      UBSAN_OPTIONS: print_stacktrace=1
+    steps:
+      - run: sudo apt-get update
+      - run: sudo apt-get install --no-install-recommends -y cscope libclang-dev llvm python3-pytest xxd vim
+      - run: echo "cloning ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}"
+      - run: git clone --no-checkout --recurse-submodules -- ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY} wd
+      - run: >
+          cd wd &&
+          git fetch -- origin ${{ github.event.pull_request.head.sha }} &&
+          git checkout FETCH_HEAD &&
+          ./misc/ci.sh

clink/src/ui.c

@@ -941,6 +941,10 @@ static int handle_select(void) {
                            results.rows[select_index].lineno,
                            results.rows[select_index].colno, clink_repl,
                            clink_repl == NULL ? NULL : database);
+    } else if (clink_is_editor_emacs()) {
+      (void)clink_emacs_open(results.rows[select_index].path,
+                             results.rows[select_index].lineno,
+                             results.rows[select_index].colno);
     } else {
       (void)open_editor(results.rows[select_index].path);
     }

libclink/CMakeLists.txt

@@ -28,10 +28,11 @@ add_library(libclink
   src/eat_num.c
   src/eat_rest_of_line.c
   src/editor_open.c
+  src/emacs_open.c
   src/get_environ.c
   src/get_id.c
   src/have_cscope.c
-  src/is_editor_vim.c
+  src/is_editor.c
   src/iter.c
   src/make_relative_to.c
   src/mmap.c

libclink/include/clink/clink.h

@@ -17,10 +17,10 @@
 #include <clink/db.h>
 #include <clink/debug.h>
 #include <clink/def.h>
+#include <clink/editor.h>
 #include <clink/generic.h>
 #include <clink/iter.h>
 #include <clink/python.h>
 #include <clink/symbol.h>
 #include <clink/tablegen.h>
 #include <clink/version.h>
-#include <clink/vim.h>

libclink/include/clink/vim.h → libclink/include/clink/editor.h

@@ -36,6 +36,22 @@ CLINK_API int clink_vim_open(const char *filename, unsigned long lineno,
                              unsigned long colno, const char *cscopeprg,
                              const clink_db_t *db);
 
+/** does the user’s editor look like Emacs?
+ *
+ * \return True if the editor appears Emacs-alike
+ */
+CLINK_API bool clink_is_editor_emacs(void);
+
+/** open Emacs at the given position in the given file
+ *
+ * \param filename File to open with Emacs
+ * \param lineno Line number to position cursor at within the file
+ * \param colno Column number to position cursor at within the file
+ * \return Emacs’s exit status
+ */
+CLINK_API int clink_emacs_open(const char *filename, unsigned long lineno,
+                               unsigned long colno);
+
 /** open the given editor with the given file
  *
  * This is a simple wrapper around exec-ing `{editor, "--", filename}`. This is

libclink/src/db_open.c

@@ -258,7 +258,7 @@ int clink_db_open(clink_db_t **db, const char *path) {
     slash[1] = '\0';
     d->dir = abs;
   } else {
-    char *slash = strrchr(path, '/');
+    const char *const slash = strrchr(path, '/');
     d->dir = strndup(path, (size_t)(slash + 1 - path));
     d->filename = strdup(slash + 1);
   }

libclink/src/editor_open.c

@@ -1,5 +1,5 @@
 #include "run.h"
-#include <clink/vim.h>
+#include <clink/editor.h>
 #include <errno.h>
 #include <stddef.h>
 

