GHA/mac: simplify detecting SDK version bound to GCC

Previous method extracted this information from the "hack layer"
headers' copyright comments.

It turns out that the same information can be obtained by querying
the default SDK root via a GCC option.

According to this test run, they do match:
https://github.com/curl/curl/actions/runs/11264283159/job/31323963221?pr=15193

Closes #15241

diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
index 8c137a1001694b49e4b19ab9f8cda2ba860dcbda..ffc884436529e5c5baaa6ededbfc89ce461585f3 100644 (file)
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -159,8 +159,7 @@ jobs:
       - name: 'toolchain versions'
         run: |
           [[ '${{ matrix.compiler }}' = 'llvm'* ]] && CC="$(brew --prefix ${{ matrix.compiler }})/bin/clang"
-          [[ '${{ matrix.compiler }}' = 'gcc'* ]] && \
-            grep -h -r -E -o '.+[0-9.]+\.sdk/' "$(dirname "$("${CC}" -print-libgcc-file-name)")/include-fixed" | sed -E 's/^\t+//g' | tr -d '"' | sort -u || true
+          [[ '${{ matrix.compiler }}' = 'gcc'* ]] && "${CC}" --print-sysroot
           which "${CC}"; "${CC}" --version || true
           xcodebuild -version || true
           xcrun --sdk macosx --show-sdk-path 2>/dev/null || true
@@ -326,8 +325,7 @@ jobs:
       - name: 'toolchain versions'
         run: |
           [[ '${{ matrix.compiler }}' = 'llvm'* ]] && CC="$(brew --prefix ${{ matrix.compiler }})/bin/clang"
-          [[ '${{ matrix.compiler }}' = 'gcc'* ]] && \
-            grep -h -r -E -o '.+[0-9.]+\.sdk/' "$(dirname "$("${CC}" -print-libgcc-file-name)")/include-fixed" | sed -E 's/^\t+//g' | tr -d '"' | sort -u || true
+          [[ '${{ matrix.compiler }}' = 'gcc'* ]] && "${CC}" --print-sysroot
           which "${CC}"; "${CC}" --version || true
           xcodebuild -version || true
           xcrun --sdk macosx --show-sdk-path 2>/dev/null || true
@@ -488,8 +486,7 @@ jobs:
       - name: 'toolchain versions'
         run: |
           [[ '${{ matrix.compiler }}' = 'llvm'* ]] && CC="$(brew --prefix ${{ matrix.compiler }})/bin/clang"
-          [[ '${{ matrix.compiler }}' = 'gcc'* ]] && \
-            grep -h -r -E -o '.+[0-9.]+\.sdk/' "$(dirname "$("${CC}" -print-libgcc-file-name)")/include-fixed" | sed -E 's/^\t+//g' | tr -d '"' | sort -u || true
+          [[ '${{ matrix.compiler }}' = 'gcc'* ]] && "${CC}" --print-sysroot
           which "${CC}"; "${CC}" --version || true
           xcodebuild -version || true
           xcrun --sdk macosx --show-sdk-path 2>/dev/null || true