Merge branch 'pmderodat/base64_prefix' into 'master'

gnatcov extract-base64-trace: add support for arbitrary line prefixes

Closes #114

See merge request eng/cov/gnatcoverage!245

Fixes eng/cov/gnatcoverage#114

Author: pmderodat

testsuite/tests/instr-cov/base64_prefix/main1.adb

@@ -0,0 +1,6 @@
+with Pkg; use Pkg;
+
+procedure Main1 is
+begin
+   Print_Message (Goodbye => False);
+end Main1;

testsuite/tests/instr-cov/base64_prefix/main2.adb

@@ -0,0 +1,6 @@
+with Pkg; use Pkg;
+
+procedure Main2 is
+begin
+   Print_Message (Goodbye => True);
+end Main2;

testsuite/tests/instr-cov/base64_prefix/pkg.adb

@@ -0,0 +1,18 @@
+with Ada.Text_IO; use Ada.Text_IO;
+
+package body Pkg is
+
+   -------------------
+   -- Print_Message --
+   -------------------
+
+   procedure Print_Message (Goodbye : Boolean) is
+   begin
+      if Goodbye then
+         Put_Line ("Goodbye!");
+      else
+         Put_Line ("Hello!");
+      end if;
+   end Print_Message;
+
+end Pkg;

testsuite/tests/instr-cov/base64_prefix/pkg.ads

@@ -0,0 +1,3 @@
+package Pkg is
+   procedure Print_Message (Goodbye : Boolean);
+end Pkg;

testsuite/tests/instr-cov/base64_prefix/test.py

@@ -0,0 +1,100 @@
+"""
+Check that "gnatcov extract-base64-trace" can extract trace data from outputs
+with arbitrary line prefixes.
+"""
+
+import itertools
+
+from SCOV.instr import xcov_convert_base64, xcov_instrument
+from SCOV.minicheck import check_xcov_reports
+from SUITE.context import thistest
+from SUITE.cutils import Wdir
+from SUITE.gprutils import GPRswitches
+from SUITE.tutils import exepath_to, gprbuild, gprfor, run_cov_program, xcov
+
+tmp = Wdir("tmp_")
+
+# Instrument and build the test project
+p = GPRswitches(
+    root_project=gprfor(srcdirs="..", mains=["main1.adb", "main2.adb"]),
+    units=["pkg"],
+)
+xcov_instrument(
+    gprsw=p,
+    covlevel="stmt",
+    dump_trigger="main-end",
+    dump_channel="base64-stdout",
+)
+gprbuild(p.root_project, trace_mode="src")
+
+# Run the two programs, saving their output
+mains = ["main1", "main2"]
+out_files = [f"{m}_output.txt" for m in mains]
+
+for main, out_file in zip(mains, out_files):
+    run_cov_program(exepath_to(main), out=out_file)
+
+# Expected coverage report for both program executions:
+main1_cov = {"pkg.adb.xcov": {"+": {11, 14}, "-": {12}}}
+main2_cov = {"pkg.adb.xcov": {"+": {11, 12}, "-": {14}}}
+
+# Now combine them with different prefixes and check that "gnatcov
+# extract-base64-trace" correctly loads the last one.
+for label, interleaved_outputs, trailing_output, cov in [
+    ("main1_first", out_files, None, main1_cov),
+    ("main2_first", [out_files[1], out_files[0]], None, main2_cov),
+    ("main2_trail", [out_files[0]], out_files[1], main2_cov),
+]:
+    thistest.log(f"== {label} ==")
+
+    tracedata_filename = f"{label}_trace_data.txt"
+    trace_filename = f"{label}.srctrace"
+
+    traces_lines = []
+    for i, filename in enumerate(interleaved_outputs):
+        with open(filename) as f:
+            traces_lines.append((f"DATA{i}> ", f.readlines()))
+
+    if trailing_output is None:
+        trailing_lines = []
+    else:
+        with open(trailing_output) as f:
+            trailing_lines = f.readlines()
+
+    # Interleave all lines to make sure that once gnatcov detects a source
+    # trace with some prefix, it filters that prefix only until the end of the
+    # source trace.
+    with open(tracedata_filename, "w") as f:
+        for i in itertools.count(0):
+            had_line = False
+            for prefix, lines in traces_lines:
+                if i >= len(lines):
+                    continue
+                had_line = True
+                f.write(prefix)
+                f.write(lines[i])
+            if not had_line:
+                break
+
+        for line in trailing_lines:
+            f.write("TRAILING> ")
+            f.write(line)
+
+    # Now run the source trace conversion and create a coverage report from it
+    xcov_convert_base64(tracedata_filename, trace_filename)
+    xcov_dir = f"xcov-{label}"
+    xcov(
+        [
+            "coverage",
+            "-P",
+            p.root_project,
+            "--level=stmt",
+            "--annotate=xcov",
+            "--output-dir",
+            xcov_dir,
+            trace_filename,
+        ]
+    )
+    check_xcov_reports("*.xcov", cov, cwd=xcov_dir)
+
+thistest.result()