libclink/src/emacs_open.c

@@ -0,0 +1,50 @@
+#include "debug.h"
+#include "run.h"
+#include <clink/editor.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int clink_emacs_open(const char *filename, unsigned long lineno,
+                     unsigned long colno) {
+
+  // check filename is valid
+  if (ERROR(filename == NULL))
+    return EINVAL;
+
+  // check line number is valid
+  if (ERROR(lineno == 0))
+    return EINVAL;
+
+  // check column number is valid
+  if (ERROR(colno == 0))
+    return EINVAL;
+
+  int rc = 0;
+  char *jump = NULL;
+
+  // construct a directive telling Emacs to jump to the given position
+  if (ERROR(asprintf(&jump, "+%lu:%lu", lineno, colno) < 0)) {
+    rc = ENOMEM;
+    goto done;
+  }
+
+  // assume the user’s preferred editor is Emacs, but still locate the path to
+  // it
+  const char *emacs = getenv("VISUAL");
+  if (emacs == NULL)
+    emacs = getenv("EDITOR");
+  if (emacs == NULL)
+    emacs = "emacs";
+
+  // construct a argument vector to invoke Emacs
+  char const *argv[] = {emacs, jump, "--", filename, NULL};
+
+  // run it
+  rc = run(argv);
+
+done:
+  free(jump);
+
+  return rc;
+}

libclink/src/is_editor_vim.c → libclink/src/is_editor.c

@@ -1,6 +1,6 @@
 #include "debug.h"
 #include <assert.h>
-#include <clink/vim.h>
+#include <clink/editor.h>
 #include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
@@ -9,7 +9,7 @@
  *
  * \param base Start of the path to test
  * \param length Number of bytes in the path
- * \param alias An alias for Vim
+ * \param alias An alias for Emacs or Vim
  * \return True if this is a path to a binary of the given alias
  */
 static bool is(const char *base, size_t length, const char *alias) {
@@ -67,3 +67,36 @@ bool clink_is_editor_vim(void) {
 
   return false;
 }
+
+bool clink_is_editor_emacs(void) {
+
+  // priority 1: `$VISUAL`
+  const char *editor = getenv("VISUAL");
+
+  // priority 2: `$EDITOR`
+  if (editor == NULL)
+    editor = getenv("EDITOR");
+
+  // else fallback to Vim
+  if (editor == NULL)
+    editor = "vim";
+
+  // `$EDITOR` can contain something like “emacs -q”, so assume only the first
+  // word is the actual path
+  const char *space = strchr(editor, ' ');
+  const size_t len = space == NULL ? strlen(editor) : (size_t)(space - editor);
+
+  // aliases Emacs goes by
+  const char *EMACS_NAMES[] = {"emacs"};
+
+  for (size_t i = 0; i < sizeof(EMACS_NAMES) / sizeof(EMACS_NAMES[0]); ++i) {
+    if (is(editor, len, EMACS_NAMES[i])) {
+      DEBUG("editor \"%s\" matched \"%s\"", editor, EMACS_NAMES[i]);
+      return true;
+    } else {
+      DEBUG("editor \"%s\" did not match \"%s\"", editor, EMACS_NAMES[i]);
+    }
+  }
+
+  return false;
+}

libclink/src/vim_open.c

@@ -2,7 +2,7 @@
 #include "debug.h"
 #include "run.h"
 #include <assert.h>
-#include <clink/vim.h>
+#include <clink/editor.h>
 #include <errno.h>
 #include <stdbool.h>
 #include <stdio.h>

libclink/src/vim_read.c

@@ -1,5 +1,5 @@
 #include "debug.h"
-#include <clink/vim.h>
+#include <clink/editor.h>
 #include <errno.h>
 #include <stddef.h>
 #include <stdio.h>

libclink/src/vim_read_into.c

@@ -6,7 +6,7 @@
 #include "sql.h"
 #include <assert.h>
 #include <clink/db.h>
-#include <clink/vim.h>
+#include <clink/editor.h>
 #include <errno.h>
 #include <sqlite3.h>
 #include <stddef.h>

misc/ci.sh

@@ -17,10 +17,4 @@ cmake --build build --target check
 printf "find-me says: "
 ./build/test/find-me/find-me
 
-if [ "$(uname -s)" = "Darwin" ]; then
-  SUDO=sudo
-else
-  # sudo not needed
-  SUDO=
-fi
-${SUDO} cmake --install build
+sudo cmake --install build